Lyme borreliosis

Lyme borreliosis

initiated without previous counselling and risk assessment. We believe that such practice should be strongly discouraged and might be regarded as negl...

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initiated without previous counselling and risk assessment. We believe that such practice should be strongly discouraged and might be regarded as negligent were a child to be born with CF. The members of the European Community Concerted Action for Cystic Fibrosis thus recommend that all patients with CBAVD be counselled about the specific genetic risks involved in the application of assisted reproductive techniques to their condition. Testing for mutations in the CFTR gene should be explicitly offered, and the importance of identifying unsuspected heterozygosity in the partner explained. For those couples at high risk (25 or 50%) of having a CF child, prenatal diagnosis (perhaps with preimplantation techniques) should be discussed. We thank the valuable contributions of the following members of the European Community Concerted Action for Cystic Fibrosis: E W F W Alton (London); C Bombieri (Verona); M Bonduelle (Brussels); J-J Cassiman (Leuven); M Claustres (Montpellier); B Costes (Paris); H Cuppens (Leuven); A Hill (Belfast); E Mayall (London); P Middleton (London); L Osborne (London); P F Pignatti (Verona); M Schwartz (Copenhagen); and H Veese (Rotterdam).

has been B afzelii

possible to establish a link between infection with (also named B burgdorferi group VS461) and the occurrence of prolonged erythema migrans and acrodermatitis chronica atrophicans.2,5 Among our patients with disseminated Lyme borreliosis from whom spirochaetes were cultured, infections were always caused by B garinii. Further study of B burgdorferi sensu lato strains isolated from patients with various clinical symptoms of Lyme disease might elucidate the pathogenesis of Lyme borreliosis. P van Dam, Herman Jacob Dankert

Alje

Kuiper, Lodewijk Spanjaard,

Department of Medical Microbiology, University of Amsterdam, 1005 AZ Amsterdam, Netherlands; and Department of Neurology, Flevo Hospital, Almere

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D Meschede, J Horst, C Williams, R Williamson Institute of Human Genetics of the University, Munster, Germany; and Department of Biochemistry and Molecular Genetics, St Mary’s Hospital Medical School, London W2 1PG, UK

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1

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Berger BW, Johnson RC, Kodner C, Coleman L. Cultivation of Borrelia burgdorferi from erythema migrans lesions and perilesional skin. J Clin Microbiol 1992; 30: 359-61. Van Dam AP, Kuiper H, Vos K, et al. Different genospecies of Borrelia burgdorferi are associated with distinct clinical manifestations in Lyme borreliosis. Clin Infect Dis 1993; 17: 708-17. Kuiper H, Van Dam AP, Spanjaard L, et al. Isolation of Borrelia burgdorferi from skin biopsy specimens taken from healthy-looking skin of patients with Lyme borreliosis. J Clin Microbiol 1994; 32: 715-20. Pollack RJ, Telford SR III, Spielman A. Standardization of medium for culturing Lyme disease spirochetes. J Clin Microbiol 1993; 31: 1251-55.

Culard J-F,

Desgeorges M, Costa P, et al. Analysis of the whole CFTR coding regions and splice junctions in azoospermic men with congenital aplasia of epididymis or vas deferens. Hum Genet 1994; 93:

467-70. Meschede D, Eigel A, Nieschlag E, Horst J. Screening for CFTR mutations in patients with congenital bilateral aplasia of the vas deferens. Am J Hum Genet 1993; 53: A1153. 3 Oates RD, Amos JA. The genetic basis of congenital bilateral absence of the vas deferens and cystic fibrosis. J Androl 1994; 15: 1-8. 4 Osborne LR, Lynch M, Middleton PG, et al. Nasal epithelial ion transport and genetic analysis of infertile men with congenital bilateral absence of the vas deferens. Hum Molec Genet 1993; 2: 1605-09. 5 Williams C, Mayal ES, Williamson R, Hirsch A, Cookson H. A report on CF carrier frequency among men with infertility owing to congenital absence of the vas deferens. J Med Genet 1993; 30: 973.

Canica MM, Nato F, Du Merle L, Mazie JC, Baranton G, Postic D. Monoclonal antibodies for identification of Borrelia afzelii ap nov associated with late cutaneous manifestations of Lyme borreliosis.

Scand J Infect Dis 1993;

25: 441-48.

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Lyme borreliosis SiR-Pfister and colleagues (April 23, p 1013) emphasise the importance of serology in establishing the diagnosis of Lyme disease. However, culture of the causative organism Borrelia burgdorferi definitely establishes the diagnosis. Culture yields from body fluids are low, but those from skin biopsy specimens of patients with erythema migrans can be over 85%.1,2 Moreover, we have succeeded in culturing spirochaetes from biopsy specimens from healthy-looking skin of patients with disseminated Lyme disease.3 These specimens had been taken at the site of preceding erythema or a preceding tick-bite, up to six months after disappearance of the lesion. Whether this finding represents persistent local infection or widespread cutaneous dissemination of spirochaetes is still under investigation. Although culture of B burgdorferi is only possible in specialised laboratories, efficient transport of specimens in BSK medium from a distant site has been described.’ The availability of a standardised, commercially available culture medium4 will probably soon facilitate culture of B burgdorferi at more laboratories. Importantly, culture spirochaetes from patients with Lyme disease gives the possibility of studying the relation between the clinical presentation of Lyme borreliosis and the three genospecies of B burgdorferi sensu lato. By contrast with the situation in the USA, where only B burgdorferi sensu stricto is found, all three genospecies of B burgdorferi sensu lato occur in Europe. By culture of spirochaetes from patients, it

Targeting breast

cancer

tumours

SIR-Your April 30 editorial on breast cancer confuses the response of the National Cancer Institute to the discovery of flaws in the National Surgical Adjuvant Breast and Bowel Project (NSABP) data with the response of tumours to treatment. From "the suspension of new patient recruitment in fourteen studies being co-ordinated by the NSABP’ through "bad news for other trials" the reader is led to "any attempt to divert funds away from randomised trials to nonrandomised studies would be rank foolishness". What is the evidence for this last statement? Randomised trials have shown that variation in the local treatment does not affect the eventual outcome and that adjuvant treatments cure some patients. The enormous numbers needed to show a modest improvement mean that the particular tumours that benefited cannot be identified to guide further progress. Proper randomisation needs groups of patients with relevant common factors; the treatment should be the only variable. Survival in breast cancer depends on the presence or absence of metastasis. Patients without metastases will be cured by any satisfactory local procedure and those who have distant spread will not. We cannot identify metastases that are smaller than about 10 mm in diameter (roughly 109 cells or resulting from about twenty-nine doublings of volume from a single cell). We are ignorant of the presence of a metastasis over a range which represents three-quarters of its life span. Breast cancers have a very wide range of growth rates. The timing of clinical detection of metastasis will depend on starting size and growth rate, as well as the site. These variables are unknown at the time of randomisation, yet exert far more influence than any meagre effect of treatment. I presented a poster at the Lancet conference on breast cancer in April,’ showing growth rates extrapolated from measurement of the shrinkage of tumours in response to neoadjuvant therapy.2 Women with subclinical metastasis from rapidly growing tumours will appear in the clinic before 1567