MICROWAVE TREATMENT OF SERUM FACILITATES DETECTION OF HEPATITIS-B VIRUS-DNA BY THE POLYMERASE CHAIN-REACTION - RESULTS OF A STUDY IN ANTI-HBE POSITIVE CHRONIC HEPATITIS-B

Investigation by polymerase chain reaction of HBV-DNA in serum from ch ronic hepatitis B virus carriers is not widely used for routine diagno sis because polymerase chain reaction assays are complex and may be to o sensitive, We investigated the sensitivity, the specificity and the possible value for clinical use of a simplified polymerase chain react ion method in which a single, 30 cycles round of polymerase chain reac tion is performed using only 10 mu l of serum treated with microwaves. The efficiency of the polymerase chain reaction in amplifying HBV-DNA was greater after microwave irradiation of serum than after alkaline extraction, but lower than after protein digestion and phenol chlorofo rm precipitation, Despite its simplicity and high sensitivity, the ass ay was very specific, Studies in anti-HBe positive chronic hepatitis B virus carriers demonstrated HBV-DNA sequences in 1/15 (7%) healthy ca rriers, in 4120 (20%) patients with slight alanine aminotransferase el evation, in 16/18 (89%) with-marked alanine aminotransferase elevation and in all 20 with fluctuating alanine aminotransferase levels. In th e latter, HBV-DNA was detected either at exacerbation (two cases), dur ing remission (one case) or both (17 cases). HBV-DNA was detected by c lassical dot-blot hybridization in only 24/58 (41%) samples that were positive by the simplified polymerase chain reaction method. Although extremely high sensitivity is not achieved, microwave irradiation of s erum simplifies considerably the detection of small amounts of HBV-DNA and makes polymerase chain reaction suitable for monitoring patients in whom weak hepatitis B virus replication is associated with ongoing liver disease.