NON-HODGKINS-LYMPHOMA PRESENTING AS NEUTROPENIA RELATED TO AN IGM MONOCLONAL ANTI-I ANTIBODY

A sixty-year old female was referred to the Internal Medicine Departme nt for the treatment of a diffuse high-grade non Hodgkin's lymphoma. S he presented episodes of fever in a context of neutropenia (neutrophil s 0.35 x 10(9)/l from 1.6 x 10(9)/l white blood cells). Hemoglobin lev el was 8.2 g/dl and platelets 132 x 10(12)/l. A monoclonal IgM-kappa p rotein (48 g/l) was detected in her serum. A direct antiglobulin test on the red cells proved positive with anti- C3d but not with anti-IgG antiglobulin, due to the presence of an IgM cold antibody with a serol ogical anti-i specificity. The IgM antibody was found on the patient's neutrophils as well as in her serum. This antibody recognized all neu trophils tested in conventional serological tests whatever the neutrop hil phenotypes in systems NA, NB, and 5. It was demonstrated that it r ecognized the i antigen expressed on the neutrophils. These results su ggest that a cold agglutinin anti-i might be responsible for neutropen ia in some patients.