C. Nieuwhof et al., CHRONICITY INDEX AND MESANGIAL IGG DEPOSITION ARE RISK-FACTORS FOR HYPERTENSION AND RENAL-FAILURE IN EARLY IGA NEPHROPATHY, American journal of kidney diseases, 31(6), 1998, pp. 962-970
To determine the natural history in early immunoglobulin A (IgA) nephr
opathy, we evaluated the long-term follow-up of 27 normotensive nonazo
temic adult idiopathic IgA nephropathy patients with chronic hematuria
who derived from a prospective regional epidemiological study of glom
erulonephritis conducted between 1978 and 1984. As controls, 17 thin g
lomerular basement membrane (GBM) patients, 24 patients with normal re
nal tissue, and nine patients with miscellaneous nephropathies were fo
llowed up. Median follow-up was 11 years (range, 8 to 14 years). Renal
biopsies, performed within 2 years after patient identification, were
scored semiquantitatively in terms of activity and chronicity indices
, using a modified National Institutes of Health (NIH) scoring system.
During follow-up, two patients with IgA nephropathy went into histolo
gical remission, and 12 IgA nephropathy patients showed disease progre
ssion, of whom three developed renal failure. Initial proteinuria over
1 g/d was associated with a high activity score, extracapillary lesio
ns, and late onset of uremia. Mesangial IgG deposition and a higher in
itial chronicity index were associated with development of hypertensio
n during follow-up. In the multivariate analysis, a high initial chron
icity index, erythrocyturia, and mesangial IgG deposition are independ
ent determinants of progression of disease. We conclude that in patien
ts with IgA nephropathy, identified early in the course of disease, er
ythrocyturia, a high chronicity index, and mesangial IgG deposition in
the presence of normal renal function are risk factors for decreased
renal survival. Disappearance of hematuria is associated with remissio
n of IgA nephropathy immunopathologically and low activity and chronic
ity indices at initial biopsy. (C) 1998 by the National Kidney Foundat
ion, Inc.