Late infectious complications in hematopoietic cell transplantation survivors: a population-based study

Abstract

Few studies have compared the incidence of infections occurring ≥2 years after hematopoietic cell transplant (HCT) with other cancer patients and the general population. In this study, ≥2-year HCT survivors who were Washington residents treated from 1992 through 2009 (n = 1792; median age, 46 years; 52% allogeneic; 90% hematologic malignancies) were matched to individuals from the state cancer registry (n = 5455, non-HCT) and driver's license files (n = 16 340; Department of Licensing [DOL]). Based on hospital and death registry codes, incidence rate ratios (IRRs; 95% confidence interval [CI]) of infections by organism type and organ system were estimated using Poisson regression. With 7-year median follow-up, the incidence rate (per 1000 person-years) of all infections was 65.4 for HCT survivors vs 39.6 for the non-HCT group (IRR, 1.6; 95% CI, 1.3-1.9) and 7.2 for DOL (IRR, 10.0; 95% CI, 8.3-12.1). Bacterial and fungal infections were each 70% more common in HCT vs non-HCT cancer survivors (IRR, 1.7; P < .01), whereas the risk for viral infection was lower (IRR, 1.4; P = .07). Among potentially vaccine-preventable organisms, the IRR was 3.0 (95% CI, 2.1-4.3) vs the non-HCT group. Although the incidences of all infections decreased with time, the relative risk in almost all categories remained significantly increased in ≥5-year HCT survivors vs other groups. Risk factors for late infection included history of relapse and for some infections, history of chronic graft-versus-host disease. Providers caring for HCT survivors should maintain vigilance for infections and ensure adherence to antimicrobial prophylaxis and vaccination guidelines.

Conflict of interest statement

Conflict-of-interest disclosure: The following authors report disclosures not directly relevant to this publication: M.J.B. (Helocyte, Pulmocide, Chimerix, Gilead, Janssen, ReViral, Allovir, ADMA, Symbio, VirBio, Moderna, Ansun Biopharma, Merck, Astellas, GlaxoSmithKline, Takeda), P.A.C. (Incyte, Mallinckrodt, Mesoblast, Pharmacyclics), M.E.D.F. (Astellas, Mallinckrodt, CSL Behring, Pharmacyclics, Incyte, Therakos),S.J.L. (Mallinckrodt, EMD Serono, Genzyme, Incyte, Kadmon, MSD Oncology, Pfizer, Regeneron, Sanofi, Amgen, Bristol-Myers Squibb, Takeda), and B.A.M. (AstraZeneca). The remaining authors declare no competing financial interests.

© 2020 by The American Society of Hematology.

Figures

Graphical abstract

Figure 1.

Comparative IRRs of the 3 study groups. IRR with 95% CI of infections among ≥2-year HCT survivors vs non-HCT cancer survivors (circles), and HCT survivors vs the general population (squares). Estimates included adjustment for sex, age, and underlying cancer diagnosis and HCT/cancer diagnosis year (if applicable). IRRs with 95% CI that do not cross 1 are statistically significant.

Figure 2.

Rates of infection by organism type. Incidence rate with 95% CI of infections by organism type among HCT survivors, non-HCT cancer survivors, and the general population (DOL), shown separately by time since index date: all infections (A), bacterial (B), fungal (C), and viral (D). The y-axis ranges vary among the panels.

Figure 3.

Rates of infection by organ type. Incidence rate of infections with 95% CI by organ system among hematopoietic cell transplantation (HCT) survivors, non-HCT cancer survivors, and the general population (DOL), shown separately by time since index date: respiratory (A), genitourinary (B), gastrointestinal (C), skin (D), nervous/sensory (E), and musculoskeletal (F). The y-axis range may vary among the panels.