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

This study was carried out to analyze clinical presentation, laboratory parameters and histology in lupus nephritis in males in comparison with females.

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.

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.

Renal dysfunction and activity index are significantly higher in male patients with lupus nephritis.