Anaplastic large cell lymphoma in human immunodeficiency virus-infected people and solid organ transplant recipients

Human immunodeficiency virus (HIV)-infected people and solid organ transplant recipients have elevated risk of anaplastic large cell lymphoma (ALCL). Little is known regarding ALCL risk factors in immunosuppressed populations. We used data from US cancer registries linked to HIV registries (1996-2016) and to the national transplant registry (1992-2017). ALCL risk in HIV-infected people and transplant recipients relative to the general population was calculated as a standardized incidence ratio (SIR). ALCL risk factors were evaluated using Poisson regression. We identified 121 incident ALCL cases in the HIV (n = 86) and transplant (n = 35) populations. We reviewed pathology reports for 45 cases and most (86 center dot 7%) were confirmed as ALCL. Epstein-Barr virus tested positive in 1/8 (12 center dot 5%) cases. Compared to the general population, ALCL risk was strongly elevated among HIV-infected people [SIR 5 center dot 43; 95% confidence interval (CI) 4 center dot 27-6 center dot 81] and transplant recipients (5 center dot 96; 4 center dot 03-8 center dot 49). Among HIV-infected people, ALCL incidence was strongly related to CD4 count [adjusted incidence rate ratio (aIRR) 0 center dot 15 for >= 500 vs. P trend < 0 center dot 001]. Among transplant recipients, risk was highest within the first year (aIRR 6 center dot 82) and 10+ years post-transplant (5 center dot 99). In conclusion, ALCL risk is strongly increased in these immunosuppressed populations but may be unrelated to EBV infection based on limited reports.