Coincident chronic inflammatory demyelinating polyneuropathy and focal segmental glomerulosclerosis: a common autoimmunity?

A 40-year-old male developed swallowing difficulties, loss of strength, and imbalance. On admission, the patient exhibited bifacial, extremity weakness, ataxia, impaired sensation, and areflexia. Electrophysiology and nerve biopsy suggested demyelination. Spinal fluid revealed increased protein content. Plasmapheresis showed benefit, but neuropathy relapsed. At second recurrence, urine analysis showed heavy proteinuria. Renal biopsy revealed focal segmental glomerulosclerosis (FSGS). Methylprednisolone and oral cyclophosphamide were given. Long-term steroids and immunoglobulin showed steady benefit. Concurrence of chronic inflammatory demyelinating polyneuropathy and FSGS suggests synergistic cellular and humoral autoimmune mechanisms related to either cross-reactivity within antigenic targets or mimicry between neural and renal epitopes.