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Objective: To study the performance and cardiovascular function after a 3-week training camp in athletes competing in an anaerobically dominant sport. Methods: Twenty-three competitive 400-m athletes were enrolled in this non-randomized study, 17 took part in a 3-week training camp in South-Africa (intervention), but one declined follow-up assessment, while 6 pursued in-door winter training in Sweden and served as controls. Electrocardiography, transthoracic echocardiography, blood test analyses, maximal exercise tolerance test, and a 300-m sprint test with lactate measurements ([La]peak) were performed before and after the training camp period. Results: At baseline, there were no clinically significant pathological findings in any measurements. The training period resulted in improved 300m-sprint performance [n = 16; running time 36.71 (1.39) vs. 35.98 (1.13) s; p<0.01] and higher peak lactate values. Despite 48% more training sessions than performed on home ground (n = 6), myocardial biomarkers decreased significantly (NT-pro BNP -38%; p<0.05, troponin T -16%; p<0.05). Furthermore, resting heart rate (-7%; p<0.01) and left ventricular systolic and diastolic volumes decreased -6% (p<0.01) and -10% (p<0.05), respectively. Conclusions: Intense physical activity at training camp improved the performance level, likely due to improved anaerobic capacity indicated by higher [La]peak. There were no clinically significant adverse cardiac changes after this period of predominantly anaerobic training. [ABSTRACT FROM AUTHOR]

We studied major histocompatibility complex (MHC) class I peptide-presentation and nature of the antigen-specific CD8+ T-cell response from South African tuberculosis (TB) patients with active TB. 361 MHC class I binding epitopes were identified from three immunogenic TB proteins (ESAT-6 [Rv3875], Ag85B [Rv1886c], and TB10.4 [Rv0288], including amino acid variations for Rv0288, i.e., A10T, G13D, S27N, and A71S for MHC allotypes common in a South African population (e.g., human leukocyte antigen [HLA]-A*30, B*58, and C*07). Inter-allelic differences were identified regarding the broadness of the peptide-binding capacity. Mapping of frequencies of Mycobacterium tuberculosis (M. tb) antigen-specific CD8+ T-cells using 48 different multimers, including the newly constructed recombinant MHC class I alleles HLA-B*58:01 and C*0701, revealed a low frequency of CD8+ T-cell responses directed against a broad panel of co-dominant M. tb epitopes in the peripheral circulation of most patients. The antigen-specific responses were dominated by CD8+ T-cells with a precursor-like phenotype (CD45RA+CCR7+). The data show that the CD8+ T-cell response from patients with pulmonary TB (prior to treatment) is directed against subdominant epitopes derived from secreted and non-secreted M. tb antigens and that variant, natural occurring M. tb Rv0288 ligands, have a profound impact on T-cell recognition.