Hello. I am Dr. Jonathan Kay, Professor of Medicine and Director of Clinical Research in the Division of Rheumatology at UMass Memorial Medical Center and the University of Massachusetts Medical School, both in Worcester, Massachusetts. Welcome to my Medscape blog.
Today I would like to share with you an interesting case that I encountered on the inpatient consultation service. This was a 50-year-old man with a history of hepatitis C viral infection and mixed cryoglobulinemia who presented with palpable purpura on his lower extremities. At the time of admission, his cryocrit was 7%, but the serum revealed no detectable hepatitis C viral mRNA by polymerase chain reaction (PCR). As a result, the infectious disease service recommended against treating for hepatitis C virus infection, and the team decided to treat the patient with prednisone, initially beginning at a dose of 80 mg orally once daily. Despite prednisone therapy, the patient progressed, and his cryocrit rose to 12%. We were consulted, and we recommended that the patient be treated with antiviral therapy.
This decision was based on a 1992 New England Journal of Medicine article by Vincent Agnello and colleagues, who showed that the hepatitis C virus is concentrated 1000-fold within the cryoglobulin compared with the plasma. From this patient, blood was obtained, which clotted at room temperature, and cryoglobulins would have been consumed within the clot. Testing his serum for hepatitis C viral mRNA by PCR would be unrevealing because any hepatitis C virus that was consumed within the cryoglobulin would be contained within the clot and not within the serum. We had the team obtain cryoglobulin, which was then prepared, washed, and sent to another laboratory for PCR testing to determine whether the cryoglobulin itself contained hepatitis C virus. Presumably, because hepatitis C virus is a polyclonal activator of B cells, this virus is driving the patient's cryoglobulin production and, hence, its clinical manifestations. We recommended empiric treatment for hepatitis C virus infection pending the results of this assay. I hope to see this patient improve and will inform you of the patient's progress in a subsequent blog on Medscape.
Thank you very much for your attention.
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Cite this: Is This Patient's Cryoglobulin Hiding Something? - Medscape - May 21, 2014.