Adaptation of ISTH Guidelines on Vaccine Induced Thrombocytopenic Thrombosis to Clinical Practice and Analysis of Patient Cases

The International Society on Thrombosis and Haemostasis (ISTH) published guidelines for the diagnosis and treatment on Vaccine-Induced Thrombotic Thrombocytopenia (VITT) in April of 2021. Guidelines were inclusive of those persons at risk for VITT, screening, initial evaluation, and treatment. A study was conducted to evaluate case reports of patients with VITT in regard to diagnostic testing and treatment options as recommended by the ISTH. Ten case reports were identified employing the PubMed database where VITT was diagnosed in patients who received the Astra Zeneca vaccine. The average fibrinogen level was 166.9 mg/dL, the average platelet count was 47.2 x 10 9 /L, and the average D-Dimer level was 39.3 mg/L. All cases of VITT exhibited a positive anti-PF4 assay. Anticoagulants administered to patients varied across cases however all patients received IVIG to increase platelet counts in patients. A one sample t test was performed to ascertain if statistical significance was present comparing average fibrinogen, platelet count, and D-Dimer levels to normal values. Statistical significance was found with platelet count and D- Dimer parameters. Organizations like the ISTH has provided timely therapeutic information and guidance to clinicians in combating SARS-CoV2 related clinical manifestations. These findings serve to illuminate the nexus between ISTH VITT guidelines and clinical adaptation.