Using a rapid, highly sensitive immunoprecipitin nephelometric technique, a retrospective study was undertaken to evaluate the clinical usefulness of determining serum haptoglobin in the diagnosis of hemolysis. Haptoglobin assays were performed shortly after admission in 100 patients with a variety of hematologic and nonhematologic conditions and the results correlated with the clinical diagnosis. An ad hoc boolean computer program allowed for the separation of hemolytic from nonhemolytic disorders with a haptoglobin limit of 25 mg/dL or less. The sensitivity and specificity of the test are high (83% and 96%, respectively), providing 87% probability of predicting hemolytic disease when the serum haptoglobin level falls below this limit. These data support the routine use of serum haptoglobin determinations in the diagnosis of hemolytic disease.
(JAMA 243:1909-1911, 1980)