GENETIC ASPECTS OF PANNICULITIS IN A RUSSIAN POPULATION: A PILOT STUDY

Numerous  clinical observations show that the human genetic background plays an important  role in predisposition to many diseases. Objective: to investigate a possible relationship of the polymorphisms in 19 A/G leptin (LEP) gene, in the interleukin (IL)-1  receptor antagonist (IL-1RA) gene VNTR (variable number of tandem repeats), and in the -174G/C IL-6 gene to the risk of developing the clinical phenotypes of panniculitis (PN), clinical and laboratory parameters. Subjects and methods. The study enrolled 54 patients (48 women and 6 men) aged 15 to 76 years with a documented diagnosis of PN who had been treated at the V.A. Nasonova Research Institute  of Rheumatology.  Group  1 of 46 patients with erythema nodosum  (EN)  and Group  2 of 8 with Weber-Christian panniculitis  (WCP) were formed for genetic study. The genotyping data on 197 healthy unrelated  individuals were used as a control.  Clinical and laboratory information  was available from 39 patients for genotyping 19A/G  LEP gene polymorphism, that from 43 patients for -174G/C IL-6  gene polymorphism, and that from 46 patients for IL-1RA polymorphism. Genotyping  was performed by a polymerase chain reaction-restriction fragment length polymorphism  (PCRRFLP)  analysis. Results and discussion. The frequencies of the LEP 19 GG genotype and the LEP G allele in patients with EN and WCP were significantly higher than those in the controls (48.7 and 18.2%, p = 0.0004; 50.0 and 18.2%, p = 0.053; and 70.5 and 45.4%, p = 0.0002, respectively). The frequencies of the A1A1 genotype and A1 allele of IL-1RA  gene VNTR polymorphism in EN group were significantly higher than those in the controls (67.4 and 44.2%, p=0.011; 80.4 and 61.6%, p = 0.002, respectively). The frequency of IL-6 -174GC  polymorphism was also higher in the EN group than that in the controls (58.1 and 34.7%, p = 0.008). The -174G/C polymorphism showed a significant association with the site of erythema (p = 0.028). In patients with a single lesion of erythema on the body, the frequency of the -174 GC genotype was significantly higher than that in those with multiple foci of erythema (72.0 and 31.2%, respectively; p = 0.025). In the WCP group, analysis of variance showed an association of IL-1RA  gene VNTR polymorphism with the intensity of pain, assessed by the visual analogue scale. The carriers of the A1A1 genotype had more severe pain than those of the A1A2 genotype (83.3±11.5 and 20.0±18.2 mm, respectively; p = 0.008). Conclusion. The findings suggest that genetic testing can be used to predict the clinical course of PN.