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Biomedical subjects

E A Ottesen

Publications and source records attributed to E A Ottesen.

17 recordsLinked to original sources

Specific allergic sensitsation to filarial antigens in tropical eosinophilia syndrome.

Reaginic antibodies to antigens from the human filarial parasites Wuchereria bancrofti and Brugia malayi and the animal parasite Dirofilaria immitis were studied by histamine release from basophils in 7 patients with tropical eosinophilia (T.E.) and 18 patients with other manifestations of filarial infection (lymphatic changes or symptomless microfilaraemia). All the patients had antibodies to all three filariae but T.E. patients were more highly sensitised. T.E. patients responded more to antigens from microfilariae than did patients with non-T.E. filariasis and responded more to microfilarial antigens from the human parasites than to those from the animal parasite. These findings support the view that T.E. is a form of occult filariasis which results from host hypersensitivity to the microfilarial stage of parasites which, in other individuals, cause the more common lymphatic manifestations of filarial disease.

Adolescent

Eosinophilia following treatment of patients with schistosomiasis mansoni and Bancroft's filariasis.

Eosinophilia is frequently observed after treatment of patients with infections due to parasitic helminths. For definition of the characteristics and causes of post-treatment eosinophilic responses, 47 patients with Bancroft's filariasis, who were treated with diethylcarbamazine, and eight patients with schistosomiasis mansoni, who were treated with niridazole, were studied. After therapy for eight days, both groups developed significant (P less than 0.05) increases in their levels of eosinophilia, which peaked in two to four weeks. Maximal levels averaged two and one-half to three time the levels before treatment. Before therapy the number of circulating eosinophils was unrelated to intensity of infection in both groups, but after treatment, when the same relationship was examined in the larger group (the patients with filariasis), the degree of post-treatment eosinophilia was significantly correlated with the patients' worm burdens before treatment (r = 0.727; P less than 0.001). Thus, treatment of helminthic infections can provide a unique opportunity for studying eosinophil responses of humans to graded doses of antigen and has shown that acute responses are determined quantitatively by the amount of antigen initially presented to the host.

Adolescent

HLA histocompatibility antigens in a Polynesian population -- Cook islanders of Mauke.

Polynesians living on the island of Mauke in the Cook Island group were typed for HLA-A and -B locus antigens. The Mauke population has restricted HLA polymorphism, with five A-locus antigens and four B-locus antigens accounting for a majority of the HLA phenotypes. Although some differences in antigen frequency were found when Mauke Islanders were compared with Polynesians from Easter Island and Samoa, the Mauke Islanders were closer in their HLA antigenic profile to polynesians than to Melanesians.

Epitopes

Serological differences between acute and chronic schistosomiasis mansoni detected by enzyme-linked immunosorbent assay (ELISA).

Sera from patients with acute and chronic schistosomiasis mansoni, and from laboratory-infected monkeys, were examined by an enzyme-linked immunosorbent assay technique using antigens prepared from eggs, cercariae, and adult worms. Sera from patients with acute schistosomiasis and from monkeys 2 months post-infection reacted more positively to cercarial antigen than to adult worm antigen whereas sera from both patients with chronic schistosomiasis and monkeys infected for longer than 4 months reacted more positively to adult worm antigen. These differential responses to antigen serologically differentiated between acute and chronic schistosome infections.

Acute Disease

Zoonotic Brugia filariasis in New England.

Three human infections with an animal filarial parasite of a Brugia species have been identification in residents of New England over the past 2 years. All patients were asymptomatic except for local, superficial lymphadenopathy. The diagnosis was established pathologically by the finding of immature brugia worms in the biopsied lymph nodes. Peripheral blood eosinophilia was lacking; in one patient, no lymphocyte blastogenesis to filarial antigens and no antifilarial antibodies were detectable. These cases document a wider geographic range in the Northeast for this zoonosis, which had been previously recognized in two residents of the Middle-Atlantic states. The clinical and pathologic features resulting from the worm's intralymphatic localization and the structure of the brugia worm distinguish this entity from other zoonotic filarial infections.

Adolescent

Circulating immune complexes in acute schistosomiasis.

The sera of patients with acute and chronic schistosomasis were tested for the presence of circulating immune complexes with the 125I-Clq binding assay. Fourteen out of fifteen (93%) patients with acute schistosomiasis had elevated 125I-Clq binding activity, while only two out of eleven (18%) patients with chronic disease had C1q binding complexes. This difference was significant (P less than 0.001) and paralleled the degree of clinical didsease activity between the two groups of patients. IgG and IgM were readily detected in all of these circulating complexes but the specific parasite antigens initiating their formation could not be defined. The level of circulating immune complexes was inversely correlated with the absolute eosinophil counts for individuals in the acutely infected group, an observation compatible wiht the hypothesis that a functional role for the eosinophil is the destruction and elimination of immune complexes.

Acute Disease

Failure of diethylcarbamazine as a provocative test in subperiodic Wuchereria bancrofti filariasis.

The effect of diethylcarbamazine (DEC) on levels of microfilaraemia in 70 patients with subperiodic, Pacific-variant Wuchereria bancrofti infection was studied one hour after oral administration of 5 mg/kg of drug. In contrast to the immediate DEC-induced increase in microfilaraemia which had been previously described in patients with nocturnally periodic filariasis, diethylcarbamazine failed to elicit such a response in patients with subperiodic bancrofti infection. Indeed, one hour after oral DEC the number of circulating microfilariae was reduced to about 8% of pre-treatment values.

Adolescent

Antibody response to a polysaccharide antigen present in the schistosome gut. II. Modulation of antibody response.

Specific IgM and IgG antibody to a polysaccharide present in the epithelial cells of the gut of adult schistosomes was measured in four groups of infected patients: I) patients with documented acute schistosomiasis; II) Americans exposed to schistosomiasis within the preceding 0--4 years; III) chronically and heavily infected patients, mostly from Puerto Rico, without hepatomegaly or hepatosplenomegaly; and IV) heavily infected Brazilian children with hepatic or hepatosplenic schistosomiasis. Specific IgM and IgG titers were both highest in the acute Group I patients and lowest in the chronically infected Groups III and IV. Total IgG and IgM levels were compared to specific antibody titers. Immunoglobulin levels tended to follow specific antibody titers except in the chronically infected Groups III and IV in which total IgG rose to high levels. The decrease in specific antigen titers over the course of time occurred despite continued antigenic stimulation and suggests a modulation of the humoral response. The mechanism remains obscure.

Adult

The acquisition and loss of antigen-specific cellular immune responsiveness in acute and chronic schistosomiasis in man.

To characterize the development and evolution of cellular immune responsiveness in individuals infected with the parasite Schistosoma mansoni, we studied fifteen patients with acute, subacute and chronic schistosomiasis. Lymphocytes from the three acutely infected patients responded vigorously to schistosome antigens in an in vitro blastogenic assay. By contrast, cells from nine chronically infected individuals were essentially unreactive to these same antigens. Patients infected for an intermediate period of time (9 months) generated responses between those of acute and chronic patients. The diminished responsiveness of chronically infected individuals was specific for schistosome antigens and did not extend to humoral immune responses. Following treatment of the infection with niridazole, these patients temporarily regained responsiveness to schistosome antigens. From these data we speculate that during the course of this parasitic helminth infection there develops a progressive and specific modulation of antigen recognition and proliferation by lymphocytes to schistosome antigens, and that such diminished immune reactivity may be important in maintaining the unique biological relationship which exists between a host and its parasites.

Acute Disease

'Long-distance' lymphocyte study. The effects of transporting blood in lymphocyte blastogenic responses.

A comparison of blastogenic responsiveness to antigens and mitogen by human lymphocytes was made between cells which had been processed for culture immediately following blood collection and cells obtained from blood collected 9-11 hr previously and transported via commercial airline from the patients' homes to our laboratory. There were no significant differences in the responses of transported and non-transported cells if the blood was maintained at ambient temperature during the period of shipment. Chilling the blood during transport, however, resulted both in decreased stimulation of the cells and increased 'background' activity in unstimulated cultures. These findings indicate the feasibility of carrying out both limited immunological evaluations and extended periods of follow-up for patients located at considerable distances from a research laboratory.

Adult

Cellular immunity in Peyer's patches of rats infected with Trichinella spiralis.

A rat model of Trichinella spiralis gut infection was used to observe the sequence of developing cellular immunity in Peyer's patches and other lymphoid tissues. Whereas cellular reactivity (lymphocyte blastogenesis) for worm antigens was evident in mesenteric lymph nodes draining the gastrointestinal tract within 3 days after infection, Peyer's patch lymphocytes developed maximal reactivity 2 to 3 weeks later at the same time as the spleen and other lymphoid tissues. Furthermore, the immune reactivity found in Peyer's patches was only transient. Thus, in this parasitic gut infection, the Peyer's patch lymphoid tissue does not appear to be the first site of cellular responsiveness but rather to acquire cellular reactivity only when other lymphoid elements in the infected host have also acquired similar antigen-induced reactivity.

Animals

Immune response to Trichinella spiralis in the rat. I. Development of cellular and humoral responses during chronic infection.

The immune response of rats to infection with Trichinella spiralis was studied serially for more than 1 year. Initial antigen-specific cellular reactivity, assessed by the lymphocyte transformation response, developed in the draining mesenteric nodes 3 days after infection. After 1 week reactive lymphocytes were detectable in the spleen and circulating blood, but the more 'remote' peripheral nodes did not harbor antigen-reactive cells until late in the second week. Thereafter, the patterns of antigen-responsiveness varied among the different lymphoid pools, but in all cases a decline in reactivity was seen after the first month. Serum hemagglutinating and homocytotropic antibodies, detectable by the tenth day, reached their peaks after 1 month of infection. Hemagglutinating titers persisted for more than 1 year but homocytotropic antibody was lost over this period. Comparisons are drawn between the evolution of the natural infection and the development of the host's immune response.

Animals