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Biomedical subjects

Robert G Lahita

Publications and source records attributed to Robert G Lahita.

10 recordsLinked to original sources
PubMed2005

Estrogens and arthritis.

Sex hormones seem to play an important role as modulators and perpetuators of rheumatic disorders with autoimmune involvement, such as rheumatoid arthritis or systemic lupus erythematosus. Estrogens are implicated in the immune response as enhancers of the humoral immunity. Sex hormones can exert local actions (paracrine) in the tissues in which they are formed; an accelerated peripheral metabolic conversion of upstream androgen precursors to estrogens has been well-assessed. Local effects of sex hormones in autoimmune rheumatic diseases seem to consist mainly of the modulation of cell proliferation and cytokine production. All of these data further suggest caution in exogenous estrogen administration in patients who have autoimmune diseases.

Arthritis, Rheumatoid↗
PubMed2005

The neuroendocrine-immune interactions in systemic lupus erythematosus: a basis for understanding disease pathogenesis and complexity.

Much progress has been made in the understanding of the impact of the neuroendocrine immune interactions and the pathogenic role in systemic lupus erythematosus, clinically and at the molecular level. This article focuses on the intertwining networks that involve the hypothalamic-pituitary-adrenal axis, cytokines within the central nervous system, and the sympathetic system. Hormones (estrogen, prolactin, gonadotropin-releasing hormone, and leptin) play an important role as immunomodulatory agents.

GTP-Binding Proteins↗
PubMed2004

Effects of prasterone on disease activity and symptoms in women with active systemic lupus erythematosus.

OBJECTIVE: To determine whether prasterone administration results in improvement or stabilization of systemic lupus erythematosus (SLE) disease activity and its symptoms. METHODS: Women with active SLE were treated with prasterone 200 mg/day plus standard SLE treatments or with placebo plus standard SLE treatments for up to 12 months in this randomized, double-blind investigation conducted at 27 centers. Standard SLE treatments included prednisone (</=10 mg/day), antimalarials, and immunosuppressive agents; dosages were required to be stable for >/=6 weeks prior to enrollment and remain unchanged during protocol treatment. Responders were patients who experienced no clinical deterioration and had improvement or stabilization over the duration of the study in 2 disease activity measures (the SLE Disease Activity Index [SLEDAI] and the Systemic Lupus Activity Measure) and 2 quality of life measures (patient's global assessment and the Krupp Fatigue Severity Scale). RESULTS: A total of 381 women with SLE were enrolled. Among patients with clinically active disease at baseline (SLEDAI score >2), 86 of 147 in the prasterone group (58.5%) demonstrated improvement or stabilization without clinical deterioration, as compared with 65 of 146 in the placebo group (44.5%) (P = 0.017). Acne and hirsutism were reported in 33% and 16%, respectively, of the prasterone group and in 14% and 2%, respectively, of the placebo group (P < 0.05 for both comparisons). However, most cases of acne and hirsutism were mild and did not require withdrawal from therapy. Myalgias and oral stomatitis were reported less frequently in the prasterone group (22% and 15%, respectively) than in the placebo group (36% and 23%, respectively) (P < 0.05 for both comparisons). Serum levels of high-density lipoprotein cholesterol, triglycerides, and C3 complement significantly decreased, while levels of testosterone and, to a lesser extent, estradiol increased in the prasterone group. CONCLUSION: In adult women with active SLE, administration of prasterone at a dosage of 200 mg/day improved or stabilized signs and symptoms of disease and was generally well tolerated.

Adjuvants, Immunologic↗
PubMed2003

A critical evaluation of enzyme immunoassay kits for detection of antinuclear autoantibodies of defined specificities. III. Comparative performance characteristics of academic and manufacturers' laboratories.

OBJECTIVE: To analyze the performance of different commercial enzyme immunoassay (EIA) kits for measuring antinuclear antibodies (ANA) specific for dsDNA, SSB/La, Sm, and Scl-70. METHODS: EIA kits for detection of ANA from 9 commercial manufacturers were evaluated. The manufacturers were advised that they would be sent coded sera containing mixtures of the Arthritis Foundation/Centers for Disease Control reference reagents, and that they were to use their own test kits to analyze the antibody specificities of these sera and to report the data, in optical density (OD) units or their equivalent. Independently, 12 investigators in academic institutions who have done research in this field agreed to participate in a parallel study. The concentration of the antibodies and the specificities were blinded to the analysts and the coefficients of variation (CV) were computed for each participant. RESULTS: There were statistically significant differences between laboratories in terms of CV for all 9 kits tested. With the exception of one kit, there were no significant CV differences between the various autoantibody kits provided by each manufacturer and, with the exception of kits from 2 manufacturers, there were no significant differences between the various antibody kits in terms of reproducibility (CV). From the point of view of interlaboratory variability, manufacturers could be separated into either a high or low performance group. CONCLUSION: We found a disconcertingly large range of performance characteristics in the various laboratories, which could be quite detrimental in routine utilization of EIA ANA kits. Clinicians should be aware of the performance issues raised in our study, and should know and be involved in how their service laboratory assesses its own performance and the performance of commercial testing systems utilized. Manufacturers and clinical laboratories need to exercise constant quality assurance and surveillance of kit performance in the hands of medical laboratory technologists involved in routine testing.

Analysis of Variance↗
PubMed2002

Effects of prasterone on corticosteroid requirements of women with systemic lupus erythematosus: a double-blind, randomized, placebo-controlled trial.

OBJECTIVE: To evaluate whether treatment with prasterone (dehydroepiandrosterone [DHEA]) would allow the dosage of prednisone (or an equivalent corticosteroid) to be reduced to < or = 7.5 mg/day for 2 months or longer while maintaining stable or reduced disease activity in steroid-dependent women with systemic lupus erythematosus (SLE). METHODS: In a double-blind, randomized trial, 191 female SLE patients receiving prednisone (10-30 mg/day) were treated daily with either placebo, 100 mg of oral prasterone (an adrenal androgen), or 200 mg of oral prasterone for 7-9-months. At monthly intervals, corticosteroid dosages were reduced by algorithm in patients whose SLE Disease Activity Index (SLEDAI) score was stable or improved. Patients for whom a sustained reduction in the dosage of prednisone (< or = 7.5 mg/day) was achieved for at least the last 2 months of the 7-9-month treatment period were classified as responders. RESULTS: Response rates were 41% in the placebo group, 44% in the 100-mg prasterone group, and 55% in the 200-mg group (P = 0.110, 200 mg versus placebo). Among the 137 subjects (45 in the placebo group, 47 in the 100-mg group, and 45 in the 200-mg group) who had active disease at baseline (defined as SLEDAI score >2), 29%, 38%, and 51%, respectively, were responders (P = 0.031 for 200 mg prasterone versus placebo). Acne was the most common adverse event but was generally mild. Clinical and laboratory changes primarily reflected androgenic effects of prasterone. CONCLUSION: Among women with lupus disease activity, reducing the dosage of prednisone to < or = 7.5 mg/day for a sustained period of time while maintaining stabilization or a reduction of disease activity was possible in a significantly greater proportion of patients treated with oral prasterone, 200 mg once daily, compared with patients treated with placebo.

Administration, Oral↗
PubMed2002

A critical evaluation of enzyme immunoassay kits for detection of antinuclear autoantibodies of defined specificities. II. Potential for quantitation of antibody content.

OBJECTIVE: To analyze the performance of different commercial enzyme immunoassay (EIA) kits for measuring antibody levels of antinuclear antibodies (ANA) specific for double stranded (ds) DNA, SSB/La, Sm, and Scl-70. METHODS: Twenty companies that were known major purveyors of EIA kits for detection of ANA were approached to determine their interest and willingness to participate in this study. The manufacturers were advised that they would be sent coded sera containing mixtures of the Arthritis Foundation/Centers for Disease Control reference reagents, and that they were to use their own test kits to analyze the antibody specificities of these sera and to report the data, in optical density (OD) units, or their equivalent. The analysts were blinded to the concentration of the antibodies and the specificities. RESULTS: Initially, 11 manufacturers out of 20 agreed to participate, but 2 subsequently withdrew. The commercial EIA kits have the potential of being able to quantitate specific autoantibody content to ds-DNA, SSB/La, Sm, and Scl-70. However, certain deficiencies in these kits were also detected, the most obvious being lack of uniformly good performance, with kits of certain manufacturers showing exceptional accuracy in 3 out of 4 of their antibody-specific kits and poor accuracy for a 4th kit. CONCLUSION: It is important for clinicians to appreciate that there is marked inter-manufacturer variation in the performance of EIA kits used as an aid in the diagnosis of systemic rheumatic diseases. Manufacturers need to exercise constant surveillance of kit performance and to provide assurance that such is being done. Improved EIA kits would lend themselves to reliable quantitation of antibody levels in human sera and help to determine whether serial measurement of antibody levels might be useful in monitoring disease activity.

Antibodies, Antinuclear↗