Kidney biopsy in lupus nephritis: look before you leap

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease primarily affecting women of reproductive age. There is a particular pre-disposition to develop SLE in those of African descent, including a growing incidence in sub-Saharan Africa [1,2]. When compared with white patients, a more aggressive course of disease and poorer outcomes are noted. Such effects are also seen with lupus kidney disease, which is also more common in black patients [3]. Indeed, during the course of their disease, the kidney is a major target organ in up to 60% of patients with SLE, with 25–50% presenting with kidney involvement already at the time of lupus diagnosis. The presentation of lupus nephritis is highly variable, ranging from mild asymptomatic proteinuria to rapidly progressive glomerulonephritis with haematuria and red cell casts. Features invariably include some degree of glomerular proteinuria—nephrotic in 45–65% of the cases. Several studies have illustrated the lack of reliability of diagnoses rendered on the basis of clinical features alone [4,5]. Therefore, making a diagnosis on clinical grounds alone is problematic and risky, underscoring the need for kidney biopsy. With diverse renal histopathological findings possible in SLE-affected patients, biopsy determines not only the diagnosis and prognosis, but also substantially guides management of this complex disease. As the therapeutic armamentarium for lupus nephritis expands, it becomes even more imperative that the correct diagnosis be made prior to instituting therapy. In deciding whether to perform a biopsy, one must balance the risks of the biopsy procedure against the risks of limited diagnostic information, which may result in progression of potentially preventable renal disease or the unnecessary use of a possibly toxic therapy.