A Diagnostics & Imaging Week

The FDA has reported the recall of the Vitros Immuno-diagnostic HBsAg Confirmatory Kit made by Ortho-Clinical Diagnostics (Raritan, New Jersey), saying that "an unknown component in the diluting solution used to test blood and serum samples may produce 'Not Confirmed' results for samples found to be positive with the initial test." The agency said this could cause some result to be classified as false negatives.

The HBsAg Confirmatory Kit is used to confirm the presence of Hepatitis B surface antigen in human blood and plasma that has initially been found to be reactive using the VITROS Immunodiagnostic Products HBsAg Reagent Pack .

The FDA said that the false negative results may prevent some patients infected with or carrying the hepatitis B virus from receiving necessary treatment.

"This is especially true for pregnant women whose tests show false negative results. When their fetuses are born, they will be presumed negative, and not treated with the HBIG (hepatitis B immunoglobulin) and hepatitis B vaccine. Such infants have a 90% chance of progressing to chronic hepatitis B virus infection resulting in possible liver transplantation or early death."

Ortho-Clinical sent letters to medical facilities, testing labs and public health agencies on Dec. 15, instructing customers to discontinue use and discard remaining inventory. In a separate Q&A sheet, the company recommends that previously reported results be reviewed.

The FDA classified the recall as Class I, the most serious type since there is a probability of serious injury or death.