Samuel E. Chee, United Kingdom
Manchester Royal Infirmary ImmunologyPresenter of 1 Presentation
CHARACTERISATION OF THE IMMUNE RISK PROFILE (IRP) AND T-CELL SUB-POPULATIONS IN PATIENTS WITH IMMUNE DISORDERS
Abstract
Background and Aims
Immunosenescence is typified by expansions of late-differentiated pro-inflammatory T-cells and a diminished naïve repertoire. The “Immune Risk Profile” (IRP) characterized by a CD4/CD8 ratio < 1 and latent cytomegalovirus (CMV) infection from the Swedish OCTA/NONA studies in octagenarians and nonagenarians is predictive of two-year mortality. This study examines IRP and T-cell subsets in patients with immune disorders.
Methods
Sixty-three patients under follow up by the Royal Free Hospital Immunology Department (London, UK) were identified on the hospital’s pathology database from routine investigations requested by the attending Immunologist. Patients were separated to IRP (Case) and non-IRP (Control) populations based on IRP definition of CD4/CD8 ratio <1. Case-control statistical differences were analysed for T-cell subpopulations, serum immunoglobulin levels and herpesvirus infections; as well as for ongoing immunological diagnoses, comorbidities and treatments detailed in clinic letters.
Results
Nine patients were IRP positive (Mean age = 56) with a corresponding control mean age of 53. IRP individuals had larger CD8+CD28- (% absolute CD8+: 40.9 vs 25.6; p = 0.01) and CD4+CD28- populations (% absolute CD4+:15.22 vs 2.89; p = 0.003); and diminished CD8+CD25+ populations (% absolute CD8+: 2.17 vs 14.05; p <0.0001) compared to controls. CMV infection, neoplastic disease, auto-inflammation/autoimmunity and systemic immunosuppression were significantly associated with IRP positivity.
Conclusions
IRP positivity is associated with expansions of CD4+28- and CD8+28- cells and diminished CD8+CD25+ populations. Latent viral infections, auto-inflammation/autoimmunity, neoplastic disease and systemic immunosuppression is likely to facilitate T-cell subpopulation skewing towards the IRP.