Background Clinical, genetic aspects of rheumatic diseases with a relation to the patients' ethnicity have increasingly become the subject of wide discussion in recent years. The significance of this problem is clearly seen in systemic lupus erythematosus (SLE).
Objectives Explore ethnic, genetic features in children with SLE.
Methods The basis of this work was aimed to survey results and data of archival materials of 153 SLE patients observed in the clinic of the Scientific Center of Pediatrics and Pediatric Surgery, the Republic of Kazakhstan. We studied the course and outcome of systemic lupus erythematosus in children of Kazakh and Russian population and features of distribution of HLA-class I loci in children Kazakh population.
Results We observed 153 patients with SLE at the age from 3 to 15 years and older, including 120 children of Kazakh nationality (78.4%), and 33 - of Russian nationality (21.6%). Evaluating the activity of pathological processes, depending on the ethnicity, revealed that the highest activity (74.1% vs. 24.2%) and acute (69.2% vs. 33.3%) were in Kazakh children. In assessing the overall disease activity by SLEDAI scale, the children of the Kazakh population had 38,9±5,1 against Russian 22,1± 4,1 points. Thus, acute and the high degree of activity of SLE prevailed in Kazakh children (P<0.05).
Given the severity and outcome of SLE in the indigenous children, we studied the association between SLE and HLA - class I antigens in Kazakhs children. This study was carried out for the first time in Kazakh children. Antigens of HLA system loci A, B and C were determined in 62 Kazakh children between the 7–16 years with SLE. The control group included 277 healthy test donors of the same nationality. The most common alleles in locus HLA-A SLE was HLA-A1 (p<0.001); the highest rate in the locus B was found in: HLA-B5 (p<0,01), HLA-B7 (p<0.01), HLA-B15 (p<0.01), HLA-B35 (p<0.01); in the locus C: HLA-CW3 (p<0.01). Among them the increase of the frequency of antigen HLA-A1 and HLA-CW3 were significant (Pcorr.=0.01–0.08).
Compared with donors, the positive level of association was found in HLA - A1 (χ2=14,62, RR=3,04, p<0,001), HLA-B7 (χ2=6,16, RR=2,30, p<0, 01), HLA-B15 (χ2=6,61, RR=2,51, p<0,01), HLA-CW3 (χ2=7,91, RR=2,91, p<0.01) and negative association in HLA-B5 (χ2=6,29, RR=0,41, p=0,01), HLA-B35 (χ2=7,06, RR=0,26, p=0,01).
As a result of the studies, four tentatively called “risk” antigens were found and the severity of its clinical manifestations - HLA-A1, HLA-B7, HLA-B15 and HLA-CW3. HLA-B5 and HLA-B35 had the protective nature of SLE. Given the fact that the studies discovered four tentatively called “risk” antigens – HLA-A1, HLA-B7, HLA-B15, HLA-CW3 and two protector antigens – HLA-B5, HLA -V35, they were compared with the position of the risk attribute (etiologic and preventive fraction).
It was found that the greatest contribution to the development of the disease was brought by the antigen HLA-A1 (RR=3,04, EF=0,32), and vice versa, a contribution to the resistance of the disease was made by HLA-B5 (RR=0,41, PF=0, 21).
Conclusions Acute and the high degree of activity of SLE prevailed in children of Kazakh population. Determination of loci HLA- A1, HLA -B15, HLA-B7 and HLA-CW3 has a great importance in the prediction of severity and related tactics of management and treatment of patients.
Disclosure of Interest None declared