Background & Aims
Persistent pain and psychosocial distress are common and related concerns among people living with HIV (PLH), but the mechanistic links between distress and pain are poorly understood. Both distress and pain are also related to subtle changes in provoked inflammatory response. A heightened inflammatory response may also increase spinal amplification of nociception and, thus, contribute to pain. This study aimed to take the first steps towards investigating characterising the relationships between distress, inflammatory reactivity (i.e. provoked inflammatory response), spinal amplification of nociception, and persistent pain, in PLH.
Methods
Adult PLH were recruited into two groups (no pain vs persistent pain) matched for age and sex. Participants provided self-reports of distress (Hopkins 25 scale), pain severity score (Brief Pain Inventory), number of painful sites (18-region body map), and a sample of whole blood. Blood was provoked in vitro using lipopolysaccharide; multiplex assays will quantify IL-6, IL-1beta, and TNF-alpha in the supernatant. To model spinal amplification of nociception, a subsample underwent assessments of temporal summation and experimentally induced secondary hypersensitivity. Mediation analysis (pain group only) will be used to test the hypothesis that IR partly mediates the relationship between distress and pain, by estimating direct and indirect contributions of distress and IR to pain (intensity and number of painful sites separately). Generalised mixed effects models (full subsample) will test the hypothesis that IR is positively associated with induced secondary hypersensitivity (magnitude/area) in both groups.
Results
Complete self-report data were obtained from 99 participants (72 female; mean (range) age: 43 (28-64) y/o), 45 with persistent pain and 54 without pain. The median (IQR) distress score was 1.44 (0.88). In the 45 people with persistent pain, persistent pain severity score was 5 (2); number of sites with persistent pain was 3 (4). Preliminary data analysis suggests a positive relationship between distress and both pain severity score and number of painful sites, but data analysis is yet to be completed. Full results will be reported at the congress.
Conclusions
Data analysis outstanding.
References
N/A
Presenting Author
Victoria J Madden
Poster Authors
Victoria Madden
BSc(Hons)
University of Cape Town
Lead Author
Luyanduthando Mqadi
BSc
University of Cape Town
Lead Author
Ncumisa Msolo
PGDip
University of Cape Town
Lead Author
Gillian J Bedwell
MSc
University of Cape Town
Lead Author
Maia Lesosky
PhD
University of Cape Town
Lead Author
Mark Hutchinson
University of Adelaide
Lead Author
Jonathan Grant Peter
PhD
University of Cape Town
Lead Author
Romy Parker
University of Cape Town
Lead Author
Andrew Schrepf
University of Michigan
Lead Author
Robert Edwards
PhD
Brigham & Women's Hospital/Harvard Medical School
Lead Author
Topics
- Mechanisms: Psychosocial and Biopsychosocial