In the early days of the AIDS epidemic, pneumocystis pneumonia was a big killer of people stricken with the immune-destroying disease.
Now that people with HIV infections can survive with drug treatment, you don't hear as much about pneumocystis -- pronounced numo-SIS-tiss -- but it's still a major problem for people with suppressed immune systems.
The fungal infection is a significant threat for people with HIV, as well as those with chronic lung diseases, organ transplant recipients taking immunosuppressive drugs, and cancer patients whose immunity has been battered by radiation and chemotherapy.
If treatment isn't successful, the fungus can trigger a lethal form of pneumonia that causes people to drown in their own fluids.
Most of us occasionally have pneumocystis organisms in our lungs, but if our immune system is healthy, they rarely cause problems.
For those who get a pneumocystis infection, there are antibiotic and antimalarial drugs that are effective, but they have a high rate of serious side effects, says Sherry Queener, an Indiana University pharmacology professor. Among the worst are a skin rash that can be deadly, severe diarrhea and a reduced ability of red blood cells to carry oxygen.
Because of that, scientists for many years have been eager to find better treatments for pneumocystis, and even a vaccine that could prevent vulnerable patients from getting it in the first place.
Studies like those done on rhesus monkeys at the University of Pittsburgh have shown that even when the animals have suppressed immune systems, they can still mount an antibody attack on the pneumocystis if the right substance is used as a vaccine.
At the same time, it's difficult to translate many animal studies into effective human treatments, so no working pneumocystis vaccine for people has emerged yet.
While startup companies like MiniVax in New Orleans believe the potential market for a pneumocystis vaccine is a lucrative one, Ms. Queener isn't so sure.
"I'm not sure Big Pharma is very interested, because the pneumocystis patients would be a niche market. And I think the big companies are interested in billion dollar products."
Mark Roth: email@example.com or 412-263-1130.