Prevalence and clinicopathologic findings of antiphospholipid syndrome nephropathy in Thai systemic lupus erythematosus patients who underwent renal biopsies

Aim: To determine the prevalence of anti phospholipid syndrome nephropathy (APSN) in Thai systemic lupus erythematosus (SLE) patients who underwent renal biopsy and to compare the relationship of renal histopathology and other significant clinical parameters between SLE patients with and without APSN. Methods: A retrospective analysis was undertaken in systemic lupus erythematosus patients (n = 150, 44 <15 years old, 106 >= 5 years old) who underwent renal biopsy. The specimens were evaluated for histological features of APSN and other significant clinical parameters. The result of antiphospholipid antibodies, clinical course, and renal function from chart review were analysed. Results: The prevalence of APSN in systemic lupus erythematosus patients who underwent renal biopsies was 34% (16% in <15-year-old group, 41.5% in >= 15-year-old group). APSN was associated with more severe hypertension (P = 0.002 for systolic and P = 0.004 for diastolic blood pressure), acute renal failure (P = 0.003), persistent heavy proteinuria (P < 0.001 for 4+ proteinuria), severe lupus nephritis (class III and IV, P = 0.014, high activity and chronicity indices, P < 0.001) and a tendency to progress to end-stage renal disease. Conclusion: Systemic lupus erythematosus patients who underwent renal biopsies in our institute showed a prevalence of APSN comparable to those in western countries. The presence of APSN was significantly higher in the adult than in the paediatric population. Its association with poor prognostic indicators suggests poor renal outcome. Clinicians should be aware of this condition in order to give proper care to systemic lupus erythematosus patients.