Page 1 of 1: platelet abnormalities most likely be found in this child?

mdali007 · Credits: 5763 My Scrapbook

A 10 year-old child develops prolonged bleeding following a dental extraction. The child is referred to a hematologist; evaluation of the child's hematologic parameters demonstrates a prolonged partial thromboplastin time and an elevated bleeding time. Which of the following platelet abnormalities would most likely be found in this child?

Options:bdi

A. Abnormal platelet morphology.

B. Impaired platelet adhesion.

C. Impaired platelet primary aggregation.

D. Impaired release of platelet vesicles.

E. Impaired secondary aggregation of platelets.

dosha · Credits: 365 My Scrapbook

ans is B

mdali007 · Credits: 5763 My Scrapbook

dosha is right

The correct answer is B.

This child probably has autosomal dominant von Willebrand's disease, in which an abnormal von Willebrand's factor (which also carries factor VIII in the blood) causes a defect in the initial adhesion of normal platelets to a damaged vessel wall. Since factor VIII levels are also consequently low, the partial thromboplastin time is also prolonged. Defects in platelet adhesion are also seen in Bernard-Soulier disease.

Abnormal platelet morphology (choice A) is not seen in von Willebrand's disease, but may be observed with infiltration of the bone marrow by tumor or fibrosis, or after splenectomy.

Defects in primary platelet aggregation (choice C) are seen in thrombasthenia, which is caused by a deficiency or defect in the glycoprotein GpIIb-IIIa complex.

Defects of release of platelet vesicles (choice D) or secondary aggregation (choice E) are seen in storage pool disease and aspirin use.

		Sign In New User? Sign Up Sign in to access your control panel and messenger!
				TechZone \| SpiderNevi \| HowTo? \| Scrapbook!