Blood hyperviscosity with reduced skin blood flow in scleroderma

Area of Science:

• Rheumatology
• Vascular Medicine
• Hematology

Background:

• Scleroderma is associated with vascular complications, primarily attributed to small vessel obliteration.
• The role of blood viscosity in scleroderma's ischemic processes requires further investigation.

Purpose of the Study:

• To investigate blood viscosity abnormalities in scleroderma patients.
• To determine if altered blood viscosity contributes to ischemic complications in scleroderma.
• To differentiate scleroderma from primary Raynaud's disease using blood flow patterns.

Main Methods:

• Blood viscosity was measured in 20 scleroderma patients using a rotational viscometer.
• Plasma viscosity was assessed, implicating changes in plasma proteins.
• Hand blood flow was measured using venous occlusion plethysmography at varying temperatures.

Main Results:

• Hyperviscosity was observed in 35% of patients at high shear rates and 70% at low shear rates.
• Significantly increased plasma viscosity was found, linked to elevated fibrinogen and immunoglobulin levels.
• Reduced hand blood flow and delayed recovery after cooling were noted, suggesting impaired microcirculation.

Conclusions:

• Increased blood viscosity, particularly plasma hyperviscosity, is a significant factor in scleroderma's vascular complications.
• The combination of vascular lesions and hyperviscosity exacerbates blood flow resistance in scleroderma.
• Blood flow patterns and viscosity measurements may aid in distinguishing scleroderma from primary Raynaud's disease.