Muscle vasculitis in patients with polymyalgia rheumatica: Three case series

Area of Science:

• Rheumatology
• Immunology
• Pathology

Background:

• Polymyalgia rheumatica (PMR) is a prevalent inflammatory disorder affecting the shoulder and hip girdles.
• Key diagnostic markers include elevated C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR).
• The precise pathogenesis of PMR remains incompletely understood.

Purpose of the Study:

• To investigate potential underlying pathologies in patients with Polymyalgia Rheumatica (PMR) refractory to standard treatments.
• To explore the role of vasculitis in atypical PMR presentations.

Main Methods:

• Case series reporting on three patients with refractory PMR.
• Clinical assessment including myalgia, muscle weakness, and laboratory markers (CRP, creatine kinase).
• Histopathological examination of muscle specimens to identify inflammatory changes and vasculitis.

Main Results:

• All three patients presented with typical PMR symptoms and elevated CRP, but normal creatine kinase levels.
• Muscle biopsies revealed evidence of vasculitis in all cases.
• These findings suggest muscular limited vasculitis (MLV) as a potential cause in these refractory PMR cases.

Conclusions:

• Muscular limited vasculitis (MLV) may be an underlying pathology in a subset of Polymyalgia Rheumatica (PMR) patients.
• This is particularly relevant for cases that do not respond adequately to conventional therapies.
• Further research is warranted to confirm MLV as a distinct entity within PMR spectrum.