Volunteer unrelated donor experience after administration of filgrastim and apheresis for the collection of haemopoietic stem cells: the Australian perspective

BACKGROUND

Voluntary donations of peripheral blood stem cells after administration of filgrastim (granulocyte-colony stimulating factor, G-CSF) are undertaken throughout the world by healthy individuals, but the short-, medium- and long-term adverse events during and after donation are not fully understood.

AIMS

We document the experience of donors of peripheral blood stem cells mobilised by G-CSF at Australian Bone Marrow Donor Registry collection centres.

METHODS

When the Australian Bone Marrow Donor Registry commenced collecting mobilised peripheral blood stem cells, based on data used for registration of G-CSF, all adverse reactions in donors were documented prospectively to determine the rate and severity of events. A total of 512 consecutive first-time donors assessed between July 2001 and March 2010 were included in this study.

RESULTS

The median age at work-up was 40 years and 71% of donors were male. A large proportion of donors (91%) experienced bone pain during administration of G-CSF, and in fewer numbers headache (61%) and fatigue (61%). Bone pain was associated with a body mass index of overweight/obese (P = 0.03). Headache (P = 0.03), muscle pain (P = 0.03) and fatigue (P = 0.001) were all significantly associated with female sex. More than a quarter (28%) of donations involved a range of complications at collection.

CONCLUSION

The incidence of short- and medium-term symptoms and events observed provide support for the information provided to unrelated donors at counselling. Follow up of the consequences of unrelated voluntary donation remains important to provide accurate and relevant information to prospective donors.

Effects of transmembrane region variability on cell surface expression and allorecognition of HLA-DP3

The functional relevance of polymorphisms outside the peptide binding groove of HLA molecules is poorly understood. Here we have addressed this issue by studying HLA-DP3, a common antigen relevant for functional matching algorithms of unrelated hematopoietic stem cell transplantation (HSCT) encoded by two transmembrane (TM) region variants, DPB1(*)03:01 and DPB1(*)104:01. The two HLA-DP3 variants were found at a overall allelic frequency of 10.4% in 201 volunteer stem cell donors, at a ratio of 4.2:1. No significant differences were observed in cell surface expression levels of the two variants on B lymphoblastoid cell lines (BLCL), primary B cells or monocytes. Three different alloreactive T cell lines or clones showed similar levels of activation marker CD107a and/or CD137 upregulation in response to HLA-DP3 encoded by DPB1(*)03:01 and DPB1(*)104:01, either endogenously on BLCL or after lentiveral-vector mediated transfer into the same cellular background. These data provide, for the first time, direct evidence for a limited functional role of a TM region polymorphism on expression and allorecognition of HLA-DP3 and are compatible with the notion that the two variants can be considered as a single functional entity for unrelated stem cell donor selection.