Rapidly progressive glomerulonephritis: analysis of prevalence and clinical course.

Over a period of 68 months we observed 33 patients with biopsy-confirmed severe crescentic glomerulonephritis (GN) and another 5 patients who fulfilled the clinical criteria of rapidly progressive glomerulonephritis (RPGN; no biopsy confirmation) in a region comprising approximately 930,000 inhabitants. Additional 7 patients with Wegener's granulomatosis (WG)/microscopic polyarteritis (MP) from the same region were not seen by nephrologists. The calculated annual incidence of crescentic GN/RPGN is 0.7/100,000. Of the 38 patients 13 had classical WG, 7 MP, 3 systemic lupus erythematosus, 5 Schönlein-Henoch purpura, 3 Goodpasture's syndrome, 2 IgA glomerulonephritis. Of note is the high prevalence of WG/MP and the relative frequency of Schönlein-Henoch purpura. At the last follow-up, 3 patients were dead (8%), 7 patients were on dialysis (18%), 7 patients had elevated serum creatinine (18%) and 21 patients had normal serum creatinine (55%). We conclude that: (i) RPGN is more frequent than reported; (ii) WG and MP account for more than 50% of cases of RPGN; (iii) renal functional prognosis is good in WG/MP, but less favorable in RPGN of other causes; (iv) severe hypertension is not a feature of RPGN; (v) WG/MP, and not Goodpasture's syndrome, is the most common cause of pulmonary hemorrhage in association with RPGN; (vi) death from infection or malignoma is uncommon (not observed in this series); (vii) de novo IgA GN may occur in patients in remission from WG (2 observations).