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Biomedical subjects

H D Ochs

Publications and source records attributed to H D Ochs.

At least 19 recordsLinked to original sources

Antibody responses to bacteriophage phi X174 in patients with adenosine deaminase deficiency.

Adenosine deaminase (ADA) deficiency and its biochemical consequences cause severe combined immunodeficiency (SCID). Treatment strategies, designed to correct the biochemical abnormalities, include transplantation of matched bone marrow or haploidentical bone marrow stem cells, repeated partial exchange transfusions with frozen irradiated human red blood cells (RBC), or weekly injection of polyethylene glycol-modified bovine ADA (PEG-ADA). To evaluate the effect of these therapeutic options, we studied in vitro T-cell function and in vivo antibody responses to the T-cell-dependent neoantigen, bacteriophage phi X174, in 10 children with ADA-deficient SCID. In untreated patients, T-cell function was severely depressed, and only minute amounts of antibacteriophage antibody were produced. Transplantation of bone marrow from a matched sibling (one patient) or a phenotypically matched parent (one patient) resulted in a stable graft, normal T-cell function, and substantial but subnormal antibody titers to bacteriophage, with reduced memory and impaired switch from IgM to IgG. Patients receiving T-cell-depleted haploidentical bone marrow stem cells had markedly depressed antibody responses for as long as 3 years posttransplantation, despite rapidly improving T-cell function that became normal in two of four patients. Two methods of enzyme replacement were explored. During treatment with human RBC transfusions, antibody responses to bacteriophage were as severely depressed as in untreated ADA-deficient patients. Treatment with weekly injections of PEG-ADA resulted in normalization of T-cell numbers in all four patients, normal or near-normal T-cell function in two, and mildly but variably improved T-cell function in the other two patients. Quantitatively and qualitatively normal antibody responses to bacteriophage were observed in three of four patients. Assessment of antibody responses to immunization with bacteriophage phi X174 is a useful method to monitor humoral immune function in treated ADA-deficient patients and can be used to estimate when intravenous immunoglobulin (IVIG) prophylaxis may be safely discontinued.

Adenosine Deaminase

Intravenous immunoglobulin therapy for active, extensive, and medically refractory idiopathic ulcerative or Crohn's colitis.

To determine whether intravenous immunoglobulin produces demonstrable clinical improvement in patients with refractory idiopathic inflammatory bowel disease, a pilot, open-label, nonrandomized, safety and therapeutic efficacy study was carried out at a tertiary care referral medical center. Twelve consecutive patients with refractory idiopathic colitis (nine ulcerative colitis, three Crohn's colitis) who were reluctant to receive immunosuppressive therapy or have surgical intervention were referred by physicians not participating as investigators in this study. Eleven patients were symptomatic for at least 6 months, with endoscopically moderate or severe mucosal inflammation despite medical therapy, including systemic corticosteroids in all cases, and one patient was dependent on oral prednisone to remain in clinical remission. Ten patients had extensive colitis, six of whom had pancolitis and four of whom had colitis extending to the hepatic flexure or transverse colon. Nine patients required hospitalization for treatment of colitis. Intravenous immunoglobulin was administered in one or two induction phases (2 g/kg over 2 or 5 days), followed by a maintenance phase (200-500 mg/kg every 2 wk for 12 or 24 wk). Tapering of systemic corticosteroid therapy was attempted, whereas other medications for idiopathic colitis were continued. Treatment response was assessed clinically and by colonoscopy with multiple biopsies whenever possible. Immunoglobulin therapy was well-tolerated and did not produce any biochemical abnormalities. In six patients who completed the treatment protocol, mean reductions +/- SE were achieved in subjective symptoms as quantified by a colitis activity score, 13.3 +/- 1.2 to 4.7 +/- 0.9 (p less than 0.001), and daily mg dose of prednisone, 41.7 +/- 8.0 to 1.9 +/- 1.2 (p less than 0.001). For all 12 patients, statistically significant reductions were achieved in the colitis activity score and daily prednisone dose. Of five patients who completed the treatment protocol and improved clinically, four underwent post-treatment colonoscopic and biopsy evaluations and had unequivocal reductions in the intensity of colonic mucosal inflammation. Three patients who had objective improvement with intravenous immunoglobulin experienced relapses of colitis after discontinuation of this therapy. Six patients did not complete the treatment protocol, two of whom required surgical intervention and four of whom withdrew to undergo colectomy electively. Intravenous immunoglobulin may be beneficial in subsets of patients with idiopathic colitis. The results of our pilot study justify the undertaking of a prospective, randomized controlled trial to determine the efficacy of intravenous immunoglobulin in carefully defined subsets of patients with idiopathic inflammatory bowel disease.

Adolescent

Maternal-fetal transmission of SIV in macaques: disseminated adenovirus infection in an offspring with congenital SIV infection.

To develop a nonhuman primate model for maternal-fetal transmission of HIV infection, we have inoculated pregnant Macaca nemestrina with uncloned SIVMne. Three animals inoculated during the third trimester delivered healthy infants. One of the three infants, a male born 31 days after the mother was inoculated with SIV, became virus-positive but failed to produce SIV-specific antibody and died with overt simian immunodeficiency and disseminated adenovirus (SV20) infection at age six and one-half months. SIV and adenovirus antigen could be demonstrated by immunohistochemical methods in multiple organ systems.

Adenoviridae Infections

Home-based immunoglobulin infusion therapy: quality of life and patient health perceptions.

Thirty-seven antibody-deficient patients who were participating in a multicenter trial evaluating home-based, self-administered IVIG therapy anonymously completed questionnaires regarding beliefs concerning health control, quality of life, and attitudes toward active participation in medical care. Their responses were compared with a group of 29 patients undergoing traditional IVIG therapy in a medical clinic setting. A subsample of the home-based group who later returned to clinic-based IVIG therapy allowed comparison of responses given by the same patients in both settings. Home-based therapy was preferred to clinic-based therapy. Independence, convenience, comfort, decreased disruption of activities, travel time, and costs were specific factors rated most favorably. On the Health Belief Questionnaires, patients preferred informed, self-involved medical care regardless of the setting for their IVIG treatments.

Adult

Origin of mutations in two families with X-linked chronic granulomatous disease.

The most common X-linked recessive form of chronic granulomatous disease (X-CGD) is characterized by the absence of cytochrome b558 in neutrophils. In a rare variant form of X-CGD, cytochrome b558 is present but not functional. The gene (locus symbol CYBB) was localized to band Xp21 by studies of patients with small chromosome deletions. The gene was cloned based on its location and found to encode the 91-Kd subunit of the cytochrome b558 complex. Most female carriers for X-CGD can be identified by their X-inactivation mosaicism; on average 50% of their neutrophils express the mutant phenotype and fail to reduce nitroblue tetrazolium (NBT). In 2 of 4 families studied, the maternal grandmothers had normal NBT tests, suggesting either nonrandom X-inactivation or new mutations. Restriction fragment length polymorphism analysis using closely linked flanking markers or the NsiI polymorphism detected by the CYBB probe itself, allowed us to identify the X chromosome carrying the mutation as derived from a healthy NBT-positive maternal grandfather. The mothers of the affected boys must have received a paternal X chromosome carrying a new mutation, consistent with the maternal grandmothers' normal NBT tests. In all of eight potential carriers studied, the results of the NBT and DNA marker testing were in complete agreement. Prenatal diagnosis by DNA testing can be performed in early gestation obviating the need for fetal blood sampling.

DNA

Identification of surface proteins mediating adherence of CD11/CD18-deficient lymphoblastoid cells to cultured human endothelium.

Patients with the severe form of leukocyte adhesion deficiency syndrome do not express the CD11/CD18 adhesion complex on any of their leukocytes. Nevertheless, their lymphocytes, unlike their phagocytes, emigrate to extravascular sites of inflammation, demonstrating that surface proteins other than CD11/CD18 can mediate lymphocyte adherence to endothelium. Using a B-lymphoblastoid cell line (B-LCL) established from a CD11/CD18-deficient patient and cultured human umbilical vein endothelial cells (HEC), we investigated the CD11/CD18-independent mechanism(s) of lymphocyte adherence to endothelium. Monoclonal antibodies directed to the alpha 4 polypeptide (CD49d) and the beta 1 polypeptide (CD29) of the lymphocyte VLA-4 integrin receptor (CD49d/CD29), and to vascular cell adhesion molecule-1 (VCAM-1) on the endothelial cell significantly inhibited the adherence of the CD11/CD18-deficient B-LCL to untreated HEC and to HEC treated with recombinant human tumor necrosis factor-alpha. We suggest that the interaction of the lymphocyte receptor VLA-4 with the endothelial ligand VCAM-1 induced by cytokines at sites of inflammation or immune reaction represents a CD11/CD18-independent pathway of lymphocyte emigration.

Antibodies, Monoclonal

Phorbol ester causes down-regulation of CD11/CD18-independent neutrophil adherence to endothelium.

Neutrophils adhere to interleukin-1 (IL-1)-, tumour necrosis factor (TNF)- or lipopolysaccharide (LPS)-pretreated human umbilical vein endothelial cells (HEC) by CD11/CD18-dependent and independent mechanisms. We investigated CD11/CD18-independent neutrophil adherence to LPS-pretreated HEC by: (i) pretreating neutrophils with the anti-CD18 monoclonal antibody mAb 60.3; (ii) performing assays in the absence of Mg2; or (iii) using neutrophils isolated from a patient with leucocyte adhesion deficiency (CD11/CD18-deficiency). Under each of these conditions, CD11/CD18-independent neutrophil adherence to LPS-pretreated HEC was significantly greater than adherence to untreated HEC (15-18% versus 3-7%). In each case, however, stimulation of neutrophils with phorbol ester (PMA) abolished CD11/CD18-independent adherence to LPS-pretreated HEC (less than 5% adherence). Stimulation of neutrophils with bacterial chemotactic peptide (FMLP) or calcium ionophore (A23187) likewise reduced CD18-independent adherence to LPS-pretreated HEC. PMA also inhibited CD11/CD18-independent neutrophil adherence to HEC pretreated with IL-1 or TNF (80-90% inhibition). In contrast, PMA markedly enhanced CD11/CD18-dependent adherence to untreated or LPS-treated HEC. We conclude that stimulation of neutrophils with phorbol ester or other direct agonists down-regulates the CD11/CD18-independent mechanism of neutrophil adherence to IL-1, TNF- or LPS-pretreated HEC.

Antigens, CD

Home self-administration of intravenous immunoglobulin therapy in children.

Twelve children with primary immunodeficiency, aged 2 to 17 years (mean +/- 1 SD = 9.8 +/- 5.3), were enrolled in a 9-month study to evaluate the feasibility and safety of home self-infusion of intravenous immunoglobulin (IVIg). An initial 2-month training and supervisory period was followed by a 6- to 7-month period during which the children or their parents infused IVIg in a home setting. Eight children received an average dose of 204 +/- 12 mg/kg every 2 weeks, two children received a dose of 400 mg/kg every month, and an additional two children received 240 to 250 mg/kg every 10 days. Peak and trough levels varied from 946 +/- 20 mg/dL and 627 +/- 16 mg/dL, respectively, in children receiving IVIg every 2 weeks. The peak-trough values for the children receiving IVIg every month were 1105 +/- 94 mg/dL and 457 +/- 78 mg/dL, while those of children receiving IVIg every 10 days were 840 +/- 24 mg/dL and 553 +/- 109 mg/dL. A total of 224 infusions were administered, with only two minor reactions occurring (reaction rate of 0.9%). There was no difference in the frequency of infections and antibiotic use during the study compared with the previous phase. The results demonstrate that home self-infusion of IVIg in children is safe and feasible.

Adolescent

Heterogeneity of chromosomal breakage levels in epithelial tissue of ataxia-telangiectasia homozygotes and heterozygotes.

The objective of this study was to obtain an estimate of the frequency distribution of spontaneous chromosomal breakage occurring in vivo in oral epithelia of 20 ataxia-telangiectasia patients (A-T homozygotes) and 26 parents (A-T obligate heterozygotes). Samples of exfoliated cells were obtained from each individual by swabbing the oral cavity and preparing air-dried slides. The percentage of exfoliated cells with micronuclei (MEC frequency) was used as an in vivo indicator for the amount of chromosomal breakage occurring in the tissue. As a population group, MEC frequencies of the A-T patients differed significantly from controls (mean for A-T patients, 1.51; for controls, 0.29; P less than 0.01). However, the values observed in individual patients ranged from MEC frequencies 10- to 12-fold above control values, to frequencies overlapping the upper values observed in the controls. Similarly, MEC frequencies observed among the A-T heterozygotes differed significantly from controls (mean for A-T heterozygotes, 1.02, mean for controls, 0.29; P less than 0.01). However, only 16 of the 26 individuals sampled had MEC frequencies greater than 0.5%, the 90th percentile for controls (compared with 16 of the 20 A-T patients examined). Of the A-T patients 11 had been previously assigned to complementation groups on the basis of sensitivity to x-irradiation. Seven of the patients belonged to group A and had MEC frequencies ranging from 0.3% to 1.9% with the remaining patients belonging to group C with MEC frequencies of 0.2% to 0.9%. The data presented in this paper suggest that although levels of spontaneous breakage in epithelial tissues of A-T patients and A-T obligate heterozygotes are often significantly elevated, this is not the case in all individuals.

Adolescent

Human antibody responses to bacteriophage phi X 174: sequential induction of IgM and IgG subclass antibody.

We studied the appearance of antigen-specific immunoglobulin classes and IgG subclasses in normal adult human subjects in response to primary, secondary, and tertiary immunization with the T-cell-dependent neo-antigen bacteriophage phi X 174. To complete the study we developed a sensitive, specific, and reproducible ELISA assay which was closely comparable to the widely used neutralization assay for total antibody (r = +0.97) and for IgG antibody (r = +0.93), and reasonably comparable for IgM antibody (r = +0.76). We confirmed that the initial response to primary immunization was predominantly, but not exclusively, IgM antibody. The secondary and tertiary responses demonstrated memory, amplification, and switch from IgM to IgG antibody. There was an orderly appearance of phage-specific IgG subclasses. IgG3 and IgG1 antibodies appeared 2 to 6 weeks after primary immunization. In all subjects there was a marked increase in IgG1 and IgG3 antibody after secondary immunization, and IgG2 antibody followed closely; IgG4 antibody appeared in some subjects. IgM antibody persisted in significant amounts (approx 50%) throughout the secondary response period. Following tertiary immunization, IgG1, IgG2, and IgG3 antibody consistently increased, and IgG4 antibody appeared in all subjects; IgG1 antibody predominated. Low levels of IgM antibody (approx 1% of total) persisted during the tertiary response. The persisting antibody on long-term follow-up (median 4 years after immunization) was virtually all (greater than 90%) IgG1.

Adult

Lymphocyte alterations in zinc-deficient calves with lethal trait A46.

Lymphocyte numbers and activities were evaluated at 2, 4, 8 and 12 weeks of age in two calves with lethal trait A46 (A46), a genetic disorder affecting intestinal zinc absorption. Plasma zinc concentrations declined to subnormal by 3 weeks of age, after which anorexia, diarrhea, alopecia and hyperkeratosis occurred. Lymphocyte response to phytohemagglutinin-P (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) stimulation was variably reduced. CD4+ T-lymphocytes were subnormal on at least one observation period following onset of zinc deficiency, and relative numbers of B lymphocytes were decreased at 8 weeks. Secondary antibody responses to bacteriophage phi X 174 were significantly reduced. The results demonstrate that calves homozygous for the A46 trait have normal numbers of functional lymphocyte subpopulations at birth, and that the activity of their lymphocytes is altered once the calves become zinc deficient.

Animals

Immune dysfunction associated with graft-versus-host reaction in mice transplanted across minor histocompatibility barriers. I. Depressed antigen-specific antibody responses to bacteriophage phi chi 174.

The effect of the graft-versus-host reaction in response to minor histocompatibility antigens on the antibody response to a T-dependent antigen was studied in four strains of mice. Lethally irradiated mice were transplanted with bone marrow plus graded numbers of spleen cells from H-2-compatible donors. Recipients of syngeneic bone marrow transplants and recipients of allogeneic bone marrow depleted of T cells made normal antibody responses to bacteriophage phi chi 174 when immunized on day 28 (primary) and day 56 (secondary) after marrow transplantation. Recipients of allogeneic bone marrow plus spleen cells made only small amounts of specific antibody and failed to make IgG antibody after secondary immunization. The pattern of the depressed antibody response suggests that the primary mechanism of immune dysfunction in mice with the minor antigen GVHR is a lack of T helper cell function.

Animals

CD11/CD18-independent neutrophil adherence to inducible endothelial-leucocyte adhesion molecules (E-LAM) in vitro.

We examined the mechanisms involved in neutrophil adherence to cultured human umbilical vein endothelial cells (HEC) induced by direct stimulation of the neutrophils by phorbol myristate acetate (PMA), formylmethionyl-leucyl-phenylalanine (FMLP), or the calcium ionophore A23187 (neutrophil-dependent adherence), or by pretreatment of HEC with interleukin-1 (IL-1), tumour necrosis factor (TNF) or lipopolysaccharide (LPS) (endothelial-dependent adherence). Two distinct mechanisms for neutrophil adherence to HEC were demonstrated by performing adherence assays: (i) at 37 degrees versus 4 degrees; (ii) in the presence of Ca2+ only versus Mg2+ only; and (iii) in the presence or absence of monoclonal antibodies (mAb) to the CD11/CD18 adhesion complex of neutrophils. A CD11/CD18-dependent mechanism (i.e. inhibited by anti-CD18 mAb) was identified that was active in the presence of Mg2+ only but not of Ca2+ only, and at 37 degrees but not at 4 degrees. A CD11/CD18-independent mechanism (i.e. not inhibited by anti-CD18 mAb) was active at 4 degrees and at 37 degrees, and in the presence of Ca2+ only and of Mg2+ only. Neutrophil-dependent adherence induced by FMLP or PMA occurred solely via the CD11/CD18-dependent mechanism, whereas endothelial-dependent adherence induced by a 4-hr pretreatment with IL-1, TNF, or LPS involved both CD11/CD18-dependent and/independent mechanisms. CD11/CD18-deficient neutrophils isolated from a patient with leucocyte adherence deficiency (LAD) maintained the ability to adhere to LPS-pretreated HEC in the presence of Ca2+ only, indicating that this mechanism of adherence involves a receptor on the neutrophil distinct from CD11/CD18. Furthermore, the disappearance of the CD11/CD18-independent, but not of the CD11/CD18-dependent mechanism of adherence, in HEC treated with TNF for 24 hr suggests that the two mechanisms of neutrophil adherence also involve distinct inducible endothelial-leucocyte adhesion molecules (E-LAM).

Antigens, Surface

IgM deficiency: clinical spectrum and immunologic assessment.

Selective IgM deficiency has been associated with recurrent infections and enteric protein loss. We have evaluated eight patients with IgM deficiency presenting with recurrent infections and manifestation of atopy. A variety of subtle immunologic aberrations were noted, including depressed IgM and elevated IgG responses to immunization with bacteriophage OX174. Despite normal quantitative IgG in most patients, IgG antibody responses to diphtheria-tetanus and/or pneumococcal polysaccharide antigens were generally depressed. No correlation could be made between antibody responses (or lack thereof) and the nature of infections in any given patient.

Adolescent

Role of C3 in humoral immunity. Defective antibody production in C3-deficient dogs.

Previous studies have shown that animals pharmacologically depleted of C3 have impaired antibody responses. However, such C depletion is neither complete nor sustained, and the C3 cleavage products generated by C3 depletion can both enhance and inhibit the immune response. To clarify the role of C3 in humoral immunity, the antibody response of dogs with genetically determined total deficiency of C3 (C3D) was examined. Serum IgG levels of the C3D animals were within the normal range, but were significantly lower than levels seen in normal controls or C3D heterozygotes. Specific antibody production was defective: the antibody titers of C3D dogs in response to primary intravenous immunization with two different T cell-dependent Ag (sheep E and bacteriophage phi X-174) were markedly reduced when compared to either normal controls or C3D heterozygotes. After secondary immunization with T-dependent Ag, the total antibody titers were normal, but the C3D dogs made proportionately more IgM and less IgG antibody than did either control group. After i.v. immunization with a T cell-independent Ag (DNP-Ficoll), the C3D dogs had reduced levels of IgM and IgG antibody after primary and secondary immunization. Neither i.m. immunization nor the use of a 20-fold increase in Ag dose i.v. could correct the defect seen in the antibody response of C3D dogs. The results herein demonstrate that C3 plays a critical role in the generation of a normal humoral immune response.

Agammaglobulinemia