Reynolds Syndrome: A Rare Autoimmune Overlap Syndrome — A Case Series and Literature Review

The human immune system is designed to be a vigilant guardian, constantly patrolling the body to identify and neutralize foreign invaders like bacteria and viruses. However, in autoimmune diseases, this protective force turns inward, mistakenly attacking the body's own healthy tissues. Two such conditions, systemic sclerosis and primary biliary cholangitis, illustrate how this internal conflict can manifest in different parts of the body. Systemic sclerosis causes the skin to become thick and tight, while also affecting internal organs like the lungs and heart. Primary biliary cholangitis is a disease that slowly destroys the tiny tubes within the liver that carry bile, a fluid essential for digestion. While these conditions are distinct, they occasionally appear together in the same patient, creating a rare and complex medical puzzle known as Reynolds syndrome. Understanding how these two diseases interact is crucial because their combination can change how a patient is treated and how their health evolves over time.

Researchers from Morocco recently investigated this rare overlap by examining the cases of two patients and reviewing existing medical literature. Their work, published as a case series, aims to clarify how doctors can spot this specific combination early and manage it effectively. The study focuses on two individuals who presented with symptoms that, when viewed separately, pointed to different diseases, but when combined, revealed a shared underlying cause. The first patient was a 52-year-old woman who arrived at the hospital complaining of severe fatigue, joint pain, and a profound dryness in her eyes and mouth. Upon examination, doctors noticed her fingers were swollen and her skin had become tight, a hallmark of the skin-hardening condition. Blood tests revealed a cholestatic liver profile, meaning the enzymes associated with bile flow were elevated, suggesting liver distress. Further testing showed her immune system was producing high levels of specific antibodies, including those that target the center of cell nuclei and others that attack the mitochondria, the energy-producing structures inside cells. A small biopsy of her salivary glands confirmed inflammation consistent with a third condition, Sjögren's syndrome. The medical team diagnosed her with Reynolds syndrome, a combination of limited skin involvement, liver disease, and secondary Sjögren's syndrome. By treating her with a combination of medications to support the liver, reduce inflammation, and manage the autoimmune response, her liver function returned to normal.

The second case involved a 57-year-old man who sought help for difficulty swallowing and persistent itching. His physical exam revealed tight facial skin, a tapered nose, and small red spots on his skin, all signs of the skin-hardening condition. He also had elevated liver enzymes and mixed bilirubin levels. Imaging scans showed that his lungs were developing a pattern of scarring known as interstitial lung disease, and his liver showed signs of long-term damage with increased pressure in the blood vessels leading to it. Despite having these clear signs of both diseases, his blood tests did not show the specific antibodies often associated with the skin condition, a finding that highlights a critical lesson from the study. He was diagnosed with the same overlap syndrome, complicated by lung involvement and portal hypertension. His treatment included medication for the liver, a drug to manage the lung scarring, and a beta-blocker to lower the pressure in his liver veins.

The researchers used these two stories to draw broader conclusions about the nature of Reynolds syndrome. They found that the timing of when these diseases appear is unpredictable; in some patients, the liver disease appears first, in others the skin condition comes first, and in cases like the one described here, they can be diagnosed at the same time. The study emphasizes that doctors must be vigilant in checking for one condition when a patient is diagnosed with the other. For instance, a patient with the skin condition should be screened for liver issues, and a patient with liver disease should be checked for signs of skin tightening. The authors noted that while the liver disease in this overlap syndrome often progresses more slowly than it does on its own, the overall outlook for the patient depends heavily on how the skin condition affects internal organs like the lungs.

A key takeaway from the research is that the absence of certain antibodies does not rule out the diagnosis. In the second patient, the lack of a specific antibody marker for the skin condition did not prevent the diagnosis, proving that doctors cannot rely on a single test. The study also touches on the potential causes of this overlap, suggesting that shared genetic factors and specific mutations in genes that control the structure of the cell nucleus might play a role. While the exact mechanism remains a subject of ongoing investigation, the authors propose that the immune system may be targeting similar proteins found in both the skin and the bile ducts. The paper concludes that recognizing this rare combination is essential for optimizing patient care. By screening patients across both conditions, medical teams can detect problems early and tailor treatments to address the specific needs of each individual, ultimately improving the management of these complex autoimmune challenges.