Renal infarction. Elevation of serum and urinary lactic dehydrogenase (LDH)

Although renal infarction is not rare, clinical diagnosis is difficult. In one series of 205 patients found at autopsy to have a renal infarction, only two cases were diagnosed during life.1Recently, we have observed two patients in whom striking elevation of serum lactic dehydrogenase (LDH) was a clue to the diagnosis of renal infarction; in one of these patients, urinary LDH also was markedly increased. The association of increased serum and urine LDH with renal infarction has been described in detail only once previously,2although it has been mentioned in passing in two other reports.3,4 The purpose of the present paper is to emphasize that renal infarction must be considered in the differential diagnosis of serum and urinary LDH elevations. Patient Summaries Patient. 1. —A 69-year-old Negro woman was admitted to St. Louis City Hospital on July 14, 1966, during a heat wave, prostrate and with