Concomitant IgA nephropathy and cyclical neutropaenia.

A case of concomitant cyclical neutropaenia and IgA nephropathy, a previously undescribed combination is reported. The patient has recurrent aphthous ulceration, and haematuria occurs with these episodes. The diagnosis of cyclical neutropaenia was based on the clinical features and serial peripheral blood studies, and a renal biopsy studied by light, electron and immunofluorescence microscopy in conjunction with the clinical features established the diagnosis of IgA nephropathy. Elevation of serum immunoglobulin, with a disproportionate elevation of IgA was found. The features of this case emphasise the importance of infection as an initiating event in the pathogenesis of IgA nephropathy, and they provide further evidence for the formation of poorly soluble immune complexes as a likely pathogenetic mechanism.