The clinical and bioptic aspects of 211 cases of primary mesangioproliferative glomerulonephritis with urinary abnormalities lasting mre than 1 year were reviewed. We observed the following clinical syndromes: 1) Persistent proteinuria, isolated or with microhematuria: - a) with latent onset: 39% with hypertension (H); 10% with renal failure (RF); - b) with acute nephritic syndrome at onset: 31% with H; 6% with RF; 2) Recurrent macroscopic hematuria: 26% with H; 10% with RF; 3) Nephrotic syndrome: 70% with H; 29% with RF. The histological lesions, diffuse in all cases, appeared unrelated to the clinical syndromes and/or immunofluorescent patterns. In 65 cases with prevalent mesangial deposits of IgA, 46% showed persistent proteinuria with latent onset, 23% persistent proteinuria with acute nephritic syndrome at onset, 28% recurrent hematuria and 3% nephrotic syndrome. 37% of such patients developed H, 14% RF and 6% remission (R). On the other hand in 65 patients with other deposits the clinical aspects were as follows: persistent proteinuria with latent onset: 46%; persistent proteinuria with acute nephritic syndrome at onset: 31%; recurrent hematuria: 17%; nephrotic syndrome: 6%. 35% of these cases displayed H; 9% RF and 8% R.
Conclusion: primary mesangioproliferative glomerulonephritis appears to represent a heterogeneous group with only the morphological aspects in common and associated with one of the three above-mentioned clinical syndromes. Immunohistology shows different Ig and/or complement which bear no specific relationship with clinical courses. In particular IgA deposits are present in 50% of the cases and are only related to higher incidence of recurrent hematuria and abnormal IgA serum levels.