Posted: Tuesday, May 24, 2022
Direct visualization of leukocyte-endothelial interactions in the skin after allogeneic hematopoietic cell transplantation (HCT) assisted in the prediction of outcomes among a cohort of patients with hematologic malignancies, including acute myeloid leukemia (AML). Eric R. Tkaczyk, MD, PhD, of Vanderbilt University Medical Center, Nashville, and his colleagues published their work in JAMA Dermatology.
“Our study raises the prospect of a new application of so-called diagnostic optical biopsy. While this is a pilot study of just over 50 patients, it would appear to point strongly to potential clinical application for improved patient evaluation and management,” said Dr. Tkaczyk in a Vanderbilt University Medical Center press release.
Researchers enrolled a total of 56 patients; they included 25 with AML, 12 with myelodysplastic syndrome, 5 with acute lymphoblastic leukemia, and 14 with another hematologic malignancy. Approximately 38 to 58 days after receiving an allogeneic hematopoietic cell transplant, the team used confocal microscopy to record white blood cell activity within the skin microvasculature of each patient. Two blinded observers counted the number of leukocytes adherent to and rolling (A&R) along the vessel wall per hour and categorized patients into high A&R (≥ 14 \ leukocytes) or low A&R (≤ 13).
Among the patients with AML, 10 had high A&R, whereas 15 had low A&R. In the entire study cohort, patients with a high A&R had higher rates of relapse (hazard ratio [HR] = 4.24, P = .02) and lower relapse-free survival (HR = 3.29, P = .02) compared with those with low A&R counts. In addition, higher scores seemed to correlate with reduced overall survival (HR = 3.06, P = .05). These associations remained even after investigators corrected for confounding variables such as steroid treatment and acute graft-versus-host disease status.
Use of leukocyte A&R as a biomarker accounted for 82% to 95% of the prognostic information needed to predict each assessed outcome. In comparison, the currently used Disease Risk Index accounted for 10% to 28% of the prognostic information in the same model.
Disclosure: For a full list of authors’ disclosures, visit jamanetwork.com.