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First, you're diagnosed with a life-threatening illness, and then you wait months and months on the UNOS list (along with about 100,000 other Americans) for an organ. But your case is rare; you actually get the transplant you need. Hurray! Unless you're one of four transplant recipients in Chicago whose new organs gave them HIV and hepatitis C. This is the first time in more than 20 years that donor organs have transmitted the virus.
The donor organs were tested for these and other diseases, but the tests were negative, "most likely because the donor had acquired the infections in the last three weeks before death," according to the Trib. The organs were tested by Elmhurst's Gift of Hope Organ & Tissue Donation with an ELISA (enzyme-linked immunosorbent assay, duh) test, which detects the presence of HIV antibodies. But those antibodies take a few weeks to develop--that's why people who've been exposed to HIV are tested again three and six months after their first negative result. According to Gift of Hope, "information obtained through the medical/social history of the donor at the time of donation indicated high risk behavior," but because the donor tested negative for diseases, the organs were approved. Patients at Northwestern Memorial Hospital, Rush University Medical Center and the University of Chicago Medical Center received transplants.
What's "high-risk" behavior for an organ donor? A lot like the list for blood donors:
- Men who have had sex with other men in the last five years
- People who have had non-medical injections in the last five years
- People with blood clotting disorders who have received human-derived clotting factor concentrates
- People who have had sex in exchange for money or drugs in the last five years
- People who have had sex in the last year with someone suspected to be HIV-positive or have had sex with anyone who has engaged in any of the high-risk behaviors listed above
- People who have come in contact with suspected HIV-positive blood in the last year
- People who are inmates of correctional systems
These are the first four cases in the more than 400,000 organ transplants in the last 20 years, so it's still an exceptionally rare occurrence.
Balloon organs by Christoph Brach
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This is tragic, and I feel really bad for the organ recipients. But why the hell is the protocol still to use ELISA (antibody) testing? PCR (RNA) testing is far more sensitive and detects the viral presence earlier. It's much more expensive, and it returns a high number of false positives (which can later be resolved with an ELISA test), which is why it's not the primary diagnostic test. But if it's a matter of donating organs to other people, shouldn't they pay the extra expense and be extra careful?
Medically speaking, if PCR returns a high number of false positives, then it's not a sensitive test.
Actually, if a test returns a high number of false positives (like the PCR test), it is not a SPECIFIC test. But it can be (and is) a sensitive test.
Sensitivity measures the number of true positives. Specificity measures the number of true negatives. A low sensitivity test would return a high number of false negatives.