Inflammatory demyelinating neuropathies with focal segmental glomerulosclerosis: Two case reports

RATIONALE: Inflammatory demyelinating neuropathies such as Guillain–Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), and focal segmental glomerulosclerosis (FSGS) are autoimmune disorders that may have a common pathogenesis. Here, we describe 2 unique cases of FSGS, 1 with GBS and the other with CIPD. We believe that reviewing these multisystemic diseases will help in better understanding of FSGS pathogenesis. PATIENT CONCERNS: The 1st patient, a 66-year-old woman, complained of tingling and numbness in the limbs and within 2 days, she developed progressive muscle weakness. The 2nd patient was a 63-year-old man with a complaint of lower-limb edema, lower-limb weakness, and numbness. DIAGNOSIS: In the 1st patient, a diagnosis of GBS was confirmed with the nerve conduction velocity test as well as CSF studies. A renal biopsy revealed FSGS. The 2nd patient was diagnosed with CIDP and a subsequent renal biopsy revealed FSGS. INTERVENTIONS: Large dose of steroid with calcineurin inhibitor, intravenous immunoglobulin, and supportive treatment. OUTCOMES: Neurologic symptoms disappeared, urine protein was maintained at low levels, and no further recurrences were noted in 2 cases. INF2 gene mutation was not found in either case. LESSONS: Co-occurrence of inflammatory demyelinating polyneuropathy, GBS, CIDP, and FSGS suggests synergistic cellular and humoral autoimmune mechanisms related to either cross-reactivity within antigenic targets or mimicry epitopes. Further follow-up and intensive study for the pathogenesis are necessary.