In Response (Letter 1).

We thank Drs Vuorio, Kaste, and Kovanen for their comment on our report on Cerebral Venous Sinus Thrombosis in COVID-19 Patients: A Multicenter Study and Review of Literature .

We acknowledge that serum lipoprotein(a)(Lp(a)) merits inclusion in future studies for cerebral venous sinus thrombosis (CVST) patients given the growing evidence of arterial and venous thromboembolic complications in patients with COVID-19 infections.

While elevated Lp (a) has been established as a risk factor of coronary heart disease and stroke, findings concerning the related risk in CVST is limited to one case series of 80 patients , with higher risk of recurrent CVST noted in patients with higher Lp(a) levels. Moreover, the relationship between Lp (a) and systemic venous thromboembolism events (VTE) in adults are contradictory.  Vormittag et al. found no association between Lp (a) and VTE when they compared 128 patients with spontaneous symptomatic deep vein thrombosis, 105 with spontaneous symptomatic pulmonary embolism and 122 healthy controls . Kunutsor et al. suggested that Lp(a) is not prospectively associated with VTE risk when they studied plasma Lp(a) concentrations to the incidence of VTE in 2,180 men. One patient of our 8 patient's series with COVID-19 infections and CVST (12.5%) had hyperlipidemia.

We agree additional research evaluating the relationship between Lp (a) and CVST would be of high interest in better understanding the pathogenesis of this disease and we thank the authors for highlighting this relative gap in our current knowledge.

Sincerely,

Declaration of Competing Interest

None