Clinical relevance of iron deficiency anemia and thrombocyctosis in hereditary hemorrhagic teleangiectasia (HHT)

Introduction 

It has been shown that patients with hereditary hemorrhagic teleangiectasia (HHT) and pulmonary arteriovenous malformations (PAVM) are at higher risk for the development of (septic) thrombi. Many HHT patients also suffer from recurring bleeding and consecutive iron deficiency anemia. The latter often concurs with thrombocytosis which can further favour the development of thrombi in non-HHT patients. This study examined whether these correlations could also be verified for patients with HHT. 

Methods 

Patients who fulfilled at least 3 Curaçao criteria or who had tested positive for HHT in moleculargenetic diagnostics routinely received blood tests on presentation in our Morbus Osler Centre (including workup for anemia and iron levels). Thromboembolic events were recorded as well.

Results 

45.7% (112/245) of patients had a microcytic anaemia (average haemoglobin level: 12.7 g/dl ± 7.5; N = 245) and 58/245 patients (23.6%) showed a thrombocytosis (average thrombocyte level 272 ± 90/nl, N = 245). There was a significant correlation between rising thrombocyte levels and declining serum iron levels (p = 0.022). Thrombocytosis occurred more frequently in cases of microcytic anaemia (p = 0,004), but didn’t lead to a higher risk of thromboembolic events (OR = 0.77; 95%-confidence interval 0.39-1.52). Patients with PAVM (N = 70/245, 28.6%) had a higher risk for cerebral thromboembolic events (p < 0.001) but not for peripheral thromboembolic events, e.g. deep vein thrombosis.

Discussion 

In HHT patients, thrombocytosis often occurs in patients with microcytic anaemia. However, PAVM are the only significant risk factor for cerebral thromboembolic events.

Publication History

Article published online:
24 May 2022