A modified, solid phase radioimmunoassay for the differential diagnosis of acute and convalescent phases of hepatitis A infection.
The commercial assays for diagnosing the presence of hepatitis A antibodies (HAVAB; Abbott Laboratories, North Chicago, IL) or the presence of IgM class anti-hepatitis A virus antibodies (HAVAB-M; Abbott) do not provide precise information as to the timing of the acute infection. IgM class antibodies are detected as late as six months after the acute infection. In this study the authors describe a modified HAVAB test that inactivates the IgM class antibodies. It thus measures the proportion of IgG antibodies out of the total anti-hepatitis A virus antibodies. In a study of 139 patients with impaired liver function, the available and modified tests showed good agreement except for the convalescent phase of hepatitis A. During serial testing for three months after the acute infection, the commercial tests continuously detected IgM class antibodies. The modified test detected predominantly IgG class antibodies from four weeks on. By six weeks, 85% of the patients had predominantly IgG class antibodies. The modified test thus provides information on the timing of recent hepatitis A infection.
Rabinowitz
M
M
Blood Banks, Ichilov Hospital, Tel Aviv Medical Center, Israel.
Hallak
A
A
Grunberg
J
J
Levy
Y
Y
Gilat
T
T
D000208:Acute Disease; D003937:Diagnosis, Differential; D006506:Hepatitis A / Q000175:diagnosis* / Q000276:immunology; D006508:Hepatitis Antibodies / Q000032:analysis; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D011863:Radioimmunoassay; D013997:Time Factors
D006508:Hepatitis Antibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M