Background: Lupus nephritis (LN) is uncommon after the age of 50 years and studies of elderly patients with LN are rare. The authors conducted the current study to determine the clinical manifestations, pathological features and prognosis of 30 Thai patients with late onset LN in Siriraj hospital in Bangkok from 1989 to 2006.
Material and Method: Thirty LN patients with a disease onset beyond the age of 50 years from 1989 to 2006 were enrolled in this retrospective study. All of them received renal biopsy. The histological classifications were categorized according to 2003 International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification.
Results: Clinical and pathologic records were collected from 30 patients (23 female and 7 men) who were followed-up for a mean period of 25.8 months (range, 6 to 96 months). The mean age was 56.6 + 4 years. Hypertension was diagnosed in 66.7% of patients and 41.3% had serum creatinine greater than 1.5 mg/dL. Nephrotic-range proteinuria was found in 63.3% of patients and creatinine clearance less than 50 ml/min was found in 70%. Of the 30 patients, the most common renal histologic finding was diffuse proliferative glomerulonephritis (63.3%). The overall probability of patient survival was 94.1% at 12 months, 68.6% at 36 months and 34.3% at 60 months. During the follow-up period (25.8 months; range, 6 to 96 months), 4 patients died. Infection was the leading cause of death (75%).
Conclusion: Lupus nephritis in the elderly patients is not uncommon. Prompt diagnosis should be made for appropriate management and optimal outcome.

Keywords: Late onset lupus nephritis, Elderly, Nephrotic-range proteinuria, Renal pathology