258 Journal of Hepatology, 1993; 17:258-259 © 1993 Elsevier Scientific Publishers Ireland Ltd. All rights reserved. 0168-8278/93/$06.00

Letter to the Editor

HEPAT 01240

HBeAg in the absence of HBsAg

It is generally believed that patients seropositive for hepatitis B virus (HBV) e antigen (HBeAg) are always seropositive for HBV surface antigen (HBsAg) (1). In most patients who respond successfully to interferon-~z therapy, an hepatitic flare occurs followed by the loss of serum HBeAg and the development of antibody to HBeAg (anti-HBe) (2). We report an unusual serological profile in a girl with chronic HBV infection following steroid priming and interferon-or therapy.

A 7-year-old Vietnamese girl born to a mother with chronic HBV infection (HBsAg +, anti-HBe +) was found on routine screening to be seropositive for both HBsAg and HBeAg. Two of her three siblings were seropositive for anti-HBs and one was seronegative for all HBV markers. She was referred for consideration of interferon- ct therapy. Further investigations showed that she had mildly elevated serum aspartate transaminase (AST, 50-60 IU/1), was seropositive for HBV-DNA (244 pg/40/~1 serum by dot-blot hybridisation assay) and seronegative for both IgM anti-HBc and total antibody to hepatitis D virus (Abbott Diagnostics, Maidenhead, UK). Liver biopsy revealed chronic persistent hepatitis. Immunohistochemical staining of the liver sections using standard peroxidase anti-peroxidase technique showed the presence of cytoplasmic HBsAg (detected by monoclonal antibodies D2H5, kind gift of Professor R.S. Tedder and Dr. B. Ferns, London, UK), and pre-S1 (monoclonal antibody MA18/7, Professor W.H. Gerlich and Dr. K.H. Heermann, G6ttingen, Germany), as well as nuclear HBV core antigen (HBcAg) (rabbit polyclonal antibody, Dako, Bucks, UK) and HBeAg (monoclonal antibodies E2E6, Professor R.S. Tedder and Dr. B. Ferns) in around 10% of the hepatocytes. She was randomized to receive interferon-or with steroid priming: prednisone in tapering doses for 4 weeks (1, 0.75, 0.5, 0.25 mg/kg each for 1 week), no treatment for 2 weeks, and then lymphoblastoid interferon-c~ (5 MU/m 2, Wellcome Research Laboratories, Kent, UK) thrice weekly for 12 weeks. She remained well during the prednisone priming period. Four weeks after the commencement of interferon-or therapy, she developed a hepatitic flare. Six weeks after the start of interferon-or, her AST went up from 142 to 491 IU/I before falling to 136 IU/I at the end of treatment (Fig. I). This was accompanied by a

loss of serum HBV-DNA within 4 weeks of interferon- ct therapy. The serum HBsAg titre fell during therapy and she seroconverted to anti-HBs at the end of treat- ment. IgM anti-HBc was not detected during this period. She was well with normal serum AST, seropositive for anti-HBs and seronegative for HBV-DNA throughout follow-up. However, she remained strongly seropositive for HBeAg (reading 4730 cpm, negative control: 244 cpm, cut-off value: 512 cpm, radioimmunoassay, Abbott Diag- nostics) for another 5 months (with three serum samples during this period) and is presently seronegative for both HBeAg and anti-HBe, 11 months after the development of anti-HBs. A repeat liver biopsy at 1 year showed normal liver histology with no detectable HBsAg, pre- $I, HBcAg or HBeAg.

This girl developed an unusual serological profile during e-seroconversion, namely seropositivity for both

• 1:51200 I--

1:3200 -

m 1:400 - "I- :E

NEGATIVE In

HBeAg/Ab I

o....-.4 • \ 1-o, e

HmeAg

AntI-HBs +

2 0 0 HBVDNA 244 lit 71 0 0

5 0 0

I-- ~ 300

~ 200

m'" ~ x B x

,oo \ 1 ~O-O--O sa ~'-'-"--'- O o-..-O •

0 FEB JUN OCT FEB

1 9 9 0 1 9 9 1

Fig. I . Biochemical and serological profile of the girl before, during and after interferon-or therapy. AST, serum aspartate transaminase; ULN, upper limit of normal; Bx, liver biopsy; OT, oral treatment

(prednisone); IFNe, interferon-e therapy.

LETTER TO THE EDITOR 259

anti-HBs and HBeAg. The persistence of high levels of

HBeAg for 5 months after the development of anti-HBs suggested that this is unlikely to be due simply to a

difference in their half-lives. There are two possible

explanations. Firstly, a fragment of HBV genome which

contains the precore and core genome might have been

transiently integrated into the host genome with synthe-

sis and secretion of HBeAg (4,5). Alternatively,

interferon-or therapy may have induced the development

of a transient mutant virus which is defective in the

production of pre-S and HBsAg protein in a similar way

to the recently reported precore mutants with stop codon

for HBeAg (6). In the absence of surface proteins,

complete virion could not be formed and HBcAg/HBV-

DNA would have accumulated in the HBV-infected

hepatocytes while HBeAg was secreted since this process

has been shown to be independent of the formation of complete virion. If this hypothesis is true, the accumula-

tion of HBV genome/templates and HBcAg would have

initiated a second hepatitic flare. The absence of a

hepatitic flare in this girl before losing serum HBeAg is

in favour of the former hypothesis.

Johnson Y.N. Lau a, Heather M. Smith ", Helena M.

Daniels a, Roger Williams ~ and Giorgina Mieli-Vergani b

*Institute of Liver Studies and bDepartment of Child Health, King's College School of Medicine and Dentistry, London SE5, UK

References

I Hoofnagle JH, Schafer DF. Serological markers of hepatitis B virus infection. Semin Liver Dis 1986; 6: 1-10.

2 Perrillo RP. Treatment of chronic hepatitis B with interferon. Semin Liver Dis 1989; 9: 240-8.

3 Ou J, Laub O, Rutter WJ. Hepatitis B 8ene function: the precore region targets the core antigen to cellular membranes and causes

the secretion of the e antigen. Proc Natl Acad Sci USA 1986; 83: 1578-82.

4 Uy A, Bruss V, Gerlich WH, Kochel HG, Thomssen R. Precore sequence of hepatitis B virus including e antigen and membrane association of the viral core antigen. Virology 1986; 155: 89-96.

5 Alberti A. Do single nucleotide mutations result in clinically signifi- cant changes in hepatitis B virus pathogenicity? J Hepatol 1990; 10: 268-70.