A new study from Serbia has confirmed that anti-HPA-1a remains the most prevalent antibody detected in cases of fetal and neonatal alloimmune thrombocytopenia (FNAIT), reinforcing findings from across Europe and providing the first such data from the Serbian population.
The study, published in the journal Medicina, tested 259 patients with suspected immune-mediated platelet disorders at the Blood Transfusion Institute of Vojvodina in Serbia. While overall antibody positivity across the cohort was 27.8%, the rate was notably higher among the 11 patients with suspected or confirmed FNAIT, reaching 72.7%, with anti-HPA-1a accounting for 75% of those cases, consistent with the 75–80% prevalence reported in previous studies of Caucasian populations.
The high prevalence of anti-HPA-1a is consistent with its well-established biology. The antigen it targets is present in exceptionally high numbers on platelet surfaces, making it a potent trigger of immune response.
Learn more about FNAIT causes and risk factors
Additionally, the tendency to develop anti-HPA-1a antibodies is strongly linked to the HLA-DRB3*01:01 allele, a specific genetic variant found in more than 90% of immunized women of European descent, which helps explain why this antibody appears so consistently across Caucasian populations, and why studies from different European countries, including this one from Serbia, continue to report similar findings.
The authors highlighted that their findings carry significant implications for the diagnosis and management of FNAIT, particularly in Serbia and the surrounding region. They noted that the high frequency of anti-HPA-1a antibodies supports the introduction of antenatal screening programs to identify HPA-1a incompatibility in pregnant women, an approach already explored in several European countries, including the Netherlands.
The researchers emphasized that such screening could enable doctors to detect at-risk pregnancies early and intervene promptly, for example, by administering intravenous immunoglobulin during pregnancy or planning an earlier delivery.
“Future prospective studies with larger cohorts, particularly in NAIT and platelet transfusion refractoriness, are warranted to validate these findings and to further evaluate their impact on clinical outcomes and transfusion strategies,” the researchers noted.
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