Inflammation after a spinal cord injury is nonresolving, and can be characterized by quantification of lymphocytes using resolution indexes (Ri) and resolution plateaus (Rp), according to an experimental study published online March 22 in Brain Pathology.
FRIDAY, April 15 (HealthDay News) — Inflammation after a spinal cord injury (SCI) is nonresolving, and can be characterized by quantification of lymphocytes using resolution indexes (Ri) and resolution plateaus (Rp), according to an experimental study published online March 22 in Brain Pathology.
Harald Prüss, M.D., from the Charité University Medicine Berlin, and colleagues characterized inflammatory resolution and quantified the persistence of differential leukocyte subpopulations at the lesion site after acute experimental SCI. Spinal cords from 28 rats that were from 8 to 12 weeks old were randomly subjected to an SCI and perfused at one, three, seven, and 14 days, and at four or 10 weeks, and were compared to those of three control rats (sham-injured) who underwent bilaminectomy without SCI. Differential lymphocyte influx and clearance were evaluated by operative and quantitative Ri. The time between the maximal cell numbers and the point at which they were reduced by 50 percent (resolution interval Ri) and the persistence of components of cellular inflammation (Rp) were measured.
The investigators found that resolution interval Ri of different cell types in the SCI group were 1.2 days for neutrophils, 1.5 days for T-cell lymphocytes, and 55 days for microglia/macrophages. Rp values for different cell types in the SCI group were 0 percent for polymorphonuclear cells (complete resolution), 10 percent for T-cells (incomplete resolution), and 45 percent for macrophages (partial resolution).
“Both extended resolution intervals (reduced leukocyte clearance) and elevated plateaus (permanent lesional cell numbers) provide quantitative measures to characterize residual, sustained inflammation and define cognate timeframes of impaired resolution after acute SCI,” the authors write.