Adding ELISA (enzyme-linked immunosorbent assay) testing to platelet antibody screening helped researchers in Taiwan detect more platelet antibodies than an older testing approach, according to a study published in Vox Sanguinis.
The findings may have implications for fetal and neonatal alloimmune thrombocytopenia (FNAIT), because the newer approach appeared to improve the detection of anti-CD36, an antibody that can cause FNAIT.
The analysis reviewed 36 years of data at MacKay Memorial Hospital, comparing a period when the hospital mainly used SPRCA with a later period when SPRCA and ELISA were used together. After ELISA was added, researchers detected platelet antibodies more often overall, and anti-CD36 detection increased 15-fold compared with the earlier testing period.
In FNAIT, identifying the antibody involved can help confirm the diagnosis, explain why the baby’s platelet count is low and guide treatment if a baby needs a platelet transfusion.
Read more about FNAIT testing and diagnosis
From 2019 to 2024, the hospital used both SPRCA and ELISA to screen 2,037 samples for platelet antibodies. Overall, 778 samples, or 38.19%, tested positive by at least one of the two methods. ELISA detected more positive samples than SPRCA, with positivity rates of 34.95% and 19.24%, respectively.
During that same period, researchers were able to identify the specific antibody in eight cases. Six were anti-CD36, including one FNAIT case. The other two were anti-HPA-5a and anti-HPA-5b, other platelet antibodies.
By comparison, from 1988 to 2018, when the hospital mainly used SPRCA, the test detected platelet antibodies in 2,800 of 9,268 samples, or 30.2%. Researchers also identified six earlier cases of neonatal alloimmune thrombocytopenia with specific platelet antibodies: two anti-HPA-3a, two anti-HPA-5a and two anti-CD36.
The study also described a possible case of post-transfusion purpura linked to anti-CD36, showing that the antibody may have serious effects beyond neonatal disease. The case involved a 79-year-old woman who developed severe platelet transfusion refractoriness and generalized purpura after massive transfusion. Investigators identified anti-CD36 on day 21 of hospitalization and started CD36-negative platelet transfusions the following day, but the patient died of multi-organ failure on day 29.
“It is important to use multiple methods simultaneously to enhance the detection of platelet antibodies,” the authors wrote, noting that the technical limitations of older, single-test approaches can lead to the underestimation of rare antibody types.
For FNAIT, the findings reinforce the importance of identifying the antibody involved, especially in populations where anti-CD36 may be more common than previously recognized. Better antibody detection could help guide diagnosis and transfusion decisions.
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