Sex-based differences in lupus nephritis: a study of 235 Indian patients

Background: This study was carried out to analyze clinical presentation, laboratory parameters and histology in lupus nephritis in males in comparison with females. Methods: Patients diagnosed with lupus nephritis between January 2001 and December 2005 were divided into 2 groups: males and females, and were analyzed with regard to clinical presentation, renal profile, serology and histology. All biopsies were reported by a single histopathologist as per WHO classification. Activity and chronicity indices were calculated. Comparison was made between the 2 groups. Statistical analysis was done using Strata version 6 software for Windows. Results: Of the 235 patients diagnosed to have lupus nephritis, 35 were males (14.9%) and 200 females (85.1%). Males were younger (mean age 23.22 +/- 9.32 years, range 9-44) compared with females (mean age 24.7 +/- 8.93 years, range 5-55). Extrarenal manifestations such as joint pains, alopecia, rash, fever, serous effusions and oral ulcers were comparable in both groups, as were hypertension (68.5% vs. 67%), nephrotic proteinuria (40% vs. 36%) and hematuria (80% vs. 73%). Renal dysfunction was significantly more common in males (60% vs. 37.5%, p<0.05) with higher levels of mean serum creatinine (2.67 vs. 1.62 mg/dL, p<0.05) and blood urea (63.25 vs. 48 mg/dL, p<0.01). Histologically, class IV lupus was the most common lesion in both groups (71.4% in males, 60% in females). Membranous lupus nephritis was more common in females (22% vs. 5.7%, p<0.05). Activity index (8.51 vs. 6.76, p<0.05) was higher in males. Conclusions: Renal dysfunction and activity index are significantly higher in male patients with lupus nephritis.