In September 2010, study results from the European COHERE study were published showing that some people could stop taking preventive treatment for PCP (Pneumocystis jiroveci pneumonia) provided that their viral loads were under control by a potent HIV regimen. Earlier in the epidemic, PCP quickly became an AIDS-defining illness and a leading cause of death for people living with HIV. It most often appeared when CD4 counts fell below 200.
In response, PCP preventive treatment (usually Bactrim) was recommended for anyone with CD4s in this range and certain others whose health warranted it. Many new cases of PCP were avoided because of this new standard of care, but also because of many improvements HIV therapy over the years. Taking Bactrim can be an added burden for some, so being able to stop it safely would be welcome news.
COHERE did two analyses by examining the medical files of HIV-positive people across Europe. Their first analysis looked at more than 23,000 people and their risk factors for PCP. Their second one of about 5,000 people focused on issues related to stopping PCP preventive treatment.
Of the 5,000 studied, 24 cases of PCP occurred after stopping their preventive therapy. Most cases were in people with CD4s below 100. When they looked at those in the range of 101-200 CD4s, there was no difference in the rate of cases in those on and those not on preventive treatment. In fact, no one who took HIV drugs with CD4s in this range and whose viral load was undetectable developed PCP.
Still, anyone whose CD4 count is below 100 should continue taking PCP preventive therapy, regardless of their viral load. The U.S. Guidelines still recommend taking PCP preventive therapy until the CD4 count rises above 200 for at least three months, which may change in the next revision. In light of this new information, people may want to consult their doctors and weigh the pros and cons of stopping PCP preventive treatment between 101-200 CD4s.