Glomerulonephritis as a renal manifestation in a patient with systemic sclerosis overlapped with anti-neutrophil cytoplasmic antibody-associated vasculitis

Introduction and Importance: Systemic sclerosis (SSc) is a systemic immune disorder that may overlap with other rheumatologic disease; however, overlapping with antineutrophil cytoplasmic antibody-associated vasculitis is rare. Case Presentation: A 28-year-old Syrian male patient with SSc diagnosed according to the American College of Rheumatology/European League against Rheumatism 2013 criteria with a disease duration of 4 years, was admitted to the hospital complaining of palpable purpura in the lower limbs and hemoptysis and later, a rise in creatinine level. Laboratory tests showed high levels of perinuclear antineutrophil cytoplasmic antibodies (p-ANCA). The renal biopsy results were consistent with the diagnosis of glomerulonephritis. He was treated with methylprednisolone, cyclophosphamide, and rituximab, as he was diagnosed with SSc overlapping antineutrophil cytoplasmic antibody-associated vasculitis. Clinical Discussion: SSc most commonly renal manifestations are proliferative vasculopathy leading to scleroderma renal crisis. However, other types of renal involvement were also reported in SSc patients with comorbid autoimmune diseases such as glomerulonephritis and signs of concurrent vasculitis. SSc may overlap with rheumatoid arthritis, systemic lupus erythromatosus, polymyositis/dermatomyositis (PM/DM), and Sjogren Syndrome. Overlapping with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is mentioned in rare cases. The authors reported a rare case of overlapping SSc with antineutrophil cytoplasmic antibody-associated vasculitis with renal involvement. Conclusion: The authors revealed a rare case of overlapping SSc with antineutrophil cytoplasmic antibody-associated vasculitis with renal involvement. In SSc, renal involvement as glomerulonephritis is infrequent and should be detect in other rheumatologic disease such as systemic lupus erythematosus or antineutrophil cytoplasmic antibody-associated vasculitis.