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Biomedical subjects

H H Peter

Publications and source records attributed to H H Peter.

At least 235 records · Page 13Linked to original sources
PubMed1989

The DiGeorge sequence. II. Immunologic findings in partial and complete forms of the disorder.

We present immunological in vitro data on a group of 16 patients with the DiGeorge sequence (DGS). Detailed tests gave evidence that the decrease in number and function of mature T-cells is closely correlated with phenotypic expression and represents a wide immunological spectrum ranging from normal function to severe combined immunodeficiency with B-cells. Careful immunological testing in DGS may help to plan therapeutic procedures (i.e. thymic factor therapy or bone marrow transplantation), may also have prognostic significance and help to gain insight into mechanisms operative in disturbances of T-cell regulation.

Adenosine Deaminase↗
PubMed1989

Autoreactive T cells in rheumatic disease (1). Analysis of growth frequencies and autoreactivity of T cells in patients with rheumatoid arthritis and Lyme disease.

A limiting dilution system was established in order to estimate frequencies of interleukin-2 (IL-2)-responsive, autoreactive and alloreactive T cells in samples of peripheral blood (PBL) and synovial fluid lymphocytes (SFL), from patients with rheumatoid arthritis (RA) and lyme disease, as well as from healthy donors and a patient with osteoarthrosis. The frequencies of IL-2-dependent T-cell colony formation were significantly higher in patients with RA and lyme disease (median: 1/287) as compared to controls (median: 1/1,313) indicating a preactivation of T cells in these patients in vivo. Autoreactivity was measured by the proliferative response of T-cell lines to autologous irradiated PBL as stimulating cells. The frequencies of autoreactive T cells in blood were significantly higher in patients (median: 1/2,615) as compared to controls (median: 1/19,607). There was no significant difference in autoreactive T-cell frequencies between the patients' SFL (median: 1/3,185) and PBL (median: 1/2,615). In every case the frequency of alloreactive T cells exceeded the frequency of autoreactive T cells. Most autoreactive T-cell lines were also alloreactive and were shown to be MHC Class II-restricted. There is evidence of a down regulation of autoreactive T cells by suppressor cells in peripheral blood in two cases with elevated autoreactive T-cell frequencies (one RA patient and one control patient suffering from a viral infection). In contrast, no suppression of autoreactive T cells was observed in the RA patients' SFL or in PBL and SFL from patients with lyme disease. These results suggest that the chronic inflammation observed in RA and lyme disease may be supported by an elevated number of autoreactive T cells in the absence of suppressive mechanisms.

Arthritis, Rheumatoid↗
PubMed1989

Predominant immunoglobulin gene rearrangements in two patients with immunodeficiency: restricted use of V gene segments and DNA hypermethylation.

The majority of common variable immunodeficiencies (CVID) is caused by intrinsic B cell defects which impede distinct stages of B cell differentiation. B cell differentiation is accompanied by the rearrangement of immunoglobulin (Ig) genes. The first step in the rearrangement process is the assembly of IgH genes, and subsequently, IgL genes are rearranged. During B cell maturation, Ig genes are demethylated in a stepwise, locus-specific manner. Here, we examined the Ig gene rearrangements of four patients with classical CVID and of one child suffering from an unusual immunodeficiency associated with CD5+ B cell lymphocytosis. In one of the four adult patients with CVID, we observed a predominant type of VHDJH-gene rearrangement. In the child, different polyclonal VHDJH-gene rearrangements were found together with a predominant type of kappa light chain gene rearrangement. The rearranged kappa chain genes were methylated (as in the pre-B cell stage). These findings together with the cell phenotype analysis and the clinical course of the disease in the child suggests that in some patients with primary immunodeficiency a maturation arrest may occur in B cells leading to a predominant Ig V gene rearrangement.

Adolescent↗
PubMed1989

Transient hypogammaglobulinemia of infancy: Five new cases, review of the literature and redefinition.

The clinical and immunological data of 5 patients with transient h hypogammaglobulinemia of infancy (THI) are presented and compared to published data. In THI, there is distinction between patients who can mount a specific immune response, by producing specific antibodies to bovine serum albumin, diphtheria toxin, and isohemagglutinins, and patients with more severe forms of immunodeficiency. With only 5 reported cases of THI in 11 years and analysis of more than 8000 sera-, our data support the notion that THI is a relatively rare disorder. THI can only be diagnosed with certainty in retrospect, although the ability to mount an active, specific immune response is a strong indicator for the diagnosis. We propose a more accurate definition of THI to help avoid clinical misjudgement.

Agammaglobulinemia↗
PubMed1989

[Unusual immunoglobulin gene rearrangements in patients with immunodeficiency].

In a 64-year-old patient with typical common variable immunodeficiency (CVID) DNA prepared from peripheral blood lymphocytes (PBL) showed a prominent immunoglobulin heavy chain (IgH) gene rearrangement; the immunoglobulin light chain (IgL) genes were found to be in the germline configuration. In contrast, a 13-year-old girl with a hitherto unidentified immunodeficiency showed polyclonal IgH gene rearrangements and a dominant IgL gene rearrangement. In both cases neither monoclonal B-lymphocytes nor monoclonal immunoglobulins were detectable. Our explanation for this unusual observation is that V-gene use in a given B-cell is not entirely random. This may be the consequence of a maturation arrest of B-cells.

Adolescent↗
PubMed1989

[An unusual slow course of systemic vasculitis with multiorgan involvement].

This paper reports on an unusually slowly progressing course seen in systemic vasculitis of the median and smaller arteries and small veins associated with dermatomyositis, chronically active hepatitis, glomerulonephritis of the immune complex and restrictive cardiomyopathy in a 35-year-old patient. The authors discuss the difficulties in establishing the diagnosis and in finding the exact classification of this disease.

Adult↗
PubMed1988

Paroxysmal nocturnal hemoglobinuria. Enhanced stimulation of platelets by the terminal complement components is related to the lack of C8bp in the membrane.

Recently, a protein isolated from the membrane of human E, the so-called C8 binding protein (C8bp), has been described. C8bp is characterized as a 65-kDa protein that binds to C8 and inhibits the C5b-9-mediated lysis in a homologous system. In the present study, membranes of peripheral blood cells were tested for the presence of C8bp by SDS-PAGE and immunoblotting. In all cells a protein band reacting with anti-C8bp was seen, the Mr, however, was only about 50 kDa. To further analyze the 50-kDa protein, we isolated the protein by phenol-water extraction and isoelectric focusing from papain-treated platelets. The isolated protein behaved similar to the E-derived C8bp: it inhibited the lysis of model target cells by C5b-9. To examine the function of C8bp in platelets, we tested platelets from patients suffering from paroxysmal nocturnal hemoglobinuria (PNH). These platelets were deficient in C8bp, being in accordance with their higher lytic susceptibility in vitro. In response to sublytic C5b-9 doses, the PNH platelets released considerably more serotonin and thromboxane B2 than normal platelets. By addition of purified C8bp, the thromboxane B2 release was suppressed, indicating that C8bp not only restricts the lytic complement attack, but also regulates the C5b-9-mediated stimulation of target cells. Thus, lack of C8bp might not only result in enhanced hemolysis, but also in enhanced stimulation of platelets, which in turn might contribute to the thrombotic complications seen in some PNH-type III patients.

Blood Platelets↗
PubMed1988

C-reactive protein-mediated complement activation in polymyalgia rheumatica and other systemic inflammatory diseases.

An immunoglobulin-independent deposition of the complement (C) components C4 and C3 occurs on rat kidney medullary structures, when sera of patients with various inflammatory diseases are studied by indirect immunofluorescence. The diagnostic value of this new test (C4-C3-IFT) for polymyalgia rheumatica (PMR) is stressed, since all sera from patients with active disease yielded positive reactions. Though highly sensitive with respect to PMR, C4/C3-IFT is not specific for this syndrome. Examples of positive reactions in systemic inflammatory diseases other than PMR are documented. Besides the clinical studies, C4/C3-IFT reactivity was analyzed with regard to the mechanisms of the reaction. Experimental data are presented which suggest that C-reactive protein (CRP) binds to rat kidney structures, thereby activating the classical C cascade. As a result of CRP-C interaction, C4 and C3 components are fixed to distinct renal medullary structures. Because of its technical simplicity, C4/C3-IFT can routinely be used to screen patients' sera for CRP-mediated C activation. This ex vivo test system may contribute to a better understanding of pathophysiological functions of serum CRP in various inflammatory diseases.

Antigen-Antibody Complex↗
PubMed1988

Results of a multicenter placebo-controlled double-blind randomized phase III clinical study of treatment of rheumatoid arthritis with recombinant interferon-gamma.

In a multicenter placebo-controlled double-blind randomized clinical study, 91 patients with rheumatoid arthritis were given 28 days' treatment with recombinant interferon-gamma (50 micrograms daily for 20 days, then 50 micrograms each second day up to day 28, given by subcutaneous injection). The aim of the study was to provide a methodologically clear demonstration of the efficacy of treatment with interferon-gamma, using criteria that could be handled by statistical tests. Evaluatable documentation was available for 79 patients, of whom 40 were treated with the active compound. The principal criterion for the statistical evaluation of the therapeutic success was improvement of the Ritchie "joint pain index" or Lansbury "joint pain index" by at least 30% within 28 days. The chi-square test showed superiority of the interferon arm over the placebo arm with an error probability of alpha less than 1%. In addition, efficacy of interferon-gamma was demonstrated in respect of practically all parameters investigated. The frequency of side-effects, including febrile reactions, was the same for the active compound and the placebo. During interferon treatment the daily maximum body temperature was raised by 0.3 degrees C on average, but was below 37.2 degrees C at all times.

Adolescent↗
PubMed1988

The DiGeorge syndrome. I. Clinical evaluation and course of partial and complete forms of the syndrome.

This study describes clinical signs and symptoms in 16 patients with the DiGeorge syndrome (DGS). Diagnosed on the basis of typical facial stigmata, a broad spectrum of severity is seen with respect to congenital heart disease, hypoparathyroidism and immunologic parameters. A simple index of severity is introduced that clearly differentiates complete forms of the syndrome (cDGS) with poor prognosis from partial forms of the syndrome (pDGS). Of 13 pDGS patients, 12 are still living; 8 underwent corrective heart surgery without infectious complications. Moderate to severe mental retardation is seen in all pDGS patients. Due to the lack of thymus function, immunodeficiency is a result of cDGS, whereas immunoregulatory disturbances (hypergammaglobulinaemia, high titres of specific antibody production) prevail in pDGS patients.

Adolescent↗
PubMed1988

IgD/lambda plasmocytoma with immunoglobulin kappa light-chain genes in the germ-line configuration.

Human immunoglobulin (Ig) genes are rearranged in an ordered sequence of events during B-cell differentiation: starting at the IgH locus, a productive VHDJH rearrangement leads to the expression of mu chains. Light-chain gene rearrangements have been found in pre-B cells which express mu chains. In these cells rearrangements of Ig kappa light-chain genes precede that of lambda genes. In an IgD/lambda-producing plasmocytoma, however, we found an apparent exception to this rule: the kappa genes were not rearranged. Together with the observation that roughly 90% of human IgD plasmocytomas produce lambda light-chain proteins, the finding reported here leads us to suggest that lambda light-chain genes are rearranged preferentially in IgD-producing plasma cells. Ig gene rearrangement, isotype switch, and the phenomenon of isotypic and allelic exclusion are discussed with special reference to our findings.

Gene Rearrangement↗
PubMed1988

Autoreactive T cells in rheumatic disease. II. Function and specificity of an autoreactive T helper cell clone established from a HLA-B27+ reactive arthritis.

T cell lines were established by limiting dilution of peripheral blood (PBL) and synovial fluid lymphocytes (SFL) of a patient with HLA-B27+ reactive arthritis. Among these cell lines, the CD4 phenotype was dominant. Functionally, the majority of these cell lines exhibited helper activity for the immunoglobulin production by autologous B cells and proliferated in response to autologous mononuclear cells. In most cases, this autoreactive response was associated with alloreactivity. Only one cell line, the autoreactive CD4+ T cell clone, UA-S2, which was derived from the synovial fluid, proliferated in a highly specific manner in response to a determinant associated with MHC class II products present on autologous mononuclear cells. The restriction element was shown to be associated with DR molecules by inhibition experiments with monoclonal antibodies. Within the patient's family, the capacity of mononuclear cells to stimulate a proliferative response of UA-S2 segregated together with the HLA haplotype A2 or 32, B27, Cw1, DRw11 which was contributed by the patient's mother. UA-S2 proved to be a functional helper T cell clone. In the absence of additional antigen or mitogen, it induced IgG and IgM synthesis of autologous and family members' B cells. This helper activity of UA-S2 showed the same MHC restriction as the proliferative response. Although the patient's father also typed DRw11, this haplotype was not recognized by UA-S2. It is suggested that this autoreactive T cell clone detects a microheterogeneity of the serologically defined DRw11 haplotype. Indeed, typing of the patient's family members with cellular reagents established a difference between the two DRw11 haplotypes.

Arthritis, Rheumatoid↗
PubMed1988

Epidermodysplasia verruciformis in a patient with Hodgkin's disease: characterization of a new papillomavirus type and interferon treatment.

A new human papillomavirus (HPV) was discovered in disseminated, macular, pityriasis versicolor-like lesions on the skin of the neck, face, scalp, and pubic region of a 42-year-old male suffering from Hodgkin's disease. Histopathology revealed features characteristic of epidermodysplasia verruciformis (ev). In contrast to classical ev, the lesions were almost exclusively seen in previously irradiated and UV-exposed skin areas. Papillomavirus capsid antigen was demonstrated with the genus-specific antiserum and the patient's serum, which had IgM and IgG antibody titers. HPV DNA was isolated from biopsies and cloned into the vector pIC20H. It proved to be related to ev-associated viruses, showing 23% cross-hybridization with DNA of the closest relative HPV14. The new HPV type was named HPV46. The genome was physically mapped and colinearly aligned with HPV8 DNA to establish its gene organization. Interferon treatment of the patient did not significantly change the clinical picture nor was the concentration of viral DNA per lesion affected. However, no virus capsid antigen was detectable after starting treatment.

Adult↗
PubMed1988

Immune response in chronic Schistosomiasis haematobium and mansoni. Reversibility of alterations after anti-parasitic treatment with praziquantel.

Peripheral blood mononuclear cells from Sudanese children heavily infected with Schistosoma haematobium and S. mansoni were examined for lymphocyte subpopulations, for mitogen and antigen responsiveness, and for natural killer (NK) cell activity before and 5 months after treatment with praziquantel. The humoral immune response was simultaneously investigated by determination of parasite-specific IgG and IgE antibodies, IgE-containing circulating immune complexes, and circulating schistosome antigen. A single dose treatment with praziquantel (40 mg/kg) resulted in a normalization of numerical imbalances in lymphocyte subpopulations, a significant increase in the blastogenic response upon stimulation with adult worm antigen, phytohaemagglutinin (PHA), and concanavalin A (Con A), and restoration of natural killer (NK) cell-mediated lysis of K562 targets. These findings were paralleled by a remarkable decrease in parasite-specific IgE antibodies, IgE-containing circulating immune complexes, and circulating schistosome antigen. The results indicate that the modulation of immune responses in chronic schistosomiasis is associated with active infection and is reversible after successful chemotherapy.

Antibodies, Helminth↗