Examination of the Level of Circulating Plasmablasts and Their Characteristics as Diagnostic Tools for Immunoglobulin
Shelly Tartakover Matalon1, Noa Rabinowicz2, Or Carmi3
1Autoimmune Research Laboratory, Meir Medical Center, Kfar Saba, Israel, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Background:
Immunoglobulin G4-related disease (IgG4-RD) is a chronic, immune-mediated condition characterized by fibro-inflammatory lesions with lymphoplasmacytic infiltration. Diagnosis traditionally relies on histopathological findings, including the presence of IgG4+ plasma cells. However, due to challenges in biopsy accessibility, additional measures are needed to facilitate diagnosis.
Objectives:
To identify additional parameters for characterizing IgG4-RD patients.
Methods:
We compared several circulating factors between a cohort of patients with IgG4-RD disease seen at our hospital between 2017 and 2023 and healthy controls.
Results:
Among 16 suspected patients, 13 were confirmed to have IgG4-RD, and 3 were classified as highly likely. Comparison with controls revealed differences in white blood cell count (WBC) (Folf change (FC) 1.46, P < 0.05), plasmablasts (FC 3.76, P< 0.05), plasmablasts CD38 (FC 1.43, P < 0.05), and CD27 (FC 0.66, P = 0.054), thus highlighting potential markers for IgG4-RD diagnosis. Treatments with steroids/rituximab tend to reduce plasmablast (FC 0.6) and IgG4 (FC 0.28) levels and to increase Gal-3 levels.
Conclusions:
Levels of plasmablasts are a significant diagnostic feature in IgG4-RD. Healthy individuals have a lower level of plasmablasts. Elevated Gal-3 in serum of patients with IgG4-RD suggests a role in plasmablast activation. CD38/CD27 expression by plasmablasts emerges as a potential marker. Further research on a larger cohort is needed to confirm these findings.
