Mild and moderate Mannose Binding Lectin deficiency are associated with systemic lupus erythematosus and lupus nephritis in Brazilian patients

Association of mannose binding lectin with chronic obstructive pulmonary disease susceptibility and its clinical outcomes

BACKGROUND

The physiological interactions of MBL suggest its contribution towards the pathogenesis of COPD.

OBJECTIVE

The present case-control study was undertaken to elucidate the role of MBL with COPD risk and clinical outcomes in north Indian cohort.

METHODS

Patients were enrolled as per GOLD criteria. MBL2 variants were selected based on the literature and their putative functional significance. Genotyping of six single nucleotide polymorphisms of MBL2 comprising of two coding (rs1800450, rs1800451) and four non-coding variants (rs11003125, rs7096206, rs11003123 and rs7095891) was done by using PCR-RFLP and ARMS-PCR. Serum MBL levels were analysed by sandwich ELISA.

RESULTS

Overall findings of the molecular genetic analysis of MBL2 indicated significant difference in frequency of three of the six studied variants, between patients and controls or among different disease severity stages. Heterozygous genotype of rs7095891 showed significant protective association towards severity of disease. Linkage disequilibrium (LD) analysis indicated a strong LD between rs1800450 and rs7095891 while intermediate LD was observed for rs11003123/rs11003125 and rs7096206/rs11003125. Haplotype analysis revealed 17.14-fold risk of developing exacerbations conferred by GGGTGG haplotype. Significantly low serum MBL levels observed in COPD patients as compared to controls. Significant difference in MBL deficiency levels were also observed for homozygous wild and variant genotypes of rs11003125 and rs7096206 respectively, as well as for all genotypes of rs11003123 than respective controls.

CONCLUSION

The present study reinforces the role played by MBL in the susceptibility, protection and clinical outcomes of COPD. Therefore, including the reported associations at diagnostic, prognostic and therapeutic interventions may prove helpful.

Mannose-binding lectin (MBL) deficiency and tuberculosis infection in patients with ankylosing spondylitis

Ankylosing spondylitis (AS) patients may have higher prevalence of mannose-binding lectin (MBL) deficiency than normal individuals. MBL deficiency may influence susceptibility to infections. The aim of the study was to verify if MBL deficiency in patients with AS predisposes to infections. We studied 60 patients with AS diagnosed according to the Assessment of SpondyloArthritis international Society (ASAS) criteria. These patients had their MBL serum levels determinated. Twenty-five individuals were identified as MBL deficient (serum values 100 ng/mL). These patients were paired with 35 "sufficient" MBL producers (median serum level = 700 ng/mL; range 150-4100 ng/mL) for gender, age, use of medications, and tobacco exposure. Medical records of all patients were retrospectively investigated for the period of 5 years and the rate of infection occurrence was compared in the two groups. AS patients with MBL deficiency had higher number of urinary tract infections (p = 0.03; IRR = 2.33; 95% CI = 0.95-6.04) and tuberculosis (p = 0.008; IRR = 9.8; 95% CI = 1.2-441.6) than controls. Regarding tuberculosis infection, one patient (2.8%) in the MBL-sufficient group and six (24.0%) from the deficient group had this infection. The MBL-sufficient patient and five from the deficient group have had latent infections, detected in the screening tests done previous to anti-TNF drug use. The other, in the deficient group, had lung infection while not on anti-TNF treatment. Another patient, from the deficient group, has had tuberculosis skeletal infection in the past. We found a significant association between MBL deficiency and higher risk of tuberculosis and urinary tract infection in patients with AS. More studies with higher number of patients are needed to confirm this finding.