Widespread involvement of purpura related to gastrointestinal involvements in adults with immunoglobulin A vasculitis

Immunoglobulin A vasculitis (IgAV) is a type of vasculitis affecting small vessels with deposition of immune complexes consisting of IgA and complement component 3. IgAV involves the skin, gastrointestinal (GI) tract, joints, and kidneys. Adult patients have higher risks of gastrointestinal tract involvement than children. To investigate the risk factors of the GI tract involvements in adult IgAV patients, we enrolled 29 adult (aged ≥ 20 years) Japanese patients recently (from 2013 to 2019) histopathologically diagnosed with IgAV and classified them into the GI lesion (+) group and the GI lesion (−) group. All patients presented with purpura on the lower extremities; moreover, GI lesion (+) patients presented significantly more with extensive purpura on the upper extremities, and low levels of factor XIII activity (≤70%) than gastrointestinal lesion (−) patients (87.5% vs 28.6% [P = .004]; odds ratio [OR], 17.5; 95% confidence interval [CI], 2.4 to 366], and 57.1% vs 14.3% [P = .04]; OR, 8; 95% CI, 1.06 to 83.9, respectively). There was no significant difference between the two groups in the populations with extensive purpura on the trunk, arthralgia, hematuria, proteinuria, or elevated serum levels of C‐reactive protein or IgA. Widespread purpura on the upper extremities accompanied by a low factor XIII activity is a suggestive factor for severe GI lesions in adult IgAV patients.