Absence of monoclonal-antibody-defined protein complex in boy with abnormal leucocyte function.

An 8-year-old boy with severe recurrent bacterial infections was found to lack the cell-surface multimeric polypeptide complex defined by murine monoclonal antibody 60.3. This complex is expressed on the surface of all normal polymorphonuclear leucocytes (PMN), monocytes, and lymphocytes. Incubation of normal lymphocytes or PMN with antibody 60.3 produced functional abnormalities comparable with those observed in the patient's cells, suggesting that the polypeptide complex plays a significant part in several membrane-dependent leucocyte functions.