Analysis of VH genes rearranged by individual B cells in dermal infiltrates of patients with mycosis fungoides

Abstract

SUMMARYIn patients with cutaneous T cell lymphomas such as mycosis fungoides B cells can frequently be detected in the lymphocytic dermal infiltrate. To analyse their immunoglobulin heavy chain gene repertoire, single B cells were obtained from tissue sections of two typical patients with mycosis fungoides using hydraulic micromanipulation followed by specific amplification of the respective gene segments by single-cell polymerase chain reaction (PCR) technique. A total of 21 V H DJ H genes was sequenced. From each individual B cell a single productive V H DJ H rearrangement was obtained. There was no clonal relationship detected between any of these rearrangements suggesting polyclonality of the infiltrating B cells. The representation of V H families was in accordance with the germ-line complexity. A remarkably high number of V H genes (5/13 in patient 1; 3/8 in patient 2) was completely or nearly germ-line-identical. Five of seven V H 4 family genes were nearly unmutated. On the other hand, most of the V H 3 gene family members were somatically mutated in an antigen-driven manner. The proportion of germ-line-identical V H genes, the usage of individual V H , D, J H gene elements, and the pattern of somatic mutations found in the B cells infiltrating skin lesions of patients with mycosis fungoides resembles the peripheral blood repertoire, suggesting a bystander role of these cells.

Cutaneous Peripheral T-Cell Lymphoma Associated With a Proliferation of B Cells

“…Few other authors have described the presence of B cells in CTCL, many of which represented cases of mycosis fungoides. [11][12][13][14][15] Similar to our findings, the presence of numerous B cells complicated the diagnosis and resulted in misdiagnoses such as a reactive process or T cell-rich B-cell lymphoma. Golembowski et al 12 The mixed infiltrates in our cases, with a range in cell size in both B-and T-cell lineages, raises a differential diagnosis that includes T cell-rich large B-cell lymphoma or benign cutaneous lymphoid hyperplasia (CLH).…”

Concurrent Presentation of Mycosis Fungoides and Primary Cutaneous Marginal Zone LPD: Clinicopathological Study of 4 Cases and Literature Review

“…The presence of a prominent CD20 + population in the context of a MF may be a diagnostic challenge. On one hand, polyclonal nature of B cells in MF has been demonstrated in several studies, 26,27 and on the other hand, the expression of CD20 by neoplastic T cells is infrequent but well-recognized in a variety of lymphomas. 28 Cases of CD20 + MF reported so far have been distinguished from B-cell lymphomas due to their coexpression of CD20 and T-cell markers (ie, CD3 and CD4) by the atypical cells, the lack of other B-cell markers, and the absence of monoclonal IgH gene rearrangement.…”

Μορφολογική Και Ανοσοϊστοχημική Διερεύνηση Βιοψιών Δέρματος Σε Ασθενείς Με Σπογγοειδή Μυκητίαση

“…Έχει αναφερθεί ότι η λειτουργία των λεμφοκυττάρων-φυσικών φονέων (ΝΚ) είναι μειωμένη σε ασθενείς με CTCL [Wysocka, 2004;Jensen, 1986 [Förste, 1997]. Οι αλλοιώσεις, ιδίως σε προχωρημένα στάδια, αλλά και σε κλινικώς επίπεδες βλάβες, δύνανται να παρουσιάσουν σημαντικό αριθμό CD20 + αντιδραστικών Β-κυττάρων, ενίοτε σχηματίζοντας και βλαστικά κέντρα στην βάση της επιδερμοτροπικής διήθησης , ακόμη και με συνοδό παρουσία κοκκιωματώδους αντίδρασης ή και συριγγοτροπισμού , κυριαρχώντας ενίοτε στην ιστολογική εικόνα και συγκαλύπτοντας την Τ-κυτταρική προέλευση της νεοπλασματικής διήθησης, περίπτωση που δεν πρέπει να παρερμηνεύεται ως δερματική Β-κυτταρική λεμφοϋπερπλαστική διαταραχή/νεοπλασία [Tan, 2004].…”