A malaria attack can substantially reduce the CD4 cell count of an HIV-positive person, while successful treatment of malaria can result in large CD4 cell increases, a study in Zambia has shown. The authors of the study say that malarial status needs to be determined in all patients deemed eligible for treatment where CD4 counts are being used, in order to avoid premature initiation of treatment.
Malaria and HIV/AIDS occur together in many countries in Sub-Saharan Africa where 25.4 million people are living with HIV/AIDS (PLWA). Over the years, there have been concerns about the interaction between the two infections but it is only of recent that concrete data have been collected about HIV/malaria interaction.
HIV-infected individuals are at an increased risk of malaria attacks and experience higher treatment failure rates. Malaria, on the other hand, increases HIV viral loads in HIV-infected patients and might accelerate disease progression to full blown AIDS.
PLWA therefore constitute another important vulnerable target population, in addition to pregnant women and children under 5 years old, on which malaria control efforts in Africa should be focused. In addition to malaria, PLWA are susceptible to a legion of opportunistic infections some of which are predominant at certain threshold CD4 counts.
The CD4 cell count has become an important clinical decision-making tool in the care of PLWA. It is used for monitoring PLWA so that treatment with antiretroviral drugs (ARV) can be started or changed. However, in order for CD4 counts to guide clinical decision-making, CD4 count changes must reliability reflect the progression of HIV/AIDS.
Changes in absolute lymphocyte and CD4 counts have been reported during malaria attacks in HIV-uninfected subjects. However, the impact of clinical malaria attacks on CD4 counts in PLWA in malaria-prone areas has not been investigated. A team of Belgian and Zambian investigators from the Institute of Tropical Medicine in Antwerp (Belgium) and the Tropical Disease Research Center in Ndola (Zambia) has addressed this issue in HIV-1-infected Zambian patients with uncomplicated malaria.
The study took place in four peri-urban health centers in Ndola, Zambia. All individuals aged 15-50 years with fever or history of fever in the previous 48 hours were screened for malaria infection and pregnancy. The exclusion criteria included parasite density of 1000 parasites/l, pregnancy, severe malaria, history of antimalarial drug use, and other causes of fever. HIV testing was done anonymously and patients wanting to know their HIV status received voluntary counseling and testing services. Malaria parasitemia, CD4 cell counts, and HIV-1 viral loads were assessed at enrolment (day 0) and after 28 and 45 days of antimalarial treatment.
Three hundred and twenty seven patients had microscopically-confirmed uncomplicated malaria and 32.1 % (105/327) of these were HIV-1 positive at enrollment. HIV-1 positive patients were older, had lower mean hemoglobin levels and higher body temperatures, and were more likely to be females. HIV-1 negative patients had higher median CD4 counts (459 cells/mm3; 95 % confidence interval: 425-517) than HIV-1 positive patients (274 cells/mm3; 234-347).
Among the HIV-1-uninfected and HIV-1-infected subjects with uncomplicated malaria, CD4 counts
Following successful antimalarial treatment, the median CD4 count on day 28 post-treatment increased to 811 cells /mm3 (73 % increment) in HIV-1 negative patients and to 447 cells/mm3 (51 % increment) in HIV-1 positive patients. The CD4 increment was inversely correlated with the CD4 count at enrollment for both HIV-1 negative and HIV-1 positive patients. The proportion of patients with CD4 counts
CD4 counts and HIV-1 RNA viral loads at day 45 after treatment were similar to those at enrollment. In HIV-1 negative patients with detectable parasitemia the median CD4 count on day 45 was significantly lower than that in successfully treated patients (598 versus 831, P
Thus, by monitoring CD4 counts in Zambian subjects who had uncomplicated malaria at enrollment and at 28 and 45 days after successful treatment, van Geertruyden et al have clearly demonstrated that uncomplicated malaria has a significant impact on CD4 counts in both HIV-1-infected and uninfected patients. These findings suggest that the usefulness of CD4 counts as a decision-making tool for providing health care to PLWA in malaria-endemic countries might be confounded by malaria.
In most resource-poor countries like Zambia and Uganda, the CD4 count is currently the marker of choice for monitoring HIV-1/AIDS progression in PLWA. The immediate policy implications of the study is that the malaria status of PLWA need to be unequivocally established before using CD4 counts to guide treatment options.
Reference
Van Geertruyden J-P et al. CD4 T-cell count and HIV-1 infection in adults with uncomplicated malaria. J Aquir Immune Defic Syndr 43 (3): 363-367, 2006.