Contribution of Toll-Like Receptor 9 Gene Single-Nucleotide Polymorphism to Systemic Lupus Erythematosus in Egyptian Patients

Background: Systemic lupus erythematosus (SLE) is an autoimmune disease, with multiple genetic and environmental factors involved in its etiology. The toll-like receptor 9 (TLR9) gene has been reported to have important roles in the development and progression of SLE. In this case-control study, the effect of TLR9 polymorphism on susceptibility to SLE was investigated in Egyptian patients.

Methods: We studied the distribution of the TLR9 rs352139 (G + 1174A) single nucleotide polymorphism (SNP) by allele-specific polymerase chain reaction (PCR) in 104 Egyptian patients with SLE and 108 age-, sex-, and ethnically matched controls.

Results: There was no statistically significant difference in the distribution of the AA genotype and alleles between SLE patients and the control group in our study; however, the GA heterozygous patients were three times more likely to develop SLE (P < 0.001). A significant association was detected between TLR9 genotypes and some of the disease manifestations as myositis (p = 0.032), psychosis (p = 0.014), photosensitivity (p = 0.002), and pleurisy (p = <0.001). Moreover, we observed a significant association between the TLR9 AA and GA genotypes and the presence of antinuclear antibodies (ANA) (p = 0.038).

Conclusion: The G + 1174A SNP in the toll receptor 9 gene may contribute to the genetic susceptibility of SLE in Egyptian patients. Also, an influence for this polymorphism on disease manifestations has been elucidated.     

IL12 Gene Polymorphism in Association with Hepatocellular Carcinoma in HCV-infected Egyptian Patients

Background: Hepatocellular carcinoma has been recorded the commonest cancer in Egypt. This increasing incidence may be attributed to the high prevalence of hepatitis C virus with its complications, so this study aimed to investigate the association between the potentially functional polymorphisms of IL12A and IL12B genes as a risk factor of development of hepatocellular carcinoma (HCC) on top of hepatitis C virus (HCV) infection in an Egyptian population.

Materials and methods: We genotyped two loci of IL12 which were rs568408 (3’UTR G>A) for IL12A and rs3212227 (3’UTR A>C) for IL12B in 78 patients with HCC on top of chronic HCV infection. In addition, 64 cancer-free chronic HCV patients were studied, besides 92 healthy subjects who were included as control.

Results: Study of rs568408 (G>A) gene polymorphism showed that the A allele is higher while the G allele is lower in HCC cases than cancer-free chronic HCV patients (p = 0.006*). The A-containing genotypes AG and (AG+AA) were higher while the GG was lower (p = 0.009* and p = 0.005*), respectively. The study of the rs3212227 (A>C) polymorphism showed neither statistically significant differences between the C and A allele (p = 0.2) nor between CC, AC, or AC+CC in HCC cases and cancer-free chronic HCV patients (p = 0.7, p = 0.2, and p = 0.29), respectively.

Conclusion: Our findings showed that IL12A rs568408 (G>A) polymorphism may contribute to the risk of HCC on top of chronic HCV infection, whereas that of IL12B rs3212227 (A>C) do not.     

PTPN22 Single-Nucleotide Polymorphisms in Iranian Patients with Type 1 Diabetes Mellitus

Background: PTPN22 plays a crucial role in regulating the function of various cells of the immune system, particularly T cells. Polymorphisms of the PTPN22 gene have been associated with many autoimmune diseases, including type 1 diabetes (T1D) which is a T-cell-mediated disease.

Objective: The present study was aimed at genotyping of an Iranian population for five polymorphisms of the PTPN22 gene.

Methods: The study population consisted of 99 T1D patients and 100 healthy controls. We genotyped five single-nucleotide polymorphisms (SNPs) (rs12760457, rs1310182, rs1217414, rs33996649, and rs2476601) of the PTPN22 gene.

Results: Regarding the variant rs2476601, genotypes AG and GG were increased and decreased in T1D patients compared with controls, respectively. Further, alleles G and A of this SNP were found to be decreased and increased in T1D patients, respectively (p value = 0.001). However, T1D and control groups did not differ on genotype distribution or allele frequency for other investigated SNPs.

Conclusions: The PTPN22 rs2476601 minor allele (A) was associated with T1D in Iran, accounting for its pathophysiology in autoimmune diseases.     

Matrix Metalloproteinase-9 rs17576 Gene Polymorphism and Behçet’s Disease: Is There an Association?

Background: Clinical studies have reported a significant association between matrix metalloproteinases (MMP), particularly (MMP-9), and inflammatory diseases including Behçet’s disease (BD).

Purpose: To study the relationship between MMP-9 rs17576 gene polymorphism and the development of BD, and its relation to disease activity among Egyptian patients.

Methods: A total of 100 BD patients and 100 healthy control volunteers were genotyped for MMP-9 rs17576 polymorphism with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), followed by the confirmation of our results in random subgroups using direct DNA sequencing technique.

Results: The frequency of the GG genotype and G allele was significantly higher in BD patients as compared to the normal controls (p = 0.011, OR 8.61; p = 0.03, OR 1.65, respectively). There was no significant association between the MMP-9 rs17576 polymorphism and the clinical outcomes of BD.

Conclusion: our study suggests a significant association of the MMP-9 rs17576 A/G polymorphism with increased risk of BD development in Egyptian patients.     

Association of FAM167A-BLK rs2736340 Polymorphism with Susceptibility to Autoimmune Diseases: A Meta-Analysis

Objective: The purpose of this study is to evaluate the correlation between family with sequence similarity 167A-B lymphoid tyrosine kinase (FAM167A-BLK) rs2736340 polymorphism and autoimmune diseases.

Methods: Databases including PubMed, EMBASE, Chinese National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature database (CBM) and Chinese database, Wan Fang database were used in searching eligible studies from January 1, 1966 to October 2, 2015. The odds ratios (ORs) and their 95% confidence intervals (CIs) were pooled to estimate the strength of the association.

Results: A total of 25 studies with 30,217 patients and 44,754 controls were included in the meta-analysis. The overall results showed FAM167A-BLK rs2736340 T allele was a risk allele for autoimmune diseases (OR 1.36, 95% CI 1.28–1.44, p < 0.001). In the subgroup by ethnicities, the results suggested T allele was an increased risk in North America, Europe, and Asia (OR 1.33, 95% CI 1.10–1.60, p = 0.004; OR 1.26, 95% CI 1.22–1.31, p < 0.001; and OR 1.46, 95% CI 1.40–1563, p < 0.001, respectively), but not in Africa. Subgroup analysis in different genetic models (recessive, dominant, and additive) revealed significant association between rs2736340 and autoimmune diseases in Asia and North America, but not the recessive model in Europe or Africa, or the additive model in Africa. Stratification analysis by diseases suggested FAM167A-BLK rs2736340 had a positive association with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and Kawasaki disease, primary Sjogren’s syndrome (pSS), primary antiphosholipid syndrome (APS), and myositis.

Conclusion: The current meta-analysis suggested that FAM167A-BLK rs2736340 polymorphism is associated with several autoimmune diseases.     

Association between IL-33 Gene Polymorphisms (rs1929992, rs7044343) and Systemic Lupus Erythematosus in a Chinese Han Population

Objective: Interleukin-33 (IL-33) is a member of the IL-1 family, and previous studies found the single-nucleotide polymorphisms (SNPs) in the IL-33 gene was related to susceptibility to autoimmune diseases, including rheumatoid arthritis, ankylosing spondylitis and Behcet’s disease. To date, no study has discussed the potential association between IL-33 gene polymorphisms and systemic lupus erythematosus (SLE).

Methods: We conducted a case-control study including 371 SLE patients and 408 healthy controls to investigate the correlation between the SNPs of IL-33 gene (rs1929992, rs7044343) and SLE in a Chinese Han population.

Results: There was significantly lower expression of allele G for rs1929992 in SLE patients than that in controls (G versus A, P = 0.012, OR = 1.310, 95% CI: 1.060–1.624 after adjustment with sex). Similarly, genotype GG was associated with the susceptibility to SLE as compared with the AA genotype (P = 0.017, OR = 1.714, 95% CI: 1.101–2.669 after adjustment with sex). We also found statistical significance in the dominant model (GG+GA versus AA, P = 0.017, OR = 1.481, 95% CI: 1.074–2.044 after adjustment with sex). However, we found no strong evidence for the association of IL-33 rs7044343 polymorphism with SLE. Moreover, association studies were performed on the relationship between the IL-33 gene polymorphisms and lupus nephritis as well as nine clinical features of SLE, but there was no significant association regarding the distribution of allele and genotype frequencies between SLE patients positive and negative for the presence of sub-phenotypes.

Conclusion: Our findings indicate that IL-33 rs1929992 polymorphism may be a potential biomarker for susceptibility to SLE.     

Association between Functional CYP2D6 Polymorphisms and Susceptibility to Autoimmune Diseases: A Meta-Analysis

Objective: This study aimed to explore whether functional CYP2D6 polymorphisms are associated with susceptibility to autoimmune diseases.

Methods: A meta-analysis was conducted on associations between autoimmune diseases and functional CYP2D6*4 1934 A/G and *3 polymorphisms and CYP2D6 phenotypes.

Results: Twelve studies with 1,472 patients and 3,328 controls were included. Autoimmune disease and the CYP2D6 1934 A allele were significantly associated in the overall group, consistent with the Hardy–Weinberg equilibrium (OR = 1.227, 95% CI = 1.071–1.406, p = 0.003); stratification by ethnicity indicated that the CYP2D6 1934 A allele and autoimmune diseases were associated in Caucasians (OR = 1.225, 95% CI = 1.010–1.485, p = 0.039). The CYP2D6*3 allele was also associated with autoimmune diseases in Caucasians (OR = 1.977, 95% CI = 1.125–3.472, p = 0.018). Stratified by autoimmune disease type revealed that the CYP2D6 1934 AA genotype was associated with systemic lupus erythematosus (SLE; OR = 2.007, 95% CI = 1.170–3.442, p = 0.011) and ankylosing spondylitis (AS; OR = 2.317, 95% CI = 1.422–3.774, p = 0.001). The CYP2D6 PM+IM phenotype was significantly associated with autoimmune diseases in Caucasians (OR = 1.526, 95% CI = 1.038–2.246, p = 0.032) and with SLE (OR = 1.778, 95% CI = 1.249–2.532, p = 0.001).

Conclusions: This meta-analysis indicates that CYP2D6*4 and *3 polymorphisms and the CYP2D6 phenotype are associated with susceptibility to autoimmune diseases in Caucasians; particularly, the CYP2D6*4 polymorphism and CYP2D6 PM+IM phenotype are risk factors for SLE development.     

The histological spectrum of tubulo-reticular inclusion positive renal biopsies: a tertiary hospital experience and review of the literature

Aim: To identify the underlying diseases with TRI-positive kidney biopsies, and describe the histological pattern and spectrum of TRI-positive kidney biopsies.

Methods: A retrospective analysis of all patients’ chart that underwent renal biopsy at King Saud University Medical City between 2012 and 2017 was done. Kidney biopsies that indicated a positive result for tubuloreticular inclusions (TRI’s) on electron microscopy were reviewed and the underlying disease and histological pattern was extracted.

Results: Of 1,473 native kidney biopsies reviewed, 96 (6.5%) were TRI-positive. Of the 96 TRI-positive kidney biopsies, 87 (90.6%) were TRI-positive lupus nephritis (LN); of which 10 (11.5%) were Class V, 49 (56.3%) were active LN, and 28 (32.2%) were inactive LN. The underlying diseases of the nine non-LN TRI-positive cases included diabetic nephropathy, connective tissue disorders, immune complex mediated Glomerulonephritis (GN), acute thrombotic microangiopathy, rhabdomyolysis, and Wegener’s disease.

Conclusion: LN is a very common finding in TRI-positive kidney biopsies. Active LN and chronic LN are the more common classes of TRI-positive LN kidney biopsies, than pure membranous (Class V) LN. TRI positive kidney biopsies without LN are commonly found in diabetic nephropathy, connective tissue disorders and immune mediated GN’s.

This study highlights this finding in our patients cohort in opposition to what has been reported in the literature.     

Rheumatic Disease Autoantibodies in Autoimmune Liver Diseases

Background: Autoimmune liver diseases (ALDs) are known to be associated with systemic autoimmune rheumatic diseases (SARDs) and their autoantibodies. We aimed to study the prevalence of SARDs and related autoantibodies, as well as their prognostic implications in a group of patients with ALDs.

Methods: This was a cross-sectional study. Sixty patients with ALDs (38.3% with autoimmune hepatitis; 11.7% with primary biliary cirrhosis; 25% with primary sclerosing cholangitis and 25% with overlap syndrome) were studied for the presence of SARDs and their autoantibodies.

Results: There was autoimmune rheumatic disease in 20% of the studied sample. Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) were the commonest (11.6% and 5%, respectively). Antinuclear antibodies (ANAs) were present in 35% of the patients, followed by anti-Ro (20.0%); anti-nucleosome (18.3%); rheumatoid factor (10%) anti-CCP (8.3%); anti-RNP (8.3%); anti-ds-DNA (6.6%); anti-La (3.3%); anti-Sm (3.3%), anti-ribosomal P (3.3%). Anti-Ro (p = 0.0004), anti-La (p = 0.03), anti-RNP (p = 0.04) and anti-Sm (p = 0.03) were commonly found in patients with SARD, but not anti-DNA, anti-nucleosome and anti-ribosomal P. No differences were found in liver function tests regarding to the presence of autoantibodies.

Conclusions: There was a high prevalence of SARD and their autoantibodies in ALD patients. Anti-Ro, anti-La, anti-RNP and anti-Sm positivity points to an association with systemic autoimmune rheumatic diseases. The presence of autoantibodies was not related to liver function tests.     

Complex role of IL-23R polymorphisms on ankylosing spondylitis: a meta-analysis

Background: The aim of the meta-analysis was to evaluate the association between 10 widely studied polymorphisms of interleukin-23 receptor gene (IL-23R) and ankylosing spondylitis (AS).

Methods: A comprehensive literature search, screening of eligible articles and data extraction was performed independently by two investigators. Further meta-analysis was conducted with STATA 12.0 software (Stata Corp.; College Station, TX, USA). The association between IL-23R polymorphisms and AS was evaluated by odds ratio (OR) and 95% confidence intervals (95% CI).

Results: Twenty-five case–control studies with 8431 cases and 8972 controls were included in this meta-analysis. Quantitative meta-analysis revealed that minor allele frequency (MAF) of rs1004819, rs1495965, and rs2201841 was significantly higher in the AS group (p value < .001, < .001, = .010, respectively). MAF of rs10489629, rs11209026, rs11465804, and rs1343151was significantly lower in the AS group (p value = .002, < .001, = .032, < .001, respectively). However, there is no significant difference between these two groups in rs10889677, rs11209032, and rs7517847 frequency (p value = .128, .237, .131, respectively).

Conclusions: The present study indicates that minor allele carriers of rs1004819, rs1495965, and rs2201841 are susceptible to AS. Conversely, minor alleles of rs10489629, rs11209026, rs11465804, and rs1343151 have protective effect on AS.     

Pregnane X Receptor Polymorphisms and Risk of Inflammatory Bowel Disease: A Meta-Analysis

Background: Pregnane X receptor (PXR) gene polymorphisms have been widely studied in terms of the association with inflammatory bowel disease (IBD), with inconsistent results.

Objective: The present meta-analysis was performed to assess the association between PXR gene polymorphisms and the susceptibility of IBD, Crohn’s disease (CD), and ulcerative colitis (UC).

Methods: PubMed, Wanfang, and CNKI databases were searched for eligible studies before November 1, 2016. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to calculate the various genetic models using either a fixed-effect or a random-effect model. The heterogeneity of the included studies was examined with Cochran Q and I² statistics. Begg’s rank correlation test and Egger’s linear regression test were used to assess the publication bias.

Results: A total of six studies with 4248 cases and 3853 controls were included in this meta-analysis. Three PXR gene polymorphisms were evaluated: rs1523127, rs2276707, and rs6785049. Our analyses of rs1523127, rs2276707, and rs6785049 suggested that PXR gene polymorphism had no obvious influence on the risk of IBD in Caucasians. Subgroup analyses based on disease type showed similar results.

Conclusion: Our meta-analysis revealed that PXR gene polymorphism may not be significantly associated with IBD susceptibility. However, the number of original studies was limited and further studies with large samples are needed to verify the results.

Abbreviations: PXR = pregnane X receptor, IBD = inflammatory bowel disease, CD = Crohn’s disease, UC = ulcerative colitis, ORs = pooled odds ratios, 95% CIs = 95% confidence intervals, NOS = Newcastle–Ottawa scale, HWE = Hardy–Weinberg equilibrium.     

Evaluation of TLR9 expression on PBMCs and CpG ODN-TLR9 ligation on IFN-α production in SLE patients

Context: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by autoreactive antibodies. Recent findings revealed the importance of innate immune responses, especially Toll-like receptors (TLRs) in the pathogenesis of SLE.

Objective: In this study, the level of TLR9 expression on peripheral blood mononuclear cells (PBMCs) was analyzed. The levels of produced IFN-α were also measured in supernatant of PBMCs from SLE patients and healthy controls after stimulation with CpG ODN2216 which is a plasmocytoid dendritic cell (pDC)-specific TLR9 ligand.

Materials and methods: TLR9 expression was analyzed by real-time polymerase chain reaction (PCR) and flow cytometry in 35 SLE patients and 38 healthy controls and IFN-α concentration was measured in supernatants using enzyme-linked immunosorbent assay (ELISA).

Results: The results showed that the TLR9 expression in the mRNA and the protein level was significantly higher in PBMCs from SLE patients. However, IFN-α concentration in patients and controls significantly increased in response to CpG stimulation but this increase was significantly higher in healthy controls compared with SLE patients. Our results do not show any association between taking hydroxychloroquine and reduction in IFN-α production in SLE patients.

Discussion and conclusions: Regarding the findings of the study, there is the possibility that TLR9 has played a role in SLE pathogenesis, and consequently it implies that TLRs can be considered to be the therapeutic targets for systemic autoimmunity. We may conclude that PBMCs in patients are functionally impaired in response to TLR ligation via innate response stimulating pathogen-associated molecular patterns (PAMPs).     

Lupus nephritis and B-cell targeting therapy

Introduction: Lupus Nephritis (LN) is a severe manifestation of Systemic Lupus Erythematosus (SLE) with a significant prognostic impact. Over a prolonged course, an exhaustion of treatment alternatives may occur and further therapeutic options are needed. B cells play a pivotal role in disease pathogenesis and represent an attractive therapeutic target.

Areas covered: This review provides an update regarding targeting B cells in LN. The rational for this approach, as well as currently available and future targets are discussed.

Expert commentary: Despite its wide clinical use and the encouraging results from retrospective studies, a role of rituximab in LN has not been prospectively confirmed. Trial design methodologies as well as intrinsic limitations of this approach may be responsible and rituximab use is currently limited as a rescue treatment or in settings where a strong steroid sparing effect is warranted. Despite belimumab now being licensed for use in SLE, the evidence in LN is weak although prospective trials are on-going. The combination of different targeted approaches as well as a focus on new clinical end-points may be strategies to identify new therapeutic options.     

Lack of Association between MYO9B Gene Polymorphisms and Susceptibility to Coeliac Disease in Caucasians: Evidence from a Meta-Analysis

Objective: Coeliac disease (CD) is a complex disorder influenced by environmental and genetic factors. Recently, a number of studies reported MYO9B gene is associated with CD, but the results are controversial. The aim of this study is to clarify this dispute by means of a meta-analysis.

Methods: The databases of PubMed, Web of Science, and Embase updated to August 2015 were retrieved. Crude odds ratio (OR) and corresponding 95% confidence interval (95%CI) as effect size were calculated by fixed or random effect model according to the heterogeneity.

Results: A total of 8 studies including 2272 cases and 5419 controls were enrolled in this meta-analysis. There was no significant association both in allele and genotype comparisons between the MYO9B (rs2305764, rs2305767, rs1457092) polymorphism and CD in Caucasian populations. No publication bias was detected in this meta-analysis.

Conclusions: This meta-analysis indicates that MYO9B gene polymorphisms might be not associated with CD susceptibility in Caucasians. Further studies are still needed for definitive conclusions.     

The role of TNF alpha polymorphism and expression in susceptibility to nasal polyposis

Objective: In this study, we first performed a meta-analysis to assess the role of single-nucleotide polymorphism (SNP) within tumor necrosis factor alpha (TNF alpha) gene and TNF alpha expression in the risk of nasal polyposis.

Methods: STATA 12.0 software was utilized to conduct the Mantel–Haenszel statistics, Cohen statistics, Begg’s test, Egger’s tests and sensitivity analysis.

Results: We systemically carried out the database retrieval and initially identified 486 articles. After screening, 15 articles were included in our meta-analysis. For TNF alpha rs1800629 G/A SNP, compared with control group, an increased risk of nasal polyposis of case group was observed in the models of A vs. G [p (P value of association) = 0.009, OR (odds ratio) = 1.35], GA vs. GG (p = 0.001, OR = 1.69), GA+AA vs. GG (p = 0.010, OR = 1.47). The similar results were observed in Caucasian subgroup (p < 0.05, OR > 1). For TNF alpha rs361525 G/A SNP, no significant difference between control and case group was detected (all p > 0.05). In addition, a significant difference exists between case and control groups in the meta-analyses of TNF alpha expression in nasal mucosal cells, secreted TNF alpha (p < 0.05, OR > 1), but not serum TNF alpha (p = 0.090).

Conclusion: The present meta-analysis revealed that TNF alpha rs1800629, increased TNF alpha expression and secretion of nasal mucosal cells were associated with an increased risk of nasal polyposis.     

Common gene variants interactions related to uric acid transport are associated with knee osteoarthritis susceptibility

Background: The presence of genetic variants in uric acid (UA) transporters can be associated with hyperuricemia, and therefore with an increased risk of monosodium urate (MSU) crystal precipitation. The inflammatory process triggered by these crystals leads to cartilage damage, which, in turn, could promote knee osteoarthritis (KOA).

Objective: To determine whether genetic polymorphisms of the UA transporters and their interactions are associated with KOA.

Materials and Methods: Two hundred forty-three unrelated Mexican-mestizo individuals were recruited for this case-control study. Ninety-three of them were KOA patients but without gout, and one hundred and fifty healthy individuals with no symptoms or signs of KOA were recruited as controls. Forty-one single-nucleotide polymorphisms (SNPs) involved in the UA transporters were genotyped with OpenArray technology in a QuantStudio 12K flex-System with both cases and controls.

Results: After adjusting by age, gender, BMI, and ancestry, significant associations were found for eight SNPs: rs1260326 (GCKR), rs780093 (GCKR), rs17050272 (INHBB), rs1471633 (PDZK1), rs12129861 (PDZK1), rs7193778 (IGF1R), rs17786744 (STC1), and rs1106766 (R3HDM2). With respect to gene–gene interactions, the pairwise interactions of rs112129861 (PDZK1) and rs7193778 (IGF1R); rs17050272 (INHBB) and rs1106766 (R3HDM2); rs1106766 (R3HDM2) and rs780093 (GCKR); rs1260326 (GCKR) and rs17786744 (STC1); and rs17786744 (STC1) and rs1106766 (R3HDM2) make it possible to visualize the synergistic or antagonistic effect of their genotypes or alleles on KOA development.

Conclusions: Our preliminary results show that the common gene variants related to UA transport are associated with KOA in the Mexican population. Further studies must be carried out to corroborate it.     

An observational study on the incidence of tuberculosis among a cohort of HIV infected adults in a setting with low prevalence of tuberculosis

Background: Tuberculosis (TB) remains a main cause of morbidity and mortality among individuals infected with HIV. We investigated the incidence of TB among a cohort of HIV infected patients attending a setting with low TB burden where screening for latent TB infection is not routinely carried out.

Methods: an observational cohort study on HIV-infected adults attending the HIV clinic at Queen Elizabeth Hospital Birmingham, UK between 1 January 2011 and 30 September 2015. Patients with culture-proven TB after HIV diagnosis, or those treated for clinical diagnosis of the infection, were classified as having “active TB”.

Results: 1824 patients were included in the study (5347 patient years of follow up), of whom 21 patients developed TB (16 microbiology confirmed). Of the 666 new HIV diagnoses, six patients developed TB within one month, giving a TB prevalence at the time of HIV diagnosis of 0.9%. The total TB incidence for the remaining 1818 patients was 2.81 cases per 1000 patient years (95% CI: 1.63–4.53). TB incidence was significantly more common among patients with CD4 ≤ 200 cells/mm³ compared to those with CD4 > 500 cells/mm³ (28.2 vs. 1.22 per 1000 patient years, p < 0.001), and in patients with VL ≥ 40 copies/mL compared to <40 copies/mL (8.30 vs. 1.42, p < 0.001).

Conclusion: In settings with low TB prevalence, early start of combined antiretroviral therapy and intensified TB case finding protocols may significantly reduce the incidence of TB.     

VDR polymorphisms are associated with bone mineral density in post-menopausal Mayan-Mestizo women

Background: Osteoporosis is characterized by low bone mineral density (BMD), which is determined by an interaction of genetic, metabolic and environmental factors.

Aim: To analyse the association between two polymorphisms of VDR as well as their haplotypes with BMD in post-menopausal Maya-Mestizo women.

Subjects and methods: This study comprised 600 post-menopausal Maya-Mestizo women. A structured questionnaire for risk factors was applied and BMD was assessed at the lumbar spine (LS) and total hip (TH) by dual-energy X-ray absorptiometry. DNA was extracted from blood leukocytes. Two single-nucleotide polymorphisms of VDR (rs731236 and rs2228570) were studied using real-time PCR allelic discrimination for genotyping. Differences between the means of the BMDs according to the genotype were analysed with covariance. Haplotype analysis was conducted.

Results: TT genotype of rs731236 of VDR had higher BMD at total hip and femoral neck (FN), and one haplotype formed by the two polymorphisms was associated with only TH-BMD variations. This difference was statistically significant after adjustment for confounders. The genotype of rs2228570 of VDR analysis showed no significant differences with BMD variations.

Conclusion: The results showed that the TT genotype of rs731236 of VDR and one haplotype formed by rs731236 and rs2228570 polymorphisms were associated with higher BMD at TH and FN.