Stopping Preventive Treatments
"Simply Medical" presents information on a variety of topics in HIV/AIDS treatment and research. It is published as a service to our readers and is intended for information purposes only. Treatment decisions should always be made in consultation with physicians and other healthcare providers.
PCP (Pneumocystis Carinii Pneumonitis)
While studies have shown that HAART, known more formally as Highly Active AntiRetroviral Therapy, combinations can increase CD4 (T-cell) counts, doctors have been cautious about stopping preventive treatments, or prophylaxis, such as Bactrim for PCP. PCP prevention is usually prescribed if your CD4 count drops below 200. Two important new studies have suggested that if HAART increases T-cells to over 200 for an extended period of time, PCP prevention can safely be stopped.
The first study appeared in the January 1999 issue of a medical journal called The Lancet. Researchers at the University Hospital in Utrecht studied 78 people whose T-cell counts had increased to over 200 as a result of HAART. For the sake of safety, study participants had to have had two separate T-cell count measurements over 200, taken at least a month apart. Most people in this study had started PCP prevention because of low T-cell counts before HAART, but a few participants had already had PCP and were on "secondary" prevention.
All participants stopped their PCP prevention and had their T-cell counts monitored every three months. At the time of stopping, the average T-cell count was 347 and the average time on HAART was 9.8 months. The study participants have now been monitored for an average of about a year. So far, so good. No one in the study has developed PCP.
A second study recently appeared in the This study involved 262 people, and was set up a little differently from the Lancet study described above. Study participants had to have T-cell counts that had been over 200 for at least twelve weeks. Also, no one in this study had previously had PCP.
Researchers stopped PCP prevention and monitored study participants every three months. The average T-cell count at the time of stopping was 325. After nearly a year of follow-up, no one had developed PCP.
The researchers in this second study also monitored for another opportunistic infection called toxoplasmosis, or toxo. Anti-PCP drugs may help prevent this infection too. No one in the study developed toxo.
Because of drops in their T-cell counts, nine of the 262 participants did restart PCP prevention during the study.
Partly as a result of these encouraging studies, updated guidelines on the prevention of opportunistic infections are being prepared by the United States Public Health Service. A draft version of the guidelines has recently been issued. The recommendations for starting PCP prevention -- a T-cell count of less than 200 or a history of thrush -- have not changed. A new section on stopping PCP prevention, however, has been added to the PHS guidelines. This section says that "providers may wish" to stop PCP prevention when an individual's T-cell count has stayed over 200 for at least three to six months. Regarding restarting PCP prevention, the guidelines suggest the same rules as for starting in the first place, that is, if the T-cell count drops below 200 again.
MAC (Mycobacterium Avium Complex)
The recommendations for preventing mycobacterium avium complex have also changed. MAC used to be a common opportunistic infection in people with low T-cell counts. The symptoms of MAC can include weight loss, fevers, chills, night sweats, swollen glands, abdominal pains, diarrhea, and overall weakness. The risk of developing MAC is highest in people with fewer than fifty T-cells, and the PHS guidelines recommend preventive therapy for MAC if the T-cell count gets this low. The recommended drugs are either Biaxin (clarithromycin) or Zithromax (azithromycin).
As with PCP, the new PHS guidelines contain the first-ever recommendations for stopping MAC prevention. The guidelines say that it is "reasonable to consider" stopping MAC prevention if the T-cell count increases to over 100 for at least three to six months. The guidelines also recommend restarting MAC prevention if the T-cell count drops below 50 again.
The other HAART-related change in the PHS opportunistic infection guidelines relates to cytomegalovirus. CMV is a herpes virus that can cause illness, most commonly when the T-cell count is less than fifty. CMV causes retinitis, an eye infection that can lead to loss of vision. Standard treatment for CMV involves drugs given intravenously, and ongoing "maintenance" treatment is normally needed to prevent CMV from coming back.
Several studies have found that when HAART increases T-cell counts to over 100 to 150 cells, maintenance treatment for CMV may not be so important. The PHS guidelines are cautious about this information, because active CMV disease can be very serious. The guidelines note, however, that stopping maintenance treatment "may be considered" if there is a sustained T-cell increase to over 100 to 150 cells.
The guidelines point out that any decision to stop CMV maintenance therapy should be made in consultation with an experienced eye doctor, an ophthalmologist. There are several factors that need to be taken into account, including how sight-threatening the CMV infection might be.
All in all, these new studies and the revised PHS guidelines are good news. A few years ago, it was difficult to imagine a time when we'd be talking about stopping PCP or MAC prevention. The important message is that the immune system is much tougher than many people had thought. It's clear that when HIV activity is reduced, immunity to opportunistic infections can be restored.
This article was provided by Body Positive. It is a part of the publication Body Positive.