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Biomedical subjects

A J Ammann

Publications and source records attributed to A J Ammann.

At least 73 records · Page 4Linked to original sources
PubMed1985

Deoxycytidine therapy in two patients with adenosine deaminase deficiency and severe immunodeficiency disease.

Two children with adenosine deaminase (ADA) deficiency and combined immunodeficiency disease were given parenteral deoxycytidine in order to reverse the severe T-cell immunodeficiency associated with this disease. One patient received a total of three courses of parenteral deoxycytidine. On two occasions deoxycytidine (50 mg/kg/day) was infused intravenously continuously for 2 weeks. During one of the infusions she received the deoxycytidine deaminase inhibitor tetrahydrouridine (THU). Steady-state levels of plasma deoxycytidine increased 4-fold with THU. RBC dCTP/dATP increased more than 10-fold after 48 hr of deoxycytidine infusion. Immunologic studies following the intravenous infusion of deoxycytidine showed transient improvement in T-cell immunity. The third course of deoxycytidine (50 mg/kg/day) was administered subcutaneously during a 10-hr night-time infusion. After 6 and 12 weeks of nightly subcutaneous infusions, there was minimal improvement in the in vitro immunologic studies and no clinical improvement. The second patient received a single 2-week course of continuous intravenous deoxycytidine (50 mg/kg/day) following which there was no significant change in T-cell immunity. This study defines some of the pharmacologic parameters of human deoxycytidine metabolism and suggests that some patients with ADA deficiency may respond to deoxycytidine therapy with improvement in T-cell-mediated immunity, although the changes are small and the effect on clinical status appears to be limited.

Adenosine Deaminase↗
PubMed1985

Acquired immune deficiency syndrome in childhood.

The acquired immunodeficiency syndrome has been observed with increasing frequency in children with associated hemophilia, high-risk environmental backgrounds, and blood transfusions. AIDS should be considered in the differential diagnosis of childhood immunodeficiency, and it must be distinguished from congenital disorders. We emphasize the importance of epidemiologic, clinical, and laboratory data in diagnosis and aggressive management of infectious complications. The relationship between human retrovirus infection and AIDS remains to be precisely defined, especially with regard to cofactors that may play a role in the development of severe immunodeficiency following exposure to the agent.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Behçet syndrome.

Behcet syndrome, a multisystem disorder characterized by ocular, mucocutaneous, articular, vascular, gastrointestinal, and neurologic abnormalities, is described in six pediatric patients. The patients ranged in age from 2 months to 11 years at time of onset. Several years were usually required before additional manifestations of the disease occurred. Aphthous ulceration was present in all six patients, arthritis in three, erythema nodosum in four, sterile cellulitis in three, gastrointestinal manifestations in five, neurologic manifestations in two, and genital or perianal ulcerations in three; ocular involvement was present in only one. There were no diagnostic laboratory studies, and, as in the adult population, no cause for Behçet syndrome was found. Patients had a variable response to corticosteroid therapy. Two patients who had significant morbidity and who responded poorly to corticosteroid therapy also received chlorambucil therapy, which appeared to provide improved control of signs and symptoms. Based on the prolonged interval between onset and the appearance of complete manifestations, Behcet syndrome may be more common in children than previously reported.

Arthritis↗
PubMed1985

Cytomegalovirus infection and abnormal T-lymphocyte subset ratios in homosexual men.

T-helper:T-suppressor cell ratios of 1 or less were found in 2 of 42 homosexual men without antibodies to cytomegalovirus but in 33 of 67 homosexual men with antibodies (p less than 0.001). Of 34 men without antibody who were followed prospectively, 12 became seropositive for cytomegalovirus and all 12 developed helper: suppressor ratios of less than 1.0. These ratios remained at 1 or less for an average of 9.6 months but persisted for 15 months or more in 3 men. None of the men in the prospective study developed antibodies to the acquired-immunodeficiency-syndrome-associated retrovirus. These results indicate that in the homosexual men studied, abnormally low T-lymphocyte helper: suppressor ratios occurred almost exclusively in those who were infected with cytomegalovirus, and in those prospectively followed low ratios did not reflect contact with the syndrome-associated retrovirus. Abnormal ratios were rarely seen in men who had never been exposed to cytomegalovirus. Thus, cytomegalovirus infection may be an important cofactor in the immunologic disorders leading to the acquired immunodeficiency syndrome.

Antibodies, Viral↗
PubMed1985

The acquired immunodeficiency syndrome in infants and children.

The classification of the pediatric acquired immunodeficiency syndrome (AIDS) is based on epidemiologic, immunologic, and virologic data. Persons at risk include mothers who use intravenous drugs, infants who have received blood transfusions from subjects with risk factors, patients receiving factor VIII therapy, and infants born to heterosexual mothers with bisexual husbands. A distinct immunologic phenotype, rarely seen in other immunodeficiency disorders, is associated with pediatric AIDS consisting of polyclonal hypergammaglobulinemia and T-cell immunodeficiency. Detection of antibody to the AIDS retrovirus or isolation of virus are essential in establishing a diagnosis. During early infancy, viral isolation is essential as passive transfer of material IgG may occur. Primary immunodeficiency diseases, in particular adenosine deaminase and purine nucleoside phosphorylase deficiency, should be excluded. A diagnosis of pediatric AIDS may be established in a patient who has a risk factor associated with AIDS, polyclonal hypergammaglobulinemia, T-cell immunodeficiency, and antibody to the AIDS retrovirus or isolation of virus.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Etiology of AIDS.

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Acquired Immunodeficiency Syndrome↗
PubMed1984

Comparison of high-dose and low-dose intravenous immunoglobulin therapy in patients with primary immunodeficiency diseases.

To assess safety and efficacy of high-dose intravenous immunoglobulin therapy in patients with primary immunodeficiency syndromes we treated a group of 19 patients with a monthly dose of 400 mg/kg of reduced and alkylated, maltose-containing immunoglobulin (Gamimune, Cutter Biological, Berkeley, California) and compared their responses with a group of 16 patients receiving 100 mg/kg per month intravenously. Side effects observed were mild to moderately severe and similar in both groups. In one adult patient receiving the high dose a severe enough reaction developed during the first infusion to exclude her from the study. Serum IgG levels of patients receiving high-dose immunoglobulin showed a stepwise increase in both trough and peak values until a new plateau was reached after four to six infusions. None of the patients receiving the low dose showed such a stepwise increase. On average, serum IgG levels rose by approximately 250 mg/dl for each 100 mg/kg immunoglobulin infused. The mean catabolic rate of the infused IgG was estimated to be 26 days in patients receiving high-dose immunoglobulin infusions. We demonstrated that 400 mg/kg immunoglobulin given intravenously every four weeks to patients with immunodeficiency results in a substantial increase in serum IgG during the postinfusion period, suggesting persistence of specific antibody throughout the interval between infusions.

Adult↗
PubMed1984

B-cell immunodeficiency in acquired immune deficiency syndrome.

To investigate B-cell function in acquired immune deficiency syndrome (AIDS), we immunized a group of patients with AIDS with pneumococcal polysaccharide (tetradecavalent) and protein (keyhole-limpet hemocyanin) antigens. Antibody responses were determined three to four weeks after immunization. Compared with controls, patients with AIDS had significantly lower geometric mean antibody levels to polysaccharide before and after immunization. Levels before and after immunization were frequently below a level thought to correlate with protection. Patients with AIDS also had a significant reduction in their primary antibody response to the protein antigens. The results of these studies indicate that AIDS is associated with an acquired B-cell as well as T-cell immunodeficiency. It is suggested that future studies should consider the evaluation of passive antibody in the prevention of infection and/or prevention of progressive immunodeficiency.

Acquired Immunodeficiency Syndrome↗
PubMed1984

New insight into the causes of immunodeficiency disorders.

The ability to define subpopulations of immunologically competent lymphocytes has permitted an enhanced understanding of the interaction between functionally distinct components of the immune system. T cells can provide help in antibody formation or they may suppress antibody production. Abnormal immunoregulatory mechanisms have been demonstrated in the hyperimmunoglobulin E-recurrent infection syndrome. This disorder is associated with a marked elevation of IgE and specific elevations of IgE antibodies directed toward staphylococcal antigens. Abnormal T cell regulation of immune responses has been demonstrated. Graft-versus-host disease (GVHD) occurs in an immunodeficient patient who has received an infusion of immunocompetent cells. The diagnosis of graft-versus-host (GVH) reaction may be complicated by the protean manifestations of the disorder. The acute form, consisting of a maculopapular rash, fever, and diarrhea, may be confused with acute infection or drug reaction. Chronic GVHD has been incorrectly diagnosed as histiocytosis X, acrodermatitis enteropathica, or scleroderma. Utilizing chromosome markers and/or identification of histocompatibility antigens, the presence of circulating lymphocytes from donor immunocompetent cells (blood transfusion, maternal source) can be documented. The development of sensitive technics for identifying cells can establish a precise diagnosis. Certain immunodeficiency disorders can be identified by biochemical means. Biotin-dependent multiple carboxylase enzyme deficiency is associated with a chronic dermatitis, alopecia, ataxia, and secondary infection of the skin with Candida. The disorder responds promptly to the administration of biotin with correction of dermatologic, neurologic, and immunologic abnormalities.

Animals↗
PubMed1984

Pediatric acquired immunodeficiency syndrome.

Approximately 40 to 50 infants and children with similar epidemiologic, clinical, and laboratory features of AIDS have been described. The occurrence of significant numbers of patients with PAIDS in geographic areas that are associated with similar risk factors and clinical features of AIDS suggests a common cause. Immunologic evaluation reveals hypergammaglobulinemia, decreased or absent antibody responses after immunization, normal to decreased T-cell numbers, decreased helper/suppressor cell ratios, and abnormal results of functional studies of T-cells. None of the patients described has the clinical or laboratory features of well-established congenital immunodeficiency disorders. No consistent viral agent has been documented except for antibody to ARV and HTLV III. The frequent finding of T-cell abnormalities in the mothers of infants with PAIDS is in contrast to the absence of such abnormalities in the mothers of infants with congenital immunodeficiency disorders. Future studies in PAIDS should be directed toward uncovering the etiology and risk factors as well as determining the response to treatment with various methods of immunologic reconstitution.

Acquired Immunodeficiency Syndrome↗
PubMed1984

IgG and IgM pneumococcal polysaccharide antibody responses in infants.

The ontogeny of human antibody responses to pneumococcal polysaccharide antigens was studied by determining whether the age at immunization affects the level and/or immunoglobulin isotype of antibody produced. Twenty-nine healthy infants between 2 and 18 months of age and 13 normal adults were studied. Responses were found to vary markedly with the age at the time of immunization and with the pneumococcal serotype tested. Three general patterns of isotype-specific antibody response were observed in the infants: a high response in IgG antibody occurred as early as 2 months of age following immunization with type 3 pneumococcal polysaccharide; little or no response was noted in either IgG or IgM antibody with types 6, 18, and 19; and intermediate responses with IgM antibody increases greater than IgG increases were found for type 23. These data suggest that different factors control the immunologic response of infants to various pneumococcal polysaccharide serotypes following immunization at various ages.

Age Factors↗
PubMed1984

Maternal transmission of acquired immune deficiency syndrome.

Acquired immune deficiency syndrome (AIDS) has been reported in previously healthy homosexual or bisexual males, intravenous drug users, heterosexual men with hemophilia, and Haitians. The finding of heterosexual hemophiliacs with AIDS has raised the possibility of a transmittable blood-borne agent as a cause of this disease. We have found three female half-siblings who had clinical and laboratory evidence for AIDS. All three had evidence of abnormal in vitro cellular immunity; two had chronic active Epstein-Barr virus infection and lymphadenopathy; all three had chronic cutaneous Candida sp infection; and two had Pneumocystis carinii pneumonia. Their mother is a prostitute/drug addict with abnormal T-cell immunity including clinical and laboratory findings of mucocutaneous candidiasis. Histocompatibility typing is consistent with the history of different fathers for each child. Immunologic studies in one child evaluated prospectively from birth were abnormal by 2 months of age. These findings and the clinical histories indicate AIDS and strongly suggest vertical transmission of an agent(s) during the perinatal period.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Complications of co-trimoxazole in treatment of AIDS-associated Pneumocystis carinii pneumonia in homosexual men.

In 8 of 18 homosexual men with the acquired immunodeficiency syndrome (AIDS) and Pneumocystis carinii pneumonia (PCP) treated with intravenous co-trimoxazole (trimethoprim-sulphamethoxazole) apparent drug-related complications developed during the course of acute therapy. A symptom complex of fevers and increasing malaise, often with nausea and headaches, developed usually after 9 days of therapy at a daily dosage of 20 mg/kg of trimethoprim and 100 mg/kg of sulphamethoxazole. These symptoms were associated with a diffuse erythematous maculopapular eruption and peripheral cytopenias. A similar picture was noted in two children with suspected AIDS-associated PCP. The high frequency of adverse reactions to co-trimoxazole therapy for PCP seems to be characteristic of AIDS patients.

Acquired Immunodeficiency Syndrome↗