Short- and Long-Term Outcome of Systemic Lupus Erythematosus Peripheral Neuropathy: Bimodal Pattern of Onset and Treatment Response

Background/objective: Our aim was to describe the short- and long-term outcome of peripheral neuropathy (PN) attributed exclusively to systemic lupus erythematosus (SLE).

Methods: Systemic lupus erythematosus patients with defined PN (clinical and electroneuromyography) were retrospectively evaluated at onset, 1-year, and 5-year follow-up using a standardized electronic chart database that started in 2000. Exclusion criteria were comorbidities, drugs, and infections. Age-, sex-, and disease duration-matched SLE patients without PN were selected as controls.

Results: Lupus PN was identified in 38 (1.8%) of 2074 patients, and almost two thirds had PN onset in the first 5 years of SLE (63.2%). Peripheral neuropathy SLE had higher frequencies of cutaneous vasculitis (50% vs 21.1%, p = 0.002), lymphopenia (60.5% vs 36.8%, p = 0.027), anti-Sm (52.6% vs 27.6%, p = 0.013), and higher SLEDAI-2K scores (11.5 ± 10.5 vs 4.9 ± 6.7, p < 0.001) compared with controls. The most common type was polyneuropathy (71.1%) with sensory-motor pattern (68.4%). At PN diagnosis, all patients received glucocorticoid and 97.4% started immunosuppressive therapy (50% intravenous cyclophosphamide, 42.1% azathioprine). After 1-year follow-up, 92.1% had a favorable outcome with complete (36.8%) or partial remission (55.2%), in parallel with a decrease in prednisone dose (48.3 ± 17.9 vs 15.3 ± 13.4 mg/d, p < 0.001), symptomatic therapy (57.9% vs 29.7%, p = 0.02), and SLEDAI-2K score (11.5 ± 10.5 vs 1.7 ± 3.7, p < 0.001). SLEDAI-2K scores were higher in patients who had PN onset with less than 1 year of SLE duration, compared with those with more than 5 years of disease (21.3 ± 9.1 vs 3.9 ± 5.3, p < 0.001). Early-PN-onset group had a better response to treatment (complete remission at 1-year follow-up 61.5% vs 25%, p = 0.039). At 5-year follow-up, 89.3% remained with complete/partial remission.

Conclusions: Peripheral neuropathy attributed to SLE itself is a rare manifestation with a bimodal pattern, characterized by a predominant early-onset group associated with high disease activity and a higher rate of complete remission, and a late-onset group with low disease activity and a partial therapy response.