{Reference Type}: Case Reports
{Title}: Antineutrophil Cytoplasmic Antibody-Associated Vasculitis Accompanied by IgG4-Tubulointerstitial Nephritis with Underlying Sjögren Syndrome: A Case Report and Review of Literature.
{Author}: Lu C;Wang R;Liu C;Zhou G;
{Journal}: Ann Clin Lab Sci
{Volume}: 51
{Issue}: 6
{Year}: Nov 2021
{Factor}: 1.18
{Abstract}: <B>OBJECTIVE: </B>Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of autoimmune multisystemic diseases characterized by necrotizing inflammation of small vessels and the presence of circulating ANCA. The prevalence of overlap AAV with other autoimmune diseases was low.<BR><B>METHODS: </B>We report a case of a 54-year-old woman who presented with a 20-year-history of sicca symptoms, the presence of anti-Ro/SS-A, anti-La/SS-B antibodies, myeloperoxidase -ANCA (MPO-ANCA), significant increase of serum IgG4 level, microscopic hematuria, non-nephrotic proteinuria, and progressive renal dysfunction. A renal biopsy showed pauci-immune necrotizing glomerulonephritis with crescents with severe tubulointerstitial nephritis (TIN) which shows extensive infiltration of IgG4-positive plasma cells. Considering these findings and the clinical course, the disease was considered more likely to be MPO-ANCA-associated vasculitis accompanied by IgG4-TIN with underlying primary Sjögren syndrome (pSS).<BR><B>CONCLUSIONS: </B>This report shows a possible unusual disease overlap of MPO-ANCA-associated vasculitis and IgG4-TIN with underlying pSS.