Platelet Phagocytosis by Neutrophils, Platelets Lack of Granules and Giant Platelets Result in Pseudothrombocytopenia

Abstract

Pseudothrombocytopenia (PTCP) is a condition in which the decreased platelet count does not agree with the clinical status of the patient, can lead to misdiagnose, unnecessary tests, unnecessary treatment. The present case describes a 73-year-old man suffered with pulmonary tuberculosis, treated with anti-tuberculosis therapy (isoniazid, rifampicin, pyrazinamide, ethambutol, 2HRZE/4HR). One month later, the patient had a significant decrease in platelets (101 to 56 x109/L). Peripheral blood smear showed that 28% platelets were phagocytosis by neutrophils, 26% platelets were lack of granules and 6% platelets’ volume increased significantly. When the anticoagulant was changed from EDTA to sodium citrate, there was no change in the above phenomenon. By manual count, the value of platelets was 113 x 109/L. After the completion of anti-tuberculosis therapy, platelet morphology gradually returned to normal. HRZE treatment may cause platelet morphology abnormal, resulting in PTCP. In such cases, we should regularly review the peripheral blood smear to ensure the accuracy of the results and avoid unnecessary examination and treatment. The emergence of PTCP may does not mean the presence of specific disorders.