Résumé
Neonatal alloimmune neutropenia (NAN) results from neutrophil destruction by transplacental maternal neutrophil-specific immunoglobulin G (IgG) antibodies directed against the antigen inherited from the father. Treatment is usually based on recombinant human granulocyte colony-stimulating factor (G-CSF) and prevention or treatment of infection. We report the case of neutropenia in a newborn discovered because of fetomaternal infection. The bone marrow biopsy showed normal cellularity. Granulocyte typing, granulocyte cross-matching, and serum assays showed anti-neutrophil antibodies specific for human neutrophil antigen-1c, an antigen rarely involved in this disease. This NAN was refractory to G-CSF but responded to intravenous immunoglobulin (IVIG). IVIG should be considered as a second-line treatment in NAN refractory to G-CSF. Clinical trials, however, are required to define the optimal management of NAN, a rare but probably underestimated life-threatening situation for newborns.