Failure of the platelet-halothane nucleotide depletion test as a diagnostic or screening test for malignant hyperthermia.

A platelet-halothane nucleotide or bioassay test has been suggested as an accurate means for diagnosis of malignant hyperthermia (MH). For the last three years we performed this test in all patients at risk for MH and in all normal control patients undergoing skeletal muscle biopsy in our diagnostic unit. The reliability of the platelet-halothane nucleotide test has been assessed on the basis of the presence or absence of a previous MH reaction and degree of relationship of relatives to those who have had reactions, and on the basis of caffeine-halothane contracture test values (positive or negative for MH). We have found no significant difference in platelet-halothane nucleotide test values in malignant hyperthermia susceptible (MHS) patients or relatives of MHS patients and normal controls, and no relationship between the nucleotide test and caffeine-halothane contracture test results. We conclude that the platelet-halothane nucleotide test is not of assistance in the diagnosis of or in the screening for MH.