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"Based on our experience with the ImmuKnow assay we believe it is possibleto assess the probability that specific patients are at risk for organrejection or infection," stated Dr. Kobashigawa.
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Between 2005 and 2007 Dr. Kobashigawa and his colleagues studied theimmune function of 76 adult heart transplant patients. A total of 170 ImmuKnowassays were carried out in these patients between 12 and 365 days aftertransplantation. Levels of cell-mediated immunity (CMI) were classified as low(<225 ng/mL ATP), moderate (225-525 ng/mL ATP) or strong (>525 ng/mL ATP). Inthese patients, the mean CMI was 305 ng/mL of ATP with a standard deviation of+ 153 ng/mL ATP. All patients were treated with tacrolismus, mycophenolate,and corticosteroids to lower the potential risk of organ rejection.
In follow-up analysis of the available data, Kobashigawa et al. were ableto document five biopsy-proven organ rejections in patients with strongerimmune function ( CMI > 300 ng/mL ATP; based on 74 assays) as compared to norejections in patients with lower immune function (CMI < 300 ng/mL ATP; basedon 96 assays). This difference was statistically significant (p < 0.001).
The average measure of immune function during rejection was alsosignificantly higher (average CMI = 438 ng/mL ATP) than the average measureamong patients showing no signs of rejection (average CMI = 301 ng/mL ATP; p =0.05).
The analysis also looked at the incidence of infections among the studypopulation. A total of 30 infections were identified in patients with low CMI(<225 ng/mL ATP; based on 57 assays) as compared to only eight infections inpatients with moderate or strong CMI (>225 ng/mL ATP; based on 113 assays).The average CMI in samples from patients with infection was 119 ng/mL ATP ascompared to 336 ng/mL ATP in samples from patients with no sign of infection(p < 0.001). Identified infections included 13 with a viral etiology; 15 withbacterial etiology; and 10 with fungal etiology.
"Immune function monitoring of adult heart transplant patients using theImmuKnow assay may have the potential to aid in the assessment of the immunestatus of the patient and the patient's risk for organ rejection orinfection," concluded Dr. Kobashigawa. "We are currently conducting clinicalstudies using these data to manage immunosuppression in our heart transplantpatients, with the goal of limiting risk for rejection and infection."
Dr. Kobashigawa's presentation was entitled, "Success of immune monitoringwith ImmuKnow (Cylex(TM)) to assess rejection/infectious risk in hearttransplantation." Dr. Kobashigawa is Clinical Professor of Medicine and Chiefof the Division of Clinical Faculty Medicine at David Geffen School ofMedicine at UCLA. He is also Medical Director of the UCLA Heart TransplantProgram.
About ImmuKnow(R)
ImmuKnow is an immune cell function assay that can detect cell-mediatedimmunity (CMI) in adult immunosuppressed patients by measuring theconcentration of adenosine triphosphate (ATP) released from CD4 cellsfollowing cell stimulation.
The ImmuKnow test is a qualitative assay and does not directly quantifythe level of immunosuppression. Results of ImmuKnow assays should be used inconjunction with clinical presentation, medical history, and other clinicalindicators when assessing the immune status of
