Response: Lymphocyte counts prior to Hodgkin lymphoma development

The role of viral co-infection in HIV-associated non-AIDS-related cancers

HIV-infected individuals are at increased risk for most types of cancer, including those typically classified as non-AIDS-defining cancers (NADCs). This increased risk is likely multifactorial, but a prominent risk factor for the increased rate of some cancers is co-infection with oncogenic viruses. Anal cancer, hepatocellular carcinoma, and Hodgkin lymphoma are three of the most common NADCs, and they are associated with co-infection with human papillomavirus, hepatitis B and C, and Epstein Barr virus, respectively. This review will examine the epidemiology, pathogenesis, and future trends around these virally associated NADCs frequently found in HIV-infected individuals.

HIV-1–related Hodgkin lymphoma in the era of combination antiretroviral therapy: incidence and evolution of CD4+ T-cell lymphocytes

The risk of Hodgkin lymphoma (HL) is increased in patients infected with HIV-1. We studied the incidence and outcomes of HL, and compared CD4+ T-cell trajectories in HL patients and controls matched for duration of combination antiretroviral therapy (cART). A total of 40 168 adult HIV-1–infected patients (median age, 36 years; 70% male; median CD4 cell count, 234 cells/μL) from 16 European cohorts were observed during 159 133 person-years; 78 patients developed HL. The incidence was 49.0 (95% confidence interval [CI], 39.3-61.2) per 100 000 person-years, and similar on cART and not on cART (P = .96). The risk of HL declined as the most recent (time-updated) CD4 count increased: the adjusted hazard ratio comparing more than 350 with less than 50 cells/μL was 0.27 (95% CI, 0.08-0.86). Sixty-one HL cases diagnosed on cART were matched to 1652 controls: during the year before diagnosis, cases lost 98 CD4 cells (95% CI, −159 to −36 cells), whereas controls gained 35 cells (95% CI, 24-46 cells; P < .0001). The incidence of HL is not reduced by cART, and patients whose CD4 cell counts decline despite suppression of HIV-1 replication on cART may harbor HL.

Cancer biomarkers in HIV patients

PURPOSE OF REVIEW

In this review, we update investigations related to cancer biomarkers in HIV-infected populations.

RECENT FINDINGS

CD4 lymphocyte count is associated with primary central nervous system lymphoma (PCNSL), systemic non-Hodgkin's lymphoma (NHL) (except perhaps for Burkitt lymphoma), Kaposi's sarcoma, cervical cancer, and anal cancer. HIV load is associated with Burkitt lymphoma and systemic NHL (but not PCNSL), with Kaposi's sarcoma and with anal cancer. CD40 ligand incorporated into the HIV envelope and expression of activation-induced cytidine deaminase may help explain the relationship between HIV load and Burkitt lymphoma. Genetic polymorphisms have been identified that are linked to lymphoma in HIV patients. B-cell activation as manifest in immunoglobulin light chain production may be an important marker for NHL risk. Cytokines and related molecules (IL10, sCD30) may identify patients at high risk for NHL. Epstein-Barr virus (EBV) in cerebrospinal fluid (CSF) is useful as a marker for PCNSL, although with the falling incidence of PCNSL, the specificity of the test has been called into question. EBV and Kaposi's sarcoma-associated herpesvirus (KSHV) have not yet emerged as especially promising markers of risk for either lymphoma or Kaposi's sarcoma.

SUMMARY

CD4 lymphocyte count, HIV load, germline genetic polymorphisms, cytokine and related molecules, and immunoglobulin light chains all show increasing promise as biomarkers of malignancy in HIV patients.