High thrombotic burden in severe Chinese wAIHA patients: a single-center retrospective study

OBJECTIVE: Patients with warm autoimmune hemolytic anemia (wAIHA) have an established high risk of thrombosis. However, emerging data from Asia, particularly a recent Japanese study, challenge this paradigm. This study aimed to characterize thrombotic events and identify associated risk factors in a cohort of Chinese patients with wAIHA. METHODS: Retrospective analysis of 32 wAIHA patients admitted to Wuhan Hospital of Traditional Chinese and Western Medicine (2020–2024). RESULTS: The cohort comprised 32 wAIHA patients with a median age of 65 years and follow-up of 27 months, comprising 24 (75%) newly diagnosed and 8 (25%) relapsed cases, of which 53% were primary and 47% secondary. After treatment, 19 patients achieved clinical remission, 12 had partial remission, and 1 died from pulmonary embolism. Eight patients (25%) experienced 12 thrombotic events during acute hemolysis: deep vein thrombosis (5), pulmonary embolism (3), acute cerebral infarction (2), disseminated intravascular coagulation (1), and lower limb arterial embolism (1). Comparative analysis showed thrombotic patients had relatively lower hemoglobin (55.88 g/L vs. 74.87 g/L, p = 0.031) and higher lactate dehydrogenase (1064 U/L vs. 439 U/L, p = 0.045) than non-thrombotic patients. No significant differences were found in platelet count, D-dimer, antinuclear antibody, or Padua scores. Significant differences were noted in therapeutic anticoagulation (p < 0.001) and therapeutic plasma exchange (p = 0.023), but not in prophylactic anticoagulation (p = 0.250). CONCLUSIONS: In Chinese wAIHA cohort, thrombosis during acute hemolysis was common and linked to markers of severe disease (low hemoglobin, high LDH, plasma exchange). This distinct high-thrombosis phenotype indicates potential limitations of standard risk tools, necessitating prospective studies for tailored risk stratification and thromboprophylaxis evaluation in this population.