Lactoferrin deficiency as a consequence of a lack of specific granules in neutrophils from a patient with recurrent infections. Detection by immunoperoxidase staining for lactoferrin and cytochemical electron microscopy.

Neutrophils from a boy suffering from recurrent infections were found to be totally deficient in specific granules when studied by electron microscopy. In contrast, myeloperoxidase-containing azurophil granules were increased in number. This deficiency of specific granules could be detected at the light-microscopic level using an immunocytochemical technique to demonstrate the absence of lactoferrin. Neutrophils also exhibited abnormal nuclear segmentation, nuclear clefts, an abnormally weak cytochemical reaction for alkaline phosphatase, and an increased number of mitochondria and ribosomes. Some granulocytic precursors were abnormal, and many of these cells were phagocytosed by macrophages in the bone marrow. Despite these multiple abnormalities and the history of severe pyogenic infection, the in vitro bactericidal capacity of the neutrophils was within normal limits, and normal degranulation of azurophil granules occurred following phagocytosis. The precise mechanism by which the deficiency of specific granules in this patient led to an enhanced in vivo susceptibility to infection therefore remains obscure. However, attention is drawn to the fact that in three previously described cases of specific granule deficiency a history of recurrent infections was present.