Clinical and Pathological Features of Vasculitic Neuropathy: A Single-Center Study in China.

All 112 VN patients presented with axonal sensorimotor neuropathy, most commonly involving the tibial and peroneal nerves.

• Total cohort included 112 patients diagnosed pathologically between June 1999 and December 2024 at a single center in mainland China.
• Tibial nerve involvement was present in 90.63% of patients.
• Peroneal nerve involvement was present in 87.50% of patients.
• The study was retrospective in design, reviewing demographic data, clinical manifestations, biopsy features, and outcomes.

Systemic VN (SVN) showed more frequent transmural inflammatory cell infiltration (ICI) than non-systemic VN (NSVN).

• The difference in transmural ICI frequency between SVN and NSVN was statistically significant (p = 0.046).
• ICI refers to inflammatory cell infiltration identified on nerve biopsy specimens.
• This finding highlights a pathological distinction between systemic and non-systemic forms of vasculitic neuropathy.

Eosinophilic granulomatosis with polyangiitis (EGPA) was more common in VN without ICI than VN with ICI.

• The association between EGPA and absence of ICI on biopsy was statistically significant (p = 0.008).
• The authors interpreted this as suggesting EGPA has a lower diagnostic yield on biopsy.
• This finding suggests diverse mechanisms of vascular injury in EGPA compared to other forms of VN.

In SVN, ICI-positive patients exhibited more severe distal upper limb weakness and higher thrombosis rates than ICI-negative patients.

• More severe distal upper limb weakness in ICI-positive SVN compared to ICI-negative SVN was significant (p = 0.042).
• Higher thrombosis rates in ICI-positive SVN compared to ICI-negative SVN was significant (p = 0.001).
• These clinicopathological correlations were identified within the SVN subgroup specifically.

The 5-year all-survival rate for VN patients was 80.23%.

• The 5-year all-survival rate was 80.23% (95% CI 66.83%–88.66%).
• Of 63 patients followed, 62 received glucocorticoids with or without immunosuppressants.
• Thirteen patients died from multi-organ complications, comprising 12 SVN and 1 NSVN patient.
• Patients who did not die achieved remission.
• The authors characterized the overall prognosis of VN as 'relatively favorable.'

Nerve biopsy was identified as the diagnostic gold standard for vasculitic neuropathy.

• All patients were diagnosed pathologically via nerve biopsy.
• The diagnostic period spanned June 1999 to December 2024.
• EGPA's lower diagnostic yield on biopsy (due to absent ICI) was noted as a caveat to biopsy interpretation.
• The authors emphasized that nerve biopsy remains the gold standard despite variable pathological findings across VN subtypes.