A rare case of systemic sclerosis accompanied with antibody-negative cholangitis treated with methotrexate: A case report

Rationale: Systemic sclerosis (SSc) is an autoimmune disease characterized by skin thickening and organ involvement. Often, when it is combined with primary biliary cholangitis (PBC), it is associated with specific autoantibodies, such as anticentromere antibodies (ACA). This case presents a patient with SSc associated with PBC who tested negative for ACA. The significance of this case lies in its management approach: the decision to administer methotrexate (MTX) despite its hepatotoxic potential and the patient’s liver involvement. Patient concerns: A 53-year-old, non-smoking female presented with constitutional symptoms of fever and weight loss. She reported a seven-year history of Raynaud’s phenomenon. Physical examination revealed mild icterus of the skin and sclera, and during clinical examination, SSc was suspected. Tests for Scl-70 and PM-Scl antibodies were negative. Additionally, the ACA test was negative. Diagnoses: A skin biopsy confirmed the diagnosis of SSc. Laboratory tests showed an elevated ANA titer of 1:320 and elevated ESR, leukocyte count, and CRP levels. All hepatic enzymes were elevated (ALT, AST, alkaline phosphatase, and total bilirubin) and demonstrated a cholestatic pattern. The antimitochondrial antibody-M2 antibody test was positive, leading to a diagnosis of PBC in conjunction with the icterus and elevated hepatic enzymes. Interventions: The patient was treated with MTX for SSc and prescribed ursodeoxycholic acid for PBC. Outcomes: During follow-up, the skin induration began to decrease, and hepatic enzyme levels showed improvement. Lesson: A negative result for ACA does not rule out the diagnosis of PBC in conjunction with SSc. MTX can be considered for the treatment of SSc, even in patients with elevated hepatic enzymes; however, it is crucial to exercise caution and conduct close monitoring. Further large-scale studies are necessary to validate these findings.