Kate Johnson

September 15, 2014

WASHINGTON — The HIV Organ Policy Equity (HOPE) Act, which legalizes research into organ tranplants from HIV-positive donors to HIV-positive recipients, is less than a year old, but a new study already suggests the organs may be of poor quality.

"It takes a bit of a shine off the HOPE Act, at least in Philadelphia," the study's lead investigator, Emily Blumberg, MD, from the University of Pennsylvania, told Medscape Medical News. "It is possible this will not provide what we were hoping for — which is a large amount of high-quality donors."

Still, "The HIV donors in Philadelphia may not reflect the patients with HIV in other high-volume areas of the US, but we think they're relatively representative," said Dr. Blumberg about the study, presented here at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC).

Investiagtors reviewed charts of 578 HIV-positive patients who died at 6 large Philadelphia HIV clinics to determine their potential suitability as deceased donors. Their mean age was 53 years, 68% were male, and 73% were African American.

 
It takes a bit of a shine off the HOPE Act, at least in Philadelphia. Dr. Emily Blumberg
 

"Because the greatest need in this population is kidney and liver, we chose to focus on these organs," said coinvestigator Aaron Richterman, a medical student also from the University of Pennsylvania, who presented the results.

"We were interested specifically in patients who were in care at the time of their death, because it's likely that this group would form the core of future potential donors," he said.

Out of the pool of 578 patients, 70 were excluded because they were not classified as being in care, another 260 were excluded because they did not die in hospital, 75 were excluded because of an unknown place of death, 63 were excluded for not being on mechanical ventilation, 87 were excluded for not having documented brain death, and 3 and 7 patients were excluded for having a history of malignancy or an elevated viral load.

Of the 13 potential donors that remained (mean age, 53 years), 46% had diabetes, 62% had hypertenion, 54% had hepatitis C antibodies, 23% had cirrhosis, and 15% had end-stage renal disease, reported Richterman.

"As far as HIV history, all potential donors by definition had a suppressed viral load," he added. "Their median CD4 count was 319, 4 had a history of opportunistic infection, 6 were on a protease inhibitor at the time of death, and 2 had documented drug-resistant HIV mutations."

Using organ-specific mathematical models from the Scientific Registry of Transplant Recipients, the investigators estimated that this group of potential donors might have yielded 7 kidneys and 9 livers between 2009 and 2014.

Low Numbers, Poor Quality

Extrapolated annually to the city of Philadelphia, this would have meant 4 to 5 potential donors per year who might have yielded 2 to 3 kidneys and 3 to 4 livers, explained Richterman.

Using models developed to estimate the quality of donated organs and predict organ survival, the researchers also predicted reduced organ quality.

Using the Kidney Donor Risk Index, they predicted an 80% increased risk for graft failure in kidneys donated from the potential donors, compared with the median transplanted kidney in 2013, and a 50% predicted risk for graft failure, compared with the risk with a kidney from an average donor.

More optimistically, the Liver Donor Risk Index predicted a 71% chance of 3-year graft survival — only slightly below the 74% predicted chance from an average donor.

Richterman added that the presence of drug-resistant mutations and protease inhibitor therapy in donors could also cause potential drug reactions with antirejection medications.

"We think there are about 80 to 100 HIV-positive patients currently on the wait list for transplant in Philadelphia, and since only about 5 to 10 of these are getting transplanted each year, this would significantly increase the donor pool," he noted.

"However, the potential donors we've identified are older, with a high prevalence of hypertension, diabetes, and hepatitis C antibodies, and consequently we feel that the organs from these potential donors would be of reduced quality. In spite of its very optimistic name, the HOPE Act may not significantly impact the availability of high-quality organs for HIV-positive patients on the wait list."

Still HOPE

But Dorry Segev, MD, a transplant specialist from Johns Hopkins University in Baltimore, Maryland, who lobbied for the HOPE Act, said he questions the findings.

"I feel strongly that the HOPE Act will indeed help HIV-positive patients," said Dr. Segev, who was the senior author of the only previous study that has tried to assess the HIV-positive donor pool in the United States ( Am J Transplant. 2011 Jun;11:1209-17).

His analysis of databases predicted that HIV-positive donors could increase the donor pool by 500 donors per year for HIV-positive recipients.

 
I feel strongly that the HOPE Act will indeed help HIV-positive patients. Dr. Dorry Segev
 

"Based on the study abstract, it seems that the criteria for calling a patient a potential donor were very conservative. So it is likely that Philadelphia has more than 6 potential HIV-positive donors each year," he told Medscape Medical News.

Dr. Segev said he looked into the data for Philadelphia and discovered that the rate of expanded-criteria donors, meaning marginal quality organs, is twice as high in that city compared with the rest of the country. "And that is HIV-negative donors," he emphasized. "So it shouldn't be surprising that the rate of marginal HIV-positive donors is also higher."

"But even if Philadelphia only has 6, remember that Philadelphia only has 1% of the HIV-positive population in the United States. So, nationally, we would expect about 600 HIV-positive donors," he said. "This would be a huge increase in the deceased donor pool. In fact, it would be the largest increase in the last decade. So in my mind, this is very optimistic and shows how important the HOPE Act will be."

Dr. Blumberg has worked with Pfizer, Bristol Myers Squibb, Viropharma, Cubist, Achaogen, Ansun, and Actelion. Dr. Segev reports no relevant financial relationships.

54th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC): Abstract H-1199a. Presented September 7, 2014.

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