Guillain-Barré Syndrome as an Initial Manifestation of Systemic Lupus Erythematous: Rare Case Report.

Systemic lupus erythematosus (SLE) is an autoimmune connective tissue disorder characterized by a wide spectrum of clinical features ranging from skin and joint involvement to organ dysfunction, including the central nervous system, peripheral nervous system (PNS), and renal failure. Guillain-Barré syndrome (GBS) is an immune-mediated acute polyradiculoneuropathy involving the PNS and represents an unusual initial manifestation of SLE. An 18-year-old female presented with subacute, progressive, ascending weakness of the lower and upper limbs, accompanied by hyporeflexia. Further clinical and laboratory evaluation revealed that the patient fulfilled the diagnostic criteria for SLE. Electromyography and nerve conduction studies demonstrated normal conduction velocities and latencies, but there was a reduced amplitude of compound motor action potentials in the distal muscles of the upper and lower limbs, without conduction block. Needle electromyography findings were consistent with a diagnosis of acute motor axonal neuropathy, considered a moderate-to-severe form of GBS. On evaluation, the patient exhibited polyarthralgia, widespread generalized erythematous rash, microcytic anemia, and bilateral pleural effusion. Immunological profiling revealed high-titer antinuclear antibody (1:1280), elevated anti-dsDNA (171 IU/mL), positive anti-Sm antibodies, and low C3/C4 levels. Treatment with pulse steroids (methylprednisolone 1 g/day for 3 days), immunosuppressants, and intravenous immunoglobulin led to marked improvement. This case emphasizes that SLE can precipitate GBS, and early recognition of this overlap may influence therapeutic strategies and improve outcomes.