The epidemiology and prognosis of glomerulonephritis in Denmark 1985-1997

Background. The existence of a national renal biopsy register and a nationa l terminal uraemia status register in Denmark provides an opportunity to st udy the prognosis of glomerulonephritis (GN), and factors influencing progn osis. Methods. Multivariate analysis of 2380 renal biopsies with GN perform ed between 1985 and 1997 was done to determine the influence of clinical an d histological factors on prognosis. Results. The incidence of GN (39/mio/y ear) and individual diagnoses did not change during the period. After 10 ye ars, 32% were dead, 13% terminally uraemic, 5% uraemic and 50% well. Older age increased mortality, but not the incidence of renal failure after the f irst year. Male sex increased both mortality and incidence of renal failure (34 vs 24% at 10 years, P < 0.001). The diagnoses could be divided into th ree prognostic groups compared with the general population: a good prognost ic group (minimal change GN and membranous GN), with a relative mortality o f three and a combined renal and patient mortality of four; a poor prognost ic group [crescentic GN, HUS/TTP, chronic GN] with relative mortalities of 8-19 and 13-33, respectively; and the remainder with mortalities of 4-7 and 6-12. The presence of multiple glomerular pathology, chronic GN, nephroscl erosis and chronic interstitial nephropathy worsened the prognosis, while t he presence of immune deposits only worsened the prognosis of focal segment al glomerulopathy. Mortality was related to uraemia and co-morbidity at bio psy, and to the incidence of renal failure. Renal failure was correlated to uraemia and hypertension at biopsy but not to nephrotic syndrome or athero sclerosis. All vascular complications were increased and were positively re lated to hypertension and negatively correlated to the incidence of uraemia . Crescentric glomerulonephritis combined with anti-GEM disease had a worse prognosis than Wegener's granulomatosis, with microscopic polyangiitis and pauci-immune disease occupying an intermediate position. The prognosis of mesangioproliferative GN was unaffected by the presence of IgA nephropathy and systemic lupus erythematosus.