2008-12-07

The goal of the Minority Medical Student Award Program (MMSAP) is to increase the number of medical students in hematology from under-represented minority groups by introducing them to hematology in their early years of medical school. ASH News Daily is pleased to share a summary of the research conducted by current MMSAP participant Jamie Brewere in the summer of 2008. Her research mentor was Anaadriana Zakarija, MD, of Northwestern University.

Background

Hemophilia A is a disease of the blood clotting system in which there is a deficiency of factor VIII, an essential clotting factor. When factor VIII is deficient or absent there is an increased risk of bleeding. Treatment of hemophilia A can be made more difficult if the patient has an allo-antibody, referred to as an inhibitor, to factor VIII. This summer’s research experience focused on recruiting patients diagnosed with hemophilia A and testing their blood samples for the presence of inhibitors using the standard Bethesda assay and a newer test, the factor VIII inhibitor ELISA assay.

Method

Patients with hemophilia A were recruited for participation in this study. Participation in the study included a blood draw, completion of questionnaires, and joint range of motion measurements. The questionnaires used in this study collected demographic and clinical information. They also included the Hemophilia Activities List questionnaire to help determine the effect each subject’s hemophilia had on his or her ability to complete everyday activities.

Outcomes

In a study of 23 subjects, all tested for inhibitors with Bethesda assay and ELISA assay, 11 subjects were found to have inhibitors by ELISA assay. However, no subjects were found to have an inhibitor by Bethesda assay. Seventeen subjects had severe hemophilia, two with moderate hemophilia and five with mild hemophilia. Fifteen subjects were HIV-positive, and 22 subjects were Hep-C positive.

Within the subjects that had detectable inhibitors by ELISA assay, 10 had severe hemophilia and one subject had mild hemophilia. Seven subjects were HIV-positive, and 10 subjects were Hep-C positive. There was not a significant difference in age, HIV infection, or Hepatitis C infection between the two groups. The group with detectable factor VIII inhibitors had a higher number of factor VIII infusion over the prior six-month period (48 vs. 17), as compared to the group without an inhibitor.

Conclusion

The GTI factor VIII ELISA detected inhibitors in 48 percent of patients with hemophilia A who had undetectable inhibitor by standard Bethesda assay.

The presence of an inhibitor was associated with more frequent exposure to factor replacement in the six months prior to study enrollment. The clinical significance of these factors is not yet known.

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