179

Intestinal secretions were sampled by whole-gut lavage (essentially a gut perfusion, at a rate of 20 ml per min) with ’Golytely’, a commercially available gut cleansing fluid.2 Serum and whole-gut lavage fluid (WGLF) were obtained before and at three weeks after a course of three enteric-coated capsules, each containing 109 live Ty21aorganisms. Isotype-specific antibodies to Ty2la lipopolysaccharide (Sigma) were assayed by ELISA, and expressed in relation to a serum standard arbitrarily designated as containing 1000 units of each class of antibody, IgG, IgA, and IgM. One patient (patient 1) had very high concentrations of serum IgG and IgM antibody before vaccination; in the other subjects concentrations were low. Serum IgA antibody varied from 38-140

units/ml. Serum antibodies did not differ before and after vaccination. Intestinal IgA values (units/ml WGLF) were: MRI, T2 weighted image, showing hyperintense resolution

along right optic

nerve.

The clinical picture in our patient was probably attributable to tetanus toxoid. In experimental allergic neuritis, myelin injury may occur before macrophage-mediated demyelination, and provides support for an early role of serum factorsThe early onset of symptoms in our patient may partly be explained on this basis. We cannot judge how steroids and/or immunoglobulin affected the course and outcome in our patient and others.6 Optic neuritis and myelitis have been reported after rubella vaccination.’ Relapse has been reported with further injections of tetanus toxoid,4 and this should be a consideration in patients such as ours.

Departments of Paediatric Neurology, Neuro-ophthalmology, and Paediatrics, Hacettepe Children’s Hospital, 06100 Ankara, Turkey

HALUK TOPALOGLU MUSTAFA BERKER TULAY KANSU UMIT SAATCI YAVUZ RENDA

1 Immunization Practices Advisory Committee, Centers for Disease Control. Diptheria, tetanus and pertussis guidelines for vaccine prophylaxis and other preventive measures. Ann Intern Med 1981; 95: 723-28. 2. Beghi E, Kurland LT, Mulder DW, Nicolasi A. Brachial plexus neuropathy m the population of Rochester, Minnesota, 1970-1981 Ann Neurol 1985, 18: 320-23. 3 Holliday PL, Baver RB Polyradiculoneuritis secondary to immunization with tetanus and diphtheria toxoids. Arch Neurol 1983; 40: 56-57. 4 Pollard JD, Selby G Relapsing neuropathy due to tetanus toxoid. J Neurol Sci 1978; 37: 113-25. 5 Rosen JL, Brown MJ, Hickey WF, Rostami A. Early myelin lesions m experimental allergic neuritis Muscle Nerve 1990; 13: 629-36. 6. Schlenska GK. Unusual neurologic complications following tetanus toxoid administration. J Neurol 1977, 215: 299-302. 7 Kline LB, Margulies SL, Oh SJ. Optic neuritis and myelitis following rubella vaccination. Arch Neurol 1982; 39: 443-46.

Mucosal

immunity to oral vaccines

SiR,-Your correspondence (Dec 7, p 1455) about the efficacy, formulations, and doses of the oral typhoid vaccine Ty21aa (Oct 26, p 1055) reads strangely to those of us working in clinical gastrointestinal immunology. Large scale field trials have been done to measure protective efficacy without any knowledge of the intestinal antibody status of vaccinees. The only published data showing that the vaccine strain can induce local mucosal immunity seem to be those of Forrest et al,l who investigated healthy Australian volunteers and excluded individuals with a history of salmonella infection or food-poisoning. Most volunteers received doses of the organism one or two log values greater than those used in recent trials. Mucosal immunity is separate from systemic immunity in the types of cells and isotypes of antibody involved, and in the factors that regulate its induction and expression. Surely present methods for testing intestinal secretions should be used to defme the baseline intestinal antibody status of a study population, changes in antibody concentrations after vaccination, and the relation (if any) between serum antibody concentrations, intestinal secretory antibody titres, and clinical protection? We use enteric vaccines as oral immunogens in protocols for investigation of intestinal immunity and its regulatory mechanisms and report our experience with the oral Ty2la vaccine in four healthy individuals.

Pahenf

Prevaccination

Postvaccination*

1 2 3 4

129 9 7-4 6-5 1-8

11 7 12.8 11-7 2-2

*3 weeks after first vaccine dose

Vaccination had no effect in patient 1 with high and patient 4 with very low baseline intestinal IgA antibody. However, there was a striking rise in antibody concentration in patients 2 and 3 with intermediate baseline titres (total intestinal production estimated at 15 360 and 14 040 units/h, respectively). No subject had detectable IgG or IgM intestinal antibody. Thus, the regimen probably boosted intestinal antibody production only in partly primed individuals. These few data, similar experiments with oral killed whole cell/cholera toxin B subunit vaccine,-’ and our findings in volunteers and in patients with coeliac disease, inflammatory bowel disease, and ankylosing spondylitis (refs 4-6, and O’Mahony S, Anderson N, Nuki G, Ferguson A, unpublished) show that gut antibody production can be investigated directly by whole-gut lavage. Our experience also shows that it is misleading to extrapolate determinations of serum or salivary antibodies to the gut.3,4,7 In the complex microenvironment of the gut, and in view of the narrow range of properties of IgA molecules, it should also be recognised that the presence of specific antibody is not necessarily correlated with immunoprotection. Although methods for the measurement of intestinal cellular immunity are not yet fully developed, the humoral component of mucosal immunity can be readily assessed either by duodenal intubation or by use of the gut lavage procedure. Clinical tests of intestinal immunity in the course of oral vaccine development should be more widely used, so that the effects of key variables such as malnutrition or previous antigen exposure are measured rather than assumed. Gastro-Intestinal Unit, Western General Hospital and University of Edinburgh,

Edinburgh EH4 2XU, UK

ANNE FERGUSON JAMAL SALLAM

1. Forrest BD, LaBrooy JT, Beyer L, Dearlove CE, Shearman DJC The human humoral immune response to Salmonella typhi Ty21a. J Infect Dis 1991; 163: 336-45. 2. O’Mahony S, Barton JR, Crichton S, Ferguson A. Appraisal of gut lavage in the study of intestinal humoral immunity. Gut 1990; 31: 1341-44. 3. O’Mahony S. The investigation of human intestinal humoral immunity [MD thesis.] Cork: University of Cork, 1990. 4 O’Mahony S, Arranz E, Barton JR, Ferguson A. Dissociation between systemic and mucosal humoral immune responses in coeliac disease. Gut 1991; 32: 29-35. 5. O’Mahony S, Choudari CP, Barton JR, Walker S, Ferguson A. Gut lavage fluid proteins as markers of activity of inflammatory bowel disease. Scand J Gastroenterol

1991; 26: 940-44. E, O’Mahony S, Barton JR, Ferguson A Immunosenescence and mucosal immunity: significant effects of old age on serum and secretory IgA concentrations and on intraepithelial lymphocyte counts Gut (in press). 7. Barton JR. Human gastrointestinal mucosal secretory immunity: investigation and regulation [PhD thesis.] Edinburgh: University of Edinburgh, 1991. 6. Arranz

Thalassaemia strategy in Sicily S;R,—p-thatassaemia and haemoglobin S carriers make up 5-9% and 2 0%, respectively, of the Sicilian population,"2 and the Sicilian Regional Health Department has taken an active part in tackling this complex medicosocial issue. The department set up fourteen centres, staffed by physicians, nurses, technicians, psychologists, and social workers, to improve the treatment of thalassaemia and

180

promote preventive measures. It also set up a centre for prenatal diagnosis in Palermo, and in 1984 it instituted a regional register for thalassaemia and haemoglobinopathies which provides up-to-date to

information on these diseases in all the fourteen Sicilian centres. 3,4 On Jan 1, 1990, there were 1109 recorded cases of thalassaemia major and 441 of thalassaemia intermedia. The fall in incidence (new cases per year per 10 000 newborn) over the years 1982-89 can be attributed to the prenatal diagnosis centre at the Ospedale Cervello, Palermo, which opened in 1982-83: Year 1982 1983 1984 1985 *New

Incidence* 6-0 4-6 4-9 34

cases/yr per

Incidence 32 2 32 1-7 30

Year 1986 1987 1988 1989

10 000 newborn

The very low incidence in 1988 has not yet been explained, and further analysis of the data is underway. Comparison of observed and expected cases confirms the efficacy of prenatal diagnosis but it does seem that the improvement has stabilised due to a gap in health information: Year Avoided Year Avoided E/O E/O 1982 10% 49/44 1983 33% 48/33 1984 27% 48/35 1985 48% 47/24 E/O= = expected/observed Avoided = (E

1986 1987 1988 1989

46/22 46/22 45/12 47/21

52% 52% 73% 55%

- 0) - E as % Data for 1990 are incomplete since thalassaemia can be diagnosed only after the first year of life. However, the number of registered cases to June, 1991, was 9, suggesting that the situation has not changed. More encouraging are data on the age distribution of patients with thalassaemia: the average age was 10 years 8 months in 1984, 12 years 7 months in 1988, and 14 years 4 months in 1990, confirming the satisfactory treatment offered by the Sicilian centres. 1990 saw the introduction of a regional law setting up a health information campaign for the whole of Sicily. All the local authorities have to distribute information booklets about the disease to all newly married couples and a massive information campaign began at the end of 1991. The law also envisages social and economic support to patients, such as a$4800 per y. ar payment for every patient, free travel to the nearest treatment centre, and$1 million in support for private associations and research centres. The increasing age of patients is now presenting problems in terms of jobs. ’I he regional law also provides for employment of people with thalassaemia but that initiative has not been fully acted on and few patients with thalassaemia have a permanent job, although the number is rising. For the 1990s one challenge is to move the incidence figures down from an apparent plateau; another is to decide whether to maintain social and financial support to the families or to try to help patients find a job.

Supported by CNR grant 91:04205.ST75. Centre for Health Education, CERDES, Palermo

S. GIAMBELLUCA A. M. GENTILE

Epidemiological Unit, Regional Health Department, Palermo

F. PINZONE

Department of Paediatric Haematology, University of Catania, 95125 Catania, Italy

G. SCHILIRÒ

1. Schilirò G, Di Gregono F, Romeo MA, Testa R, Russo A. Incidence of hemoglobin S carriers m Sicily. Hemoglobin 1986; 10: 95. 2. Schilirò G, Spena M, Giambelluca E, Maggio A. Sickle hemoglobinopathies in Sicily.

Am J Hematol 1990; 33: 81. 3. Giambelluca SE Boll Epidemiol Naz 1986; 22: 5. 4. Giambelluca SE. Rapp Osserv Epidemiol Reg 1986; 1: 5.

Hepatic hamartoma

in tuberous sclerosis

SiR,—Hepatic hamartomas in tuberous sclerosis (TS) have mostly been reported in necropsy material,l and a few cases have been described radiologically.2,3 To evaluate the frequency of hepatic hamartomas in patients with TS we did abdominal ultrasonography in 25 boys and 26 girls (aged 3 months to 18 years) with TS. The diagnosis of TS was established by anamnesis and examination of the skin, nails, hair, and eyes,

according to Gomez’

criteria.4 Cerebral computed tomography and ultrasonography of the heart were also done. Hepatic hamartomas were seen in 12 (24%) of the 51 children. The frequency increased with age. Areas of increased echogenicity were found in 2 (10%) of 20 children who were 5 years of age or younger (an 8-month-old girl and a 5-year-old boy), in 5 (25%) of 20 children aged between 5 and 10, and in 5 (45 % ) of 11over the age of 10. Hepatic hamartomas were more common in girls than in boys (5:1). In 9 of the 12 children hepatic hamartomas coexisted with renal angiomyolipomas. As with renal changes, hepatic hamartomas did not produce any clinical or biochemical manifestations. The frequency of hepatic hamartomas in TS seems to be underestimated, as we have pointed out before.5 Renal lesions have been investigated by many workers and are seen in 40-80% of affected patients.6 The frequency of hepatic lesions has been evaluated in only a few reports. 5 of 8 patients with TS described by Compton et at’ demonstrated vascular tumours of the liver with coeliac angiography, these patients were aged 10 months (2 patients) and 11, 24, and 29 years. Fleury et aP reported, in 36 patients, a frequency of hepatic hamartomas of 13% in those below 16 years of age and 23 % in older patients. In our study the frequency of hepatic lesions in children over 10 was about 45%. We conclude that hamartomas should be regarded as in the helpful diagnosis of TS, especially of formes frustes, even in childhood.

hepatic

Department of Child Neurology, Child Health Centre, Al Dzieci Polskich 20, 04-736 Warsaw, Poland Department of Radiology, Child Health Centre 1. 2.

S. JÓŹWIAK R. MICHALOWICZ M. PEDICH P. RAJSZYS

Compton WR, Lester PD, Kyow MM, et al. The abdominal angiographic spectrum of tuberous sclerosis. Am J Roentgenol 1976; 126: 807-13. Kristal H, Sperber F Hepatic angiomyolipoma in a tuberous sclerosis patient. Isr J

Med Sci 1989; 25: 412-14. Fleury P, Smits N, van Baal S. The incidence of hepatic hamartomas in tuberous sclerosis. Fortsch Rontgenstr 1987; 146: 694-96. 4. Gomez MR Criteria for diagnosis. In: Gomez MR, ed. Tuberous sclerosis. New York Raven, 1988: 9-19. 5. Michalowicz R, Jóźwiak S. Hepatic angiomyolipoma in a tuberous sclerosis patient. Isr J Med Sci 1990; 26: 479-80. 6. Stillwell TJ, Gomez MR, Kelalis PP. Renal lesions in tuberous sclerosis J Urol 1987; 3.

Prenatal cytogenetic and postnatal molecular studies on 46,XX male SIR,-Prenatal chorionic villus studies were done on the 14th week of the third pregnancy in a 33-year-old woman. The first pregnancy had been terminated when a 45,X fetus was suspected because of hygroma, the karyotype being confirmed in amniotic cells. In the second pregnancy amniotic fluid was monitored because of a recurrence risk for aneuploidy; a normal female karyotype was found and a normal girl was born. The third pregnancy also had a normal female karyotype but the outcome was the birth of a normal male infant with bilateral descended testes. The parents complained about a wrong prenatal diagnosis. We thought of three possibilities for this discrepancy. The first was a mix-up of samples. However, the other ten pregnancies in which chorionic villi had been sampled that day had all resulted in the birth of a child of the predicted sex. A second possibility was maternal cell contamination. Since only one maternal cell was seen in 3000 direct chorionic villus studies in our centrel this was ruled out. The third possibility was a 46,XX male, and chromosome studies on the newborn baby’s lymphocytes revealed a 46,XX karyotype. Y-chromosome-specific probe pDP105 (DYZ 4) demonstrated a translocation from the short arm of the Y chromosome (Ypll.2) to the short arm of the X chromosome (Xp22.3), explaining the male phenotype (figure). The translocation must therefore have included the gene for the testis-determining factor (TDF)2 since the baby had bilateral descended testes. The parents were informed about the possibility of a future Klinefelter syndrome. They did not want to undergo karyotyping themselves and did not plan any more pregnancies, so