Lymphomas amongst patients with HIV in South Africa described for first time

Investigators in Johannesburg have found that the majority of certain lymphomas diagnosed in the city are in people with HIV. Their findings, which are published in the April 15^th edition of the Journal of Acquired Immune Deficiency Syndromes provide the first characterisation of lymphomas in a setting with a high HIV prevalence.

“This article makes an important contribution to the characterization of these lymphomas and allows the establishment of a baseline that will enable ongoing monitoring of trends in lymphoproliferative disorders as the HIV epidemic matures and access to antiretroviral therapy increases”, comment the investigators.

HIV is associated with an increased risk of certain lymphomas, especially high-grade B-cell non-Hodgkin lymphoma and lymphoma of the central nervous system.

However, lymphomas are not regarded as a significant cause of death amongst HIV-positive patients in Africa, possibly because such malignancies are not properly recognised or recorded. An alternative explanation could patients are dying of other causes before lymphomas have had the opportunity to develop.

Investigators from the pathology departments of the Charlotte Maxeke Johannesburg Hospital wanted to establish a better understanding of the types of lymphomas being which are developing in patients with HIV.

They therefore designed a retrospective study involving 1897 patients treated at the hospital for lymphoma between 2004 and 2006.

HIV tests results were available for 709 patients, and 37% of these individuals were HIV-positive.

The most commonly diagnosed lymphomas included diffuse large B-cell lymphoma (21%), B-cell non-Hodgkin lymphoma (17%), and Hodgkin lymphoma (7%).

There was a high prevalence of HIV in the patients diagnosed with these malignancies.

Some 80% of individuals with diffuse large B-cell lymphoma were HIV-positive. These patients had a mean CD4 cell count of 158 cells/mm³ and a mean age of 44 years.

HIV prevalence amongst individuals with B-cell non-Hodgkin lymphoma was 59%. The mean CD4 cell count of these HIV-positive individuals was 143 cells/mm³.

Just under half (46%) of all patients with Hodgkin lymphoma were HIV-positive.

Burkitt lymphoma was rare in the overall patient population, contributing just 6% all lymphoma diagnoses. However, 86% of these cases involved patients with HIV. In addition, all five patients diagnosed with primary effusion lymphoma were HIV-positive.

By contrast, none of the patients diagnosed with either follicular lymphoma and mantle cell lymphoma were HIV-positive. Few of the patients with T small lymphocytic lymphoma/chronic lymphocytic leukaemia (4%), or pre-B-cell lymphoma (5%) were HIV-infected.

“This study represents the first detailed description of lymphoproliferative disorders in Johannesburg…these data support the association between HIV and certain non-Hodgkin lymphoma categories seen in other African studies”, comment the investigators.

The researchers acknowledge that their inability to determine the HIV status of a large number of patients was an important limitation of their study.

“This study further underscores the importance of establishing sustainable South African and regional cancer registries and highlights the need for linking these to HIV-testing databases” conclude the investigators. They believe that these steps are essential “to monitor the potential rise of non-AIDS-defining malignancies that may emerge as a result of the HIV epidemic.”