PHILADELPHIA, Sept. 11 /PRNewswire/ -- An antibody developed by scientists at The Wistar Institute is making it possible to rapidly and accurately diagnose hidden infections such as appendicitis, abscesses and osteomyelitis.
Palatin Technologies, Inc., a Princeton-based medical technology company, has developed a simple kit, called LeuTech, that contains a vial of freeze- dried Wistar antibody. At the time of use, the
Wistar antibody is mixed with a radioisotope and injected into the patient"s blood stream, where it quickly binds to white blood cells. The infection site can then be imaged, often within minutes of
injection, using conventional imaging techniques.
The Wistar antibody"s potential was first recognized by Dr. Matthew Thakur, scientific advisor for Palatin. As he explains it, "Wistar"s antibody recognizes the CD-15 antigen expressed on human neutrophils, the white blood cells that combat invading bacteria. When labeled with radionuclide Tc-99m and injected into a patient"s blood stream, the antibody avidly binds, to neutrophils, which in part carry the radioactivity to the abscesses. This permits nuclear medicine physicians to visualize the hidden abscesses within minutes after injection."
"Although the technology that preceded LeuTech has worked well," explains, Thakur, "it has drawbacks. One is that it requires from 12 to 24 hours to show a result. Another is that about two ounces of the patient"s blood must be drawn and sent to the lab. The neutrophils are then separated out, incubated, and injected with a radioactive isotope. Finally, the blood is reinjected into the patient. Obviously, blood handling poses potentially serious health risks, both to the patient and to the staff. By comparison, LeuTech is simple, eliminates blood handling and promises to be rapid and highly reliable."
Initial clinical studies of LeuTech were conducted by researchers at Harbor UCLA Medical Center in Los Angeles and at the University of Gottingen in Germany. Aggregate results showed that patients with appendicitis, osteomyelitis, infected prostheses, inflammatory bowel disease, abscesses, ulcers, and other soft tissue infections were accurately diagnosed in from 2 to 90 minutes.
LeuTech diagnoses were confirmed by surgery, pathology, ultrasound or computerized tomography. None of the patients experienced side-effects from the LeuTech procedure.
According to Dr. Carol S. Marcus, the Harbor-UCLA team"s principal investigator, there is a tremendous need for LeuTech. "Its beauty," she explains, "is that it can be used anywhere, for anybody. It"s going to have a lot of use in emergency rooms and for pediatric patients. In fact, I think pediatricians will be especially big fans of LeuTech. Their patients were often excluded from previous tests because such a large volume of blood had to be drawn and results were too slow."
"The LeuTech test is the simplest thing you can do," continues Marcus, "plus it"s relatively cheap and has low radiation exposure. As far I"m concerned," she says, "the, up-front chemistry and Wistar antibody are state of the art and far more sophisticated than current methods."
Approximately 200,000 infection imaging procedures are performed each year in the U.S. using today"s nuclear medicine techniques. They typically require 12 to 24 hours to produce diagnostic quality images. Because of the speed and clarity of images produced by LeuTech, its developers believe it will be the agent of choice for these procedures once it is approved for use by the FDA.
Further, LeuTech"s superior imaging time should allow for its use in acute care situations when the need for immediate diagnosis is critical. That is not possible with today"s techniques. As an example,
there are 230,000 cases of appendicitis each year in the U.S. Of those, approximately 35% are misdiagnosed because of the lack of a fast and effective imaging agent. That, ill turn, often results in
the removal of a healthy appendix. In other cases, patients are not appropriately treated for early stage appendicitis, causing disease progression and possible perforation of the appendix. Both are
associated with increased cost and morbidity. Dr. Marcus believes LeuTech will prove to be very useful for this indication.
Other Wistar antibodies are being used daily in research laboratories and clinical facilities around the world. Many are used for the diagnosis and treatment of cancer. One Wistar antibody in particular,
now in Phase III clinical trials, is showing positive results in the treatment of patients with colon carcinoma.
The Wistar Institute, founded in 1892, is the country"s oldest independent research facility dedicated to basic biomedical research and training. It is recognized worldwide for its discoveries of
vaccines against rabies and rubella and ground-breaking research into the causes and treatment of illnesses that include breast cancer, prostate cancer and brain tumors. Wistar is designated by the
National Cancer Institute as one of only 10 Basic Science Cancer Centers in the nation. SOURCE
The Wistar Institute
-0- 09/11/97 /CONTACT: Diana Cutshall of The Wistar Institute, 215-898-3716/ CO: Wistar
Institute; Palatin Technologies, Inc. ST: Pennsylvania IN: MTC SU: PDT |
