Low producer MBL genotypes are associated with susceptibility to systemic lupus erythematosus in Odisha, India

Association of IL13 polymorphisms with susceptibility to myocardial infarction: A case-control study in Chinese population

BACKGROUND

Inflammatory cytokines play a major role in the pathogenesis of myocardial infarction (MI). Although information on the importance of interleukin 13 (IL13) in human MI is limited, it has been well documented in the mouse model. Genetic variation in the IL13 gene has been associated with the structure and expression of the IL13. In the present study, we hypothesized that IL13 common genetic variants would be associated with a predisposition to the development of MI.

MATERIALS AND METHODS

The present study enrolled 305 MI patients and 310 matched healthy controls. Common genetic polymorphisms in the IL13 gene (rs20541, rs1881457, and rs1800925) were genotyped using the TaqMan SNP genotyping method. Plasma levels of IL13 were measured using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

In MI patients, minor alleles of the IL13 rs1881457 and rs1800925 polymorphisms were less common than in healthy controls [rs1881457: AC (P = 0.004, OR = 0.61), C (P = 0.001, OR = 0.66); rs1800925: CT (P = 0.006, OR = 0.59)]. Further haplotype analysis of three studied SNPs revealed a significant association with predisposition to MI. Interestingly, IL13 rs1881457 and rs1800925 were linked to plasma levels of IL13: the reference genotype had higher levels, heterozygotes were intermediate, and the alternate genotype had the lowest levels.

CONCLUSIONS

In the Chinese population, IL13 (rs1881457 and rs180092) variants are associated with different plasma IL13 levels and offer protection against MI development. However, additional research is required to validate our findings in different populations, including descent samples.

The role of MBL, PCT, CRP, neutrophil-lymphocyte ratio, and platelet lymphocyte ratio in differentiating infections from flares in lupus

BACKGROUND

The distinction between infection and flare in systemic lupus erythematosus (SLE) has always been a dilemma for clinicians as the clinical and biochemical profiles overlap. The present study evaluated affordable biomarkers to distinguish infection from flare in an SLE cohort in a tertiary care center in eastern India.

METHODS

One hundred and fifty-two SLE patients were clinically evaluated and enrolled in the present study. Hematological, immunological, and biochemical profiles and various biomarkers such as C reactive protein (CRP), procalcitonin (PCT), and Mannose-binding lectin (MBL) were quantified.

RESULTS

One hundred and fifty-two patients (152) were enrolled in the present study and all had SLEDAI scores of more than 4. From which 70 had infection, and the common infections were urinary tract infection (34.28%) followed by pneumonia (27.14%). Neutrophil-lymphocyte ratio (NLR) and C-reactive protein (CRP) were significantly elevated in SLE with infections (NLR: 5.84 ± 2.47; CRP: 30.56 ± 41.63) than those with flare (NLR: 3.87 ± 2.62; CRP: 8.73 ± 9.53). The receiver operating characteristic curve (ROC) analysis revealed CRP, PLR, and NLR as important markers for predicting infections (CRP: AUC = 0.682, p = 0.0001; PLR: AUC = 0.668, p = 0.0008; NLR: AUC = 0.742, p < 0.0001). The MBL and PCT levels were comparable among SLE flare and those with infections.

CONCLUSIONS

NLR and CRP levels are affordable biomarkers to distinguish infections from flares in SLE. MBL and PCT could not differentiate flare from an infection. Key Points • Biomarkers for the differentiation of infection and flare in SLE are limited. • NLR, PLR, and CRP are promising biomarkers to enable differentiation. • PCT and MBL are not ideal biomarkers to differentiate infection from flare.

Association of mannose-binding lectin 2 gene polymorphisms with Guillain-Barré syndrome

Complement activation plays a critical role in the pathogenesis of Guillain-Barré syndrome (GBS), a debilitating immune-mediated neuropathy. Mannose-binding lectin (MBL) is a complement activation factor of lectin pathway which as genetic host factor may influence the susceptibility or severity of GBS. We investigated the frequency of MBL2 promoter (- 550H/L and - 221X/Y) and functional region (exon 1 A/O) polymorphisms and their association with disease susceptibility, clinical features and serum MBL among GBS patients (n = 300) and healthy controls (n = 300) in Bangladesh. The median patient age was 30 years (IQR: 18-42; males, 68%). MBL2 polymorphisms were not significantly associated with GBS susceptibility compared to healthy controls. HL heterozygosity in GBS patients was significantly associated with mild functional disability at enrolment (P = 0.0145, OR, 95% CI 2.1, 1.17-3.82). The HY, YA, HA and HYA heterozygous haplotypes were more common among mildly affected (P = 0.0067, P = 0.0086, P = 0.0075, P = 0.0032, respectively) than severely affected patients with GBS. Reduced serum MBL was significantly associated with the LL, OO and no HYA variants and GBS disease severity. No significant association was observed between MBL2 polymorphisms and electrophysiological variants, recent Campylobacter jejuni infection or anti-ganglioside (GM1) antibody responses in GBS. In conclusion, MBL2 gene polymorphisms are related to reduced serum MBL and associated with the severity of GBS.

The role of the lectin pathway of the complement system in SARS-CoV-2 lung injury

Although some evidence showed the activation of complement systems in COVID-19 patients, proinflammatory status and lectin pathway remain unclear. Thus, the present study aimed to demonstrate the role of MBL and ficolin-3 in the complement system activation and compared to pandemic Influenza A virus H1N1 subtype infection (H1N1pdm09) and control patients. A total of 27 lungs formalin-fixed paraffin-embedded samples (10 from H1N1 group, 6 from the COVID-19 group, and 11 from the control group) were analyzed by immunohistochemistry using anti-IL-6, TNF-alfa, CD163, MBL e FCN3 antibodies. Genotyping of target polymorphisms in the MBL2 gene was performed by real-time PCR. Proinflammatory cytokines such as IL-6 and TNF-alpha presented higher tissue expression in the COVID-19 group compared to H1N1 and control groups. The same results were observed for ICAM-1 tissue expression. Increased expression of the FCN3 was observed in the COVID-19 group and H1N1 group compared to the control group. The MBL tissue expression was higher in the COVID-19 group compared to H1N1 and control groups. The genotypes AA for rs180040 (G/A), GG for rs1800451 (G/A) and CC for rs5030737 (T/C) showed a higher prevalence in the COVID-19 group. The intense activation of the lectin pathway, with particular emphasis on the MBL pathway, together with endothelial dysfunction and a massive proinflammatory cytokines production, possibly lead to a worse outcome in patients infected with SARS-Cov-2. Moreover, 3 SNPs of our study presented genotypes that might be correlated with high MBL tissue expression in the COVID-19 pulmonary samples.

A Plausible Role for Collectins in Skin Immune Homeostasis

The skin is a complex organ that faces the external environment and participates in the innate immune system. Skin immune homeostasis is necessary to defend against external microorganisms and to recover from stress to the skin. This homeostasis depends on interactions among a variety of cells, cytokines, and the complement system. Collectins belong to the lectin pathway of the complement system, and have various roles in innate immune responses. Mannose-binding lectin (MBL), collectin kidney 1, and liver (CL-K1, CL-L1) activate the lectin pathway, while all have multiple functions, including recognition of pathogens, opsonization of phagocytosis, and modulation of cytokine-mediated inflammatory responses. Certain collectins are localized in the skin, and their expressions change during skin diseases. In this review, we summarize important advances in our understanding of how MBL, surfactant proteins A and D, CL-L1, and CL-K1 function in skin immune homeostasis. Based on the potential roles of collectins in skin diseases, we suggest therapeutic strategies for skin diseases through the targeting of collectins and relevant regulators.

Association of MBL2 gene polymorphisms and systemic lupus erythematosus susceptibility: A meta-analysis

OBJECTIVES

Mannose binding lectin (MBL) gene single nucleotide polymorphisms have been associated with systemic lupus erythematosus (SLE) risk with inconsistent results. This study aimed to explore whether MBL2 A\B, A\C, A\D, A\O, L\H and Y\X polymorphisms affected SLE susceptibility.

METHODS

A meta-analysis was performed on 20 studies, containing allelic contrast, additive, dominant and recessive models. Odds ratio (OR) was calculated to reflect the effect of association.

RESULTS

A total of 64 pooled comparisons were conducted, including 7194 SLE patients and 7401 healthy controls. The meta-analysis inducted a significant association between allele B and SLE (OR = 0.766, 95% CI = 0.681-0.862, P < .001). The genotype BB in the additive model and AB + BB in the recessive model both reduced the risk of SLE (OR = 0.611, 95% CI = 0.422-0.882, P = .009; OR = 0.806, 95% CI = 0.688-0.944, P = .008). Regarding A\O polymorphisms, results revealed statistical differences in allelic contrast, additive model and recessive models (OR = 0.826, 95% CI = 0.732-0.931, P = .002; OR = 0.737, 95% CI = 0.557-0.977, P = .034 and OR = 0.793, 95% CI = 0.683-0.921, P = .002, respectively). As for L\H, meta-analysis revealed that allele H and genotype HH both decreased SLE susceptibility in allelic contrast and dominant models (OR = 1.463, 95% CI = 1.097-2.007, P = .018; OR = 1.383, 95% CI = 1.124-1.701, P = .002). Stratification by ethnicity indicated that allele H related to SLE in European populations (OR = 0.736, 95% CI = 0.617-0.879, P = .001), and the recessive model correlated with SLE in Asians (OR = 0.808, 95% CI = 0.667-0.979, P = .03).

CONCLUSION

The present study suggests that A\B and A\O polymorphisms were associated with SLE susceptibility, and the allele H may be a protective factor in SLE.

Association of MBL-2 gene polymorphisms with systemic lupus erythematosus: an updated meta-analysis and trial sequential analysis

OBJECTIVES

Mannose-binding lectin (MBL), an essential innate immune molecule, enhances the opsonization process and activates the complement system. Genetic variations at the promoter and coding region of the MBL-2 gene have been associated with susceptibility to systemic lupus erythematosus (SLE); however, reports remained inconsistent. The present study performs a meta-analysis of published peer-reviewed articles to draw a definitive conclusion.

MATERIALS AND METHODS

Published peer-reviewed articles on the association of MBL-2 gene polymorphisms and SLE were screened on various databases such as PubMed (Medline), ScienceDirect, and Google Scholar. A total of 23 eligible articles were included in the present study, comprising 3074 SLE patients and 3985 controls. Genotype and/or allele data for MBL-2 polymorphisms (A > B, A > C, A > D, A > O, Y > X and H > L) were extracted and analyzed by Comprehensive Meta-Analysis software (CMA V3.1).

RESULTS

The overall analysis revealed a significant association of MBL-2 (A > O) polymorphism with a predisposition to SLE in allele contrast (p = 0.000; OR = 1.261), homozygous (p = 0.005; OR = 1.482), heterozygous (p = 0.004; OR = 1.247), dominant (p = 0.000; OR = 1.303) and recessive (p = 0.025; OR = 1.356) genetic comparison model. Similar results were also observed in the comparison of allele and the dominant genetic model of MBL-2 (A > B) polymorphism in overall (allele: p = 0.000, OR = 1.46, dominant: p = 0.001, OR = 1.31) and in the Asian cohorts (allele: p = 0.007, OR = 1.43, dominant: p = 0.008, OR = 1.32). Interestingly, MBL-2 (Y-221X) polymorphism exhibited protection against the development of SLE in heterozygous (p = 0.005, OR = 0.619) and dominant genetic comparison (p = 0.01, OR = 0.672) models.

CONCLUSIONS

MBL-2 variants (A > O and A > B) are associated with predisposition to SLE. Conversely, promoter polymorphism (Y-221X) offers protection against SLE development.

No association of complement mannose-binding lectin deficiency with cardiovascular disease in patients with Systemic Lupus Erythematosus

Cardiovascular (CV) morbidity is the major cause of death in patients with Systemic Lupus Erythematosus (SLE). Previous studies on mannose-binding lectin (MBL) gene polymorphisms in SLE patients suggest that low levels of complement MBL are associated with cardiovascular disease (CVD). However, as large studies on MBL deficiency based on resulting MBL plasma concentrations are lacking, the aim of our study was to analyze the association of MBL concentrations with CVD in SLE patients. Plasma MBL levels SLE patients included in the Swiss SLE Cohort Study were quantified by ELISA. Five different CV organ manifestations were documented. Of 373 included patients (85.5% female) 62 patients had at least one CV manifestation. Patients with MBL deficiency (levels below 500 ng/ml or 1000 ng/ml) had no significantly increased frequency of CVD (19.4% vs. 15.2%, P = 0.3 or 17.7% vs. 15.7%, P = 0.7). After adjustment for traditional CV risk factors, MBL levels and positive antiphospholipid serology (APL+) a significant association of CVD with age, hypertension, disease duration and APL+ was demonstrated. In our study of a large cohort of patients with SLE, we could not confirm previous studies suggesting MBL deficiency to be associated with an increased risk for CVD.

Genetic association of MBL-2 gene polymorphisms with Filarial chyluria

Lymphatic filariasis has become a significant public health issue in North India. The association of polymorphisms in MBL2 gene with filarial chyluria (FC) is evaluated in the North Indian patients for the first time. Hence, a tertiary care hospital based case-control study was conducted in north India where FC is endemic. Therefore, 186 confirmed patients of FC as cases and 210 age-, sex- and residence-matched subjects as controls were enrolled for the study. Filarial etiology was confirmed using diethylcarbamazine (DEC)-provocation test, immune chromatographic test and IgG/IgM antibody test. MBL2 gene polymorphisms at codon 54 and -221 promoter region were genotyped by PCR followed by RFLP. Wild-type, heterozygous and homozygous mutant frequencies of MBL2 genotype at the codon 54 were 57.5%, 32.8% and 9.7% in the case group and 62.9%, 30.5% and 6.7%, in controls, respectively. The same at the -221 position were 51.1%, 44.1% and 4.8% in FC patients and 44.3%, 40.0% and 15.7% in controls, respectively. Thus, results no significant association between MBL2 polymorphism at codon 54 and FC. However, polymorphism at the -221 promoter region is linked with FC with a significant odd-ratio of 0.27 (confidence interval at 95% was 0.12-0.59; p<0.001). This preliminary finding is intriguing for further confirmation using a larger study with more patients.

TNF-α promoter polymorphisms (G-238A and G-308A) are associated with susceptibility to Systemic Lupus Erythematosus (SLE) and P. falciparum malaria: a study in malaria endemic area

Tumor necrosis factor-α (TNF-α) is a proinflammatory cytokine associated with autoimmune and infectious diseases. Importance of TNF-α in P. falciparum malaria and systemic lupus erythematosus (SLE) have been demonstrated. However, association of functional promoter variants with SLE and malaria is lacking in malaria endemic population. A total of 204 female SLE patients and 224 age and sex matched healthy controls were enrolled in the study. Three hundred fourteen P. falciparum infected patients with different clinical phenotypes were included. TNF-α polymorphisms (G-238A & G-308A) were genotyped by PCR-RFLP. Plasma levels of TNF-α was quantified by ELISA. Heterozygous mutants and minor alleles of TNF-α (G-238A and G-308A) polymorphisms were significantly higher in SLE patients compared to healthy controls and associated with development of lupus nephritis. In addition, both promoter variants were associated with severe P. falciparum malaria. SLE patients demonstrated higher levels of plasma TNF-α compared to healthy controls. TNF-α (G-238A and G-308A) variants were associated with higher plasma TNF-α. In conclusion, TNF-α (G-238A & G-308A) variants are associated with higher plasma TNF-α levels in SLE patients residing in malaria endemic areas and could be a contributing factor in the development of SLE and susceptibility to severe P. falciparum malaria.

Mannose-Binding Lectin 2 Gene Polymorphism in PANDAS Patients

Introduction

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS), a subgroup of obsessive-compulsive disorder (OCD), has received much attention even though the specific underlying mechanisms remain unknown. Mannose-binding lectin (MBL) is a key factor in the innate immune response. The aim of this study was to investigate the role of MBL2 gene polymorphisms in pediatric OCD patients diagnosed as PANDAS, PANDAS-Variant and non-PANDAS.

Methods

The study included 102 pediatric OCD patients (59 [57.8% ] PANDAS, 20 [19.6% ] non-PANDAS, and 23 [22.5% ] PANDAS-Variant) and 60 healthy controls. Polymorphisms at codon 52, 54 and 57 of the MBL2 gene were investigated.

Results

Codon 54 polymorphism and any variant of MBL2 gene were significantly more frequent in the OCD group than in the control group (OR=2.97, 95% CI: 1.26-6.97; and OR=2.66, 95% CI: 1.32-5.38, respectively). According to regression analysis, the presence of any variant of MBL2 gene was found in 14.50-fold increased frequency in the PANDAS subgroup compared with the non-PANDAS subgroup (95% CI: 2.49-84.19).

Conclusions

Our findings support an association between MBL2 genotypes and pediatric OCD, particularly PANDAS-OCD.

Functional mannose binding lectin levels in patients with pediatric onset systemic lupus erythematosus in remission

BACKGROUND

Complement system plays a crucial role in the pathogenesis of systemic lupus erythematosus (SLE). Excessive activation of complement causes tissue injury and SLE occurrence is typically associated with congenital deficiencies of the early components of the classical complement pathway. Mannose-binding lectin (MBL) is recognized as important causative factor in the etio-pathogenesis of SLE and MBL-2 gene has evolved as a candidate gene for SLE susceptibility.

AIM

This study was done to assess the functional MBL (fMBL) level in SLE patients in remission and its co-relation with disease severity and outcome.

METHODS

Functional MBL levels were compared with age and sex matched healthy controls and were correlated with duration of illness,complement levels and anti-double- stranded DNA antibody levels.

RESULTS

Mean fMBL level in patients was found to be 696.19 ± 408.98 U/mL and 579.52 ± 393.87 U/mL in the control group. Four children had very low fMBL levels (< 40 U/mL). Functional MBL levels were higher in patients with SLE even when the disease was in remission as compared to healthy controls, although not statistically significant.

CONCLUSION

Large variation exists in fMBL levels in patients with SLE even when in remission. Very low fMBL levels were found in some children with younger age of onset of SLE, multisystem involvement and severe course of the disease. Positive correlation of MBL levels with anti-ds DNA titers suggest that its values vary with activity and could be a potential biomarker of the disease.

Genetic polymorphisms of C-type lectin receptors in Behcet's disease in a Chinese Han population

C-type lectin receptors (CLRs) have been demonstrated to be involved in several autoimmune diseases. The role of CLRs in Behcet’s disease (BD) is unknown and thus was the purpose of this study. A two-stage association study was carried out and a total of 766 BD patients and 1674 healthy controls were recruited. Genotyping of 14 SNPs of 13 genes in CLRs was carried out by iPLEX Gold genotyping or polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The expression of mannose binding lectin 2 (MBL2) and killer cell lectin like receptor C4 (KLRC4) was measured by Real-time PCR. Significantly increased frequencies of the A allele as well as AA genotype of rs1800450 in MBL2 (Pc = 2.50 × 10⁻⁶, OR = 1.494; Pc = 2.24 × 10⁻⁶,OR = 2.899; respectively) and TT genotype of rs2617170 in KLRC4 (Pc = 2.53 × 10⁻⁶, OR = 1.695) and decreased frequencies of GG genotype of rs1800450 (Pc = 1.56 × 10−3, OR = 0.689) and C allele as well as CC genotype of rs2617170 (Pc = 2.05 × 10−9,OR = 0.664; Pc = 1.20 × 10−5, OR = 0.585; respectively) were observed in BD. Two variants, p.Gly54Asp (rs1800450) and p.Asn104Ser (rs2617170) affect MBL2 and KLRC4 protein stability and expression. Our study demonstrates that the MBL2/rs1800450 and KLRC4/rs2617170 are susceptibility factors for BD in a Chinese Han population.

Genetic and Phenotypic Screening of Mannose-Binding Lectin in Relation to Risk of Recurrent Vulvovaginal Infections in Women of North India: A Prospective Cohort Study

Recurrent Vulvovaginal Infections (RVVI) is common problem associated with women of reproductive age. The function and deleterious effect of Mannose Binding Lectin 2 (MBL2) common polymorphisms are reported to be associated with various diseases. However, the role of MBL2 promoter gene polymorphisms and their combined effect with structural variant along with Serum Mannose Binding Lectin (sMBL) levels in RVVI has not been investigated. The study included 258 RVVI cases and 203 age matched healthy controls. These were investigated for the distribution of MBL2 codon 54 and promoter polymorphisms by Amplification Refractory Mutation System-Polymerase Chain Reaction (ARMS-PCR). sMBL levels were quantified by Enzyme Linked Immnosorbent Assay (ELISA). The frequency of X allele and its genotypes was significantly high in cases than controls conferring risk toward RVVI and its types (p < 0.05). The HXPA (OR; 2.0), LXQB (OR; 1.43) haplotypes were associated with susceptibility to RVVI cases while haplotype LYQB significantly protected against RVVI (OR; 0.58), Bacterial Vaginosis (BV) (OR; 0.27) and Mixed Infections (MI) cases (OR; 0.62) with high frequency observed in controls (p < 0.05). Mean sMBL levels were significantly low in RVVI, BV, Vulvovaginal Candidiasis (VVC), and MI cases compared to controls (p < 0.05). VVC patient showed significantly low sMBL levels than RVVI and MI cases (p < 0.05). The mean sMBL levels segregated based on MBL2 genotypes and haplotypes showed significant difference in different cases groups with controls. The findings of the present study suggested that MBL2 Y/X polymorphism and low sMBL levels were associated with susceptibility to RVVI either it is BV, VVC, or MI. Thus MBL deficiency in women with RVVI may contribute to decreased efficiency in clearing of pathogens. Hence, specific measures like administration of purified or recombinant MBL might decrease the incidence of vaginal infections recurrences and more-effective treatment.

Cell death in the pathogenesis of systemic lupus erythematosus and lupus nephritis

Nephritis is one of the most severe complications of systemic lupus erythematosus (SLE). One key characteristic of lupus nephritis (LN) is the deposition of immune complexes containing nucleic acids and/or proteins binding to nucleic acids and autoantibodies recognizing these molecules. A variety of cell death processes are implicated in the generation and externalization of modified nuclear autoantigens and in the development of LN. Among these processes, apoptosis, primary and secondary necrosis, NETosis, necroptosis, pyroptosis, and autophagy have been proposed to play roles in tissue damage and immune dysregulation. Cell death occurs in healthy individuals during conditions of homeostasis yet autoimmunity does not develop, at least in part, because of rapid clearance of dying cells. In SLE, accelerated cell death combined with a clearance deficiency may lead to the accumulation and externalization of nuclear autoantigens and to autoantibody production. In addition, specific types of cell death may modify autoantigens and alter their immunogenicity. These modified molecules may then become novel targets of the immune system and promote autoimmune responses in predisposed hosts. In this review, we examine various cell death pathways and discuss how enhanced cell death, impaired clearance, and post-translational modifications of proteins could contribute to the development of lupus nephritis.

Mannose binding lectin polymorphisms in systemic lupus erythematosus in Spain

Low mannose binding lectin (MBL) producer genotypes have been considered as a systemic lupus erythematosus (SLE) risk factor. The aim of this study was to explore whether polymorphisms in the MBL gene are associated with susceptibility to SLE and disease-specific clinical manifestations or with disease severity in SLE patients in Son Llàtzer Hospital. MBL2 exon 1 and promoter polymorphisms were genotyped and MBL plasma levels were quantified by ELISA in 39 SLE cases and in 96 healthy controls. High MBL producer genotypes HYPA and LXPA were the most frequent haplotypes (65 and 62 participants, respectively). LYQC/HYPD, LXPA/LYQC and LYPB/HYPD were only found in SLE, and all of them were related to severe MBL deficiency. SLE patients showed a trend towards more severe MBL deficiency (MBL <100 ng/mL) compared to controls (10 [25.6%] and 11 [11.46%] respectively, P = 0.07). The wild-type genotype was more frequent in controls compared to SLE. The trend towards more severe MBL deficiency in SLE and the fact that some of the low-MBL producer genotypes were only found in SLE patients, suggest that low MBL levels or MBL2 variant could be a risk factor for the development of SLE.

A comprehensive in silico analysis of non-synonymous and regulatory SNPs of human MBL2 gene

Mannose binding lectin (MBL) is a liver derived protein which plays an important role in innate immunity. Mannose binding lectin gene 2 (MBL2) polymorphisms are reported to be associated with various diseases. In spite of being exhaustively studied molecule, no attempt has been made till date to comprehensively and systematically analyze the SNPs of MBL2 gene. The present study was carried out to identify and prioritize the SNPs of MBL2 gene for further genotyping and functional studies. To predict the possible impact of SNPs on MBL structure and function SNP data obtained from dbSNP database were analyzed using various bioinformatics tools. Out of total 661 SNPs, only 37 validated SNPs having minor allele frequency ≥0.10 were considered for the present study. These 37 SNPs includes one in 3' near gene, nine in 3' UTR, one non-synonymous SNP (nsSNP), thirteen intronic SNPs and thirteen in 5' near gene. From these 37 SNPs, 11 non-coding SNPs were identified to be of functional significance and evolutionary conserved. Out of these, 4 SNPs from 3' UTR were found to play role in miRNA binding, 7 SNPs from 5' near and intronic region were predicted to involve in transcription factor binding and expression of MBL2 gene. One nsSNP Gly54Asp (rs1800450) was found to be deleterious and damaging by both SIFT and Polyphen-2 servers and thus affecting MBL2 protein stability and expression. Protein structural analysis with this amino acid variant was performed by using I-TASSER, RAMPAGE, Swiss-PdbViewer, Chimera and I-mutant. Information regarding solvent accessibility, molecular dynamics and energy minimization calculations showed that this variant causes clashes with neighboring amino acids residues that must interfere in the normal triple helix formation of trimeric subunit and further with the normal assembly of MBL oligomeric form, hence decrease in stability. Thus, findings of the present study indicated 12 SNPs of MBL2 gene to be functionally important. Exploration of these variants may provide novel remedial markers for various diseases.

HIV-1 Vertical Transmission in Zimbabwe in 622 Mother and Infant Pairs: Rethinking the Contribution of Mannose Binding Lectin Deficiency in Africa

Vertical transmission of human immunodeficiency virus (HIV) remains a major global health problem. We assessed the association of mannose binding lectin (MBL) deficiency and vertical transmission of HIV. Novel diagnostics would be a major breakthrough in this regard. MBL is a liver-derived protein and a key component of the innate immune system. MBL levels may be classified as normal, intermediate, or deficient in the plasma and can use MBL2 haplotypes as a proxy. These haplotypes comprise polymorphisms in the MBL2 gene and promoter region and are known to result in varying levels of MBL deficiency. MBL deficiency can be defined as presence of A/O and O/O genotypes in the mothers and their children. MBL deficiency leads to defective opsonization activities of the innate immune system and increased susceptibility to several infections, including HIV-1. We determined the prevalence of MBL deficiency, using MBL2 haplotypes among 622 HIV-positive Zimbabwean mothers and their children aged 9-18 months old, in relation to the HIV-1 vertical transmission risk. The median age of the mothers was 30 (26-34, interquartile range [IQR]) years, and the babies' median age was 13 (11-15, IQR) months old at the time of enrollment. From the sample of 622 mothers who were HIV-1 infected, 574 babies were HIV negative and 48 were HIV-1-positive babies, giving a transmission rate of 7.7%. MBL2 normal structural allele A and variants B (codon 5 A>G), C (codon 57 A>G), and promoter region SNPs -550(H/L) and -221(X/Y) were detected. Prevalence of haplotype-predicted MBL deficiency was 34% among the mothers and 32% among the children. We found no association between maternal MBL2 deficiency and HIV-1 transmission to their children. We found no difference in the distribution of HIV-1 infected and uninfected children between the MBL2 genotypes of the mothers and those of the children. Taken together, the present study in a large sample of mother-infant pairs in Zimbabwe adds to the emerging literature and the hypothesis that MBL2 variation as predicted by haplotypes does not influence the vertical transmission risk for HIV. Research from other populations from the African continent is called for to test this hypothesis further.

Mannose binding lectin (MBL) 2 gene polymorphism & its association with clinical manifestations in systemic lupus erythematosus (SLE) patients from western India

Background & objectives:

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease characterized by production of autoantibodies. Mannose binding lectin (MBL) is an important element of the innate defense system. The present study was undertaken to determine whether variant alleles in MBL2 gene were associated with disease severity in SLE patients.

Methods:

The MBL alleles [-550, -221, +4, Codon 52, Codon 54 and Codon 57] were studied by PCR- RFLP (restriction fragment length polymorphism) method in 100 SLE patients fulfilling ACR (American College of Rheumatology) criteria along with 100 healthy controls. SLE disease activity was evaluated using SLE Disease Activity Index (SLEDAI) score.

Results:

Homozygosity for MBL variant allele (O/O) was observed in 24 per cent of the SLE patients compared to 16 per cent of the normal controls, while no difference was found for heterozygosity (A/O) (37 vs 35%). A significant difference was reported in incidence of double heterozygosity for mutant allele B and D (B/D) among SLE patients as against control group (P = 0.015). MBL genotypes did not show any association with renal involvement.

Interpretation & conclusions:

In this study from western India, MBL gene polymorphism showed an influence as a possible risk factor for susceptibility to SLE, but had no direct effect on disease characteristics. Further studies need to be done on a larger number of SLE patients in different regions of the country.

MBL-2 polymorphisms (codon 54 and Y-221X) and low MBL levels are associated with susceptibility to multi organ dysfunction in P. falciparum malaria in Odisha, India

Background: Mannose binding lectin, a plasma protein protects host from virus, bacteria, and parasites. Deficiency in MBL levels has been associated with susceptibility to various infectious diseases including P. falciparum malaria. Common MBL polymorphisms in promoter and coding regions are associated with decrease in plasma MBL levels or production of deformed MBL, respectively. In the present study, we hypothesized that MBL2 variants and plasma MBL levels could be associated with different clinical phenotypes of severe P. falciparum malaria.

Methods: A hospital based study was conducted in eastern Odisha, India which is endemic to P. falciparum malaria. Common MBL-2 polymorphisms (codon 54, H-550L, and Y-221X) were typed in 336 cases of severe malaria (SM) [94 cerebral malaria (CM), 120 multi-organ dysfunction (MOD), 122 non-cerebral severe malaria (NCSM)] and 131 un-complicated malaria patients (UM). Plasma MBL levels were quantified by ELISA.

Results: Severe malaria patients displayed lower plasma levels of MBL compared to uncomplicated falciparum malaria. Furthermore, on categorization of severe malaria patients into various subtypes, plasma MBL levels were very low in MOD patients compared to other categories. Higher frequency of AB genotype and allele B was observed in MOD compared to UM (AB genotype: P = 0.006; B allele: P = 0.008). In addition, prevalence of YX genotype of MBL Y-221X polymorphism was also statistically more frequent in MOD case than UM (P = 0.009).

Conclusions: The observations of the present study reveal that MBL-2 polymorphisms (codon 54 and Y-221X) and lower plasma MBL levels are associated with increased susceptibility to multi organ dysfunctions in P. falciparum malaria.

Serum ferritin level correlates with SLEDAI scores and renal involvement in SLE

Introduction

Ferritin is an acute-phase reactant that is elevated in various autoimmune disorders. Serum ferritin levels have been positively correlated with disease activity scores of rheumatoid arthritis and systemic lupus erythematosus (SLE). Further, enhanced levels of ferritin have also been reported in lupus nephritis. However, there are no reports from the Indian subcontinent.

Methods

Seventy-six female SLE patients, diagnosed on the basis of revised ACR criteria, and 50 healthy females, age matched from similar geographical areas, were enrolled in the present study. Serum levels of ferritin, IFN-α and IL-6 were quantified by enzyme-linked immunosorbent assay (ELISA). Clinical, biochemical, serological and other markers of disease activity (C3, C4 and anti-dsDNA) were measured by standard laboratory procedure.

Results

Serum ferritin levels were significantly higher in SLE patients compared to healthy controls ( p < 0.0001). Ferritin levels positively correlated with SLE Disease Activity Index (SLEDAI) ( p = 0.001, r = 0.35), anti-dsDNA ( p = 0.001, r = 0.35), IFN-α ( p < 0.0001, r = 0.51) and IL-6 (p < 0.0001, r = 0.65) and negatively correlated with C3 ( p = 0.0006, r = −0.38) and C4 ( p = 0.01, r = −0.28). Interestingly, serum levels of ferritin were positively associated with proteinuria ( p = 0.001, r = 0.36), serum urea ( p = 0.0004, r = 0.39) and serum creatinine ( p = 0.0006, r = 0.38).

Conclusion

Serum ferritin is an excellent marker of disease activity and renal dysfunction in SLE.

Vitamin D levels in Indian systemic lupus erythematosus patients: association with disease activity index and interferon alpha

INTRODUCTION

Low levels of vitamin D have been associated with several autoimmune disorders including multiple sclerosis, rheumatoid arthritis, type 1 diabetes and systemic lupus erythematosus (SLE). The major source of vitamin D is sunlight but exposure of SLE patients to UV rays has been shown to exacerbate disease pathology. Studies in various populations have shown an association between low vitamin D levels and higher SLE disease activity.

METHODS

We enrolled 129 patients who fulfilled American College of Rheumatology criteria in the study. There were 79 treatment-naïve cases and 50 patients who were under treatment for underlying SLE. There were 100 healthy subjects from similar geographical areas included as controls. Plasma 25-OH vitamin D₃ and interferon (IFN)-α levels were quantified by enzyme-linked immunosorbent assay (ELISA). The gene expression level of IFN-α was determined by quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTS

Plasma 25-OH vitamin D₃ significantly correlated in an inverse manner with systemic lupus erythematosus disease activity index (SLEDAI) scores (P <0.0001, r = -0.42), anti-dsDNA (P <0.0001, r = -0.39), plasma IFN-α (P <0.0001, r = -0.43) and levels of IFN-α gene expression (P = 0.0009, r = -0.45). Further, plasma levels of IFN-α positively correlated with gene expression of IFN-α (P <0.0001, r = 0.84). Treatment-naïve SLE patients displayed significantly higher plasma levels of IFN-α compared to patients under treatment (P <0.001) and controls (P <0.001).

CONCLUSIONS

These results suggest an important role of vitamin D in regulating disease activity in SLE patients and the need to supplement vitamin D in their treatment.

TLR-9 promoter polymorphisms (T-1237C and T-1486C) are not associated with systemic lupus erythematosus: a case control study and meta-analysis

Toll like receptors (TLRs) are essential molecules implicated in both innate and adaptive immune response. Polymorphisms in TLR gene have been associated with various infectious diseases and autoimmune disorders. Role of TLR9 has been elegantly demonstrated in both human systemic lupus erythematosus (SLE) and mice model of lupus. In the present study we investigated association of TLR-9 promoter polymorphisms (T-1237C and T-1486C) with susceptibility/resistance to SLE in an Eastern Indian state which is endemic to parasitic diseases. 210 Female SLE patients who fulfilled the American College of Rheumatology criteria were enrolled along with matched healthy controls from Odisha, India. TLR-9 polymorphisms (T-1237C and T-1486C) were typed by polymerase chain reaction followed by restriction fragment length polymorphism. For meta-analysis, relevant literatures were searched from PubMed database and comprehensive meta-analysis V2 software was employed for analysis. Allele and genotype frequency of TLR-9 promoter polymorphisms (T-1237C and T-1486C) were comparable among SLE patients and controls. Further, meta-analysis of earlier reports and present study did not reveal a significant association of TLR-9 (T-1237C and T-1486C) polymorphisms with SLE. Data from the present study suggest that TLR-9 promoter polymorphisms are not associated with susceptibility to SLE in an area endemic to parasitic diseases.

Association of +331G/A PgR polymorphism with susceptibility to female reproductive cancer: evidence from a meta-analysis

The progesterone receptor (PgR), a sex steroid hormone receptor that binds progesterone is critical for normal breast development. The PgR (+331G/A, rs10895068) promoter polymorphism is associated with cancer risk possibly by altering the expression of progesterone receptor B isoform. Previous studies have provided inconsistent results. To validate the association between the PgR +331G/A polymorphism and female reproductive cancer risk (breast, endometrial and ovarian cancer), we performed a meta-analysis of 19 studies (19,978 cases and 24,525 controls) by using the CMA Version 2 software. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations. The overall results indicated that the variant allele and genotypes were associated with a mild increase in overall female reproductive cancer risk (A vs. G: OR = 1.063, 95% CI = 1.001–1.129; AA+AG vs. GG: OR = 1.067, 95% CI = 1.002–1.136). The results suggest that the PgR +331G/A polymorphism might be associated with an increased female reproductive cancer risk.

Mannose binding lectin: a biomarker of systemic lupus erythematosus disease activity

Introduction

A role for mannose binding lectin (MBL) in autoimmune diseases has been demonstrated earlier and elevated level of MBL has been shown in systemic lupus erythematosus (SLE) patients. In the current study, we investigated MBL as a potential biomarker for disease activity in SLE.

Methods

In a case control study SLE patients (93 females) and 67 age, sex, ethnicity matched healthy controls were enrolled. Plasma MBL levels were quantified by enzyme linked immunosorbent assay (ELISA). Clinical, serological and other markers of disease activity (C3, C4 and anti-dsDNA) were measured by standard laboratory procedures.

Results

Plasma MBL levels were significantly high in SLE patients compared to healthy controls (P < 0.0001). MBL levels were variable in different clinical categories of SLE. Lower levels were associated with musculoskeletal and cutaneous manifestations (P = 0.002), while higher and intermediate MBL levels were significantly associated with nephritis in combination with other systemic manifestations (P = 0.01 and P = 0.04 respectively). Plasma MBL correlated with systemic lupus erythematosus disease activity index (SLEDAI) (P = 0.0003, r = 0.36), anti-dsDNA (P < 0.0001, r = 0.54), proteinuria (P < 0.0001, r = 0.42) and negatively correlated with C3 (P = 0.007, r = -0.27) and C4 (P = 0.01, r = -0.29).

Conclusions

Plasma MBL is a promising marker in the assessment of SLE disease activity.