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