On Monday, Johnson & Johnson and US regulators said the company has recalled some blood tests for hepatitis B virus because they may give false negative results. The affected products, which were distributed in the United States and Europe, have been replaced, said Mary Richardson, spokesperson for the Johnson & Johnson's Ortho-Clinical Diagnostics unit. The problem has been discovered in three lots of the Vitros Immunodiagnostic HBsAG Confirmatory Kit, Richardson said. An unknown component in the diluting solution may produce a false negative result for samples that initially tested positive. Johnson & Johnson is not aware of any cases in which an incorrect result was given to a patient, said Richardson. The company is asking health care facilities and agencies that received the recalled tests to review previous results. For more information, visit www.fda.gov/medwatch/safety/2006/safety06.htm#vitros.