Renal microtophi in a patient with lupus nephritis and tophaceous gout

This case describes a 58-year-old female with systemic lupus erythematosus (SLE) and coexistent chronic tophaceous gout. A renal biopsy showed concurrent lupus nephritis and renal medullary microtophi, confirmed by electron and polarizing microscopy, respectively. Whereas clinical SLE and gout have already been shown to be rarely associated, this case further illustrates the presentation of these two diseases in a single renal specimen. In this patient the gout began shortly after menopause without known risk factors and before any overt renal disease or signs of SLE. The tophaceous gout antedating the SLE, as well as the apparently benign course of illness, suggest that the pathologic effects of SLE and gout on the kidneys are based on independent mechanisms and may not necessarily aggravate each other. Treatment of the gout with allopurinol may have contributed to improved renal function.