CD45RA+ immunophenotype in mycosis fungoides: clinical, histological and immunophenotypical features in 22 patients.
BACKGROUND
Mycosis fungoides (MF) is a cutaneous T-cell lymphoma (CTCL) usually characterized by a T-helper memory phenotype (CD3+, CD4+, CD8-, CD45R0+). Aberrant phenotypes are more commonly seen in the tumor stages. CD45RA expression has so far been documented in only a few cases of CD8+ or TCR gamma delta+ CTCL and in some pagetoid reticulosis cases.


METHODS
Two hundred and fifteen MF patients were immunophenotyped in our laboratory between January 1992 and June 2000 and 22 cases of CD45RA+ MF (8.7%) were identified by immunohistochemical analysis.


RESULTS
The majority of these CD45RA+ patients (20/22) showed a patch-plaque stage disease and an indolent clinical course, as expected in early-stage MF. The remaining 2 patients presented with stage IIB and IVA MF, and were characterized by an aggressive clinical course, with systemic spread. The immunohistochemical analysis revealed that CD45RA+ neoplastic cells belonged to the memory compartment, displaying a CD62L-, CD11a+, CD29+ phenotype. Most patients showed aberrant phenotypes, with a loss of T-cell lineage markers and expression of cytotoxic molecules or gamma-delta chain of the T-cell receptor.


CONCLUSIONS
Our data show that CD45RA+ MF is a rare variant of CTCL and shares with the classic MF cases both the clinical features and disease course, even if it is characterized by a higher incidence of immunopathological abnormalities.
Fierro
M T
MT
Department of Medical and Surgical Specialities, 1st Section of Dermatology, University of Turin, Torino, Italy.
Novelli
M
M
Savoia
P
P
Cambieri
I
I
Quaglino
P
P
Osella-Abate
S
S
Bernengo
M G
MG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D017493:Leukocyte Common Antigens / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D009182:Mycosis Fungoides / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D012867:Skin / Q000473:pathology; D012878:Skin Neoplasms / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology / Q000628:therapy
D017493:Leukocyte Common Antigens