Abstract
The excretion of cellular per litre of urine amounted in healthy persons to, in round figures, one million epithelial cells (2.5 cells per visual field) in both sexes, one million leukocytes in males, one million erythrocytes in females and 0.5 million in males. The maximal excretion was calculated to be 5-6 million per litre. In acute infections the number of epithelial cells and leukocytes in the urine rose to more than the double. Pathological microscopic haematuria, judged by exceeding of the maximal value for normal excretion during the acute phase (24 or more erythrocytes per visual field), occurred in no case of mycoplasma infection, in about 4% of measles, mononucleosis, serous meningitis and hepatitis cases, in about 8 % of mumps and streptococcal infections, and in more than 20 % of influenza A2 cases. Statistical significance or probable significance existed between influenza and other diseases. The haematuria was unrelated either to the general degenerative or to the specific inclusion-provocative reaction within the renal and urinary tract epithelium. The cause is sought in an involvement of glomeruli with increased diapedesis. The special position of influenza may be explained by the marked haemorrhagic reactions produced by this infection. In one case persistent haematuria combined with increased content of inclusion-bearing cells occurred after influenza. Immunoglobulin deposition in glomerular mesangium may perhaps be one explanation of this haematuria.