Nitroblue tetrazolium slide test. Use of the phorbol-myristate-acetate-stimulated NBT-reduction slide test for routine and prenatal detection of chronic granulomatous disease and diagnosis of heterozygous carriers.

Chronic granulomatous disease (CGD) in utero has recently been detected by a new qualitative nitro blue tetrazolium (NBT) reduction slide test using phorbol-myristate-acetate (PMA) as a stimulus. The technique is simple and inexpensive and requires only a few microlitres of blood. Reported here is an evaluation of this method as applied to routine clinical diagnosis. The blood granulocytes from 300 normal individuals and 49 CGD patients and their relatives were tested and the results compared to the conventional in vitro function tests. In normal individuals the number of abnormal cells was very low never exceeding 2% of granulocytes. CGD patients (14 out of 15) diagnosed by conventional functional tests showed no positive cells in the NBT-PMA test. One patient diagnosed by functional tests had 4% positive cells. Thirty-four relatives of these patients were tested and eleven were found to have fewer positive cells than normal in the NBT-PMA slide test ranging from 16-88% of all granulocytes. These are presumably carriers, a finding supported by granulocyte function tests. All these individuals were female, mothers, sisters or maternal aunts of male CGD patients, thus presumably X-linked heterozygote carriers of CGD. An example of successful prenatal diagnosis using the PMA-NBT test is described. The results show that the PMA-NBT test provides a simple and reproducible method for routine diagnosis of CGD and CGD X-linked heterozygote carriers.