ABSTRACT
Background: Psoriasis is associated with significant morbidity and impaired quality of life. Identification of the host genes that influence disease susceptibility and can potentially guide future, targeted therapy is the need of the hour. Aims: The aim of the study was to investigate the associations of macrophage migration inhibitory factor (MIF) gene polymorphisms, that is, a 5–8-CATT tetra nucleotide repeats at -794 (-794*CATT5–8) and a single-nucleotide polymorphism at -173 (-173*G/C) with the risk of chronic plaque psoriasis and to observe the correlation, if any, of disease determinants with genetic functional variants and circulating MIF levels. Methods: Five hundred and seventeen individuals (265 psoriasis patients and 252 controls) were genotyped for MIF gene polymorphisms. Data were analyzed with respect to disease susceptibility, serum MIF levels, disease severity, age at onset, disease duration and presence of comorbidities. Results: The presence of co-morbidities was more frequently noted in patients with late onset disease (P = 0.01). No statistically significant differences were observed either in genotype (P = 0.680) or allele frequency (P = 0.69) with respect to distribution of MIF-173*G/C polymorphism between patients and controls. The frequencies of genotypes -794*CATT 5/7 and 7/7 were significantly lower in patients (P = 0.027* and 0.038*, respectively). CATT*5/MIF-173*C haplotype occurred at a higher frequency in patients (odds ratio 3.03, 95% confidence intervals 1.09–8.47, P = 0.02). The mean serum MIF levels were significantly higher in patients as compared to controls (P < 0.001). The presence of either extended MIF -794*CATT repeats or C allele did not reveal any significant association with serum MIF levels or age at onset. Analysis of effect of various disease determinants revealed no significant association with genetic variants and serum MIF levels. Limitations: The lesional expression of MIF could not be studied. Conclusion: Our results showed that CATT*5/MIF-173*C haplotype is associated with increased susceptibility to psoriasis vulgaris.
ABSTRACT
Background: Erythema nodosum leprosum is an immune-mediated complication of leprosy which causes significant morbidity. Biomarkers in the pathogenesis of erythema nodosum leprosum are not yet fully determined. Aim: To determine macrophage migration inhibitory factor levels in the sera of leprosy patients with erythema nodosum leprosum and to correlate the same with clinical parameters. Methods: This cross-sectional study included 37 consecutive leprosy patients with active erythema nodosum leprosum and 31 age- and sex-matched controls. Detailed clinical history and examination findings were recorded including the severity and frequency of erythema nodosum leprosum. Slit skin smears and histopathologic examination were done in all patients at baseline. Serum macrophage migration inhibitory factor levels were determined using an enzyme-linked immunosorbent assay. Results: Most of our patients were males (78.4%) and suffering from lepromatous leprosy (27, 73%) with a mean initial bacillary index of 3.38 ± 1.36. Recurrent and chronic patterns of erythema nodosum leprosum were seen in 15 (40.5%) and 6 (16.3%) patients, respectively. Most (86.5%) of our patients presented with moderate to severe erythema nodosum leprosum. The mean serum macrophage migration inhibitory factor level was 21.86 ± 18.7 ng/ml among patients while it was 11.78 ± 8.4 ng/ml in the control group (P < 0.01). There were no statistically significant correlations of macrophage migration inhibitory factor levels with erythema nodosum leprosum frequency or severity. Limitation: Serum macrophage migration inhibitory factor levels in leprosy patients with no erythema nodosum leprosum and in patients with other inflammatory and autoimmune conditions were not assessed. Hence, this study falls short of providing the predictive value and specificity of higher macrophage migration inhibitory factor concentrations in serum as a biomarker of erythema nodosum leprosum. Conclusion: Macrophage migration inhibitory factor levels are elevated in erythema nodosum leprosum patients as compared to controls. A larger sample size and macrophage migration inhibitory factor gene polymorphism analysis will be needed to elucidate the role of this pro-inflammatory cytokine in erythema nodosum leprosum.