Complement abnormalities in diffuse plane xanthomatosis with paraproteinaemia

Area of Science:

• Immunodermatology
• Dermatopathology
• Clinical Immunology

Background:

• Paraproteinemia, a condition involving abnormal proteins in the blood, can manifest with cutaneous xanthomatous deposits.
• These xanthomatous deposits may occur independently of hyperlipidemia, challenging typical diagnostic associations.
• Understanding the link between paraproteinemia and skin manifestations is crucial for comprehensive patient care.

Observation:

• Two cases of benign monoclonal gammopathy presented with diffuse plane xanthomatosis.
• Case 1 demonstrated hypolipidemia and a functional deficiency of C1 esterase inhibitor.
• Case 2 exhibited a normal lipoprotein profile, abnormal platelet aggregation, and cutaneous vasculitis with complement consumption.

Findings:

• Benign monoclonal gammopathy is associated with xanthomatous skin deposits, irrespective of lipid levels.
• Associated immune dysregulation, including complement pathway activation and C1 esterase inhibitor deficiency, can be present.
• Cutaneous vasculitis and altered platelet function may coexist with these conditions.

Implications:

• These findings suggest a broader spectrum of immune-related complications associated with paraproteinemia and xanthomatosis.
• Further research into the pathomechanisms linking paraproteins, lipid metabolism, and immune responses is warranted.
• Recognition of these associations can improve diagnostic accuracy and therapeutic strategies for patients with unusual skin manifestations.