Comparison of clinical characteristics and outcomes of immune thrombocytopenia in Chinese Han children living at high altitude and sea level

Exposure to high altitude can lead to hypobaric hypoxia, which triggers adaptive hematological responses in humans. We examined clinical variation in pediatric immune thrombocytopenia (ITP) across two attitudinally distinct regions and evaluated the influence of altitude on disease outcomes. The study included 156 Chinese Han children with ITP: 68 in the high-altitude group (ALT, Xining City) and 88 in the sea-level group (SEA, Ningbo City). Children in the ALT group were older and presented with higher bleeding grades compared to those in the SEA group. Multivariate logistic regression showed that older age was associated with a significantly greater risk of a prolonged disease course. In contrast, patients who achieved complete response (CR) within 7 days of treatment, as well as those in the ALT group, were less likely to develop a prolonged course. These findings highlight altitude as a potential modifier of pediatric ITP outcomes and warrant further investigation into the underlying mechanisms.