| English |
| post-transfusional purpura |
  |
|
| Attestation |
3
|
| Part of speech |
Noun syntagm
|
| Grammatical label |
Countable
|
| Variant |
Post-transfusion purpura
|
| Definition |
This is a rare but potentially lethal complication of transfusion of red cells or platelets. It is more often seen in female patients. It is caused by platelet-specific alloantibodies. Typically, 5-9 days after transfusion the patient develops an extremely low platelet count with bleeding. Management: High-dose intravenous immunoglobulin (IVIgG) (2g/kg given over 2 or 5 days) is the current treatment of choice with responses in about 85% of cases; there is often a rapid and prompt increase in the platelet count. Steroids and plasma exchange were the preferred treatments before the availability of IVIgG, and plasma exchange, in particular, appeared to be effective in some, but not all, cases. Platelet transfusions are usually ineffective in raising the platelet count, but may be needed in large doses to control severe bleeding in the acute phase, particularly in patients who have recently undergone surgery, before there has been a response to high-dose IVIgG. There is no evidence that platelet concentrates from HPA-1a negative platelets are more effective than those from random donors in the acute thrombocytopenic phase, and the dose of platelets may be more important than the platelet type of the donor platelets. There is no evidence to suggest that further transfusions in the acute phase prolong the duration or severity of thrombocytopenia.
|
| Definition source |
UK Blood Transfusion and Tissue Transplantation Guidelines. Transfusion Handbook: Post-transfusion Purpura (PTP).
|
| Context |
In this context, it could be hypothesized that the mechanisms of recognition in multitransfused patients might be different: alloantigens expressed on the CD42 protein (HPA2) might be more immunogenic in multitransfused patients than alloantigens expressed in the CD41/61 complex (HPA1 or HPA3) or in the CD49b-related antigen (HPA5), which are more frequently involved in neonatal alloimmune thrombocytopenia or in post-transfusional purpura.
|
| Context source |
Tazzari, PL., et al. (1998). ‘Alloimmunization against human platelet antigen 2 (HPA2) in a series of multi-transfused beta-thalassemia patients’. Haematologica 83(8):765-6. (RISCEN46)
|
| Subject field |
Haemopoiesis
|
| Sub-field (level 1) |
Thalassemias
|
| Coordinate concept |
Thrombotic thrombocytopenic purpura, autoimmune thrombocytopenic purpura
|
| Related concept |
Transfusional therapy, iron-chelating agent
|
| it |
Porpora post-trasfusionale
|
| Reliability code |
3
|
