# Sydenham Chorea With Elevated Interleukin-12 Levels Responsive to Plasmapheresis and Immunotherapy

**Authors:** Zhimin Xu, Jon Rosenberg, Robert Fekete, Anila M Thomas

PMC · DOI: 10.7759/cureus.100749 · 2026-01-04

## TL;DR

A 22-year-old woman with Sydenham chorea showed elevated IL-12 levels and responded well to immunotherapy and plasmapheresis.

## Contribution

The paper reports a rare case of prolonged elevated IL-12 in Sydenham chorea and successful treatment with immunosuppressive therapy.

## Key findings

- The patient's symptoms resolved after treatment with intravenous immunoglobulin, prednisone, and amantadine.
- Interleukin-12 levels remained elevated seven months after hospital discharge, differing from typical acute-phase findings.
- Intensive immunosuppressive therapy and antibiotic adherence may be key to resolving chronic chorea.

## Abstract

Sydenham chorea (SC) presents with random abnormal involuntary movements that occur after an autoimmune reaction to a prior group A beta-hemolytic streptococcal infection. While most cases resolve spontaneously, some cases have a prolonged duration of symptoms and recurrences.

We discuss a 22-year-old woman who presented with a two-month history of involuntary, brief, random, and irregular movements of the limbs. She had a history of multiple streptococcal throat infections. At age two, she had scarlet fever. After ruling out other causes of chorea, she was diagnosed with Sydenham chorea. She was treated with intravenous immunoglobulin, oral prednisone, and amantadine, resulting in full symptom resolution. Interleukin-12 (IL-12) was elevated approximately seven months after hospital discharge.

Chronic elevation of IL-12 differs from previously published findings, which describe elevation only during the acute phase of the disease. Intensive immunosuppressive treatment during the acute phase, along with adherence to antibiotic therapy, may have contributed to the full resolution of her chorea.

## Linked entities

- **Proteins:** IL12 (Interleukin 12 level)
- **Chemicals:** prednisone (PubChem CID 5865), amantadine (PubChem CID 2130)
- **Diseases:** Sydenham chorea (MONDO:0017648), scarlet fever (MONDO:0005952)

## Full-text entities

- **Genes:** IL12B (interleukin 12B) [NCBI Gene 3593] {aka CLMF, CLMF2, IL-12B, IMD28, IMD29, NKSF}
- **Diseases:** beta-hemolytic streptococcal infection (MESH:D013290), movements (MESH:D009069), scarlet fever (MESH:D012541), abnormal involuntary movements (MESH:D004409), SC (MESH:D002819)
- **Chemicals:** amantadine (MESH:D000547), prednisone (MESH:D011241)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Figures

3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12765620/full.md

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Source: https://tomesphere.com/paper/PMC12765620