Safety of oral immunisation with recombinant urease in patients with Helicobacter pylori infection

patients with acute myocardial infarction. Low-dose thrombolytic therapy is one of the ways to prevent major haemorrhagic complications, especially catastrophic stroke, without losing a benefit of thrombolytic therapy in older patients. older

*Yoshinori L Doi, Hiromi Seo, Naohisa Hamashige, Takane Ohwaki, Taishiro Chikamori, for the Kochi Acute Myocardial Infarction (KAMI) Study Group Department of Medicine and Geriatrics. Kochi Medical School, Oko-cho, Nankoku-shi, Kochi 783, Japan

1 2

3

Reikvam A, Abdelnoor M. Thrombolytic therapy for acute myocardial infarction in older patients. Lancet 1996; 347: 840. Fibrinolytic Therapy Trialists (FTT) Collaborative Group. Indications for fibrinolytic therapy in suspected acute myocardial infarction: collaborative overview of early mortality and major morbidity results from all randomised trials of more than 1000 patients. Lancet 1994; 343: 311-22. Ketley D, Woods KL. Impact of clinical trials on clinical practice: example of thrombolysis for acute myocardial infarction. Lancet 1993; 342: 891-94.

Stress in

hospital consultants

SiR-Ramirez and colleagues (March 16, p 724)’ cite figures from my study of stress" in senior doctors and suggest that their findings are much lower than 47% of hospital consultants working in North Lincolnshire. Their findings of levels of stress averaging 27% in NHS hospital consultants seem flawed because of their rather odd choice of a threshold of four or more on the 12-item General Health Questionnaire (GHQ-12). The user’s guide to the GHQ3 reports the known validity studies of the GHQ-12. A threshold of three or more at most is suggested by the validity studies, and results of two studies have suggested that a threshold of two or more is appropriate. The user’s guide describes only one validity study out of five that would suggest a threshold of greater than three. Ramirez and coworkers’ choice of four or more requires explanation and suggests a considerable underestimate of the stress in the hospital consultants studied. It would seem appropriate to ask them to re-examine their figures with a more valid threshold. I also suggest that with the increasing number of studies in this area it would seem sensible to establish a consensus about which measures are most appropriate for such research so that valid comparisons can be drawn between studies. Richard Caplan Department of Psychiatry, Southern General Hospital, Glasgow G51 4TF, UK

1

2

3

Ramirez AG, Graham J, Richards MA, Cull A, Gregory WM. Mental health of hospital consultants: the effects of stress and satisfaction at work. Lancet 1996; 347: 724-28. Caplan RP. Stress, anxiety and depression in hospital consultants, general practitioners, and senior health service managers. BMJ 1994; 309: 1261-63. Goldberg D, Williams PA. User’s guide to the General Health Questionnaire. Windsor, Berkshire, UK: NFER, Nelson Publishing

Co, 1988.

Authors’

reply

SIR-One of the five validation studies of the GHQ-12 mentioned in the User’s Guide to the General Health Questionnaire found the optimum cutoff for estimating psychiatric morbidity to be four or more’ and others have found it to be three or more.2 In addition, a cutoff of four or more has recently been validated for use in NHS staff, including consultants, in a large study by the NHS workforce initiative. We were interested to compare the

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probable rate (27%) among consultants in the UK with the 31 % reported by medical students; and the 30% reported by junior doctors (Firth-Cozens J, University of Leeds, personal communication), with the same cutoff. In our study, we were careful to distinguish between levels of job stress rated on a scale of zero to four in response to the question "Overall how stressful do you find your work?" and psychiatric morbidity as estimated by the GHQ-12. Caplan seems to confuse these two concepts. In our study 41% of the 882 consultants reported job stress scores of three or four, while 27% had scores of four or more on the GHQ-12. As we have already highlighted, the estimated prevalence of psychiatric morbidity in our study is broadly similar to the prevalence of 21% recently reported among 374 Scottish consultants with with a cut-off of six or more.s

a

28-item version of the

GHQ

*Amanda Ramirez, Jill Graham, Michael A Richards, Ann Cull, Walter M Gregory *Psychosocial Oncology Programme, United Medical and Dental Schools of Guy’s and St Thomas’s Hospital Guy’s Hospital, London SE1 9RT, UK, and Western General Hospital, Edinburgh

1

Mari

2

651-59. Banks M. Validation of the General Health Questionnaire in community sample. Psych Med 1983; 13: 349-53.

3

4 5

J, Williams P. A comparison of the validity of two psychiatric screening questionnaires (GHQ-12 and SRQ-20) in Brazil, using relative operating characteristics (ROC) analysis. Psych Med 1985; 15: a

young

Borrill CS, Wall TD, West MA, et al. Mental health of the workforce in NHS Trust, phase I. Sheffield: University of Sheffield, and Leeds: Department of Psychology, University of Leeds, 1996. Firth J. Levels and sources of stress in medical students. BMJ 1986, 292: 533-36. Blenkin H, Deary I, Sadler A, Agius R. Stress in NHS consultants. BMJ 1995; 310: 534.

Safety of oral immunisation with recombinant urease in patients with Helicobacter pylori infection SiR-Immunisation is a promising approach to the control of Helicobacter pylori and its consequent peptic ulcers and gastric cancers. Urease, an essential virulence factor of H pylori, with no known strain variationhas been shown to be protective3 and curative4 against H felis infection in mice. An inflammatory infiltrate in the gastric corpus was observed after prophylactic immunisation.3 We determined the safety of recombinant, enzymatically-inactive H pylon urease in H-pylori-infected adults. 12 healthy adults (21-39 years, three women) with asymptomatic H pylori infection, confirmed by 13C-urea breath test and serology, participated in a double-blind, placebo-controlled phase 1 clinical trial. The volunteers were randomised to receive orally 60 mg recombinant urease or placebo once weekly for 4 weeks. Clinical assessment and laboratory safety tests were done before treatment, and 1 week and 1 month after the final dose of urease or placebo. Gastroscopy was done at baseline and 1 month after the final dose. Biopsy specimens from the corpus and antrum were with a evaluated semiquantitative score for inflammation, mucosal damage, and density of H pylori according to a modified Sydney System.’ Differences between the two treatment groups were compared by twotailed Fisher’s exact test. Urease was well tolerated and no serious adverse events occurred. All volunteers had isolated, clinically irrelevant, minor abnormalities in blood count or biochemical values, but none were attributable to urease. Baseline gastroscopies were normal except for non-erosive antral gastritis. At the

study, minor lesions (one erosion <5 mm in duodenum) were noted in one volunteer having received placebo and in three having received urease. In the placebo group, another volunteer had an erosion at the oesophagogastric junction. Mean gastritis score of the end of the antrum

or

and of the corpus was similar before and after treatment in both groups. All volunteers remained infected with H pylori throughout the study, as confirmed by "C-urea breath test, serology, H pylori culture, and histology. None of these variables showed statistically significant differences between the two groups. We conclude that oral administration of recombinant urease in H-pylori-infected, asymptomatic adults is well tolerated and, as expected in the absence of a mucosal adjuvant, does not change the course of the infection. These results represent an important step in the development of a vaccine against H pylori. Future studies combining urease with an adjuvant are now required to further evaluate the safety of oral immunisation with urease and to assess its immunogenicity and efficacy. antrum

was supported by the Swiss National Foundation (grant 32-36349.92) and by OraVax-Pasteur Mereux. The authors are indebted to A L Blum, J Biollaz (University Hospital, Lausanne), and to T Monath (OraVax, Cambridge, MA) for their helpful advice throughout this study.

of

nipple-fluid collection. samples of breast milk. We

*C Kreiss, T Buclin, M Cosma, I

Corthésy-Theulaz, P Michetti Pharmacology, University Hospital,

l Eaton KA, Brooks CL, Morgan DR, Krakowka S. Essential role of urease in pathogenesis of gastritis induced by Helicobacter pylori in gnotobiotic piglets. Infect Immun 1991; 59: 2470-75. 2 Ferrero RL, Labigne A. Cloning, expression and sequencing of Helicobacter felis urease genes. Mol Microbiol 1993; 9: 323-33. 3 Michetti P, Corthesy-Theulaz I, Davin C, et al. Immunization of BALB/c mice against Helicobacter felis infection with Helicobacter pylori urease. Gastroenterology 1994; 107: 1002-11. 4 Corthésy-Theulaz I, Porta N, Glauser M, et al. Oral immunization with Helicobacter pylori urease B subunit as a treatment against Helicobacter infection in mice. Gastroenterology 1995; 109: 115-21. 5 Price AB. The Sydney System: histological division. J Gastroenterol 1991; 6: 2O9-22

Prostate-specific antigen in nipple aspirate SIR-Better methods

are

cancer,

in

needed for

detection of breast with a genetic high particularly of predisposition.’ Reports prostate-specific antigen (PSA) in breast-cancer specimens",3 prompted us to look for PSA in nipple fluid collected from non-lactating women. Nipple fluid was collected with a disposable suction cup attached to a 20 mL syringe and suction was applied to the nipple area for several seconds. PSA was measured in 148 nipple-fluid samples from 101 women. 40 women provided fluids from both breasts, and several donated specimens on different occasions. PSA, both free (33 kD) and bound (100 kD) forms, were detected by Western blot (anti-PSA monoclonal antibody, a gift from Hybritech, San Diego, CA, USA) and quantitated with a commercially available immunoenzymometric assay kit (AlA-PACK PA Tosoh Medics, Foster City, CA, USA; detection limit was stated to be 0-05 ng/mL). PSA was detected in 112 of 148 (76%) samples; median concentration was 55 ng/mL (range 0-11000), more than the 0-0-03 ng/mL in sera of most women.4 PSA titres were similar in paired specimens collected simultaneously from the right and left breasts (r=0-96, p<0001). There was no significant difference in PSA values of women with a

personal

risk

early

women

or family history of breast cancer, as compared to without. PSA values were 50, 164, and 822 ng/mL in the three samples from women with breast cancer at the time

women

was

studying

detected in 20 whether nipple-fluid

not

PSA assays may be a useful complement to mammography for early detection of breast cancer.

screening

We thank Donna M

Joseph and Anna F F Andrade for contributions in collections, Peter G Gudrais for technical assistance, and Diane Fairclough for statistical analysis. specimen

*Lenka

Foretova, Judy E Garber, Norman L Sadowsky, Sigitas J Verselis, Frederick P Li *Division of Cancer Epidemiology and Control, Dana-Farber Cancer Institute, Boston, MA 02115, USA; and Faulkner-Sagoff Centre for Breast Imaging and Diagnosis, Faulkner Hospital, Boston, Massachusetts

1 2

Li FP. Translational research on hereditary colon, breast, and ovarian cancers. J Natl Cancer Inst Monogr 1995; 17: 1-4. Diamandis EP, Yu H, Sutherland DJ. Detection of prostate-specific antigen immunoreactivity in breast tumors. Breast Cancer Res Treat

1994; 32: 301-10. 3

This work

Divisions of Gastroenterology and *Clinical CH-1011 Lausanne, Switzerland

PSA are

4

Yu H, Diamandis EP, Sutherland DJ. Immunoreactive prostatespecific antigen levels in female and male breast tumors and its association with steroid hormone receptors and patient age. Clin Biochem 1994; 27: 75-79. Giai M, Yu H, Roagna R, et al. Prostate-specific antigen in serum of women with breast cancer. Br J Cancer 1995; 72: 728-31.

Role of

&g r;&dgr; T cells

in

Behcet’s disease

SiR-There has been considerable speculation on the involvement of immune responses to members of the 60 kDa heat-shock protein (hsp60) family, and in particular whether responses to bacterial hsp60 might also cross-react with responses to self-hsp60,’ since self-hsp60 may be upregulated at sites of disease (eg, in synovium2) or be a constituent on the target tissue (eg, granules of the pancreatic ß-cell3). Hasan and colleagues (March 23, p 789)4 make claims of this kind in relation to Beh4;et’s disease, and suggests that T-cell recognition of certain hsp60 peptides by the T-cell subset expressing the y8-T-ce!l receptor might be important in the pathogenesis of this disease. Furthermore, they suggest that measurements of these responses might be useful diagnostically. If true, these observations would be of great importance for our understanding and management of Behcet’s disease, but as presented there are several puzzling features. The first

on the phenotype of T cells Hasan and colleagues’ table 2 responding hsp60 peptides. shows that 32% and 32-7% cells were y8 positive at 24 and 48 h, respectively, after stimulation with peptides, but double staining showed only 3-3% and 8-4% CD3y8-positive cells. Since the y8 chains of the T-cell receptor cannot be expressed on the cell surface in the absence of CD3 there should be no discrepancy between the single-stained y8-positive cells and the double-stained CD3y8-positive cells. Indeed, exactly this kind of result is shown in their (partly labelled) figure 3, in which essentially all the y8-positive cells are CD3 positive. (An additional puzzling feature is that many of the mean values given for Beh7et’s disease patients’ responses to peptides cannot be derived from the individual results concerns

the data

to

shown.) Responses to peptides also have odd features; what is the explanation for the loss of response to single peptides when retested in the presence of three additional peptides? Were of the peptides toxic at the unusually high some

concentrations tested (100 Ilg/mL)? Lastly, the details of the method used to enrich for y8 T cells are unclear. Was there no activation of this subset as would be expected to occur in a 48 h culture with plasticbound-specific antibody? What cells were harvested when a control antibody was bound to the plate-were these cells

1631