Quantification of polyreactive immunoglobulin G facilitates the diagnosis of autoimmune hepatitis.

Background And Aims: Detection of autoantibodies is a mainstay of diagnosing autoimmune hepatitis (AIH). However, conventional autoantibodies for the workup of AIH lack either sensitivity or specificity, leading to substantial diagnostic uncertainty. We aimed to identify more accurate serological markers of AIH with a protein macroarray.

IgA antibodies against CD74 are associated with structural damage in the axial skeleton in patients with axial spondyloarthritis.

Objectives: To study the association between the presence of antibodies against CD74 and structural damage in the sacroiliac joints and spine in patients with axial spondyloarthritis (axSpA).

Methods: Antibodies against CD74 were measured in the sera of patients with axSpA from 2 cohorts: 1. An observational cohort from Damp in Northern Germany and 2.

Impaired proteolysis by SPPL2a causes CD74 fragment accumulation that can be recognized by anti-CD74 autoantibodies in human ankylosing spondylitis.

Ankylosing spondylitis (AS) is associated with autoantibody production to class II MHC-associated invariant chain peptide, CD74/CLIP. In this study, we considered that anti-CD74/CLIP autoantibodies present in sera from AS might recognize CD74 degradation products that accumulate upon deficiency of the enzyme signal peptide peptidase-like 2A (SPPL2a). We analyzed monocytes from healthy controls (n = 42), psoriatic arthritis (n = 25), rheumatoid arthritis (n = 16), and AS patients (n = 15) for SPPL2a enzyme activity and complemented the experiments using SPPL2a-sufficient and -deficient THP-1 cells.

Presence of Antibodies Binding to Negative Elongation Factor E in Sarcoidosis.

Sarcoidosis is characterized by multiorgan involvement and granulomatous inflammation. Its origin is unknown and the potential role of autoimmunity has not been sufficiently determined. We investigated the presence of autoantibodies in sarcoidosis using protein array technology.