Related Experiment Video
Updated: May 10, 2026
09:08
Isolating Human Peripheral Blood Mononuclear Cells and CD4+ T cells from Sézary Syndrome Patients for Transcriptomic Profiling
Published on: October 14, 2021
Primary cutaneous marginal zone lymphomas with plasmacytic differentiation show frequent IgG4 expression
Isabel Brenner1, Sabine Roth, Bernhard Puppe
1Institute of Pathology, University of Würzburg, Würzburg, Germany.
Summary
Immunoglobulin G4 (IgG4) is frequently expressed in primary cutaneous marginal zone lymphomas, a finding not seen in other marginal zone lymphomas. This suggests a localized IgG4-driven process and aids in diagnosing these skin lymphomas.
Area of Science:
- Oncology
- Immunology
- Dermatopathology
Background:
- Immunoglobulin G4 (IgG4) expression in malignant B-cell lymphomas is not well understood.
- Previous reports noted rare IgG4-expressing marginal zone lymphomas (MZLs) in ocular adnexae and dura.
- Systematic investigation of IgG4 in a large MZL cohort was lacking.
Purpose of the Study:
- To systematically investigate the expression of IgG4 in a large cohort of marginal zone lymphomas (MZLs).
- To determine the frequency and potential diagnostic significance of IgG4 expression in different MZL subtypes.
- To explore the association of IgG4 expression with clinical and histopathological features.
Main Methods:
- Immunohistochemistry was used to examine IgG4 heavy chain expression.
- A cohort of 169 marginal zone lymphomas from various primary sites was analyzed.
- Plasmacytic differentiation and light chain restriction were confirmed in the studied tumors.
Main Results:
- Unexpectedly, 39% (19 of 49) of primary cutaneous marginal zone lymphomas showed frequent IgG4 expression.
- This is the highest IgG4 expression rate reported to date in any B-cell lymphoma.
- Only 1 of 120 noncutaneous MZLs (ocular adnexae) expressed IgG4.
- IgG4-positive and negative primary cutaneous MZLs showed no significant differences in T-cell infiltrate composition.
Conclusions:
- Primary cutaneous marginal zone lymphomas exhibit a high frequency of IgG4 expression, suggesting a localized IgG4-driven pathogenesis.
- IgG4 expression in cutaneous MZLs may serve as a diagnostic clue, indicating a primary skin origin with an excellent prognosis.
- The pathogenetic role of IgG4 in these lymphomas requires further investigation.
