Browsing by Author "Spasovski, Vesna (26655022200)"

To examine whether -174G/C interleukin-6 (IL-6) gene polymorphism, previously reported to correlate with IL-6 level, influences response to etanercept therapy in patients with rheumatoid arthritis. Seventy-seven patients with active RA were studied, at baseline and 6- and 12-month follow-up after etanercept therapy. Treatment response was estimated according to the European League Against Rheumatism response criteria. RA patients were genotyped for -174G/C IL-6 gene polymorphism by the PCR-RFLP method, and influence of genotype at this polymorphism to clinical response to etanercept was assessed. After 12 months of treatment, the percentage of responders (patients who had DAS28 improvement >1.2) was significantly increased in patients carrying the IL-6 -174G/G genotype (95.7 %) compared with those with the G/C (75.6 %) or CC (44.4 %) genotype (p = 0.006 by Chi-square test). No significant difference in the mean values of DAS28 improvement was observed between groups with different genotype. RA patients with an IL-6 -174GG genotype respond to etanercept better than patients with GC or CC genotype. This finding, if confirmed in future studies, suggests that the -174G/C IL-6 polymorphism may be a genetic marker of responsiveness to tumor necrosis factor-alpha (TNF-α) blockers in RA. © 2012 Springer-Verlag Berlin Heidelberg.

To examine whether -174G/C interleukin-6 (IL-6) gene polymorphism, previously reported to correlate with IL-6 level, influences response to etanercept therapy in patients with rheumatoid arthritis. Seventy-seven patients with active RA were studied, at baseline and 6- and 12-month follow-up after etanercept therapy. Treatment response was estimated according to the European League Against Rheumatism response criteria. RA patients were genotyped for -174G/C IL-6 gene polymorphism by the PCR-RFLP method, and influence of genotype at this polymorphism to clinical response to etanercept was assessed. After 12 months of treatment, the percentage of responders (patients who had DAS28 improvement >1.2) was significantly increased in patients carrying the IL-6 -174G/G genotype (95.7 %) compared with those with the G/C (75.6 %) or CC (44.4 %) genotype (p = 0.006 by Chi-square test). No significant difference in the mean values of DAS28 improvement was observed between groups with different genotype. RA patients with an IL-6 -174GG genotype respond to etanercept better than patients with GC or CC genotype. This finding, if confirmed in future studies, suggests that the -174G/C IL-6 polymorphism may be a genetic marker of responsiveness to tumor necrosis factor-alpha (TNF-α) blockers in RA. © 2012 Springer-Verlag Berlin Heidelberg.

Introduction: Tuberculosis (TB) continues to be a significant public health problem. The role of small non-coding RNAs, such as microRNAs (miRNAs), was investigated extensively in Mycobacterium tuberculosis (MTB) infection as well as in a variety of other pathophysiological processes in recent years. It was found that miRNAs act as regulators of both early reaction to MTB infection and in process of adaptation of the host immune cells during latent course of the disease. Molecule miRNA-146a is expressed exclusively in immune cells and it has the most prominent role in modulation of innate immunity. Methodology: We investigated the level of expression of miRNA-146a using an RT-qPCR technique in peripheral blood mononuclear cells of 44 patients with active pulmonary TB and 17 healthy individuals. We also analyzed the significance of miRNA-146a rs2910164 SNV for expression profile of miRNA-146a, in order to investigate potential usage of miRNA-146a as a biomarker for TB. Results: There was statistically significant decrease of expression of miRNA-146a in TB group compared to control group. When gender cohorts were analyzed, the expression levels in TB male and TB female subgroup were significantly lower than the expression levels in the same gender control subgroups. Conclusions: Our results indicate that miRNA-146a plays a significant role in the pathogenesis of TB, suggesting that miRNA-146a could be used as a biomarker for active pulmonary TB. © 2022 Journal of Infection in Developing Countries. All rights reserved.

Introduction: Tuberculosis (TB) continues to be a significant public health problem. The role of small non-coding RNAs, such as microRNAs (miRNAs), was investigated extensively in Mycobacterium tuberculosis (MTB) infection as well as in a variety of other pathophysiological processes in recent years. It was found that miRNAs act as regulators of both early reaction to MTB infection and in process of adaptation of the host immune cells during latent course of the disease. Molecule miRNA-146a is expressed exclusively in immune cells and it has the most prominent role in modulation of innate immunity. Methodology: We investigated the level of expression of miRNA-146a using an RT-qPCR technique in peripheral blood mononuclear cells of 44 patients with active pulmonary TB and 17 healthy individuals. We also analyzed the significance of miRNA-146a rs2910164 SNV for expression profile of miRNA-146a, in order to investigate potential usage of miRNA-146a as a biomarker for TB. Results: There was statistically significant decrease of expression of miRNA-146a in TB group compared to control group. When gender cohorts were analyzed, the expression levels in TB male and TB female subgroup were significantly lower than the expression levels in the same gender control subgroups. Conclusions: Our results indicate that miRNA-146a plays a significant role in the pathogenesis of TB, suggesting that miRNA-146a could be used as a biomarker for active pulmonary TB. © 2022 Journal of Infection in Developing Countries. All rights reserved.

Genetic predisposition to systemic sclerosis (SSc) has still not been fully revealed. Interleukin-6 (IL-6) is a mediator of T cell proliferation and fibrotic events in SSc. Polymorphisms in the IL-6 are found to be important in susceptibility to development of SSc. We aimed to assess the frequency of -174 C/G of IL-6 gene polymorphism in SSc patients and healthy controls, as well as correlation with disease manifestations. In the case-control study, 102 patients with SSc and 93 controls were included. PCR-RFLP method was performed for genotyping promotor variants -174 C/G of IL-6 gene. The expression level of IL-6 was determined by qRT-PCR on subset of 50 patients and 13 healthy controls with different IL-6 genotypes. We used UCLA GIT 2.0 questionnaire to assess gastrointestinal involvement in SSc patients. The expression level of IL-6 gene was significantly higher in patients with SSc in comparison with healthy controls (p < 0.05). Carriers of C-allele of IL-6 gene compared to those with G allele, showed higher expression of IL-6 gene (95.8 vs. 41.2, p < 0.05), higher GIT total score (0.85 vs. 0.5, p < 0.05) and higher distension scale score (1.4 ± 0.9 vs. 0.78 ± 0.8, p = 0.05). No significant differences in genotype distribution and allele frequency were observed between patients and controls. The expression of IL6 gene varies significantly during the course of SSc. The IL-6 gene variant -174 C/G (presence of C-allele) is associated with higher IL-6 gene expression and greater GIT impairment in patients with SSc. © 2018, International League of Associations for Rheumatology (ILAR).

Dysregulation of apoptosis is a distinctive feature of chronic lymphocytic leukemia (CLL), although a unique mechanism underlying apoptosis resistance of CLL B lymphocytes has not been identified yet. Aberrant expression as well as genetic and epigenetic alterations of numerous genes involved in different pathways of apoptosis regulation has been described in CLL. Here, we report the expression analysis of Bcl2L12 (Bcl2-like 12), a novel apoptotic gene belonging to Bcl2 family, in 58 Serbian CLL patients. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) analysis revealed a significant overexpression of Bcl2L12 mRNA in CLL samples compared to non-leukemic samples, implying its role in the pathogenesis of the disease. Receiver operating characteristic (ROC) analysis showed that Bcl2L12 expression efficiently discriminates CLL cases from healthy controls. However, relatively homogenous Bcl2L12 mRNA expression among patients did not reflect their clinical characteristics (with the exception of lactate dehydrogenase status and time from diagnosis to treatment) and failed to show association with the most informative prognostic markers, namely the mutational status of rearranged immunoglobulin heavy chain variable region genes, CD38 and lipoprotein lipase gene (LPL) expression. © 2013 Springer Science+Business Media New York.

Dysregulation of apoptosis is a distinctive feature of chronic lymphocytic leukemia (CLL), although a unique mechanism underlying apoptosis resistance of CLL B lymphocytes has not been identified yet. Aberrant expression as well as genetic and epigenetic alterations of numerous genes involved in different pathways of apoptosis regulation has been described in CLL. Here, we report the expression analysis of Bcl2L12 (Bcl2-like 12), a novel apoptotic gene belonging to Bcl2 family, in 58 Serbian CLL patients. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) analysis revealed a significant overexpression of Bcl2L12 mRNA in CLL samples compared to non-leukemic samples, implying its role in the pathogenesis of the disease. Receiver operating characteristic (ROC) analysis showed that Bcl2L12 expression efficiently discriminates CLL cases from healthy controls. However, relatively homogenous Bcl2L12 mRNA expression among patients did not reflect their clinical characteristics (with the exception of lactate dehydrogenase status and time from diagnosis to treatment) and failed to show association with the most informative prognostic markers, namely the mutational status of rearranged immunoglobulin heavy chain variable region genes, CD38 and lipoprotein lipase gene (LPL) expression. © 2013 Springer Science+Business Media New York.

Introduction: Sarcoidosis is a rare multisystem granulomatous disease with unknown etiology. The interplay of vitamin D deficiency and genetic polymorphisms in genes coding for the proteins relevant for metabolism of vitamin D is an important, but unexplored area. The aim of this study was to investigate the association between single nucleotide polymorphisms (SNPs) in CYP2R1 (rs10741657), CYP27B1 (rs10877012), DBP (rs7041; rs4588), and VDR (rs2228570) genes and sarcoidosis, as well as the association between these SNPs and 25(OH)D levels in sarcoidosis patients. Material and methods: For that purpose we genotyped 86 sarcoidosis patients and 50 healthy controls using the PCR-RFLP method. Results: Subjects carrying the CC genotype of CYP27B1 rs10877012 have 10 times lower odds of suffering from sarcoidosis. Moreover, DBP rs4588 AA genotype was shown to be a susceptibility factor, where carriers of this genotype had eight times higher odds for developing sarcoidosis. In addition, the A allele of the DBP gene (rs4588) was associated with lower levels of 25(OH)D in sarcoidosis patients. Conclusions: These results suggest that patients with vitamin D deficiency should be regularly tested for genetic modifiers that are related to sarcoidosis in order to prevent development of serious forms of sarcoidosis. Copyright © 2018 Termedia & Banach

Systemic sclerosis (SSc) is a heterogeneous multisystem autoimmune disease with unknown etiology. Numerous studies have indicated that the disease heterogeneity implies various genetic abnormalities. Considering that SSc is characterized by a strong sex bias and that the position of IRAK1 gene is on the X chromosome, we assume that variations in IRAK1 gene could explain female predominance of SSc. It was previously described that miR-146a has a role in ‘fine-tuning’ regulation of the TLR/NF-kB signaling pathway through down-regulation of IRAK1 gene. The aim of the present study was to analyze both variants and expression level of IRAK1 and miR-146a genes in terms of susceptibility to SSc and clinical presentation of SSc patients. We analyzed variants IRAK1 rs3027898 C > A and miR-146a rs2910164 C > G in 102 SSc patients and 66 healthy subjects. Genotyping was performed by Sanger sequencing. Expression level of IRAK1 mRNA and miR-146a in PBMCs was performed in subset of 50 patients and 13 healthy controls by RT-qPCR. Our results showed that there was no association between IRAK1 rs3027898 and the risk of SSc in women. However, the analysis of genotype distribution of the mir-146a rs2910164 C > G variant indicated that CC genotype shows strong association with lung fibrosis and active form of the disease. When expression level of IRAK1 gene was analyzed, we detected significant downregulation of IRAK1 mRNA in SSc patients compared to controls, as well as in male compared to female patients, in patients with ACAs autoantibodies and in patients with severe skin involvement. Regarding the expression level of miR-146a, we have found significantly reduced expression in SSc patients, in patients with skin involvement and in male SSc patients. The results from this study indicate that expression of IRAK1 gene could explain phenotypic heterogeneity of SSc and may be involved in the pathogenesis of SSc due to its differential expression in certain subgroups. Our results also suggested that miR-146a rs2910164 CC genotype may be predisposing factor for development lung fibrosis and more progressive form of SSc. Results from relative expression analysis of miR-146a demonstrated that changes in the level of this miRNA may have an impact on development and clinical course of SSc. © 2018 European Federation of Immunological Societies

Systemic sclerosis (SSc) is a heterogeneous multisystem autoimmune disease with unknown etiology. Numerous studies have indicated that the disease heterogeneity implies various genetic abnormalities. Considering that SSc is characterized by a strong sex bias and that the position of IRAK1 gene is on the X chromosome, we assume that variations in IRAK1 gene could explain female predominance of SSc. It was previously described that miR-146a has a role in ‘fine-tuning’ regulation of the TLR/NF-kB signaling pathway through down-regulation of IRAK1 gene. The aim of the present study was to analyze both variants and expression level of IRAK1 and miR-146a genes in terms of susceptibility to SSc and clinical presentation of SSc patients. We analyzed variants IRAK1 rs3027898 C > A and miR-146a rs2910164 C > G in 102 SSc patients and 66 healthy subjects. Genotyping was performed by Sanger sequencing. Expression level of IRAK1 mRNA and miR-146a in PBMCs was performed in subset of 50 patients and 13 healthy controls by RT-qPCR. Our results showed that there was no association between IRAK1 rs3027898 and the risk of SSc in women. However, the analysis of genotype distribution of the mir-146a rs2910164 C > G variant indicated that CC genotype shows strong association with lung fibrosis and active form of the disease. When expression level of IRAK1 gene was analyzed, we detected significant downregulation of IRAK1 mRNA in SSc patients compared to controls, as well as in male compared to female patients, in patients with ACAs autoantibodies and in patients with severe skin involvement. Regarding the expression level of miR-146a, we have found significantly reduced expression in SSc patients, in patients with skin involvement and in male SSc patients. The results from this study indicate that expression of IRAK1 gene could explain phenotypic heterogeneity of SSc and may be involved in the pathogenesis of SSc due to its differential expression in certain subgroups. Our results also suggested that miR-146a rs2910164 CC genotype may be predisposing factor for development lung fibrosis and more progressive form of SSc. Results from relative expression analysis of miR-146a demonstrated that changes in the level of this miRNA may have an impact on development and clinical course of SSc. © 2018 European Federation of Immunological Societies

Purpose: We studied changes of contact stress distribution in the hip joint after Tonnis triple pelvic osteotomy applied in the treatment of dysplasia and hip joint incongruence in adolescents. Methods: In a group of 75 patients, 54 (72 %) female, who underwent surgery by triple pelvic osteotomy in adolescence for developmental disorder of the hip and avascular necrosis of the femoral head, a three-dimensional hip joint model was used based on the radiography of the pelvis with hips. The following biomechanical parameters were calculated: resultant hip force normalised to body weight (R/Wb), inclination of the resultant hip force (θ-R), the position of the stress pole (θ), peak contact hip stress (Pmax), and peak contact hip stress normalised to body weight (Pmax/Wb). Gait quality was also assessed. Results: After surgery the Wiberg CE angle was increased by 17.85 (114 %), resultant hip force normalised to body weight (R/Wb) was decreased by 0.107 (3.3 %), the position of the stress pole was shifted medially by 27.59 (63.5 %), and peak contact hip stress normalised to body weight (Pmax/Wb) was decreased by 2249.74 (55.9 %). Waddling gait was reduced from 17 (23.9 %) to four cases (5.6 %). All changes were statistically highly significant (p<0.01). Conclusions: The effect of Tonnis triple pelvic osteotomy lies in the improvement of stress distribution across the acetabular cartilage of the hip joint, thus slowing down the degenerative damage of the hip joint. © 2012 Springer-Verlag Berlin Heidelberg.

Mutations in the fms-like tyrosine kinase 3 (FLT3) gene (internal tandem duplication (ITD) and point mutation in the tyrosine kinase domain, FLT3/D835) as well as the nucleophosmin (NPM1) gene are the most common abnormalities in adult acute myeloid leukemia (AML). Their significance in pediatric AML is still unclear. In this study we evaluated the frequency of FLT3 and NPM1 mutations in childhood AML. We also examined clinical features and outcome of these patients. FLT3 and NPM1 mutations were analysed in 42 and 37 childhood AML patients, respectively, using polymerase chain reaction (PCR) and direct sequencing. FLT3 mutations were detected in 4/42 patients (9.5%). The frequencies of FLT3/ITD and FLT3/D835 were the same, 2/42 (4.7%). NMP1 mutations were found in 1/37 patients (2.7%). FLT3 gene mutations were correlated with induction failure. Here we report the results of the study of FLT3 and NPM1 gene mutations in childhood AML patients in Serbia. Low frequencies of these molecular markers point out that these abnormalities are rare in this cohort of patients. Comparative study of data on NPM1 mutations in childhood AML revealed that various NPM1 gene mutation types are associated with childhood AML. Our findings as well as previously reported data, contributes to a hypothesis of different biology and etiology of adult and childhood AML. More extensive studies of NPM1 and FLT3 mutations in childhood AML are needed to determine their biological and clinical importance. © 2009 Humana Press Inc.

Mutations in the fms-like tyrosine kinase 3 (FLT3) gene (internal tandem duplication (ITD) and point mutation in the tyrosine kinase domain, FLT3/D835) as well as the nucleophosmin (NPM1) gene are the most common abnormalities in adult acute myeloid leukemia (AML). Their significance in pediatric AML is still unclear. In this study we evaluated the frequency of FLT3 and NPM1 mutations in childhood AML. We also examined clinical features and outcome of these patients. FLT3 and NPM1 mutations were analysed in 42 and 37 childhood AML patients, respectively, using polymerase chain reaction (PCR) and direct sequencing. FLT3 mutations were detected in 4/42 patients (9.5%). The frequencies of FLT3/ITD and FLT3/D835 were the same, 2/42 (4.7%). NMP1 mutations were found in 1/37 patients (2.7%). FLT3 gene mutations were correlated with induction failure. Here we report the results of the study of FLT3 and NPM1 gene mutations in childhood AML patients in Serbia. Low frequencies of these molecular markers point out that these abnormalities are rare in this cohort of patients. Comparative study of data on NPM1 mutations in childhood AML revealed that various NPM1 gene mutation types are associated with childhood AML. Our findings as well as previously reported data, contributes to a hypothesis of different biology and etiology of adult and childhood AML. More extensive studies of NPM1 and FLT3 mutations in childhood AML are needed to determine their biological and clinical importance. © 2009 Humana Press Inc.

Background: The study was undertaken to assess the influence of functional-308G/A TNF-α (rs 1800629) and-174G/C IL-6 (rs1800795) promoter polymorphisms on the therapeutic response to etanercept, a TNF-α blocker, in patients with rheumatoid arthritis (RA). Methods: Seventy-three patients suffering from active RA were studied, at baseline and 6 and 12 months after therapy. The therapeutic response was estimated according to the European League Against Rheumatism response criteria. Patients were genotyped for-308G/A TNF-α and-174G/C IL-6 polymorphisms by the PCR-RFLP method, and the influence of genotype on etanercept response was assessed. Results: No difference in the percentage of responders (patients who had DAS28 improvement > 1.2) between patients with the TNF-α-308GG and GA and AA genotype was detected after 6 and 12 months of treatment. After 12 months of treatment the percentage of responders was significantly increased in patients with the IL-6-174GG genotype compared with those with the GC or CC genotype (p=0.006 by Chi-square test). Evaluation of the patients according to their combined IL-6/TNF-α genotypes showed that patients with the IL-6-174GG/TNF-α-308GG genotype were more frequent among the responders compared to those with other combined genotypes (p=0.022 by Chisquare test). More precisely, all patients with the combined IL-6-174GG/TNF-α-308GG genotype were responders after 12 months of etanercept treatment. Conclusions: The study suggests that patients who are genetically low TNF-α and IL-6 producers are the best responders to etanercept therapy.

Background: The study was undertaken to assess the influence of functional-308G/A TNF-α (rs 1800629) and-174G/C IL-6 (rs1800795) promoter polymorphisms on the therapeutic response to etanercept, a TNF-α blocker, in patients with rheumatoid arthritis (RA). Methods: Seventy-three patients suffering from active RA were studied, at baseline and 6 and 12 months after therapy. The therapeutic response was estimated according to the European League Against Rheumatism response criteria. Patients were genotyped for-308G/A TNF-α and-174G/C IL-6 polymorphisms by the PCR-RFLP method, and the influence of genotype on etanercept response was assessed. Results: No difference in the percentage of responders (patients who had DAS28 improvement > 1.2) between patients with the TNF-α-308GG and GA and AA genotype was detected after 6 and 12 months of treatment. After 12 months of treatment the percentage of responders was significantly increased in patients with the IL-6-174GG genotype compared with those with the GC or CC genotype (p=0.006 by Chi-square test). Evaluation of the patients according to their combined IL-6/TNF-α genotypes showed that patients with the IL-6-174GG/TNF-α-308GG genotype were more frequent among the responders compared to those with other combined genotypes (p=0.022 by Chisquare test). More precisely, all patients with the combined IL-6-174GG/TNF-α-308GG genotype were responders after 12 months of etanercept treatment. Conclusions: The study suggests that patients who are genetically low TNF-α and IL-6 producers are the best responders to etanercept therapy.

Background: Osteoarthritis (OA) is a chronic degenerative joint disease and is considered to be the fourth leading cause of disability and the second cause of inability to work in men. Recently, adipose-derived mesenchymal stem cells (AD-MSCs) came into focus for regenerative medicine as a promising tool for the treatment of OA. The administration of stem cells into impaired joints results in pain relief and improves quality of life, accompanied by restoration of hyaline articular cartilage. Methods: In the present study, nine patients (including two patients with bilateral symptoms) diagnosed with osteoarthritis (International Knee Documentation grade B in 5 and grade D in six knees) were treated using a single injection of AD-MSCs at a concentration of 0.5–1.0 × 107 cells and were followed up for 18 months. During follow-up, all the cases were evaluated clinically by Knee Society score (KSS), Hospital for Special Surgery knee score (HSS-KS), Tegner–Lysholm (T–L) score and visual analogue scale (VAS) of pain, as well as by plain radiography and by magnetic resonance imaging visualization with 2D Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score assessment. Results: Significant improvement of all four clinical scores was observed within the first 6 months (KSS for 41.4 points, HSS-KS for 33.9 points, T–L score for 44.8 points, VAS of pain from 54.5 to 9.3) and improvement persisted throughout the rest of the follow-up. MOCART score showed significant cartilage restoration (from 43 ± 7.2 to 63 ± 17.1), whereas radiography showed neither improvement, nor further joint degeneration. Conclusions: The results obtained in the present study provide good basis for prospective randomized controlled clinical trials with respect to the use of AD-MSCs in the treatment of osteoarthritis. Copyright © 2017 John Wiley & Sons, Ltd.

Background: Osteoarthritis (OA) is a chronic degenerative joint disease and is considered to be the fourth leading cause of disability and the second cause of inability to work in men. Recently, adipose-derived mesenchymal stem cells (AD-MSCs) came into focus for regenerative medicine as a promising tool for the treatment of OA. The administration of stem cells into impaired joints results in pain relief and improves quality of life, accompanied by restoration of hyaline articular cartilage. Methods: In the present study, nine patients (including two patients with bilateral symptoms) diagnosed with osteoarthritis (International Knee Documentation grade B in 5 and grade D in six knees) were treated using a single injection of AD-MSCs at a concentration of 0.5–1.0 × 107 cells and were followed up for 18 months. During follow-up, all the cases were evaluated clinically by Knee Society score (KSS), Hospital for Special Surgery knee score (HSS-KS), Tegner–Lysholm (T–L) score and visual analogue scale (VAS) of pain, as well as by plain radiography and by magnetic resonance imaging visualization with 2D Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score assessment. Results: Significant improvement of all four clinical scores was observed within the first 6 months (KSS for 41.4 points, HSS-KS for 33.9 points, T–L score for 44.8 points, VAS of pain from 54.5 to 9.3) and improvement persisted throughout the rest of the follow-up. MOCART score showed significant cartilage restoration (from 43 ± 7.2 to 63 ± 17.1), whereas radiography showed neither improvement, nor further joint degeneration. Conclusions: The results obtained in the present study provide good basis for prospective randomized controlled clinical trials with respect to the use of AD-MSCs in the treatment of osteoarthritis. Copyright © 2017 John Wiley & Sons, Ltd.

Introduction Secondary malignancies, particularly solid tumors, are common in patients with chronic lymphocytic leukemia (CLL), but association of myeloproliferative neoplasms and chronic lymphocytic leukemia in the same patient is very rare. Case Outline We report of a 67-year-old man with B-cell chronic lymphoid leukemia (B-CLL) who developed primary myelofibrosis (PMF) nine years after initial diagnosis. Patient received alkylation agents and purine analogue, which can be a predisposing factor for the development of myeloproliferative neoplasms. JAK2V617F mutation was not present initially at the time of CLL diagnosis, but was found after nine years when PMF occurred, which indicates that B-CLL and PMF represent two separate clonal origin neoplasms. Conclusion Pathogenic mechanisms for the development of myeloproliferative and lymphoproliferative neoplasms in the same patient are unknown. Further research is needed to determine whether these malignancies originate from two different cell clones or arise from the same pluripotent hematopoietic stem cell. © 2015, Serbia Medical Society. All rights reserved.

Phenylketonuria (PKU) is caused by mutations in the gene encoding phenylalanine hydroxylase (PAH) enzyme. Here, we report the updated spectrum of PAH mutations in 61 Serbian PKU patients. By using both DGGE/DNA sequencing and PCR-RFLP, we identified 26 disease-causing mutations (detection rate 99%). The most frequent ones were p.L48S (31%), p.R408W (16.4%), p.P281L (6%), p.E390G (5.2%), and p.I306V (5.2%). Homozygosity value indicated high heterogeneity of Serbian population. To overcome possible pitfalls of patients’ phenotypic classification, we used two parameters: pretreatment/maximal phenylalanine blood concentration and Phe tolerance. The two phenotypes did not match only for patients with p.L48S. Therefore, we used Mann-Whitney statistical test to compare pretreatment/maximal blood Phe concentration and Phe tolerance detected in patients with p.[L48S];[null] and p.[missense];[null] genotypes. For patients with p.L48S, our results implied that Phe tolerance is a better parameter for phenotypic classification. Also, Fisher’s exact test was used to compare p.L48S effect on phenotype of homozygous and functionally hemizygous patients. Our findings showed that effect of p.L48S was altered in functional hemizygotes. Moreover, phenotypic inconsistency found in homozygotes suggested that interallelic complementation and/or additional factors play a role in genotype-phenotype correlation. Since BH4-supplementation therapy is not available in Serbia, we made the first estimation of its potential benefit based on patients’ genotypes. In the analyzed cohort, the total frequency of BH4-responsive mutations was 52.6%. Furthermore, we found a significant number of genotypes (26.2% BH4-responsive and 51% probably BH4-responsive) that may respond to BH4 therapy. This led us to a conclusion that BH4-supplementation therapy could bring benefit to Serbian PKU patients. © 2012, SSIEM and Springer-Verlag Berlin Heidelberg.

Phenylketonuria (PKU) is caused by mutations in the gene encoding phenylalanine hydroxylase (PAH) enzyme. Here, we report the updated spectrum of PAH mutations in 61 Serbian PKU patients. By using both DGGE/DNA sequencing and PCR-RFLP, we identified 26 disease-causing mutations (detection rate 99%). The most frequent ones were p.L48S (31%), p.R408W (16.4%), p.P281L (6%), p.E390G (5.2%), and p.I306V (5.2%). Homozygosity value indicated high heterogeneity of Serbian population. To overcome possible pitfalls of patients’ phenotypic classification, we used two parameters: pretreatment/maximal phenylalanine blood concentration and Phe tolerance. The two phenotypes did not match only for patients with p.L48S. Therefore, we used Mann-Whitney statistical test to compare pretreatment/maximal blood Phe concentration and Phe tolerance detected in patients with p.[L48S];[null] and p.[missense];[null] genotypes. For patients with p.L48S, our results implied that Phe tolerance is a better parameter for phenotypic classification. Also, Fisher’s exact test was used to compare p.L48S effect on phenotype of homozygous and functionally hemizygous patients. Our findings showed that effect of p.L48S was altered in functional hemizygotes. Moreover, phenotypic inconsistency found in homozygotes suggested that interallelic complementation and/or additional factors play a role in genotype-phenotype correlation. Since BH4-supplementation therapy is not available in Serbia, we made the first estimation of its potential benefit based on patients’ genotypes. In the analyzed cohort, the total frequency of BH4-responsive mutations was 52.6%. Furthermore, we found a significant number of genotypes (26.2% BH4-responsive and 51% probably BH4-responsive) that may respond to BH4 therapy. This led us to a conclusion that BH4-supplementation therapy could bring benefit to Serbian PKU patients. © 2012, SSIEM and Springer-Verlag Berlin Heidelberg.