Case report and review on autoimmune nodopathy with Sjogren's disease and nephrotic syndrome

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Frontiers in Medicine Published May 25, 2026 Medically reviewed May 25, 2026 DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Consider the diagnostic clues for autoimmune nodopathy in patients with Sjogren's disease and nephrotic syndrome.

This source is a case report and literature review focusing on a 45-year-old woman with autoimmune nodopathy, Sjogren's disease, and nephrotic syndrome. The authors synthesize evidence on this exceptionally rare comorbid phenotype and report that intravenous methylprednisolone therapy was associated with significantly improved neurological symptoms. The review notes that anti-CNTN1 antibodies may mediate immune injury to both peripheral nerves and kidneys by targeting shared antigens.

The authors highlight key diagnostic clues for early identification, including massive proteinuria, postural tremor, and poor response to intravenous immunoglobulin. No pooled effect sizes, p-values, or confidence intervals are provided, as this is a narrative synthesis of a single case and existing literature.

Limitations noted include the exceptionally rare nature of the condition and the lack of a comparator or controlled data. The authors acknowledge that the findings are preliminary and not generalizable. Practice relevance is restrained, emphasizing recognition of diagnostic clues to facilitate early identification of autoimmune nodopathy.

Study Details

Study typeSystematic review

EvidenceLevel 1

PublishedMay 2026

View Original Abstract ↓

BackgroundAnti-contactin-1 (CNTN1) antibody–positive autoimmune nodopathy (AN) is frequently reported in association with membranous nephropathy; however, the co-occurrence with both Sjögren’s disease and nephrotic syndrome represents an exceptionally rare comorbid phenotype. In this study, we explored the potential immunological links underlying this comorbidity and, in conjunction with a literature review, sought to identify diagnostic clues for AN.Case presentationWe report the case of a 45-year-old woman who presented with progressive numbness and weakness of all four limbs for 5 months, accompanied by xerostomia and bilateral lower limb edema. Nerve conduction studies demonstrated demyelinating features, and cerebrospinal fluid analysis revealed albuminocytologic dissociation. Serum testing was positive for anti-CNTN1 antibodies (titer 1:1000), along with nephrotic-range proteinuria (4.66 g/24 h) and positivity for anti-SSA52, anti-SSA60, and anti-SSB antibodies. The patient was ultimately diagnosed with anti-CNTN1 antibody–positive AN coexisting with Sjögren’s disease and nephrotic syndrome. Following intravenous methylprednisolone therapy, her neurological symptoms improved significantly.ConclusionThis case highlights that, within an immune context characterized by B-cell hyperactivation, anti-CNTN1 antibodies may mediate immune injury to both the peripheral nerves and kidneys by targeting shared antigens. Clinicians should recognize key diagnostic clues, including massive proteinuria, postural tremor, and poor response to intravenous immunoglobulin, to facilitate early identification of AN.