Biomedical subjects

J Opdebeeck

Publications and source records attributed to J Opdebeeck.

6 recordsLinked to original sources

PubMed1996

Immunoglobulin G subclass antibodies against excretory/secretory antigens of Ancylostoma caninum in human enteric infections.

Most patients with proven or suspected enteric infection with the common hookworm of dogs, Ancylostoma caninum, produce immunoglobulin G (IgG) and IgE antibodies to an immunodominant excretory/secretory antigen (Ac68) of the parasite. These antibodies were detected in both enzyme-linked immunosorbent assay (ELISA) and Western blots; the Western blot to detect IgG antibodies to Ac68 was the most specific and sensitive. The subclasses of IgG of the antibody response to the parasite were analyzed using Western blots with anti-IgG subclass-specific monoclonal antibodies as marker systems in an attempt to further improve the specificity of the assay. Eight patients with confirmed enteric infections with A. caninum (positive controls) were tested; six had antibodies in all IgG subclasses against Ac68. Twenty sera from patients with suspected enteric infection with A. caninum (manifested as eosinophilic enteritis or unexplained abdominal pain with peripheral eosinophilia) were tested; 16 had total IgG antibodies to Ac68, while IgG1, IgG2, IgG3, and IgG4 responses were found in 11, 10, 9, and 12 of these sera, respectively. Small numbers of sera from groups of patients infected with other helminths and from healthy blood donors had various combinations of IgG, IgG1, IgG2, and IgG3 antibodies to Ac68, but none of these sera had IgG4 antibodies to Ac68. Sera from all nine patients with human hookworm infection had IgG, IgG1, IgG2, and IgG3 antibodies to Ac68 and eight of the nine were also positive for IgG4 antibodies. These results indicate the Western blot to detect IgG4 antibodies to Ac68 is the most reliable immunodiagnostic test yet described for enteric infection with A. caninum, although this test does not discriminate between infections with human and canine hookworms.

Ancylostoma↗

PubMed1994

Human enteric infection with canine hookworms.

OBJECTIVE: To describe a zoonotic ancylostomiasis (canine), acquired from domestic pets by patients living in developed, urban communities. DESIGN: An 8-year, retrospective case study. SETTING: A clinical gastroenterologic practice in Townsville and a university parasitology department in Brisbane, Australia. PATIENTS: Nine patients, each with enteric hookworm infection diagnosed by finding a single organism in situ; five were treated by us, and the rest were referred to us for parasite identification. MEASUREMENTS: Clinical and demographic data, complete blood examinations, total serum immunoglobulin E assay, and serologic testing with enzyme-linked immunosorbent assay and Western blot using excretory-secretory antigens of Ancylostoma caninum. Gut biopsy specimens were examined histologically, and hookworms were identified using morphologic criteria. RESULTS: The infections in three of the patients were diagnosed during the initial 6 years and six in the last 2 years. All owned a dog and described activity potentially exposing them to infection with canine hookworm larvae. Three patients had a laparotomy for acute abdominal pain, and six had colonoscopies (five with pain and one without symptoms). Six of the nine had blood eosinophilia (mean, 0.97 x 10(9)/L), and five of eight had elevated immunoglobulin E levels (mean level, 756 micrograms/L); six of eight had eosinophilic inflammation of the gut. In six patients, the worm was identified as A. caninum, whereas in three, damage to the specimen did not allow specific identification; however, they were unlikely to be human parasite species. Although all parasites were in the adult stage, none were sexually mature. Positive serologic findings in seven of the eight patients tested confirmed presence of antibody to the parasite. CONCLUSIONS: Human enteric infections with A. caninum are being diagnosed more frequently in northeastern Australia. Although infection may be subclinical, the chief symptom is abdominal pain, sometimes sudden and severe. The pathologic finding is focal or diffuse eosinophilic inflammation caused by a type 1 hypersensitivity response to secreted antigens. Infection by sexually immature worms is scant and nonpatent, indicating poor adaptation to the human host. Serologic testing assists in identification of occult infection. Advanced hygiene and sanitation afford little protection because the parasite reservoir is a large and growing pool of infected domestic pets.

Abdominal Pain↗

PubMed1994

Occult enteric infection by Ancylostoma caninum: a previously unrecognized zoonosis.

BACKGROUND/AIMS: Human disease caused by the canine hookworm Ancylostoma caninum and a high incidence of eosinophilic enteritis have been reported from northern Queensland, Australia. The aim of this study was to evaluate patients with unexplained abdominal pain and a possible association with cryptic infections by A. caninum. METHODS: The clinical and demographic features of patients from this region with eosinophilic enteritis (group A1, n = 42), obscure abdominal pain associated with (group A2, n = 105) and without (group A3, n = 84) blood eosinophilia were reviewed and sera were tested against A. caninum excretory-secretory antigens by enzyme-linked immunosorbent assay (ELISA) and Western blot. Four additional patients, two with confirmed A. caninum, had hookworm infection. RESULTS: The level of dog ownership in these four groups was 79%-100%, higher than in the local population (P < 0.001). The ELISA tested positive in 71% of A1, 67% of A2, and 30% of A3, versus 8% in controls (P < 0.002). All cases tested were positive on Western blot versus 10% of controls (P < 0.0001). The ELISA values increased with chronicity and decreased during convalescence. CONCLUSIONS: We conclude occult human A. caninum infections are common and are characterized by eosinophilic enteritis and obscure abdominal pain with or without blood eosinophilia. The diagnosis can be confirmed by serology.

Adolescent↗

PubMed1994

Immunologic incrimination of Ancylostoma caninum as a human enteric pathogen.

In northeastern Australia, the incidence of human eosinophilic enteritis (EE) and unexplained abdominal pain with peripheral blood eosinophilia (PE) appear to be exceptionally high. Because adults of the common dog hookworm, Ancylostoma caninum, were found in situ in several cases, we compared specific antibody responses in patients with EE or PE with those of individuals from various control groups. Sera were obtained from three patients with confirmed dog hookworm infection, 25 patients with EE/PE, 42 with other diagnosed gastrointestinal disorders, eight with human hookworm infection, 27 with other diagnosed parasitic infections, and 100 blood donors from the State of Tasmania, where A. caninum does not occur. They were analyzed by enzyme-linked immunosorbent assay (ELISA) and Western blot for IgG and IgE antibodies to excretory-secretory (ES) antigens from adult A. caninum. In the ELISA, sera from 88% of EE/PE patients were positive for IgG and IgE antibodies to ES antigen. All eight patients infected with human hookworm (identified as A. duodenale in three) were also seropositive, while most of those with other parasitic infections, as well the blood donors, those with diagnosed gastrointestinal diseases, and the control subjects, were seronegative. In Western blots, sera from 92% of EE/PE patients demonstrated IgG and IgE antibodies to a component of ES antigen with a molecular weight of approximately 68 kD (Ac68), as did all sera from cases infected with human hookworms. Among the patients with other gastrointestinal disorders and parasitic infections, four of 42 (10%) and three of 27 (11%), respectively, reacted positively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1981

Enzyme immunoassay for detection of antibodies specific for staphylococcal alpha haemolysin in bovine milk.

Six lactating cows were inoculated in the external inguinal lymph node region with a staphylococcal cell-toxoid preparation. An additional three cows were inoculated with saline as control animals. Enzyme immunoassay (EIA) was used for detection of IgG antibodies in the milk, specific for staphylococcal alpha haemolysin. The positive EIA response in the inoculated cows was followed over an 84 day period. Saline controls showed no response.

Animals↗

PubMedDate not supplied

Detection of antibodies to secretions of Ancylostoma caninum in human eosinophilic enteritis.

To evaluate the role of canine hookworms in human eosinophilic enteritis (EE) in north-eastern Australia, we tested human sera in an enzyme-linked immunosorbent assay (ELISA) which incorporated antigens of adult Ancylostoma caninum. Sera from the following groups were examined: 10 patients with EE (unexplained recurrent abdominal pain and related symptoms, with peripheral eosinophilia) from Townsville and Brisbane; 2 persons known to be infected with A. caninum and 20 presumed unexposed healthy controls; 20 patients with other gastrointestinal diseases; 20 with other identified parasitic infections; and 20 with atopic conditions. High levels of specific immunoglobulin (Ig) G and IgE antibodies were found in patients with EE but not other gastrointestinal disease. Excretory-secretory (ES) products were more discriminating than somatic antigens in the ELISA and the IgG/ES-ELISA was the most specific; occasional cross-reactions could be explained on epidemiological or parasitological grounds. The IgM-ELISA was neither specific nor sensitive. We conclude that canine ancylostomiasis is a major cause of human EE in north-eastern Australia, and the pathogenesis is based probably on hypersensitivity to antigens secreted by the parasite.

Ancylostoma↗