The immunological effects of concomitant highly active antiretroviral therapy and liposomal anthracycline treatment of HIV-1-associated Kaposi's sarcoma

Abstract

A combination of highly active antiretroviral therapy (HAART) and liposomal anthracycline chemotherapy is the standard of care for advanced HIV-associated Kaposi's sarcoma, despite concerns that the chemotherapy may adversely affect lymphocyte subsets and HIV viraemia. We showed in 50 patients that liposomal anthracyclines used with HAART did not lead to a significant loss of CD4 or CD8 cells or an increase in HIV-1 viral load during or up to 12 months after chemotherapy. Reversible myelosuppression is a major side-effect of chemotherapy that may lead to opportunistic diseases even in patients without HIV-1 infection. Data from the pre-highly active antiretroviral therapy (HAART) era shows that liposomal anthracycline chemotherapy for Kaposi's sarcoma (KS) is associated with an increased risk of myelosuppression and opportunistic infection [1–3]. Until the advent of HAART, KS was difficult to treat in the context of advancing immunodeficiency. Since the widespread introduction of HAART there has been a significant reduction in the incidence of KS in the established market economies [4]. Moreover, in many cases KS has been successfully treated with HAART alone [5–8]. The immune reconstitution after treatment with HAART is thought to include the generation of cytotoxic T lymphocytes that are specific for human herpesvirus 8 and lead to the regression of KS lesions [9]. However, systemic chemotherapy may be necessary for patients with extensive, advanced or visceral KS, and if HAART fails to cause regression of the KS. The gold standard first-line chemotherapy is liposomal anthracycline treatment, which is myelosuppressive and thus has the potential to aggravate HIV-related immune deficiency and increase the risk of opportunistic infections. Chemotherapy-induced immunodeficiency is characterized by T lymphocyte depletion, although decreases in B cells and natural killer cells accompany this [10–12]. Chemotherapy in immunocompetent patients causes a more profound decline in CD4 than CD8 T cells [13], whereas the natural killer cell population is relatively spared [14]. The aim of this study is to define the changes in immune parameters in individuals with HIV-1 infection and KS, treated with both chemotherapy and HAART. This information has implications for planning opportunistic infection prophylaxis, and the monitoring of patients on chemotherapy. We have studied the effects of combining HAART and liposomal anthracycline chemotherapy on the lymphocyte subsets and HIV-1 viral loads both during chemotherapy and for up to one year after the completion of chemotherapy. Fifty HIV-1-infected individuals with KS who were treated with liposomal anthracyclines and HAART were studied. Total lymphocyte and subset analysis was performed using whole blood stained with murine anti-human monoclonal antibodies to CD4, CD8 and CD19 cells (TetraOne; Beckman Coulter, High Wycombe, UK), and were evaluated on an Epics XL-MCL (Beckman Coulter) flow cytometer. The viral load in patient plasma was measured at each timepoint of sample collection using the Quantiplex HIV RNA 3.0 (Chiron branched DNA) assay (detection limit < 50 HIV-1 copies/ml; Chiron Diagnostics, Halstead, UK). All patients were men, and the mean age at diagnosis of KS was 36.3 years (range 23–59) and at entry into the study 38.8 years (range 28–59). The choice of concurrent antiretroviral therapy was based upon previous antiretroviral history and current unit practice [15,16]. Most (74%) were receiving protease inhibitor-based HAART, 18% were receiving non-nucleoside reverse transcriptase inhibitors, 4% were receiving both a protease inhibitor and a non-nucleoside reverse transcriptase inhibitors, and 4% were receiving a triple nucleoside analogue reverse transcriptase inhibitor combination. The chemotherapy used for the treatment of KS was liposomal daunorubicin (DaunoXome) at a dosage of 40 mg/rn2 every 2 weeks for 30 patients and liposomal doxorubicin (Caelyx) at a dosage of 20 mg/rn2 every 3 weeks for 20 patients. A median of six cycles (range 2–14) of chemotherapy was administered. The overall response rate was 60% (58% partial response, 2% complete response) and a further 30% had stable disease. At entry, the median CD4 (helper) cell count was 21 9 cells/mm3 [interquartile range (IQR) 315] and the median CD4 cell count as a percentage of all lymphocytes was 13.8% (IQR 10.7). The median CD8 (suppressor) cell count at entry was 886 cells/mm3 (IQR 595), and the median CD19 (B) cell count at entry was 126 cells/mm3 (IQR 160). The median HIV-RNA viral load at entry was 219 copies/ml (IQR 29 000) and 42% of patients had fewer than 50 copies/mI, the detection limit of the assay. There were no significant changes in the T helper (CD4) cell count or percentage during chemotherapy or in the following 12 months (see Fig. 1). Similarly, there were no significant changes in the T suppressor (CD8) cell counts throughout the study period (see Fig. 1). The B lymphocyte count (CD19 cells) fell to a nadir after three cycles of chemotherapy and remained reduced at the completion of chemotherapy. There was thus a significant fall during chemotherapy (t test P = 0.0009) and the B cells were still suppressed 3 months after the end of chemotherapy (t test P = 0.039) but had recovered after 6 months (t test P = 0.68) (see Fig. 1).Fig. 1.: Mean (a) CD4, (b) CD8, (c) CD19 cell counts, and (d) plasma HIV-1-RNA loads before, during and after chemotherapy. VL, Viral load. Error bars represent 95% confidence intervals.There was no significant change in the HIV-1-RNA load during the whole study period, either during chemotherapy or after the completion of chemotherapy. Before chemotherapy 42% of patients had viral loads below the level of detection of the assay (< 50 copies/mI). At the completion of chemotherapy 52% had undetectable levels, and during follow-up the percentage of the cohort with undetectable viral loads was 59, 62 and 59% at 3, 6 and 12 months, respectively (see Fig. 1). Before the introduction of HAART, liposomal anthracyclines were associated with both myelosuppression and opportunistic infections [1–3]. The latter reflecting progressive decreases in CD4 cell counts during chemotherapy. HAART has changed the epidemiology and natural history of KS [5–8,17]. There is greater enthusiasm for treating patients with advanced KS or KS that has failed to respond to HAART alone with chemotherapy. This stems from the wider use of liposomal anthracyclines and the improved prognosis of HIV infection. Our study demonstrates that there is no detrimental effect on T cell subsets or HIV-1 viral load control when treating KS with liposomal anthracycline chemotherapy and concomitant HAART. These findings support the improved short-term immune function seen when HAART is given at the same time as chemotherapy for AIDS-related systemic lymphoma [18]. The findings are also of importance in terms of planning prophylaxis for opportunistic infections, and suggest that there is no indication for adding opportunistic infection prophylaxis when treating with liposomal anthracyclines unless the starting CD4 cell count is below 200 cells/mm3.