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Biomedical subjects

J B Peter

Publications and source records attributed to J B Peter.

At least 73 records · Page 4Linked to original sources
PubMed1995

Carbohydrate-deficient transferrin and false-positive results for alcohol abuse in primary biliary cirrhosis: differential diagnosis by detection of mitochondrial autoantibodies.

Primary biliary cirrhosis (PBC) is one of the few nonalcohol-induced liver pathologies that causes false positives in assays of carbohydrate-deficient transferrin (CDT) for diagnosing alcohol abuse. CDT was quantified by isoelectric focusing-immunoblotting-laser densitometry (IEF-IB-LD) analysis of serum from 117 women: 57 PBC patients, 20 alcohol abusers, and 40 healthy donors. Only 5% (3 of 57) of PBC patients were positive at the densitometric cutoff value chosen (> 90% specificity). Serum samples from 15 PBC patients were further evaluated by IEF-IB-LD and CDTect chromatography-RIA. Receiver-operating characteristic (ROC) analysis showed that IEF-IB-LD better discriminated between PBC and alcohol abuse than CDTect did. By ROC analysis, mitochondrial autoantibodies to pyruvate dehydrogenase antigen M2 detected by enzyme immunoassay yielded optimal test performance for diagnosing PBC. Of six patients falsely positive for CDT by CDTect, five (83%) tested M2-positive. Thus, abnormal CDT results should be further evaluated by mitochondrial antibody testing in patients with findings compatible with PBC.

Alcoholism↗
PubMed1995

Laboratory diagnosis of antiphospholipid syndromes.

The search for clinical outcomes associated with antiphospholipid antibodies (aPL) has been ongoing for a decade. This article focuses on the clinical use of tests for the detection of aPL. A review of the current thinking regarding the pathophysiology of antiphospholipid syndromes is relevant to the discussion of different aPL assays and methodologies. The value of aPL testing in specified patient populations is analyzed.

Antiphospholipid Syndrome↗
PubMed1994

Antibodies to histone (H2A-H2B)-DNA complexes in the absence of antibodies to double-stranded DNA or to (H2A-H2B) complexes are more sensitive and specific for scleroderma-related disorders than for lupus.

OBJECTIVE: To assess the role of antibodies to histones H2A, H2B, and anti-double-stranded DNA which form (H2A-H2B)-DNA complexes in patients with scleroderma-related disorders. METHODS: Antihistone antibodies were measured, by enzyme immunoassay, in 26 patients with scleroderma-related disorders, 100 patients with systemic lupus erythematosus (SLE), and 24 patients with rheumatoid arthritis. RESULTS: Antibodies to histone (H2A-H2B)-DNA complex were more commonly seen in patients with scleroderma-related disorders than in those with SLE (P < 0.0001). CONCLUSION: Scleroderma-related disorders should be included among conditions in which various types of antihistone antibodies are produced. A hypothesis to account for this finding is discussed.

Antibodies↗
PubMed1994

Decreased natural killer cell activity is associated with severity of chronic fatigue immune dysfunction syndrome.

Natural killer (NK) cell activity was measured blindly in vitro with blood specimens from 50 healthy individuals and 20 patients with clinically defined chronic fatigue immune dysfunction syndrome (CFIDS) who met the criteria established by the Centers for Disease Control and Prevention (Atlanta). In accordance with a group scoring system of 1-10 points, with 10 being the most severe clinical status, the patient population was stratified into three clinical groups: A (> 7 points), B (5-7 points), and C (< 5 points). NK cell activity was assessed by the number of lytic units (LU), which for the 50 healthy controls varied between 20 and 250 (50%, 20-50 LU; 32%, 51-100 LU; 6%, 101-130 LU; and 12%, > 150 LU). In none of the 20 patients with CFIDS was the NK cell activity > 100 LU. For group C, the 10 patients stratified as having the least severe clinical condition, the measure was 61.0 +/- 21.7 LU; for group B (more severe, n = 7), it was 18.3 +/- 7.3 LU; and for group A (most severe, n = 3), it was 8.0 +/- 5.3 LU. These data suggest a correlation between low levels of NK cell activity and severity of CFIDS, which, if it is confirmed by additional studies of larger groups, might be useful for subgrouping patients and monitoring therapy and/or the progression of CFIDS.

Adult↗
PubMed1994

Elevated serum levels of TNF soluble receptors in patients with positive anti-neutrophil cytoplasmic antibodies.

ANCA are found in various systemic vasculitis and are supposed to play a role in the pathogenesis of the disease, in co-operation with other factors such as cytokines. A total of 36 ANCA-positive and 10 ANCA-negative serum samples were analysed for the presence of TNF soluble receptors (TNF-sR), which are shed from the surface of activated cells and may act as TNF inhibitors. Of the ANCA-positive samples, 67% had elevated TNF-sR75 and 72% had elevated TNF-sR55 compared to ANCA-negative specimens (mean [S.E.] 18.7 [17.3] vs 3.6 [1.5] and 10.5 [9.7] vs 1.9 [0.7] ng/ml, P < 0.01). Elevation of TNF-sR in patients with ANCA suggests that cytokines and their inhibitors are involved in the pathogenesis of ANCA-associated autoimmune diseases.

Analysis of Variance↗
PubMed1994

Persistent generalized lymphadenopathy and non-Hodgkin's lymphoma in AIDS: association with Rochalimaea henselae infection.

Cat scratch disease, which is caused by infection with Rochalimaea henselae, is often manifested as lymphadenopathy. R. henselae has also been isolated from human immunodeficiency virus (HIV)-positive patients with bacillary angiomatosis. In order to determine the frequency of R. henselae-reactive antibodies in HIV-positive patients with persistent generalized lymphadenopathy (PGL) or non-Hodgkin's lymphoma (NHL), we tested a total of 124 HIV-positive patients for R. henselae-reactive immunoglobulin G (IgG), IgM, and IgA antibodies by an enzyme immunoassay procedure using whole R. henselae antigen. Of the patients, 7 had PGL, 17 had NHL, and 100 were HIV stage IV (Centers for Disease Control criteria). A total of 86% of PGL patients (6 of 7) were positive for R. henselae antibodies (three were positive for IgG, IgA, and IgM, one was positive for IgG and IgA only, and two were positive for IgG only). A total of 29% of NHL patients (5 of 17) were positive for R. henselae antibodies (two were positive for IgG, IgA, and IgM and three were positive for IgG only). Only 5% of HIV Stage IV patients without adenopathy (5 of 100) were positive for R. henselae-reactive IgG, IgA, and IgM. The high prevalence of R. henselae-reactive antibodies in HIV-positive PGL and NHL patients suggests that R. henselae is a potential etiologic agent or cofactor in these patients.

AIDS-Related Complex↗
PubMed1994

Novel in vitro method for identification of individuals at risk for beryllium hypersensitivity.

Beryllium-specific lymphocytes were generated by in vitro immunization of peripheral blood mononuclear cells (PBMC) from healthy unexposed individuals. Measurement of blastogenic responses of PBMC by [3H]thymidine uptake demonstrated that sensitization of PBMC with beryllium salts followed by stimulation with unrelated salts resulted in a negative response, whereas sensitization and restimulation of PBMC with beryllium salts produced a positive response. Flow cytometric and cell depletion analyses showed that all of the responding cells were CD4+ T cells. The in vitro immunization system was used to screen 52 human subjects for susceptibility to beryllium sensitization in vitro. The results show that of the 52 healthy unexposed subjects tested, only 1 (2%) was highly responsive, 4 subjects (8%) were moderately responsive, 20 subjects (39%) were low-level responders, and 27 subjects (52%) were nonresponders. The results showing 2% high-level responsiveness to beryllium sensitization in vitro correlate with the 1 to 5% prevalence of chronic beryllium disease in individuals sensitized to beryllium dust in vivo and thus support the thesis that the in vitro immunization system may permit the identification of individuals at risk for beryllium hypersensitivity.

Adult↗
PubMed1994

Frequency of biochemical hypothyroidism in sera referred for autoantibody testing.

We examined sera submitted for autoantibody testing for thyroid microsome antibodies (TMA), elevated thyroid-stimulating hormone (TSH), and free thyroxine concentrations. The frequency of TMA in antinuclear antibody-positive sera was higher (19%) than that in antinuclear antibody-negative sera (12%). Elevated TSH concentrations in serum and subnormal thyroxine concentrations in serum were associated with the presence of TMA; TMA titer and the frequency of elevated TSH concentrations were also associated with the presence of TMA.

Adult↗
PubMed1994

Placental transfer of immunoglobulin G subclasses.

The concentrations in cord blood of total immunoglobulin G (IgG) and the four subclasses of IgG were measured in 34 fetuses at a mean gestational age of 25 weeks (range, 18 to 35 weeks). The blood samples were obtained by percutaneous umbilical blood sampling, and results were compared with the respective IgG subclass concentrations of the mothers. The efficiency of transplacental transfer of the different IgG subclasses was determined. Transfer of IgG1 and IgG4 was found to be significantly more efficient than that of IgG3 and IgG2. IgG2 was the subclass least efficiently transferred from mother to fetus. These differences may partly explain the susceptibility of newborns to various pathogens, such as streptococcus group B.

Female↗
PubMed1994

Silicone-specific blood lymphocyte response in women with silicone breast implants.

A blinded cross-sectional study was carried out with 99 women, 44 of whom had silicone breast implants. Group I consisted of 55 healthy volunteer women without breast implants; group II comprised 13 volunteer women with breast implants or explants who felt healthy; group III comprised 21 volunteer women with breast implants who had chronic fatigue, musculoskeletal symptoms, and skin disorders; and group IV comprised 10 women who had their prostheses explanted but still presented with clinical symptoms similar to those of the women in group III. Proliferative responses of peripheral blood mononuclear cells from all 99 women were measured by [3H]thymidine uptake after exposure to SiO2 silicon, or silicone gel. The levels of proliferative responses were expressed as stimulation indices, which were obtained by dividing the counts per minute of stimulated cells by the counts per minute of unstimulated cells. Abnormal responses to SiO2, silicon, or silicone gel were defined as a stimulation index of > 2.8, > 2.1, or > 2.4, respectively. Abnormal responses were observed in 0% of group I, 15% of group II, 29% of group III, and 30% of group IV (P < 0.0005 for group I versus groups II and IV). Thirty-one percent of symptomatic women with silicone gel breast implants had elevated serum silicon levels ( > 0.18 mg/liter); however, there was no significant correlation between abnormal cellular responses and silicon levels in blood serum, type of implant, time since first implantation, prosthesis explantation, number of implants, or report of implant leakage or rupture.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Implants↗
PubMed1994

Rochalimaea antibodies in HIV-associated neurologic disease.

Rochalimaea henselae, a recently described pathogen thought to cause syndromes as varied as bacillary angiomatosis, parenchymal bacillary peliosis, fever with bacteremia, and cat-scratch disease, is associated with CNS diseases including cerebral and retinal bacillary angiomatosis, as well as cat-scratch-related encephalitis, myelitis, cerebral arteritis, and retinitis. We used a newly developed enzyme immunoassay and the polymerase chain reaction to investigate the association of R henselae infection with HIV-related CNS disease and found that whereas seroprevalence rates in HIV-positive patients unselected for neurologic disease were 4% to 5.5%, those with neurologic disease had seroprevalence rates of 32%. The ratio of organism-specific antibodies in CSF compared with serum suggested intra-blood-brain-barrier synthesis of these antibodies. CSF specimens containing only R henselae IgM had 16S rDNA specific for R henselae. Stored serum from one of these patients indicated he had developed R henselae-reactive IgM antibodies 10 months prior to the onset of neurologic disease. In the 14 patients for whom clinical data were available, evidence of CNS invasion by R henselae was accompanied by acute and subacute mental status changes including hallucinations, disorientation, and rapidly progressive dementia.

AIDS-Associated Nephropathy↗
PubMed1994

Allelic D variants of transferrin in evaluation of alcohol abuse: differential diagnosis by isoelectric focusing-immunoblotting-laser densitometry.

In the diagnosis of alcohol abuse transferrin (Tf) allelic D variants generate false-positive test results for carbohydrate-deficient transferrin (CDT) as assessed by their electrophoretic migration patterns. The predominant Tf C1 allele encodes a protein for which the most prevalent isoform has a pI of 5.4, i.e., four sialic acids and two bound ion molecules. Carriers of allele D encode Tfs with different amino acid sequences, for which the pI is > 5.7, despite their identical iron and carbohydrate composition. We used isoelectric focusing, immunoblotting, and laser densitometry (IEF-IB-LD) to distinguish Tf D variants from CDT. Alcohol abusers carrying the D chi allele tested CDT+; D chi nondrinkers were CDT-. Although normal controls (< 15 g of alcohol per day for 7-10 consecutive days) carrying variants D1, D2, or D chi exhibited abnormal IEF banding patterns, they did not generate false-positive results for CDT. D3 variants expressed isoforms that migrate at the same pI as CDT bands. Thus, IEF-IB-LD yields a highly resolved banding pattern to distinguish most Tf D variants from CDT.

Alcoholism↗
PubMed1993

Early undifferentiated connective tissue disease: III. Outcome and prognostic indicators in early scleroderma (systemic sclerosis).

OBJECTIVE: To characterize the course of early scleroderma and to delineate prognostic factors present within 1 year of disease onset that might identify patients at high risk. DESIGN: Inception cohort study. SETTING: Ten university-based rheumatology clinics participating in the Cooperative Systematic Studies of Rheumatic Diseases Program. PATIENTS: Forty-eight patients who had had scleroderma for less than 1 year. MEASUREMENTS: Fifteen patients with early scleroderma who died were compared with those still living during the initial study period (1982 to 1992). Kaplan-Meier survival estimation and Cox proportional hazards analysis were used to analyze baseline variables for their ability to predict survival duration. RESULTS: Eight of 15 deaths were due to cardiac or pulmonary system failure. The estimated 5-year survival rate was 68%. Baseline factors that were the most predictive of a poor outcome included the presence of abnormal cardiopulmonary signs and abnormal urine sediment (pyuria, hematuria). CONCLUSION: Evidence of early cardiopulmonary disease, renal disease, inflammation, or immune activation may identify a subset of patients with scleroderma who will experience rapidly progressive disease and early death.

Adult↗
PubMed1993

Neuropsychiatric disease in Sjögren's syndrome: anti-ribosomal P and anti-neuronal antibodies.

PURPOSE: Patients with Sjögren's syndrome (SS) may develop nonfocal (i.e., psychiatric and/or cognitive dysfunction) as well as focal, neuropsychiatric disease (CNS-SS). Anti-ribosomal P and anti-neuronal antibodies have been associated with nonfocal neuropsychiatric disease in systemic lupus erythematosus (SLE), particularly psychosis and depression. This study examines the spectrum of psychiatric and cognitive dysfunction observed in SS patients with focal, as well as nonfocal, central nervous system (CNS) disease and relates these observations to the presence of serum and cerebrospinal fluid (CSF) anti-ribosomal and anti-neuronal antibodies. PATIENTS AND METHODS: One hundred thirty-one patients--patients with primary SS (n = 91), patients with secondary SS (n = 34), and mothers of infants with neonatal lupus erythematosus (NLE) (n = 6)--were studied. Patients were referred to a large tertiary referral center and the population was highly selected for CNS disease. Patients were evaluated clinically for focal and nonfocal CNS disease. Sera from 131 patients and 34 paired sera/CSF samples were examined by enzyme-linked immunosorbent assay and radioimmunoassay for the presence of anti-ribosomal P and anti-neuronal autoantibodies, respectively. Clinical features were categorized and autoantibody profiles obtained and correlated independently for statistical significance. Data were analyzed using the two-tailed Fisher exact test. RESULTS: Psychiatric or cognitive impairment, usually mild or moderate, occurred in over 80% (63 of 77) of this highly selected population of SS patients, and more than 60% of patients (48 of 77) had both. Anti-ribosomal P antibodies occurred in six (4.6%) patients with SS and related disorders. None of the patients with primary SS had anti-ribosomal P antibodies, whereas they were present in a small number of patients with secondary SS (i.e., 4 of 34 [12%]) and in 2 of 6 mothers of infants with NLE. There was no correlation between nonfocal CNS disease, including psychosis or severe depression, and the presence of anti-ribosomal P antibodies. Paired serum CSF samples from 34 SS patients with active CNS disease, including 6 with psychosis and 5 with severe depression, did not contain either anti-ribosomal P or anti-neuronal antibodies. Anti-ribosomal P and anti-neuronal antibodies were present in a control subset of SLE patients defined serologically by the presence of anti-nDNA antibodies. CONCLUSION: Patients with primary SS associated with CNS disease, including psychosis and depression, do not have serum or CSF autoantibodies to ribosomal P peptide or neuronal antigens, detected by binding to neuroblastoma cells. Thus, autoantibodies associated with nonfocal or diffuse CNS disease in classical SLE (particularly psychosis and depression) are not present in CNS-SS. The observations suggest that nonfocal CNS disease in CNS-SS and CNS-SLE may be mediated by different immunopathologic mechanisms. Potentially, these observations may have diagnostic and therapeutic implications in the management of patients with CNS-SS and patients with CNS-SLE.

Amino Acid Sequence↗
PubMed1993

A new approach to quantitate carbohydrate-deficient transferrin isoforms in alcohol abusers: partial iron saturation in isoelectric focusing/immunoblotting and laser densitometry.

Carbohydrate-deficient transferrin (Tf) represents a significant advance over previous markers of alcohol abuse. Isoelectric focusing (IEF) analysis of affinity-purified Tf, under conditions of total iron saturation, identifies a major isoform at pI 5.4 in both normal consumers and alcohol abusers; three additional Tf isoforms (pI 5.6, 5.7, and 5.8) are associated with alcohol abuse. Under conditions of partial iron saturation, IEF analysis of affinity-purified Tf reveals up to seven isoforms (pI range 5.3-6.0) common to normal consumers and alcohol abusers; three additional transferrin isoforms (pI range 6.1-6.3) are present in 68% (15/22) of the alcohol abuser specimens, but in only 8% (1/12) of the specimens from normal consumers and in none of the three specimens from abstainers. These three diagnostic bands comigrate with a set of defined Tf isoforms: human iron-free Tf containing two sialic acid residues, human sialic acid-free Tf with one iron molecule, and human sialic acid-free, iron-free Tf. Serum specimens from normal consumers and alcohol abusers, analyzed for Tf isoforms by an IEF-immunoblot method under conditions of partial iron saturation, expressed Tf isoforms similar to those found using affinity-purified Tf in standard IEF. Visual examination of the immunoblots reveals the diagnostic bands in 67% (32/48) of patients with histories of sustained alcohol abuse compared with only 17% (8/48) of the normal consumers. Scanning densitometry and volume integration analysis of the immunoblots representative of normal consumer and alcohol abuser populations results in mean (+/- SE) values of 4.1 +/- 0.8 and 19.3 +/- 3.6 units, respectively (p < 0.0002).

Adult↗