Ileopopliteal fistula in Crohn's disease.

A patient with Crohn's disease is reported, in whom a fistula, which originated in the terminal ileum, ultimately reached the skin behind the right knee.

Low molecular weight IgM in selective IgA deficiency.

Thirty-nine persons with selective IgA deficiency were studied. These comprised 27 subjects found by population screening and 12 by other means. Low molecular weight (LMW) serum IgM was sought in 28 of the 39 persons. Nine of the 28 (32%) had LMW IgM detectable by a sensitive gel filtration technique. Of 17 patients discovered by screening, five (29%) had LMW IgM. In the nine positive persons, LMW IgM constituted up to 17% of the total serum IgM concentration. Eight of the nine IgA deficient persons with LMW IgM, had clinical disease while associated disease in the entire IgA deficient population was less frequent. Serum immune complexes were demonstrated in five of seven subjects with LMW IgM using a C1q-dependent radioimmunoassay; four of these had immune complex associated disorders, three with polyarthritis and one with glomerulonephritis. Because circulating immune complexes are frequently detected in IgA deficient persons without disease, it is proposed that the presence of LMW serum IgM in IgA deficiency may be associated with disease due to the formation of specific pathogenic immune complexes.

Chronic radiation injury to the intestine: a clinico-pathological study.

This paper draws attention to the continuing problem of chronic radiation injury to bowel. Fifty-seven symptomatic patients with this disorder were studied, 31 with predominantly small bowel injury and 26 with colonic disease. The mean latent interval following irradiation was 4.7 years. Small bowel disease presented initially as intestinal obstruction (19 cases) or malabsorption (11 cases) and the radiation related mortality in small bowel disease was 32%, while that for colonic disease was 4%. There was a high incidence of prior pelvic surgery and of adjunctive chemotherapy in patients developing small bowel disease. Analysis of the radiotherapy techniques used highlighted that an unsatisfactory distribution of radiation dosage occurred when parallel opposed fields were used particularly where one field only was treated daily. Difficulty in matching external beams with intracavity sources may also have contributed to radiation injury.

Whipple's disease: a case with circulating immune complexes.

A patient with Whipple's disease was studied for 56 wk from diagnosis, during which time he received continuous antibiotic therapy. Intramucosal bacillary bodies detected by electron microscopy disappeared within 12 wk and a threefold fall in antibody titer to Hemophilus influenza type B bacillus occurred during this period. Circulating immune complexes of IgG class were consistently detected during the first 28 wk of treatment but not subsequently. IgM class immune complexes were detected at a time when mucosal recovery had occurred and when IgG complexes were no longer detectable. A further rise of IgM immune complexes could be induced by enteric challenge with bovine serum albumin in our patient but not in control subjects. The detection of serum immune complexes in Whipple's disease may reflect the entry of foreign antigen through intestinal mucosa. These observations also support the possibility of an underlying defect of antigen exclusion in this disorder, which persists despite apparent mucosal recovery.

Specific IgM and IgG antibodies in IgA deficiency.

Evidence of an abnormality of IgM- and IgG-specific antibody responses was sought in subjects with selective IgA deficiency. Twenty-four patients having a serum IgA level less than 0 . 37 g/l were detected by local-population screening. Total IgM and IgG levels were measured as well as specific antibody to the lipopolysaccharides of six 0 serotypes of E. coli which are frequently isolated from human faeces. Serum IgM-class E. coli antibodies were significantly lower in IgA-deficient patients than in age- and sex-matched controls. The respective IgG-class antibody was generally elevated although more variation existed in this class. There was no correlation of specific antibody in either class with the degree of IgA deficiency. Possible explanations for these patterns of antibody response are discussed. It is concluded that some subjects with 'selective IgA deficiency' may be deficient in specific IgM antibody responses to certain antigens.

Circulating immune complexes in IgA deficiency.

Circulating immune complexes (IC) were demonstrated in patients with serum IgA deficiency. Sixteen of thirty-one IgA deficient patients had serum IC detected by solid phase C1q radioimmunoassay for IgG class complexes. The presence of cryoglobulins (thirteen out of thirty-one patients) and increased polyethylene glycol precipitation (ten out of thirty patients) provided additional evidence for the presence of IC. Fourteen patients were asymptomatic but seven had clinical evidence of disease which could have been IC mediated: two with glomerulonephritis, three with polyarthritis, one with vasculitis and one with thyroiditis. Serum IC remained detectable in multiple samples over several months but this correlated poorly with the presence or absence of disease. Serum antibody to IgA was detected in fifteen out of thirty-one patients. There was no direct relationship between the presence of IC and the level of serum anti-IgA antibody; however, this antibody was shown to be present in the IC isolate in eight patients. It is proposed that a considerable portion of the IC load in IgA deficiency results from defective antigen exclusion at the level of the mucosa.

Serratia: opportunistic pathogen of increasing clinical importance.

Serratia marcescens can become a formidable nosocomial (hospital acquired) pathogen, and is reported increasingly in the world literature. However, it is only a recently recognized problem in Australia. Serratia can carry an antibiotic-resistance plasmid, and, after entry of the organism into very sick patients, it may be hard or impossible to eliminate. Initial experience of Serratia in 34 consecutive cases isolated in a three-months period is presented. Rapid increase in the number of Serratia infections occurred after the appearance of a resistant strain. Urinary infection was the commonest presentation (91% of cases). The presence of an indwelling urinary catheter in a debilitated patient was the major predisposing factor. Significant bacteraemia followed in four cases with one death. Contamination of burns (surfaces) and surgical wounds was found in four cases. Serratia strains were found to be highly resistant to most antimicrobial agents in routine sensitivity testing, 20% being fully resistant to all tested agents, and nalidixic acid being the most effective inhibitor in the remainder. With bacteriocin typing of Serratia, two types were found to be dominant. These two bacteriocin types were not identified among strains isolated from other sources such as soil, water and local hospitals. Pharyngeal carriage was found in only one case, but faecal excretion of Serratia was found in 11 cases and may be a significant portal of dissemination. Cross-infection from a hospital reservoir of resistant organisms is postulated. A model of cross-infection is also proposed, and methods of control are discussed. In view of the established danger of Serratia in the hospital setting, its isolation can no longer be ignored.