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PubMed This is a summary of 15 peer-reviewed journal articles Updated
Rheumatology

The Science of Overlap: Diagnosis and Biology

At a Glance

Reynolds syndrome is diagnosed by finding two specific autoantibodies in your blood: Anti-Mitochondrial Antibodies (AMA) linked to primary biliary cholangitis, and Anti-Centromere Antibodies (ACA) linked to limited systemic sclerosis. Doctors also use liver enzyme tests and capillaroscopy.

The biology of Reynolds syndrome is a story of “mistaken identity” by your immune system. In this overlap syndrome, the body produces two specific types of autoantibodies—proteins that mistakenly target your own healthy cells instead of invading germs [1].

By understanding the “lab fingerprint” of this condition, you can better track how your body is responding to treatment and what your diagnostic reports actually mean.

The Two Key Markers: AMA and ACA

To be diagnosed with Reynolds syndrome, doctors typically look for the presence of two distinct markers in your blood. Each one explains a different part of the syndrome [2][3].

1. Anti-Mitochondrial Antibodies (AMA)

  • What they are: These are the “hallmark” of Primary Biliary Cholangitis (PBC) [4].
  • What they do: They target a complex called the pyruvate dehydrogenase complex (PDC-E2) found inside the mitochondria (the powerhouses) of your bile duct cells [5].
  • The Result: The immune system attacks these cells, leading to ductopenia—the slow destruction and loss of the tiny tubes that carry bile out of your liver [6].

2. Anti-Centromere Antibodies (ACA)

  • What they are: These are the primary markers for limited systemic sclerosis (the CREST variant) [3].
  • What they do: They target the centromere, a structure that helps your cells divide properly [7].
  • The Result: These antibodies are associated with damage to small blood vessels (microangiopathy) and the skin thickening seen in CREST [8].

The Biological Mechanism: Why Both?

Researchers are investigating why these two conditions happen together. One leading theory is systemic microangiopathy. This suggests that both the liver issues and the skin/vascular issues stem from a shared problem: damage to the endothelium (the delicate lining of your blood vessels) [8][9]. When this lining is damaged in the liver, it affects the bile ducts; when it happens in the skin, it causes the symptoms of CREST [9].

Your Diagnostic Checklist

A complete diagnosis of Reynolds syndrome is rarely based on a single test. Instead, doctors use a “mosaic” of findings. Use this checklist to ensure your medical record is complete:

Test Type What to Look For Why It Matters
Blood Work (Serology) Positive AMA and ACA [10] Confirms the autoimmune “fingerprint” of the syndrome.
Liver Enzymes Elevated Alkaline Phosphatase (ALP) [11] Shows if there is active bile duct blockage or inflammation.
Capillaroscopy “Scleroderma pattern” in fingernail vessels [12] A mandatory tool to visualize microscopic blood vessel damage.
Imaging/Biopsy Liver Ultrasound or Fibroscan [13] Assesses the physical health and stiffness of the liver.

In some cases, if antibody tests are unclear, a liver biopsy may be performed to look for “interface activity” or specific patterns of bile duct loss to confirm the diagnosis [14][15]. Having both AMA and ACA markers is the definitive sign that your condition is Reynolds syndrome rather than just one of the individual diseases [10]. Read more about Building Your Care Team: Treatment and Management.

Common questions in this guide

What blood tests are used to confirm Reynolds syndrome?
Doctors look for two specific autoimmune markers: Anti-Mitochondrial Antibodies (AMA) and Anti-Centromere Antibodies (ACA). Having both of these antibodies is a definitive sign of the overlap syndrome.
What do Anti-Mitochondrial Antibodies (AMA) mean for my liver?
AMA mistakenly target the mitochondria in your bile duct cells. This immune attack leads to the slow loss of bile ducts in the liver, which is a hallmark of primary biliary cholangitis.
Why do doctors check my Alkaline Phosphatase (ALP) levels?
ALP is a liver enzyme that helps show if there is active bile duct blockage or inflammation. Tracking your ALP levels helps your care team manage the liver-related components of Reynolds syndrome.
What is a nailfold capillaroscopy?
Capillaroscopy is a non-invasive test used to examine the tiny blood vessels at the base of your fingernails. It helps doctors identify microscopic blood vessel damage, which confirms a scleroderma pattern.
Will I need a liver biopsy to be diagnosed with Reynolds syndrome?
A diagnosis is often made using blood tests and imaging like a Fibroscan. However, if your antibody results are unclear, a liver biopsy may be performed to confirm bile duct loss and determine the stage of liver disease.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Which specific subtype of AMA (like M2) was found in my results?
  2. 2.My ALP levels are [number]; how does this influence our approach to managing the PBC component?
  3. 3.Can you explain the results of my nailfold capillaroscopy and what they show about my vascular health?
  4. 4.Do I need a liver biopsy to confirm the stage of my PBC, or is the antibody profile sufficient?
  5. 5.How often should my ACA and AMA levels be re-tested, or do they stay stable over time?

Questions For You

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References

References (15)
  1. 1

    Systemic Sclerosis and Primary Biliary Cholangitis: A Comprehensive Review of Two Overlapping Rare Entities With Insights on Diagnostics and Management.

    Thakkar HH, Mathew NV, Reddy EP, et al.

    Cureus 2025; (17(4)):e82008 doi:10.7759/cureus.82008.

    PMID: 40351968
  2. 2

    Positive antimitochondrial antibody but normal serum alkaline phosphatase levels: Could it be primary biliary cholangitis?

    Berdichevski T, Cohen-Ezra O, Pappo O, Ben-Ari Z

    Hepatology research : the official journal of the Japan Society of Hepatology 2017; (47(8)):742-746 doi:10.1111/hepr.12809.

    PMID: 27572231
  3. 3

    Multiple Autoimmune Syndrome: An Unusual Combination of Autoimmune Disorders.

    Sarfaraz S, Anis S

    Reviews on recent clinical trials 2020; (15(3)):240-243 doi:10.2174/1574887115666200621184110.

    PMID: 32564761
  4. 4

    Diagnostic value of anti-mitochondrial antibody in patients with primary biliary cholangitis: A systemic review and meta-analysis.

    Xu Q, Zhu W, Yin Y

    Medicine 2023; (102(45)):e36039 doi:10.1097/MD.0000000000036039.

    PMID: 37960792
  5. 5

    Detection of anti-mitochondrial antibodies by immunoprecipitation in patients with systemic sclerosis.

    Ceribelli A, Isailovic N, De Santis M, et al.

    Journal of immunological methods 2018; (452()):1-5 doi:10.1016/j.jim.2017.10.001.

    PMID: 28986201
  6. 6

    Clinical outcomes and early- prognostic biomarkers of primary biliary cholangitis with ductopenia.

    Wang W, Zhang G, Liu H, et al.

    Frontiers in immunology 2025; (16()):1680942 doi:10.3389/fimmu.2025.1680942.

    PMID: 41409297
  7. 7

    Anti-centromere antibodies target centromere-kinetochore macrocomplex: a comprehensive autoantigen profiling.

    Kajio N, Takeshita M, Suzuki K, et al.

    Annals of the rheumatic diseases 2021; (80(5)):651-659 doi:10.1136/annrheumdis-2020-218881.

    PMID: 33208344
  8. 8

    Anti-centromere antibody positivity with coexisting idiopathic portal hypertension and primary biliary cholangitis progressing to limited cutaneous systemic sclerosis: a case report.

    Ando Y, Mabuchi S, Mataki N, et al.

    Journal of medical case reports 2025; (19(1)):392 doi:10.1186/s13256-025-05426-5.

    PMID: 40764937
  9. 9

    Association Between Centromere- and Topoisomerase-specific Immune Responses and the Degree of Microangiopathy in Systemic Sclerosis.

    van Leeuwen NM, Wortel CM, Fehres CM, et al.

    The Journal of rheumatology 2021; (48(3)):402-409 doi:10.3899/jrheum.191331.

    PMID: 32482649
  10. 10

    Systemic sclerosis and primary biliary cholangitis: An overlapping entity?

    Lepri G, Bellando Randone S, Matucci Cerinic M, Allanore Y

    Journal of scleroderma and related disorders 2019; (4(2)):111-117 doi:10.1177/2397198318802763.

    PMID: 35382393
  11. 11

    Current Status of Liver Transplantation for Primary Biliary Cholangitis.

    Aguilar MT, Carey EJ

    Clinics in liver disease 2018; (22(3)):613-624 doi:10.1016/j.cld.2018.03.011.

    PMID: 30259857
  12. 12

    Advances in nailfold capillaroscopic analysis in systemic sclerosis.

    Ruaro B, Sulli A, Smith V, et al.

    Journal of scleroderma and related disorders 2018; (3(2)):122-131 doi:10.1177/2397198318757699.

    PMID: 35382238
  13. 13

    Liver Failure in Autoimmune Hepatitis Overlap Syndrome With Primary Biliary Cholangitis: A Case Report.

    Batista M, Brito P, Miranda P, et al.

    Cureus 2024; (16(11)):e73574 doi:10.7759/cureus.73574.

    PMID: 39677227
  14. 14

    A case of autoimmune hepatitis-Primary biliary cholangitis overlap syndrome without any associated autoantibody.

    Lee KI, Wei YC, Yeh ML

    The Kaohsiung journal of medical sciences 2022; (38(7)):712-713 doi:10.1002/kjm2.12545.

    PMID: 35403360
  15. 15

    Aberrant cytokeratin 7 expression by hepatocytes can predict the ductopenia grade in primary biliary cholangitis.

    Liu HL, Yang AY, Xiong QF, et al.

    BMC gastroenterology 2022; (22(1)):443 doi:10.1186/s12876-022-02538-w.

    PMID: 36324070

This page explains Reynolds syndrome diagnostic tests and biology for educational purposes. Always consult your rheumatologist or hepatologist to interpret your specific lab results and imaging.

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