RESUMEN
OBJECTIVES: The aim of this study was to evaluate the effect of prior corticosteroid (CS) use on the presence of inflammatory infiltrates (InI) in muscle biopsies from dermatomyositis (DM). METHODS: Sixty-five muscle biopsy samples were obtained at the time of DM diagnosis. The patients were divided into the following three groups according to the degree of the InI present in the muscle biopsies: (I) minimal InI present only in an interstitial area (endomysium, perimysium) or in a perivascular area; (II) moderate InI in one or two areas of the interstitium or of the perivascular area; and (III) moderate InI throughout the interstitium or intense inflammation in at least one area of the interstitium or of the perivascular area. RESULTS: All groups (I=17, II=16 and III=32) were comparable regarding the patient age at the time of the muscle biopsy, gender, ethnicity distribution, time interval between the muscle biopsy and the symptom onset, clinical manifestations, degree of muscle weakness, autoantibodies and serum muscle enzyme measurements (p<0.05). The median (interquartile) duration of CS use [7 (0-60), 6 (0-105) and 14 (0-30) days in groups I, II and III, respectively] and the median cumulative CS dose used [560 (0-2100), 1005 (0-2850) and 875 (0-2850) mg] were similar between the groups (p>0.05). CONCLUSIONS: Previous CS use did not influence the presence or the degree of inflammatory infiltrates found in muscle biopsies in DM with clinical and laboratory disease activity. Therefore, muscle biopsies should be performed in this population, including patients currently undergoing CS therapy.
Asunto(s)
Corticoesteroides/uso terapéutico , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/patología , Polimiositis/tratamiento farmacológico , Polimiositis/patología , Adulto , Biopsia , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/inmunología , Polimiositis/inmunología , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
OBJECTIVES: The aim of the study was to evaluate the effect of the prior use of corticosteroids (CS) on the presence of inflammatory infiltrates (InI) in muscle biopsies of polymyositis (PM). METHODS: We retrospectively evaluated 60 muscle biopsy samples that had been obtained at the time of the diagnosis of PM. The patients were divided into three groups according to the degree of the InI present in the muscle biopsies: (a) minimal InI present only in an interstitial area of the muscle biopsy (endomysium, perimysium) or in a perivascular area; (B) moderate InI in one or two areas of the interstitium or of the perivascular area; and (C) moderate InI throughout the interstitium or intense inflammation in at least one area of the interstitium or of the perivascular area. RESULTS: The three groups were comparable regarding the demographic, clinical and laboratory features (p>0.05). Approximately half of the patients in each group were using CS at the time of the muscle biopsy. The median (interquartile) duration of CS use [4 (0-38), 4 (0-60) and 5 (0-60) days: groups A, B and C, respectively] and the median cumulative CS dose used [70 (0-1200), 300 (0-1470) and 300 (0-1800)mg] were similar between the groups (p>0.05). CONCLUSIONS: Previous CS use did not influence the presence or the degree of InI found in muscle biopsies in PM with clinical and laboratory disease activity. Our study showed that muscle biopsies should be performed this population, even in individuals who have already been taking CSs.