New Method Diagnoses Aplastic Anemia More Effectively

Researchers at Children’s Hospital of Philadelphia (CHOP) hypothesized that AA could be distinguished from IBMFSs using three laboratory findings specific to the autoimmune pathogenesis of AA: paroxysmal nocturnal hemoglobinuria (PNH) clones, copy-number–neutral loss of heterozygosity in chromosome arm 6p (6p CN-LOH), and clonal T-cell receptor (TCR) gamma gene (TRG) rearrangement.

To test their hypothesis, the researchers analyzed lab samples from 454 pediatric and adult patients with AA, IBMFSs, and other hematologic diseases. They found that PNH and acquired 6p CN-LOH clones encompassing HLA genes have 100% positive predictive value for AA and can facilitate diagnosis in approximately half of AA patients. Conversely, they found that clonal TRG rearrangement is not specific for AA.

“Our analysis demonstrates that PNH and 6p CN-LOH clones effectively distinguish AA from IBMFSs, and both measures should be incorporated early in the diagnostic evaluation of suspected AA,” said senior study author Daria V. Babushok, MD, PhD, a physician-scientist in the Comprehensive Bone Marrow Failure Center at Children's Hospital of Philadelphia and the University of Pennsylvania. “The next frontier in BMF diagnostics will include combining these two assays with more sophisticated T-cell analyses and faster, more comprehensive somatic and germline genetic studies to improve the accuracy and efficiency of diagnosis of acquired and inherited BMF disorders.”

Reference: Shah YB, Priore SF, Li Y, et al. The predictive value of PNH clones, 6p CN-LOH, and clonal TCR gene rearrangement for aplastic anemia diagnosis. Blood Adv. 2021;5(16):3216-3226. doi: 10.1182/bloodadvances.2021004201