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Further evidence of increased polymorphonuclear cell activity in patients with Raynaud's phenomenon
1University Department of Medicine, Ninewells Hospital and Medical School, Dundee.
Abstract:
The role of polymorphonuclear cells (PMNs) in the pathophysiology of ischaemic vascular disease has been increasingly recognized in recent years. Activated PMNs may physically obstruct blood flow. Subsequent release of reactive oxygen radicals and lytic enzymes lead to continued damage. Previous studies have shown increased white cell activity in patients with secondary Raynaud's syndrome (RS). However, whether this is related to the underlying condition or to digital vasospasm is not clear. Using a more physiological whole blood PMN aggregation assay, we assessed PMN activity in 38 patients with severe Raynaud's phenomenon (RP) [16 had systemic sclerosis (SSc) and secondary RS; 22 had RP alone and no other features of a connective tissue disease]. Additionally, plasma levels of malondialdehyde (MDA), an indicator of free radical activity, were measured. Results were compared with those obtained from 56 matched volunteers. In order to assess if changes in PMN activity was directly related to digital vasospasm, patients were asked to record the duration and frequency of their Raynaud's attacks during a 2-week period using a pocket sized diary. Correlation between these clinical variables of Raynaud's severity and white cell activity was assessed. Patients with RP, both with and without SSc, showed a significantly greater fall in single PMN count when compared with control subjects [SSc associated RS 48.2 (41.4-56)% versus control, P = 0.04; RP alone 49.3 (46.8-52.1)% versus control, P = 0.01 (Mann-Whitney U-test)].(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Polymorphonuclear cells (PMNs) are more active in patients with Raynaud's phenomenon (RP), indicating their role in vascular disease. This heightened PMN activity may contribute to the condition
Area of Science:
- Vascular pathophysiology
- Immunology
- Rheumatology
Background:
- Polymorphonuclear cells (PMNs) play a role in ischaemic vascular disease.
- Previous studies suggest increased white cell activity in Raynaud's syndrome (RS).
- The link between underlying conditions, digital vasospasm, and PMN activity in RS is unclear.
Purpose of the Study:
- To assess polymorphonuclear cell (PMN) activity in patients with severe Raynaud's phenomenon (RP).
- To investigate the relationship between PMN activity and digital vasospasm severity in RP.
- To measure plasma malondialdehyde (MDA) levels as an indicator of free radical activity.
Main Methods:
- A whole blood PMN aggregation assay was used to measure PMN activity.
- 38 patients with severe RP (16 with systemic sclerosis and secondary RS, 22 with RP alone) were studied.
- Plasma MDA levels were measured, and results were compared to 56 matched volunteers. Patients recorded Raynaud's attack frequency and duration.
Main Results:
- Patients with RP, with or without systemic sclerosis (SSc), exhibited significantly greater reductions in single PMN count compared to controls.
- SSc-associated RS showed a 48.2% fall (P=0.04), and RP alone showed a 49.3% fall (P=0.01) in single PMN count versus controls.
- Correlation analysis assessed the relationship between clinical variables of Raynaud's severity and white cell activity.
Conclusions:
- Elevated PMN activity is a significant finding in patients with Raynaud's phenomenon.
- This heightened PMN activity may be directly related to the pathophysiology of RP, independent of underlying conditions like SSc.
- Further research is warranted to elucidate the precise mechanisms by which PMNs contribute to RP and ischaemic vascular disease.