Sequential measurement of mesangial matrix area occupying the glomerulus in children with IgA nephropathy

Background IgA nephropathy is the most common form of primary glomerulonephropathy in children it has a variable clinical course, from spontaneous remission to progression to renal death. It has been reported that predominant mesangial hypercellularity is characteristic of early lesions, and that it changes to a gradual matricial increase, with sclerosis, according to the disease progression. Methods A sequential measurement of the ratio of mesangial matrix area to glomerular area (M/G) was done in 5 children with moderately proteinuric IgA nephropathy, who underwent 3 consecutive, repeat renal biopsies. A prompt initiation of alternate-day prednisolone therapy (an initial dosage at 1 mg/kg, maximum 60 mg) after the first renal biopsy was done in 4 cases. The remaining patient received this therapy after the second renal biopsy. Results A sequential measurement of the M/G in the former cases did not show an increase between the biopsies, while measurement of the latter one showed a progressive increase. Moreover, the case that had an increase in the M/G showed renal impairment at the third biopsy. Conclusion Although a small number of cases were examined, a sequential measurement of the M/G in children with moderately proteinuric IgA nephropathy may be a valuable indicator for a more precise evaluation of clinical outcome in a clinical setting.