Severe combined immunodeficiency (SCID) associated neutropenia: a lesson from monozygotic twins

Arch Dis Child. 1996 Apr;74(4):340-2. doi: 10.1136/adc.74.4.340.

Abstract

A case of severe combined immunodeficiency (SCID) in monozygotic twin sisters was detected at 3 months of age with neutropenia in one twin and a normal differential count in the other. The neutropenic twin, suffering from severe skin ulcers, was successfully treated with granulocyte colony stimulating factor (G-CSF). Discordant occurrence of neutropenia in identical twins shows that there may be a non-genetic cause for the neutropenia in SCID. Suppression of myelopoiesis was probably induced by activated maternal T cells. The neutropenia in this case may thus be classified as SCID associated neutropenia, as opposed to reticular dysgenesis, in which the neutropenia is G-CSF refractory and is most probably caused by a genetic stem cell defect. A response to G-CSF in a neutropenic child with SCID can be clinically beneficial and might help to distinguish between G-CSF unresponsive reticular dysgenesis and G-CSF responsive SCID associated neutropenia.

Publication types

  • Case Reports

MeSH terms

  • Diseases in Twins*
  • Female
  • Granulocyte Colony-Stimulating Factor / therapeutic use
  • Humans
  • Infant
  • Neutropenia / etiology*
  • Neutropenia / therapy
  • Severe Combined Immunodeficiency / complications*
  • Twins, Monozygotic*

Substances

  • Granulocyte Colony-Stimulating Factor