Renal Biopsy: A much needed tool in patients with Systemic Lupus Erythematosis (SLE)

BACKGROUND AND OBJECTIVE: Systemic lupus erythematosis (SLE) is an inflammatory disorder associated with significant morbidity and mortality. Kidneys are frequently affected in SLE and various stages of lupus nephritis have been identified based on severity of the disease. Treatment varies with the staging and correct diagnosis is essential for timely intervention as it can have significant impact on morbidity and mortality. The objective of the study was to determine whether laboratory parameters of lupus nephritis (LN); including urinalysis, serum creatinine (S. Cr) and 24 hours urine protein can accurately predict histologic staging of the disease. METHODS: This retrospective study was conducted in department of Nephrology, Liaquat National Hospital Karachi from January 2012 to December 2014. Fifty one patients of SLE who underwent renal biopsy were selected. Patients, urinalysis at the time of renal biopsy, serum creatinine and 24 hours urine collection for protein were noted. All patients renal biopsy was read by the same pathologist. Patients were clinically staged based on these parameters and their histologic staging based on biopsy findings were compared, to see their correlation. Data was analyzed using SPSS version 17. Chi-square test was used to analyze categorical data and p<0.05 was considered significant. Cohen’s kappa (κ) analysis was used to examine the agreement by comparing lupus nephritis staging done by laboratory and histological ground. P value <0.05 indicates that agreement was unlikely due to chance alone. RESULTS: Among 51 patients analyzed, 37 patients were females (72.5%) and 14 patients were males (27.5%) with mean age of 32.51 + 16.91 years. In stage II, kappa (κ) of 0.304 represented fair strength of agreement and a p value of 0.012 (p<0.05)which was statistically significant. In stage III, kappa was 0.209 indicating none to slight agreement and a p value of 0.131 (p>0.05). In stage IV, kappa (κ) was 0.141 (slight agreement)and p value 0.301 (p>0.05) in stage V; kappa (κ) of 0.030 represented poor agreement and a p value of 0.828 (p>0.05). CONCLUSION: Staging of lupus nephritis done on basis of laboratory findings did not correlate well with underlying histological staging. Therefore, renal biopsy is an essential tool in approach to lupus nephritis in order to provide timely and appropriate treatment to patients.