Evaluation of the effectiveness of platelet crossmatching by the solid-phase red cell adherence assay in adult patients of a tertiary care hospital in Thailand: A retrospective study.

Background and Aims: Platelet transfusion refractoriness is well aware to be associated with poor clinical outcomes. Patients with the alloantibody causing refractoriness required cross-matched compatible products to improve the platelet number. This study aims to evaluate the effectiveness and availability of platelet crossmatching provided by the solid-phase red cell adherence (SPRCA) technique in the context of a tertiary university hospital. Methods: A retrospective chart review was performed of the records of 214 patients with platelet refractoriness in Siriraj Hospital, a tertiary university hospital in Thailand, between January 1, 2017, and December 31, 2020. Results: The SPRCA technique successfully provided cross-matched compatible platelets to 114 patients (69.7%). Platelet crossmatching significantly improved the platelet counts, as shown by the increased 1- and 24-h corrected-count increments (p< 0.0001). No acute transfusion reactions were observed in these patients. Of the 114 patients who received cross-matched platelets, 82 patients (71.9%) survived at 30-day posttransfusion; whereas, 16 patients (14.0%) died within 7-day posttransfusion. Conclusion: The SPRCA method can provide a high availability rate of cross-matched platelets, which is effective at stopping and preventing clinical bleeding conditions. This method is appropriate to apply for platelet crossmatching in the context of a hospital blood bank.

Major Histocompatibility Complex Class I Chain-Related A and B (MICA and MICB) Gene, Allele, and Haplotype Associations With Dengue Infections in Ethnic Thais.

BACKGROUND: Major histocompatibility complex class I chain-related (MIC) A and B (MICA and MICB) are polymorphic stress molecules recognized by natural killer cells. This study was performed to analyze MIC gene profiles in hospitalized Thai children with acute dengue illness. METHODS: MIC allele profiles were determined in a discovery cohort of patients with dengue fever or dengue hemorrhagic fever (DHF) (n = 166) and controls (n = 149). A replication cohort of patients with dengue (n = 222) was used to confirm specific MICB associations with disease. RESULTS: MICA*045 and MICB*004 associated with susceptibility to DHF in secondary dengue virus (DENV) infections (odds ratio [OR], 3.22; [95% confidence interval (CI), 1.18-8.84] and 1.99 [1.07-2.13], respectively), and MICB*002 with protection from DHF in secondary DENV infections (OR, 0.41; 95% CI, .21-.68). The protective effect of MICB*002 against secondary DHF was confirmed in the replication cohort (OR, 0.43; 95% CI, .22-.82) and was stronger when MICB*002 is present in individuals also carrying HLA-B*18, B*40, and B*44 alleles which form the B44 supertype of functionally related alleles (0.29, 95% CI, .14-.60). CONCLUSIONS: Given that MICB*002 is a low expresser of soluble proteins, these data indicate that surface expression of MICB*002 with B44 supertype alleles on DENV-infected cells confer a protective advantage in controlling DENV infection using natural killer cells.

HLA Class I Supertype Associations With Clinical Outcome of Secondary Dengue Virus Infections in Ethnic Thais.

BACKGROUND: Human leukocyte antigen (HLA) supertypes are groups of functionally related alleles that present structurally similar antigens to the immune system. OBJECTIVES: To analyze HLA class I supertype associations with clinical outcome in hospitalized Thai children with acute dengue illness. METHODS: Seven hundred sixty-two patients and population-matched controls recruited predominantly in Bangkok were HLA-A and -B typed. HLA supertype frequencies were compared and tested for significant dengue disease associations using logistic regression analyses. Multivariable models were built by conducting forward stepwise selection procedures. RESULTS: In the final logistic regression model, the HLA-B44 supertype was protective against dengue hemorrhagic fever (DHF) in secondary infections (odds ratio [OR] = 0.46, 95% confidence interval [CI], .30-.72), while the HLA-A02 supertype (OR = 1.92, 95% CI, 1.30-2.83) and the HLA-A01/03 supertype (OR = 3.01, 95% CI, 1.01-8.92) were associated with susceptibility to secondary dengue fever. The B07 supertype was associated with susceptibility to secondary DHF in the univariate analysis (OR = 1.60, 95% CI, 1.05-2.46), whereas that was not retained in the final model. CONCLUSIONS: As the HLA-B44 supertype is predicted to target conserved epitopes in dengue, our results suggest that B44 supertype-restricted immune responses to highly conserved regions of the dengue proteome may protect against secondary DHF.