The influence of demography and referral medical specialty on the detection of autoantibodies to HEP-2 cells in a large sample of patients.

BACKGROUND: The prevalence of anti-cell autoantibodies detected by indirect immunofluorescence assay on HEp-2 cells (HEp-2-IIFA) increases with age and is higher in female sex. The number of medical specialties that use HEp-2-IIFA in the investigation of autoimmune diseases has increased lately. This study aimed to determine the prevalence and patterns of autoantibodies on HEp-2-IIFA according to demographics variables and referring medical specialties. METHODS: A retrospective analysis of the HEp-2-IIFA carried out between January and June of 2017 was performed. The International Consensus on Antinuclear Antibodies Patterns (ICAP) and the Brazilian Consensus on Autoantibodies were used for patterns definition on visual reading of the slides. Anti-cell (AC) codes from ICAP and Brazilian AC codes (BAC) were used for patterns classification. RESULTS: From 54,990 samples referred for HEp-2-IIF testing, 20.9% were positive at titer ≥ 1/80. HEp-2-IIFA positivity in females and males was 24% and 12%, respectively (p < 0.0001). The proportion of positive results in the 4 age groups analyzed: 0-19, 20-39, 40-59, and ≥ 60 years was 23.3, 20.2, 20.1, and 22.8%, respectively (p < 0.0001). Considering all positive sera (n = 11,478), AC-4 nuclear fine speckled (37.7%), AC-2 nuclear dense fine speckled (21.3%), BAC-3 nuclear quasi-homogeneous (10%) and mixed/composite patterns (8.8%) were the most prevalent patterns. The specialties that most requested HEp-2-IIFA were general practitioner (20.1%), dermatology (15%), gynecology (9.9%), rheumatology (8.5%), and cardiology (5.8%). HEp-2-IIFA positivity was higher in patients referred by rheumatologists (35.7% vs. 19.6%) (p < 0.0001). Moderate (46.4%) and high (10.8%) titers were more observed in patients referred by rheumatologists (p < 0.0001). We observed a high proportion of mixed and cytoplasmic patterns in samples referred by oncologists and a high proportion of BAC-3 (nuclear quasi-homogeneous) pattern in samples referred by pneumologists. CONCLUSIONS: One-fifth of the patients studied were HEp-2-IIFA-positive. The age groups with more positive results were 0-19 and ≥ 60 years. AC-4, AC-2, BAC-3 and mixed/composite patterns were the most frequent patterns observed. Rheumatologists requested only 8.5% of HEp-2-IIFA. Positive results and moderate to high titers of autoantibodies were more frequent in patients referred by rheumatologists.

The influence of demography and referral medical specialty on the detection of autoantibodies to HEP-2 cells in a large sample of patients

Abstract Background: The prevalence of anti-cell autoantibodies detected by indirect immunofluorescence assay on HEp-2 cells (HEp-2-IIFA) increases with age and is higher in female sex. The number of medical specialties that use HEp-2-IIFA in the investigation of autoimmune diseases has increased lately. This study aimed to determine the prevalence and patterns of autoantibodies on HEp-2-IIFA according to demographics variables and referring medical specialties. Methods: A retrospective analysis of the HEp-2-IIFA carried out between January and June of 2017 was performed. The International Consensus on Antinuclear Antibodies Patterns (ICAP) and the Brazilian Consensus on Autoantibodies were used for patterns definition on visual reading of the slides. Anti-cell (AC) codes from ICAP and Brazilian AC codes (BAC) were used for patterns classification. Results: From 54,990 samples referred for HEp-2-IIF testing, 20.9% were positive at titer ≥ 1/80. HEp-2-IIFA positivity in females and males was 24% and 12%, respectively ( p < 0.0001). The proportion of positive results in the 4 age groups analyzed: 0-19, 20-39, 40-59, and ≥ 60 years was 23.3, 20.2, 20.1, and 22.8%, respectively ( p < 0.0001). Considering all positive sera (n = 11,478), AC-4 nuclear fine speckled (37.7%), AC-2 nuclear dense fine speckled (21.3%), BAC-3 nuclear quasi -homogeneous (10%) and mixed/composite patterns (8.8%) were the most prevalent patterns. The specialties that most requested HEp-2-IIFA were general practitioner (20.1%), dermatology (15%), gynecology (9.9%), rheumatology (8.5%), and cardiology (5.8%). HEp-2-IIFA positivity was higher in patients referred by rheumatologists (35.7% vs. 19.6%) ( p < 0.0001). Moderate (46.4%) and high (10.8%) titers were more observed in patients referred by rheumatologists ( p < 0.0001). We observed a high proportion of mixed and cytoplasmic patterns in samples referred by oncologists and a high proportion of BAC-3 (nuclear quasi -homogeneous) pattern in samples referred by pneumologists. Conclusions: One-fifth of the patients studied were HEp-2-IIFA-positive. The age groups with more positive results were 0-19 and ≥ 60 years. AC-4, AC-2, BAC-3 and mixed/composite patterns were the most frequent patterns observed. Rheumatologists requested only 8.5% of HEp-2-IIFA. Positive results and moderate to high titers of autoanti-bodies were more frequent in patients referred by rheumatologists.

Influência de posições do joelho no torque e atividade mioelétrica do tríceps sural na flexão plantar isométrica máxima / Influence of knee positions on torque and myoelectric activity of triceps surae at maximum isometric plantar flexion

Os objetivos do estudo foram comparar o torque isométrico máximo de flexão plantar, em duas posições de joelho e analisar a variação da atividade miolétrica dos músculos do tríceps sural nas duas condições. A amostra composta de 14 homens saudáveis. O pé direito dos participantes foi fixado ao adaptador do aparelho isocinético com o tornozelo em 90 graus. Duas contrações isométricas voluntárias máximas de cinco segundos foram obtidas para cada posição do joelho: estendido e com 90 graus de flexão. Foram analisados o pico de torque flexor plantar médio e o valor RMS do sinal eletromiográfico (EMG) dos três segundos intermediários do gastrocnêmio lateral (GNL), gastrocnêmio medial (GNM) e sóleo para cada posição. Os torques médios nas posições de joelho em extensão e flexão foram 100,4 ± 17,4 Nm e 72,6 ± 18,4 Nm, respectivamente. Os gastrocnêmios apresentaram uma redução do valor RMS relativo com o joelho em flexão (40,5 ± 10,5 e 31,7 ± 25,6% para o GL e GM, respectivamente) enquanto o sóleo aumentou nessa condição (35,6 ± 28,9%). A redução do torque de flexão plantar parece estar associada ao resultado de um compromisso entre a inibição da atividade mioelétrica dos GNM e GNL, e otimização da ativação do sóleo. Os resultados podem contribuir no auxílio da prescrição de exercícios direcionados para o tríceps sural, enfatizando a ativação de diferentes músculos com variações no ângulo articular do joelho.

The aim of this study was to compare the maximum torque of plantar flexors using two knee positions and analyze the mioelectric activity variation of the muscles in both conditions. The sample was composed of 14 healthy men. The participants were positioned on the dynamometer with the right foot attached to the adapter in neutral position (ankle at 90º). Two five seconds of two consecutives maximum isometric voluntary contractions were obtained for each knee position: full extended and 90o. The gastrocnemius lateralis (GNL), medialis (GNM) and soleus RMS value of eletomyography signal and the plantar flexor peak torque average were acquired during three intermediate seconds. The average torques in the knee positions of extension and flexion were 100.4 ± 17.4 Nm and 72.6 ± 18.4 Nm respectively. With the knee flexed, the gastrocnemius presented a decreased activation (40.5 ± 10.5 e 31.7 ± 25.6% for lateral and medial, respectively) while the soleus showed an increased (35.6 ± 28.9%). The reduction of torque appears to result from a compromise between the inhibition of myoelectric activity of the gastrocnemius medialis and lateralis, while the soleus activation is optimized. The results may contribute to exercise prescription plantar flexors muscles emphasizing the different muscles activation varying the knee position.