Diagnostic value of dominant T-cell clones in peripheral blood in 363 patients presenting consecutively with a clinical suspicion of cutaneous lymphoma

Abstract

It is now widely accepted that polymerase chain reaction (PCR) analysis of cutaneous T-cell clonality is of diagnostic value in cutaneous T-cell lymphomas (CTCLs) and most helpful in the diagnosis of mycosis fungoides (MF). However, the diagnostic and prognostic value of circulating clonal T cells remains unclear. We studied T-cell clonality in the peripheral blood (PB) and the cutaneous lesion, sampled at the same time, in 363 consecutively seen patients with a clinical suspicion of cutaneous lymphoma. Using a PCR technique providing a specific imprint of T-cell clones (PCRγ–denaturing gradient gel electrophoresis), we found that detection of identical circulating and cutaneous T-cell clones was associated with the diagnosis of CTCL (P < .001). Detection of circulating tumor cells in patients with MF was infrequent (12.5%), except in those with erythrodermic MF (42%; P = .003). Moreover, among the 46 patients who had identical circulating and cutaneous T-cell clones, 25 (56%) had erythroderma. The finding of a dominant clone in the PB but not in the skin was frequent, regardless of the clinicohistologic classification; it occurred in 30% of patients with CTCL, 41% with non-CTCL malignant infiltrates, and 34% with benign infiltrates. This pattern was significantly more frequent in patients over 60 years of age (P < .002), even in the CTCL group (P < .01). In conclusion, dominant T-cell clones detected in the PB of patients with MF by using a routine PCR technique are rarely tumoral and are more often related to age. A multicenter prospective study is under way to establish the prognostic value of circulating tumor cells.

Heavy metal (monoclonal) bands: A link between cutaneous T‐cell lymphoma and contact allergy to potassium dichromate, nickel and cobalt?

“…Interestingly, Delfau‐Larue and colleagues noted that 57% of patients in their study with monoclonal T‐cell proliferation in skin and blood were erythrodermic . The improvement seen in patient 2 after reducing the volume of T‐cell clones using ECP suggests that these clones could be driving the erythrodermic response.…”

“…The significance of monoclonal T‐cell proliferation in the skin, blood and bone marrow in patients with suspected erythrodermic CTCL is unclear. Monoclonal T‐cell proliferation can occur as a reactive process in the skin of various benign dermatoses, with a prevalence of 14% among patients with contact dermatitis, drug‐induced dermatoses and pseudolymphoma . Delfau‐Larue and colleagues demonstrated that among 46 patients with suspected CTCL with monoclonal T‐cell proliferation in the skin and blood, 33 (72%) had skin histology suggestive of CTCL.…”

Comparison of somatic STAT3 and STAT5b gene mutations between Felty's syndrome and T-cell large granular lymphocytic leukemia with rheumatoid arthritis

“…[1,5,29] However, there is considerable discussion regarding the signi cance of dominant T-cell clones as a hallmark of T-cell malignancy because small populations of clonally expanded T-LGLs are revealed in healthy individuals and in an exuberant reactive response. [30][31][32][33][34] Considering that the difference between RA-associated T-LGLL and FS often depends on a single test with well-known gray areas in interpretation and limitations, [35] it is necessary look for additional distinctions. We can use mutations in STAT3 and STAT5b genes as molecular markers for T-LGLL diagnostics, [36] but their prevalence in FS and their diagnostic value for differential diagnosis between FS and RA-associated T-LGLL are unclear.…”

On the diagnosis of erythrodermic cutaneous T‐cell lymphoma

“…The author concludes that the presence of an identical T‐cell clone in the skin coupled with detection of an identical clone in the blood (or lymph node) is a fairly specific diagnostic criterion for E‐CTCL as indicated by Dr Russell‐Jones and others, 55 but ‘false positives’ may still occur in about 5% of cases, and the diagnostic sensitivity varies according to the PCR‐method used [14/52 (27%) for PCRγ‐DGGE and 6/16 (38%) for PCRγ‐SSCP].…”

“…Somewhat unexpectedly, a dominant T‐cell clone was found in skin samples from 11/45 (24%) of our cases considered to have non‐malignant disease compared with 33/68 (49%) of E‐CTCL cases (p = 0.017). While most investigators have found a very low frequency of T‐cell clones using PCR‐based techniques in benign inflammatory disease, Delfau‐Larue reported finding a clone in skin samples from 17/72 (24%) benign cases with a GC‐clamp multiplex PCRγ‐DGGE technique compared with 17/22 (77%) specimens from patients with SS 55 . Thus, the detection of a T‐cell clone may depend on the PCR method used.…”