Seymour stick

Doubly virus-inactivated factor VIII concentrate in haemophilia A SiR-After letters describing outbreaks of hepatitis A among with haemophilia," we present our experience of a double virus-inactivated factor VIII concentrate. 5 children from our haemophilia centre with severe haemophilia A who were treated exclusively with the same commercial factor VIII concentrate (Criostat SD2, Instituto Grifols) were studied. The factor VIII has a specific activity of 10.1 IU factor VIII/mg protein and is doubly virus-inactivated by the solvent/detergent method and dry heat for 36 h at 60°C. All children (aged 2-7 years, median 3-8) were vaccinated against hepatitis B. They were treated over 3-2 years with an average of 3000 UI of factor VIII per year. None of the children has developed inhibitors against factor VIII. All are negative for hepatitis A, hepatitis B, hepatitis C, and the human immunodeficiency virus. During treatment, all alanine aminotransferase values were normal. The average ratio of CD4/CD8 H/S is 1 6

patients

(1-1-3-0). In all children, treatment with this factor VIII seems to be safe, and in the doses used the immunological system of the patients is unaffected. J M Chacon, R Quintana, G

Iruin, P Aragües

Haematology Service, Hospital de Cruces, Bilbao, Spain

J Corral Microbiology Service, Hospital 1

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de Cruces, Bilbao

Mannucci PM. Outbreak of hepatitis A among Italian patients with haemophilia. Lancet 1992; 339: 819. Gerritzen A, Schneweis KE, Brackman HH, et al. Acute hepatitis A in haemophiliacs. Lancet 1992; 340: 1231-32. Peerlinck K, Vermylen J. Acute hepatitis A in patients with haemophilia A. Lancet 1993; 341: 179. Temperley IJ, Cotter KP, Walsh TJ, et al. Clotting factors and hepatitis A. Lancet 1992; 340: 1466.

Sexual transmission of HCV SiR-Bresters and colleagues (July 24, p 210) report that none of 50 heterosexual partners of hepatitis C viraemic (HCV) patients had detectable anti-HCV or HCV-RNA by secondgeneration antibody assay and a polymerase chain reaction (PCR) assay. They conclude that the risk of sexual transmission of HCV is absent or low. By contrast, we have found that 8 of 38 spouses of HCV-infected patients had anti-HCV (second-generation), of whom 7 were HCV-RNA positive.1 False-positive PCR results were avoided by following the method described by Kwok and Higuchi;2 and no anti-HCV-negative serum Was positive for HCV-RNA. Direct evidence for sexual transmission is further provided by the very high homology in nucleotide sequences of HCV non-structural regions in four couples. To validate this finding, we sequenced amplified PCR products of the divergent HCV envelope region3 in one couple, and found 97-6% homology. The discrepancy between our finding and Brester and colleagues’ may be explained by the mean duration of sexual relationship (42 years compared with 13 years in Bresters’ series) and by the distribution of HCV genotypes, type 2 predominating in South-East Asia and type 1 in Europe and North America. Genotype has been claimed to be associated with the severity of chronic hepatitis and response to interferon-&agr;.4-6 Whether HCV type 2 has a better efficiency of transmission than type 1 and then causes a higher prevalence of sexual transmission in Taiwan and Japan awaits further studies. However, the possibility of infection through a common external source in areas with higher prevalence of HCV infection cannot be excluded. So, the role of sexual

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transmission in the epidemiology of HCV infection remains controversial, and a large-scale, long-term study is needed to resolve this important issue.

Jia-Horng Kao, Pei-Jer Chen, Ming-Yang Lei, Teh-Hong Wang, Ding-Shinn Chen Department of Internal Medicine, Graduate Institute of Clinical Medicine; and Hepatitis Research Center, National Taiwan University Hospital, Taipei 100, Republic of China

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Kao JH, Chen PJ, Yang PM, et al. Intrafamilial transmission of hepatitis C virus: the important role of infections between spouses. J Infect Dis 1992; 166: 900-03. Kwok S, Higuchi R. Avoiding false positive with PCR. Nature 1989; 339: 237-38. Kao JH, Chen PJ, Lai MY, Chen DS. Superinfection of heterologous hepatitis C virus in a patient with chronic type C hepatitis. Gastroenterology 1993; 105: 583-87. Pozzato G, Moretti M, Franzin F, et al. Severity of liver disease with different hepatitis C viral clones. Lancet 1992; 338: 509. Takada N, Takase S, Enomoto N, Takada A, Date T. Clinical backgrounds of the patients having different types of hepatitis C virus genomes. J Hepatol 1992; 14: 35-40. Yoshioka K, Kakumu S, Wakaji T, et al. Detection of hepatitis C virus by polymerase chain reaction and response to interferon-&agr; therapy: relationship to genotypes of hepatitis C virus. Hepatology 1992; 16: 293-99.

SIR-Bresters and colleagues report no sexual transmission of HCV in 50 heterosexual individuals, but such transmission is possible in certain uncommon situations. A 44-year-old woman’s only exposure to HCV was through unprotected intercourse with her 35-year-old male partner who had just been diagnosed with AIDS after a bout of Pneumocystis carinii pneumonia. She had no history of blood transfusions, intravenous drug abuse, or other parenteral risk factors. Although titres of serum HCV-RNA are probably generally low, immunodeficiency secondary to AIDS may allow the levels to rise to a point where transmission through intercourse is possible. The woman remains HIV seronegative after 18 months of testing.

Joseph Benezra 2350 Ocean Avenue, Brooklyn, NY 11229, USA

Seymour stick SIR-Pearce (July 3, p 62) and Blau (July 24, p 250) provide proof of the ingenuity of patients, in this case with Parkinson’s disease, in dealing with difficulties related to their disorder. They report walking aids, which were used as a means to overcome freezings. These, I presume English, patients had a special stick made. A Dutch patient I know has been using his old hockey stick in much the same manner for many years now. When he freezes, he turns the stick, steps over the tip and continues on his way. Try that with a cricket bat. M A

Kuiper

Department of Neurology, Free University Hospital, 1081 HV Amsterdam, Netherlands

Corrections The CRIB (clinical risk index for babies) score: a tool for assessing initial neonatal risk and comparing performance of neonatal intensive care units-The summary and methods section of this article by the International Neonatal Network (July 24, p 193) wrongly stated that mortality was compared in 1300 infants from the development and validation cohorts plus 248 other infants of birth weight 1500 g or less or gestational age less than 31 weeks. These figures should have been 1198 and 350, respectively. The number of infants in figure 3 should have been 1548, and not 1584 as in the

legend. Reversible endothelial dysfunction in epicardial coronary arteries-In this Commentary by A H Henderson and CJ H Jones (July 31, p 253), we introduced an error into line 20, which should read "restoration of the

endothelium-dependent component".