The evaluation of the results of nephrobiopsies in patients with lupus nephritis

Abstract

Lupus nephritis is characterized by a variety of clinical and morphological manifestations. Histological changes in the renal tissue often determine the course and prognosis of the disease. The performance of nephrobiopsy provides an important information about the morphological changes in the kidneys and their severity. Objectives. To evaluate histological changes in the renal tissue determined by kidney biopsy in patients with systemic lupus erythematosus. Material and methods. We analyzed 191 specimens of renal biopsy from 161 patients with systemic lupus erythematosus. Examination was conducted using light and immunofluorescent microscopy. Results. The most significant signs of the inflammatory process and sclerotic changes in the renal tissue were revealed in class IV: the presence of crescents (p<0.001), activation of podocytes, proliferation of mesangial cells, splitting of the basement membrane and the presence of deposits, swelling and proliferation of endotheliocytes (p=0.01), detection of fibrin microthrombi (p=0.04), lymphoid infiltration of interstitial tissue (p<0.001), segmental sclerosis of glomeruli, synechia with a capsule (p=0.001), atrophy and necrosis of tubular epithelium (p=0.05), sclerosis of interstitial tissue. In class III, these manifestations were less significant. Individuals with morphological class VI of lupus nephritis had the marked signs of sclerotic changes (global glomerulosclerosis, sclerosis of interstitial tissue (p=0.002), damage of the renal arteries), degeneration/atrophy of tubulocytes, and lymphoid infiltration of interstitial tissue (p<0.001). Class II is characterized by expansion of the mesangial matrix and proliferation of mesangial cells (p<0.001), while class V is characterized by thickening of the basement membrane of glomerular capillaries (p<0.001). Conclusions. In the kidney tissue samples proliferative classes of lupus nephritis were the most frequent type of lesion (83.7%), especially morphological class IV (51.1%), which has the most significant inflammatory and sclerotic changes in the renal tissue. An activity index was 9.6 ± 0.5 points (p<0.001), chronicity index was 3.9±0.3 points (p<0.001).

Keywords

• systemic lupus erythematosus
• lupus nephritis
• nephrobiopsy
• light microscopy
• immunofluorescence microscopy