Case Report Describes Rare Coexistence of Chronic Liver Condition and MPA
In rare cases, people with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis may also have symptoms of a chronic liver disease called primary biliary cirrhosis, a case report shows.
To date, only six other cases of these overlapping conditions have been reported in the literature, so researchers have not been able to establish a causal relationship. Nonetheless, when levels of liver enzymes are elevated in vasculitis patients, “physicians should be mindful of the possible coexistence of these diseases,” the investigators caution.
The study, “Anti-neutrophil Cytoplasmic Antibody (ANCA)-associated Vasculitis Associated with Primary Biliary Cirrhosis: A Case Report and Literature Review,” was published in the journal Internal Medicine.
Primary biliary cirrhosis (PBC) is a condition in which the small bile ducts in the liver become injured and inflamed, and are ultimately destroyed. In the absence of functioning bile ducts, bile builds up and causes liver damage, leading to cirrhosis and, in extreme cases, liver failure.
It is believed to be an autoimmune disease, mediated by an overactive immune system, and is often associated with other autoimmune disorders such Sjögren’s syndrome, systemic sclerosis, and rheumatoid arthritis. However, cases of PBC overlapping with ANCA vasculitis are rare.
In this study, researchers in Japan reported the case of a 76-year-old man with PBC associated with microscopic polyangiitis (MPA), a subtype of ANCA vasculitis.
The patient was admitted to the hospital in 2005 due to a fever, decreased appetite, and high levels of liver enzymes. He began feeling lower limb numbness in 2002, but his symptoms had recently worsened.
He had active inflammation, and a biliary infection was suspected. Imaging data did not confirm this diagnosis; still, he was given antibiotics, which did not improve his symptoms. Further testing also failed to identify any virus, bacteria, or fungus that could be responsible for the presumed infection.
A computed tomography (CT) scan revealed a nodular shadow in the upper lobe of his right lung. A tissue biopsy came back positive for Mycobacterium kansasii infections, for which a specific regimen of antibiotics was prescribed.
In addition, the researchers also found signs of MPO antibodies in circulation, as well as elevated levels of proteins and red blood cells in the urine, which led to a diagnosis of MPA with renal involvement.
The patient was started on high-dose prednisolone therapy, but inflammatory markers remained elevated and cyclophosphamide was added. At this point, his numbness improved and the levels of liver enzymes dropped, and the patient was able to gradually reduce his prednisolone dose. At six months, he also switched from cyclophosphamide to azathioprine.
One year after the first hospital admission, the lung infection was almost completely resolved, but his inflammatory markers remained mildly elevated, despite normal levels of MPO autoantibodies. The patient also showed signs of renal impairment, and his liver enzymes had risen again.
The clinical team suspected ANCA vasculitis recurrence and treated the man to induce vasculitis remission, but his liver enzymes and inflammation markers remained high.
Additional analysis showed plasma cells in a specific liver region, and positive M2 anti-mitochondrial antibodies (AMAs), leading to a final diagnosis of PBC associated with MPA.
He received treatment with ursodeoxycholic acid and bezafibrate to help lower his liver enzymes, while cyclophosphamide and prednisolone were used to manage the inflammation.
This is the seventh case of ANCA vasculitis overlapping with PBC reported in the literature, including six cases of MPA and one case of granulomatosis with polyangiitis. According to the investigators, all shared some common features, including increased levels of the liver enzyme alkaline phosphatase and active inflammation.
“Due to the scarcity of similar reports, it was not possible to establish a true overlap syndrome or casual association,” the researchers wrote. Still, they suggest that “when the biliary enzyme levels are elevated in patients with vasculitis, physicians should thus be mindful of the possible coexistence of these diseases.”