Idiopathic renal acidosis in infancy

The present paper describes the clinical picture, the biochemical disorder and the natural history of idiopathic renal acidosis in infancy. This condition is due to the kidneys failing to regulate the acid-base balance of the body by excreting a sufficiently acid urine. This results in a metabolic acidosis with a urine which is weakly acid or alkaline instead of strongly acid as would be expected. The adjective 'idiopathic ' is added to distinguish this condition from the acidosis of patients with chronic nephritis. The term renal acidosis was used by Hartmann (1939) who described this condition in an infant. He was the first to ascribe it to a disturbance of kidney function. The cases described by Lightwood (1935) under the title of ' nephrocalcinosis infantum ' were almost certainly the same condition. German pathologists (Glaserfeld, 1907; Kuhn, 1918) had previously described in detail the deposition of calcium in the kidneys of infants, but Lightwood (1935) studied the history of six infants who were found at necropsy to have renal calcification with-out any detectable cause for their fatal illness and noticed a striking similarity in the clinical picture. He suggested that this was a definite clinical entity. The following year Lightwood, Maclagan and Williams (1936) described an infant with 'persistent acidosis ' who had no radiological evidence of renal calcification, and, because of the similarity of the clinical picture to that of infants with nephro-calcinosis, they thought that it might be the same condition. They failed, however, to incriminate the kidneys for the persistent acidosis although they found an alkaline urine in the presence of a low plasma total carbon dioxide content. The infant recovered from his illness. A few months later Butler, Wilson and Farber (1936) described four infants with severe acidosis during life and renal calcification at necropsy. The urine was said to be acid in three but in the fourth the reaction was not mentioned. Several workers have described similar cases