CD3+ T Cell Lineage Specific Maternal Engraftment in Pediatric Patient with Severe Combined Immunodeficiency Disorder

Abstract

<i>Background: </i>Transplacental Maternal Engraftment (TME) is common in patients with Severe Combined Immunodeficiency Disorder (SCID), however only a few are complicated by Graft Versus Host Disease (GVHD) prior to Hematopoietic Cell Transplantation (HCT). <i>Objective:</i> We will discuss a rare case of a SCID patient with complete TME at birth who later developed pre-HCT GVHD secondary to TME. <i>Materials and Methods:</i> Peripheral blood mononuclear cells or sorted cell populations are used for TME monitoring. Chimerism testing/engraftment analysis was performed by PCR based capillary electrophoresis to detect genetic polymorphisms in short tandem repeat loci. <i>Results:</i> SCID was diagnosed on newborn screen and the patient was prematurely born at 33 weeks of gestation. The patient had GVHD secondary to TME, which involved skin, liver, gut and bone marrow along with other clinical symptoms of SCID and treated with tacrolimus and methylprednisolone. The patient was transplanted three months after birth with an HLA identical sibling donor. Partial donor engraftment was seen in myeloid cells followed by B and T cell lineages from day +42 post transplantation. Testing sorted CD4+ and CD8+ T cells at day +42 revealed that the engrafted maternal CD3+ cells were exclusively of CD4+ phenotype, which represented 15% of circulating CD4+ T cells. <i>Conclusion:</i> Based on our findings, we suggest that CD3+ lineage specific T cells, presumably CD4+, might be the main contributor for pre-HCT GVHD secondary to TME.