TIC tenant pursues tropical disease test

Louis Kirchhoff, professor of internal medicine, in his laboratory, before leaving for Guadalajara to conduct research. photo by Rex Bavousett

One could envy Louis Kirchhoff for having spent the past holidays in the warm climate of Guadalajara, Mexico, but it was not simply a few days in the sun for the UI researcher. Kirchhoff used the time to continue a collaborative project with researchers at the University of Guadalajara on Chagas disease, a tropical illness common in Latin America that could pose a threat to the United States' blood supply.

Kirchhoff, a professor of internal medicine, also is president and CEO of Goldfinch Diagnostics Inc., a tenant company of the UI's Technology Innovation Center (TIC). One of the UI's technology transfer programs, TIC nurtures new technology-based business ventures and allows these companies to utilize the research resources at the University.

Established in October 1997, Goldfinch's primary aim is to develop a better test to detect Chagas disease, which is caused by the blood-borne parasite Trypanosoma cruzi. This organism usually is transmitted by beetle-like insects, but it also can be spread by transfusions of blood donated by infected persons. Between 16-18 million Latin Americans, most living in rural poverty, have Chagas disease, which results in roughly 45,000 deaths every year. The chronic form of the disease mainly affects the heart, often leading to years of severe disability.

"Medications to treat Chagas are available, but in people who do receive one of the two drugs currently available the parasites are eliminated only about 25 percent of the time," Kirchhoff says. "Moreover, most people who have Chagas don't develop symptoms for years, if at all. Thus it's possible for infected immigrants from Latin America to unknowingly donate infected blood here in the U.S."

To date, six cases of transfusion-associated transmission of Chagas have been reported in the U.S. and one of these patients died as a consequence of the infection.

Currently, U.S. blood banks do not test for Chagas disease, although some pre-donation interview questions help to identify and defer high-risk people. Many Latin American countries require that their blood banks screen for the disease, but Kirchhoff says tests currently used produce many false positive results.

Triatoma infestans, an insect which can transmit Chagas disease. The actual insect is approximately 2 cm. long and looks somewhat like the box-elder bugs found in Iowa.

"At the Blood Center in São Paulo, Brazil, for example, they receive about 600 blood donations per day. The center discards about three percent because they test positive for Chagas," Kirchhoff says. "Yet about two-thirds of those are false positives, given what is known about the tests they use. Our goal at Goldfinch is to use genetic engineering to develop a test that's more accurate, one that will maintain a high level of sensitivity but won't produce so many false positives."

Kirchhoff has been awarded a major grant by the National Institutes of Health, under the Small Business Innovation Research program, to pursue his project. He hopes to have a working prototype of a test for Chagas within two years. Goldfinch would then likely license the technology to a larger company that produces diagnostic kits for other infectious diseases for blood banks and clinical laboratories. Kirchhoff says the Goldfinch test could conceivably be used in Latin American countries before the United States, depending on if and when U.S. blood bank authorities recommend that the U.S. blood supply be screened for Chagas.

Kirchhoff's recent journey to Mexico was actually his second trip in less than four months to work with physicians at the University of Guadalajara and gather blood specimens for testing by established methods and by Goldfinch prototypes. The Guadalajara researchers already have collected more than 1,200 specimens from blood banks in the region.

"In Mexico, the prevalence of Chagas appears to be around one to two percent of the population," Kirchhoff says, "but few specific data are available. Essentially, nothing is known about the prevalence of Chagas among blood donors and no testing of donated blood is carried out. So, in addition to fulfilling Goldfinch's goals, I will provide Mexican health officials with specific information that will help them decide if screening donated blood for Chagas should be instituted."

While at the University of Guadalajara, Kirchhoff also served as a visiting professor. He gave lectures on Chagas and infectious disease diagnostic methods and participated in daily patient rounds with medical students and residents.

"The main teaching hospital at the medical school of the University of Guadalajara, the Hospital Civil Antiguo de Guadalajara, has 1,000 beds," Kirchhoff says, "but resources for diagnosis and treatment are limited in comparison to what we have here at the UIHC. Staff physicians and residents simply don't have the luxury of ordering a broad range of expensive tests and procedures for each patient."

Kirchhoff is keeping those limited resources in mind in developing a test to detect Chagas.

"I'm sensitive to the fact that there are about a dozen drugs available for treating HIV, but about 90% of infected people can't afford them," Kirchhoff says. "We're working toward coming up with a test for Chagas that's affordable for the blood banks that need it."

by David Pedersen