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nephritis, 7-8% had HBAg in their serum, compared with 0.2% in healthy people. Pedreira and his colleagues also studied the subtypes of HBAg in the serum of their 8 HBAg-positive patients and found the ad subtype predominantly. In our glomerulonephritis series, however, 7 HBAg-positive patients (41 %) had the ay subtype, and 10 (59%) had the ad subtype. This is not significantly different from our findings in 44 hepatitis patients, 21 of whom (48%) had the ay subtype and 23 (52%) the ad subtype. These proportions are also comparable with those found in 605 healthy carriers.4 We agree with Conte and Foumi61 that, in order to elucidate the role of HBAg in glomerulonephritis, it is necessary: (i) to trace HBAg in the circulating immune complexes through either a radioimmunoassay or electron microscopy 5; (ii) to show the presence of HBAg in the lesions by immunofluorescence 8; and (iii) as we mentioned in our previous article, to search systematically for histological evidence of renal lesions in patients with HBAg-positive hepatitis and even in healthy HBAg carriers.
M. F. REZNIKOPF-ETIEVANT G. LAGRUE Laboratoire d’Hémobiologie, Service de Néphrologie, Hôpital Henri Mondor, 94 Creteil, France.
J. P. MORETTI R. SYLVESTRE G. HIRBEC.
There may be a positive correlation between the presence of hepatitis-B antigen and serological evidence of syphilis, and both infections might be transmitted in comparable ways. Our results give no information about the role of sexual transmission in the spread of the disease. I wish to thank Mr J. Dierickx and Mrs L. Brants for us the sera positive for syphilis tests.
obtaining
for
Institute of
Hygiene and Epidemiology, Juliette Wytsmanstraat 14, B-1050 Brussels, Belgium.
R. VRANCKX.
HEPANOSTICON IN SCREENING FOR
HBsAg SIR,—We read with interest the letter by Dr Chicot and her colleagues (Feb. 8, p. 345), of the New York Blood Center, on the sensitivity and specificity of the reversed
passive hxmagglutination technique (’ Hepanosticon’). The sensitivity gain over counter electrophoresis, as found by Chicot et al. (38 % more positives), confirms our findings1 in another population (40% more positives). Confirmatory testing of presumptive positives by absorbing with sheep erythrocytes coated with normal sheep IgG (hepanosticon
erythrocyte
absorbent
[E.A.])
led Chicot
et
al.
to
the follow-
result: about 16% of the false positives (0-02% of the whole population) did not become negative after one of the absorption, and 4% of the true positives (