A ground-breaking study led by researchers at the University of Cape Town’s Centre for Lung Infection and Immunity has found evidence suggesting that Depo-Provera may increase women’s chances of getting tuberculosis (TB).
This is particularly disturbing news for South Africa, which has one of the highest rates of TB in the world (largely linked to HIV/Aids) – and where easy, discreet hormone injections are the most popular form of contraception. Depo-Provera is the most widely used injectable contraceptive in clinics.
Depo-Provera under scrutiny since 2011
Questions have been raised about Depo-Provera’s safety in the past. In 2011, a study in the journal Lancet found that it almost doubled women’s chances of getting HIV from an infected partner, or passing it on, but noted that more research was needed. A study last year found an association that Depo-Provera might increase women’s chances of contracting HIV by as much as 40%, because it contains a synthetic hormone that acts as an immunosuppressant. A different commonly-used injectable, NET-EN (norethisterone enanthate), did not do this. However, the Evidence for Contraceptive Options and HIV Outcomes (ECHO) study, which will recruit 7 830 patients, will definitively indicate if Depo-Provera increases your risk of acquiring HIV.
What did the UCT study show?
Now, in a study published in the Journal of Infectious Diseases, UCT’s Professor Keertan Dheda and Dr Michele Tomasicchio have found that Depo-Provera may raise women’s risk of TB. They too say that more research is needed, as the risk has not yet been officially proven.
The two have spent three years researching the link between TB and Depo-Provera, estimated to be used by around 16.5 million women in sub-Saharan Africa. In the laboratory, they used human white blood cells and infected them with live TB bacteria in the presence of immune function cells that were treated with or without the two injectable contraceptives, Depo-Provera or NET-EN. They found that Depo-Provera “subverted the protective immune response against TB” – preventing the immune system’s cells from killing TB. This did not happen when using NET-EN.
They further showed that Depo-Provera “down-regulated immune function genes associated with protection against TB, and up-regulated certain cell types that suppress the immune system”. It’s disturbing news when, according to a recent UNAIDS report, “TB is the leading infectious killer globally and leading killer of people living with HIV, accounting for one in every three AIDS-related deaths.”
What happens now?
There is still a lot of research that needs to be done to prove whether there is a causal link between TB and Depo-Provera. However, Dr Tomasicchio says he would like women to be made aware of the possible risks of using Depo-Provera, and would like to “see the study results, along with those of future studies, if appropriate, drive a change in policy surrounding Depo-Provera use in South Africa”.
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