Human parvovirus B19-associated Guillain-Barré syndrome diagnosed by cerebrospinal fluid targeted next-generation sequencing: a case report and literature review

BACKGROUND: Guillain-Barré syndrome (GBS) is a post-infectious autoimmune disorder of the peripheral nerves. While human parvovirus B19 (B19V) is a recognized rare trigger, its diagnosis can be challenging without advanced molecular techniques. CASE PRESENTATION: A 24-year-old male presented with acute symmetrical limb weakness and paresthesia following a prodrome of diarrhea, fever, and joint pain. Cerebrospinal fluid (CSF) analysis showed albuminocytological dissociation. Electromyography indicated acute motor and sensory axonal neuropathy (AMSAN). Conventional serology for common pathogens was negative. Targeted Next-generation Sequencing (tNGS) of the CSF was performed and revealed a high read count of B19V DNA, suggesting a probable B19V-triggered GBS.The patient was treated with intravenous immunoglobulin (IVIG), resulting in significant clinical improvement at discharge. At the 6-month follow-up, the patient was confirmed to have developed lower limb joint pain 3 weeks after discharge, accompanied by persistent B19V-IgM/IgG positivity, which resolved gradually after retreatment with IVIG. He ultimately achieved a G-DS score of 0 with no residual neurological sequelae. CONCLUSIONS: This case suggests that human parvovirus B19 (B19V) may be a rare cause of Guillain-Barré syndrome (GBS), and confirms that cerebrospinal fluid targeted next-generation sequencing (CSF tNGS) has important diagnostic value in identifying atypical pathogens such as B19V. B19V-associated GBS tends to respond well to immunomodulatory therapy such as intravenous immunoglobulin (IVIG), with a generally favorable prognosis. tNGS may be considered for etiological detection in GBS cases with unknown causes. CLINICAL TRIAL NUMBER: Not applicable.