Biomedical subjects

Peter A Merkel

Publications and source records attributed to Peter A Merkel.

23 records · Page 2Linked to original sources

PubMed2003

Prevalence of antineutrophil cytoplasmic antibodies in patients with various pulmonary diseases or multiorgan dysfunction.

OBJECTIVE: To determine the prevalence of antineutrophil cytoplasmic antibodies (ANCA) in patients with diseases that may mimic systemic vasculitides, such as severe multiorgan dysfunction (MOD) and parenchymal pulmonary disorders. METHODS: We conducted a prospective study of patients with MOD admitted to the medical intensive care unit and patients with various lung diseases seen at the outpatient pulmonary clinic of a tertiary care hospital. Patients with a documented diagnosis of Wegener's granulomatosis (WG) served as positive controls. ANCA were determined in serum samples from each patient by a combination of indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assays (ELISAs) for antibodies to proteinase-3 and myeloperoxidase (anti-MPO). RESULTS: Ninety-nine patients with MOD, 29 outpatients with various lung disorders, and 18 patients with WG were included in the study. ANCA were detected by IIF alone in 16% (15/96) of patients with nonvasculitic MOD and 17% (5/29) of outpatients with various pulmonary disorders. The majority of the positive IIF specimens from each group displayed an atypical IIF pattern (73% and 80%, respectively). Only 1 specimen from patients with nonvasculitic disorders was positive for anti-MPO. ANCA by both IIF and ELISA were detected in 78% (12/14) of control patients with WG. CONCLUSION: Detection of ANCA by the combination of IIF and antigen-specific assays for proteinase 3 and myeloperoxidase in diseases that mimic systemic vasculitides is highly specific for WG, microscopic polyangiitis, and Churg-Strauss syndrome.

Antibodies, Antineutrophil Cytoplasmic↗

PubMed2003

Current status of outcome measure development for clinical trials in systemic sclerosis. Report from OMERACT 6.

Systemic sclerosis (SSc), also known as scleroderma, is a complex, multisystem disease that results in severe morbidity, disability, and life-threatening complications. The wide range of biological systems clinically involved, and the large spectrum of disease activity and damage that occurs in this disease have limited clinical investigation of SSc, especially therapeutic trials. The OMERACT 6 Workshop on Systemic Sclerosis was conceived as a starting point for the process of assessing the current state of the science in outcome assessment in SSc and then setting a realistic research agenda and priorities for future work in this area This article reviews the current status of assessment tools for research in SSc within the main fundamental domains of illness in SSc, including problems related to skin, pulmonary, cardiac, peripheral vascular (Raynaud's phenomenon and digital ulceration), renal, and musculoskeletal systems as well as health-related quality of life and physical functioning. The current level of validation of outcome measures in SSc is assessed according to the guidelines set forth by prior OMERACT meetings.

Clinical Trials as Topic↗

PubMed2002

A multicenter, randomized, double-blind, placebo-controlled trial of adjuvant methotrexate treatment for giant cell arteritis.

OBJECTIVE: To evaluate treatment with methotrexate (MTX) in patients with newly diagnosed giant cell arteritis (GCA) to determine if MTX reduces GCA relapses and cumulative corticosteroid (CS) requirements and diminishes disease- and treatment-related morbidity. METHODS: This was a multicenter, randomized, double-blind study. Over 4 years, 16 centers from the International Network for the Study of Systemic Vasculitides enrolled patients with unequivocal GCA. The initial treatment was 1 mg/kg/day (<or=60 mg every day) prednisone, plus either 0.15 mg/kg/week MTX (increased to 0.25 mg/kg/week, for a maximum weekly dosage of 15 mg) or placebo. Two physicians, both blinded to treatment allocation, evaluated each patient at every trial visit. One physician was responsible for providing global medical care. The other assessed GCA status according to a standard protocol. Treatment failure was defined as 2 distinct relapses or persistence of disease activity after the first relapse, in spite of increased CS therapy. RESULTS: Ninety-eight patients were enrolled. No significant differences between treatment groups were noted with regard to age, frequency of positive findings on temporal artery biopsy (placebo 87%, MTX 79%), or comorbidities at the time of enrollment. The median dosage of MTX was 15 mg/week. The incidence of treatment failure was comparable between groups after 12 months: 57.5% in the MTX group failed treatment (95% confidence interval [95% CI] 41.6-73.4%) compared with 77.3% in the placebo group (95% CI 61.9-92.8%) (P = 0.26). In a Cox regression analysis, MTX was not associated with a reduced risk of treatment failure (relative risk 0.72; 95% CI 0.41-1.28). There were no significant differences between groups with regard to abnormal elevations of the erythrocyte sedimentation rate following initial remissions, serious morbidity due to GCA, cumulative CS dose, or treatment toxicity. In the MTX group, there were fewer cases of GCA relapse heralded by symptoms of isolated polymyalgia rheumatica (1 case versus 5 in the placebo group; P = 0.05). CONCLUSION: The results of this randomized, multicenter trial do not support the adjunctive use of MTX to control disease activity or to decrease the cumulative dose and toxicity of CS in patients with GCA.

Aged↗

PubMed2002

Measuring disease activity and functional status in patients with scleroderma and Raynaud's phenomenon.

OBJECTIVE: To document disease activity and functional status in patients with scleroderma (systemic sclerosis [SSc]) and Raynaud's phenomenon (RP) and to determine the sensitivity to change, reliability, ease of use, and validity of various outcome measures in these patients. METHODS: Patients with SSc and moderate-to-severe RP participating in a multicenter RP treatment trial completed daily diaries documenting the frequency and duration of RP attacks and recorded a daily Raynaud's Condition Score (RCS). Mean scores for the 2-week periods prior to baseline (week 0), end of trial (week 6), and posttrial followup (week 12) were calculated. At weeks 0, 6, and 12, physicians completed 3 global assessment scales and performed clinical assessments of digital ulcers and infarcts; patients completed the Health Assessment Questionnaire (HAQ), the Arthritis Impact Measurement Scales 2 (AIMS2) mood and tension subscales, 5 specific SSc/RP-related visual analog scales (VAS), and 3 other VAS global assessments. We used these measures to document baseline disease activity and to assess their construct validity, sensitivity to change, and reliability in trial data. RESULTS: Two hundred eighty-one patients (248 women, 33 men; mean age 50.4 years [range 18-82 years]) from 14 centers participated. Forty-eight percent had limited cutaneous SSc; 52% had diffuse cutaneous SSc. Fifty-nine patients (21%) had digital ulcers at baseline. Patients had 3.89 +/- 2.33 (mean +/- SD) daily RP attacks (range 0.8-14.6), with a duration of 82.1 +/- 91.6 minutes/attack. RCS for RP activity (possible range 0-10) was 4.30 +/- 1.92. HAQ scores (0-3 scale) indicated substantial disability at baseline (total disability 0.86, pain 1.19), especially among the subscales pertaining to hand function (grip, eating, dressing). AIMS2 mood and tension scores were fairly high, as were many of the VAS scores. Patients with digital ulcers had worse RCS, pain, HAQ disability (overall, grip, eating, and dressing), physician's global assessment, and tension, but no significant difference in the frequency of RP, duration of RP, patient's global assessment, or mood, compared with patients without digital ulcers. VAS scores for digital ulcers as rated by the patients were not consistent with the physician's ratings. Factor analysis of the 18 measures showed strong associations among variables in 4 distinct domains: disease activity, RP measures, digital ulcer measures, and mood/tension. Reliability of the RCS, HAQ pain and disability scales, and AIMS2 mood and tension subscales was high. The RP measures demonstrated good sensitivity to change (effect sizes 0.33-0.76). CONCLUSION: Our findings demonstrate that the significant activity, disability, pain, and psychological impact of RP and digital ulcers in SSc can be measured by a small set of valid and reliable outcome measures. These outcome measures provide information beyond the quantitative metrics of RP attacks. We propose a core set of measures for use in clinical trials of RP in SSc patients that includes the RCS, patient and physician VAS ratings of RP activity, a digital ulcer/infarct measure, measures of disability and pain (HAQ), and measures of psychological function (AIMS2).

Affect↗

PubMed2002

Evaluation and treatment of vasculitis in the critically ill patient.

The systemic vasculitides, if left untreated, often lead to major organ damage and death. When a patient presents with features that may be consistent with vasculitis, especially with pulmonary and renal findings, it is important to make a specific diagnosis as quickly as possible so that specific therapy can be started. Diagnosis is dependent on familiarity with the myriad of typical and unusual clinical features of the various vasculitides together with performance of supportive tests including serologies, angiograms, and biopsies. When evaluating a potential case of vasculitis, clinicians must comprehensively search for other more common, non-vasculitic diseases. The diagnosis may be even more difficult in patients with established diagnoses of vasculitis on immunosuppressive treatment who develop new clinical findings. Rapid initiation of immunosuppressive therapy for critically ill patients with vasculitis is crucial and may be life-saving.

Anti-Glomerular Basement Membrane Disease↗