Histopathological indicators of disease outcome in class IV lupus nephritis: a revisit of various indices.

Current management guidelines for lupus nephritis (LN) do not attach importance to histological indices of disease activity or chronicity. The present study was performed to evaluate the clinical relevance of these indices in determining outcomes in patients with class IV LN. We analyzed the data of all patients with biopsy-proven class IV LN seen over a 6-year period. The histopathological findings were reviewed; the activity and chronicity indices proposed by Austin [AI (Austin) & CI (Austin)] and the renal biopsy index proposed by Hill were calculated. As immunofluorescence was not done in all patients, this was excluded from calculation of the renal biopsy index, which was referred to as the modified Hill's index (MHI), which was a composite of glomerular activity index (GAI), chronicity index (CI) and tubulo-interstitial activity index (TIAI). Pearson's correlation coefficient, multilinear regression analysis and logistic analysis were performed, and p value of <.05 was considered significant. During the study period, 114 cases of LN were evaluated, of which 64 % (73/114) had class IV LN. The mean age was 26.5 years, and 92 % were females. The mean scores of AI (Austin), CI (Austin), GAI, CI, TIAI and MHI were 8.46, 2.50, 7.54, 3.06, 4.74 and 2.23, respectively. Serum creatinine correlated significantly with TIAI, CI, CI (Austin) as well as MHI, but not with AI (Austin) or GAI. The serum creatinine level was the strongest clinical parameter determining outcome, while none of the histological indices correlated with either treatment outcome or mortality. None of the histological indices performed better than serum creatinine level in determining the treatment outcomes and mortality.