Prospective evaluation of platelet refractoriness in haematological patients in a single Brazilian institution. (1st June 2020)

• Record Type: Journal Article
• Authors: Bub, Carolina Bonet; Gonçalez, Ana Cláudia; Barjas‐Castro, Maria Lourdes; Castro, Vagner
• Is Part Of: ISBT science series. Volume 16:Number 1(2021)
• Page Start: 2
• Page End: 11
• Publication Date: 2020-06-01
• Subjects: platelets refractoriness -- alloimunization -- platelets antigens; Blood -- Periodicals; Blood -- Transfusion -- Periodicals; Immunohematology -- Periodicals; Immunopathology -- Periodicals; 615.39
• DOI: 10.1111/voxs.12560
• Languages: English
• ISSNs: 1751-2816

Abstract

Abstract: Introduction: Platelet refractoriness (PR) is a frequent complication in multitransfused patients, due to non‐immune and immune factors. Brazilian population has a distinct ethnical background, and few data are available of PR. This study aimed to evaluate clinical and laboratory features of haematological patients with suspected PR from a Brazilian regional reference centre. Material and methods: Haematological patients (pts) with clinical suspected PR were included from February 2007 to 2014. Platelet Abs and anti‐HLAAbs identification, HPA and HLA genotyping performed. Clinical information obtained from medical records. Results: Total of 624 patients were evaluated, and incidence of PR observed was 7%. Among 93 patients with clinical suspicion of PR, 45·2% had PR confirmed. HLA antibodies were present in 80·9% among PRpts in 60·6% of non‐PRpts (no significant difference). Immune PR(IPR) isolated was identified in 11·9% of the PR patients and in association with non‐immune causes in 69·05%. Isolated non‐immune PR (NIPR) was present in 19·1% of cases. IPR patients had higher HPA‐Abs frequency compared to I+NIPR group ( P = 0·026), with similar HLA Ab frequency (100%) in both groups. Discussion: Incidence of 7% found is within the range(75%–34%) described by literature. Non‐immune factors such as fever and antibiotics were main cause found present in more than 80% of cases and immune causes were mainly associated with HLA antibodies as expected. Interestingly, no anti‐HPA‐1a antibodies were identified, the most common specificity described in other populations. However, anti‐HPA‐5b and anti‐HPA‐3b antibodies were detected. This finding suggests that possible unidentified factors would lead to a distinct pattern of platelet alloimmunization as previously described for fetal‐neonatal alloimmune thrombocytopenic purpura in Brazil.