Influence of the period between onset of IgA nephropathy and medical intervention on renal prognosis

Abstract

Background. The clinical course of IgA nephropathy (IgAN) is highly variable. In order to verify the necessity of early medical intervention in IgAN patients, the present study investigated the clinical impact of the duration between disease onset and first medical intervention on renal prognosis. Methods. We enrolled 57 patients diagnosed with IgAN on the basis of biopsy performed at our hospital. The medical records of these patients were traceable to the last 10 years, during which they had not undergone dialysis or treatment at any other hospital. On the basis of histological assessment of prognosis, these patients were classified according to the Japanese guidelines into the following groups: groups I, good prognosis; group II, relatively good prognosis; group III, relatively poor prognosis; and group IV, poor prognosis. We investigated the correlation between the duration of disease onset and the first consultation with a nephrologist and the rate of increase in serum creatinine over a 10 year period. In addition to the abovementioned patients, 6 patients with IgAN who underwent dialysis within the 10 years were separately evaluated. These patients came under the poor prognosis category; i.e., they belonged to group IV. Results. The duration between disease onset and medical consultation was significantly longer in younger patients or in those with asymptomatic proteinuria at onset when compared to that in older patients or in those with other urinary abnormalities. There was a significant correla tion between this duration and renal prognosis, particularly in group III patients. Although the duration between onset and consultation was not correlated to the serum creatinine level at the time of first medical intervention, urinary protein level among group IV patients at the time of first consultation was significantly higher in patients with dialysis than that in those without dialysis. Conclusions. Early medical intervention may lead to a better renal prognosis, particularly in group III patients, who form a major portion of the IgAN population. It therefore appears that early diagnostic screening and subsequent intervention are important for a good prognosis in IgAN patients.