**1. Introduction**

Hodgkin's lymphoma is a lymphoid neoplasm first described by Thomas Hodgkin in 1832 and subsequently by Samuel Wilks in 1865 (1,2). Greenfield (1878), Sternberg (1879) and Reed (1902) are credited with the earliest descriptions of the pathological characteristics of the disease (3,4,5). In has now become clear that the Reed-Sternberg cell is derived from clonal B-cells, more specifically post-germinal center B-cells, giving credence to the malignant nature of the disease, and hence the preferred term of Hodgkin's lymphoma –HL, instead of Hodgkin's disease (6).

Major and striking advances have been made in the biology and management of HL. More than 70% of patients with HL are curable (especially those presenting with early stage disease). Better insight has been gained with regard to the acute and long term toxicities of chemotherapy and radiotherapy. Furthermore, the advent of new imaging techniques such as PET (positron emission tomography)-scans are allowing therapy to be individualized and tailored in a risk adapted and response adapted fashion (7).

The incidence of HL varies widely throughout the world (approximately 1-3.5/100 000), based on geographical and ethnic factors. The highest rates of HL are seen in the United States, Canada and Europe, with much lower rates occurring in Japan, Korea and China. HL is more common in males compared to females, with a male to female ratio of 1.5:1. HL occurs most often in young adults, with a peak frequency in the third decade of life. A bimodal age distribution may be seen, with a second age peak noted in the 6th to 8th decades (8,9,10,11).

The exact aetiology of HL is unknown. An increased risk of HL is seen with Epstein-Barr Virus (EBV) infection, congenital and acquired immunodeficiency states (such as Human Immunodeficiency Virus – HIV infection/AIDS- Acquired Immunodeficiency Syndrome,

© 2012 Patel, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2012 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

post solid organ and haematopoietic stem cell transplantation) and autoimmune disease (12-18). There is also an increased risk of familial aggregation of HL (19).

Hodgkin's Lymphoma and Human Immunodeficiency Virus Infection 297

**Number of Seropositive Patients** 

**% Seropositive** 

the 1990's with respect to HIV-NHL showed only a modest increase of NHL in seropositive individuals, with an odds ratio of 4.8, 5 and 5.9 respectively (31-33). The first patient at this hospital with HIV-NHL was seen in 1993. Since then, there has been a steady increase in HIV-NHL up to 2000. However, since 2001, the percentage seropositivity of NHL has exceeded 50% (approximately between 60 – 80%), and since 2002, there has additionally been a significant increase in the total number of patients diagnosed with NHL at CHBAH (from 20-30 new patients per year to 70-80 patients per year) (see Table 1 and Figure 1) (25). Indeed, NHL is now the commonest haematological malignancy in South Africa, in the

current HIV/AIDS era and the number of seropositive patients continues to increase.

**Number of Seronegative Patients** 

1993 20 19 1 5% 1994 20 18 2 10% 1995 18 15 3 16.7% 1996 28 25 3 10.7% 1997 18 14 4 22.2% 1998 34 18 16 47.1% 1999 22 14 8 36.4% 2000 30 16 14 46.7% 2001 24 4 20 83.3% 2002 40 15 25 62.5% 2003 44 17 27 61.4% 2004 58 23 35 60.3% 2005 54 15 39 72.2% 2006 72 17 55 76.4% 2007 72 19 53 73.6% 2008 76 10 66 86.8% **Table 1.** Patients with non-Hodgkin's Lymphoma seen at Chris Hani Baragwanath Academic Hospital

setting of HIV in southern Africa.

**of Patients** 

**Year Total Number** 

from 1993 to 2008

With respect to Hodgkin's lymphoma (HL), the data is less dramatic, but is becoming more significant. In a study by Stein et al, 2008 (33), the percentage seropositivity of HL in a South African cohort (which included patients from CHBAH) was 19.5% (OR=1.6, 95% CI=1.0-2.7), during the period 1995-2004. The first patient with HIV-HL was seen in 1994 at CHBAH. Since then, there has been a modest increase in HIV-HL up to 2006. However, in the last 5 years (2007 - 2011) at our single institution, the percentage seropositivity is greater than 50% (see Figure 2) and the number of patients over the years are gradually increasing (doubled compared to an earlier series in the late 1980's and early 1990's – (17,34)(see Figure 3). Thus, the focus of this review relates to the emerging problem of Hodgkin's lymphoma in the

HIV infection is known to be associated with an increased risk of HL, based on linkage and cohort studies. The relative risk is now 10-15 fold higher compared with the general population (13-15,17,18,20-22). This review will focus on HL in southern Africa, and describe the differences compared to HL in developed countries, highlighting the emerging increase in HL in the HIV seropositive population/people living with HIV/AIDS (PWHA).
