{
  "abstract": "Introduction Raynaud’s phenomenon (RP) is an exaggerated transient vasoconstriction of the extremities’ microvasculature in response to cold or stress. This may be primary (pRP) (idiopathic) or secondary (sRP), mainly to systemic sclerosis (SSc) - spectrum disorders; its mechanisms are not completely understood, the treatment is often ineffective, and it causes a significant impact on patients’ quality of life. A functional evaluation of RP, which can aid in clarifying its physiopathology and inform a more effective treatment approach, is lacking.Material and Methods This study aimed to investigate the adaptation of glabrous skin perfusion in patients with pRP, sRP (with autoimmune disease other than SSc), and SSc (meeting the SSc ACR/EULAR 2013 classification criteria), compared to healthy controls (HC), in response to controlled cold exposure. Patients under prostacyclin analogs, endothelin-receptor antagonists, and 5-phosphodiesterase inhibitors were excluded. Other vasoactive treatments (calcium channel blockers) were stopped two days before the experiments. Forty-two female participants, mean age 55±12 years, were selected (10 HC, 11 pRP, 10 sRP, 11 SSc). One randomly chosen hand was placed in contact (palm) with an iced-frozen surface. Hemodynamics and local perfusion were measured in both hands using non-invasive technologies, including laser Doppler flowmetry, which measures perfusion in blood perfusion units (BPU), during baseline (10 min - phase 1), ICE (3 min - phase 2), and recovery (10 min - phase 3).Results Significant differences in perfusion were detected in both hands among HC, pRP, and SSc groups in all experimental phases (p < 0.0001), with a decrease in perfusion and temperature during the cold challenge. In the first minute of recovery, mean perfusion significantly increased in HC (p=0.0003), while it decreased in pRP (phase 2: 150BPU vs phase 3: 138BPU, p=0.0005), and in SSc (phase 2:132BPU vs phase 3:123BPU, p=0.001), with no significant response in sRP (phase 2: 78 BPU vs phase 3: 71 BPU, p=0.06). In the late recovery, perfusion further increased in HC (p=0.02), continued to decrease in pRP (p<0.0001), and increased in SSc (p<0.0001 )and in sRP (p<0.0001), however, not recovering to the baseline values, during the time of the experiment, except in HC.Conclusions Results suggest that mechanisms underlying pRP, sRP, and SSc involve different thermoregulatory adaptations to cold. This experimental approach is reproducible, easy to execute, and well tolerated, and can provide a valuable ground to explore these complex mechanisms.",
  "authors": [
    {
      "affiliations": [
        "Systemic Autoimmune Diseases Unit Department of Medicine 4 Fernando Fonseca Hospital, Amadora, Portugal"
      ],
      "name": "Joana Caetano"
    },
    {
      "affiliations": [
        "CBIOS Universidade Lusófona Research Center for Biosciences and Health Technologies, Lisbon, Portugal"
      ],
      "name": "Marisa Nicolai"
    },
    {
      "affiliations": [
        "CBIOS Universidade Lusófona Research Center for Biosciences and Health Technologies, Lisbon, Portugal"
      ],
      "name": "Elisabete Silva"
    },
    {
      "affiliations": [
        "CBIOS Universidade Lusófona Research Center for Biosciences and Health Technologies, Lisbon, Portugal"
      ],
      "name": "Clemente Rocha"
    },
    {
      "affiliations": [
        "Systemic Autoimmune Diseases Unit Department of Medicine 4 Fernando Fonseca Hospital, Amadora, Portugal"
      ],
      "name": "José Alves"
    },
    {
      "affiliations": [
        "CBIOS Universidade Lusófona Research Center for Biosciences and Health Technologies, Lisbon, Portugal"
      ],
      "name": "Luís Rodrigues"
    }
  ],
  "title": "P.202 Raynaud’s phenomenon and systemic sclerosis: differences in microcirculatory adaptive changes to cold exposure",
  "uid": "339412cf-6d75-5ea2-a976-992b90e66a81"
}