Clinical and immunological features of lupus nephritis / Монголын Анагаах Ухаан

ABSTRACT

Background Systemic Lupus Erythematous (SLE) is a multi-systemic autoimmune disease with numerous patterns of clinical and immunological manifestations. Renal disease in SLE occurs in 40–75% of patients, most often within five years of disease onset, and is one of the strongest predictors of a poor outcome. Anti-dsDNA antibodies are reported to be more prevalent in patients with SLE who have renal disease. Anti-Sm, anti SSA and anti SSB antibodies are also considered to play a pathogenic role in inducing renal symptoms in SLE, and a strong correlation has been seen in lupus nephritis (LN) between disease activity and anti-dsDNA antibody levels. Objective The aim of our study is to highlight the clinical and laboratory features in SLE patients. Methods This is a three year hospital based case-control study of patients with renal diseases, who were admitted to the nephrology and rheumatology units of the 1st central Hospital and 3rd central hospital, Mongolia. Standard methods were used for laboratory testing. Autoantibodies (C/P-ANCA, anti-dsDNA, anti-Sm, anti-SS-A/Ro, anti-SS-B/La, anti-Scl-70, anti-GBM) measured by Enzyme Immuno Assay (Germany, ORGENTEC Diagnostika GmbH). Renal function was evaluated by the eGFR (estimated glomerular filtration rate) using the Cockcroft-Gault formula. Result The study included 27 patients with lupus nephritis and 78 controls with other types of GN. There were 85.2% of female patients in the lupus nephritis group. Patients with LN were significantly younger than the controls (mean (SD) 31.9 (10.1) years vs. 37.1 (11.9) years; p=0.036). For the serology, a higher proportion of anti dsDNA (46.1%), anti Sm (29.6%), anti SSA (63%) and anti SSB (11.1%) were seen in the group with lupus nephritis (p=0.001; p=0.043; p<0.0001; p=0.096, respectively). The Pearson’s correlation analysis indicated that the level of anti-dsDNA (r=-0.249, p=0.021) and anti SSA (r=-0.195, p=0.048) were significantly correlated with the renal function (eGFR). All had dipstick proteinuria 1+/2+/3+, more than 10 red blood cells/hpf hematuria (n-12, 44.4%) in lupus nephritis group and renal function (mean eGFR (SD) 88.1 (51.3) ml/min vs. 112.3 (67) ml/min; p=0.05) was more decreased in lupus nephritis patients than controls. Conclusion Notably, rising titers of antibodies to dsDNA, SSA may indicate exacerbations of glomerulonephritis.