Meniscal Injuries Are Decreasing but Are Increasingly Being Treated Surgically With Excellent Return to Play Rates in Professional Baseball Players

Purpose: The purposes of this study were to determine the incidence and key characteristics of meniscus injuries in professional baseball players, assess current treatment strategies, determine the return to play rates at any level (RTP) and at the same level (RSL), and identify prognostic factors that predict injury severity. Methods: After approval from the Major League Baseball (MLB) Research Committee and our institutional review board, the MLB Health and Injury Tracking System was used to identify meniscus injuries occurring across MLB and Minor League Baseball (MiLB) from 2011 to 2017. Analyzed injuries occurred during normal baseball activity in a player who was active on an MLB or MiLB roster and resulted in at least 1 day missed. Results: A total of 293 professional baseball players sustained 314 meniscus injuries from 2011 to 2017 (7 years) for a mean of 44.9 injuries/y. Pitchers were the most injured position (31.8%), followed by infielders (26.4%). Catchers and infielders missed the most median number of days (50 days). When comparing injuries to landing leg vs push-off leg in pitchers, injury to the push-off leg resulted in significantly more days missed per injury compared to the lead leg (59.6 vs 39.9 days, P = .048). Overall, RTP was 93.0%, while RSL was 84.4%. Conclusions: Over 7 professional baseball seasons, 314 meniscus injuries occurred in 293 players. Pitchers and catchers were most injured, and overall, the number of meniscal injuries per year declined while the percentage of injuries that required surgery increased over time. High rates of RTP were observed. Level of Evidence: Level IV, therapeutic case series

For Protection from HIV-1 Infection, More Might Not Be Better: a Systematic Analysis of HIV Gag Epitopes of Two Alleles Associated with Different Outcomes of HIV-1 Infection

A subset of women in the Pumwani Sex Worker Cohort, established in 1985 in Nairobi, Kenya, remains uninfected despite repeated high-risk exposure (HIV-exposed, seronegative [HESN]) through active sex work. This HESN phenotype is associated with several alleles of human leukocyte antigens (HLAs) and specific CD8+ and CD4+ T cell responses to HIV-1. The associations of HLA alleles with differential HIV-1 infection are most likely due to their different abilities to present antigen and the different immune responses they induce. The characteristics of epitopes of HLA alleles associated with different outcomes of HIV-1 infection might therefore point to a vital clue for developing an effective vaccine. In this study, we systematically analyzed HIV-1 clade A and D Gag CD8+ T cell epitopes of two HLA class I alleles associated with different outcomes of HIV-1 infection. Binding affinity and off-rates of the identified epitopes were determined. Gamma interferon (IFN-γ) enzyme-linked immunospot (ELISpot) assays with patient peripheral blood mononuclear cells (PBMCs) validated the epitopes. Epitope-specific CD8+ T cells were further phenotyped for memory markers with tetramer staining. Our study showed that the protective allele A*01:01 recognizes only three Gag epitopes. By contrast, B*07:02, the allele associated with susceptibility, binds 30 epitope variants. These two alleles differ most importantly in the spectrum of Gag epitopes they can present and not in affinity, off-rates, the location of the epitopes, or epitope-specific Tem/Tcm frequencies. The binding of more epitopes and strong IFN-gamma ELISpot responses are associated with susceptibility to HIV-1 infection, while more focused antigen recognition of multiple subtypes is protective. Rational vaccine design should take these observations into account