Single-cell analysis of T-cell receptor-gamma rearrangements in large-cell anaplastic lymphoma

Prevalence of bone marrow involvement in systemic anaplastic large cell lymphoma: are immunohistochemical studies necessary?

The frequency of bone marrow involvement in anaplastic large cell lymphoma has been reported with great variation. A prior study found that anaplastic large cell lymphoma involvement of bone marrow was often not evident on routine stains and advocated using immunohistochemical studies. We evaluated 70 bone marrow biopsies from 41 patients with anaplastic large cell lymphoma and found 10 morphologically involved cases (14% of all biopsies, 22% of all patients). In most cases (9/10 biopsies), the involvement of the bone marrow by anaplastic large cell lymphoma was massive and, thus, was evident on the hematoxylin and eosin section. In only 1 biopsy (1% of all biopsies, 2% of all patients), the involvement was minimal and more difficult to detect. To determine if the hematoxylin and eosin evaluation missed bone marrow involvement, we used a panel of antibodies including CD30, ALK-1, epithelial membrane antigen, and granzyme. Only the 10 morphologically involved cases showed anaplastic large cell lymphoma cells with distinct CD30 expression. Other stains highlighted only a subset of the CD30-positive cases. Clinical follow-up was available for 30 patients and shows correlation of marrow involvement with lower overall survival (P = .033). Overall, marrow involvement in anaplastic large cell lymphoma was relatively uncommon, and when present, it was identified on hematoxylin and eosin sections.

Clonal CD8+ TCR-Vbeta expanded populations with effector memory phenotype in Churg Strauss syndrome

Churg Strauss Syndrome (CSS) is a systemic vasculitis in which oligoclonal T cell expansions might be involved in the pathogenesis. Combined analysis of TCR-Vbeta expression profile by flow cytometry and of TCR gene rearrangement by heteroduplex PCR was used to detect and characterize T cell expansions in 8 CSS patients, 10 asthmatics and 42 healthy subjects. In all CSS patients one or two Vbeta families were expanded among CD8+ cells, with an effector memory phenotype apt to populate tissues and inflammatory sites. Heteroduplex PCR showed the presence of one or more clonal TCR rearrangements, which reveals monoclonal or oligoclonal T cells subpopulations. After purification with a Vbeta specific monoclonal antibody, each CD8+/Vbeta+ expanded family showed a single TCR rearrangement, clearly suggestive of monoclonality. All CD8+ expansions were detectable throughout the disease course. TCR-Vbeta expanded or deleted populations were not observed in asthmatic patients. Clonal CD8+/Vbeta+ T cell expansions might be useful as a disease marker.

Combined analysis of T cell receptor gamma and immunoglobulin heavy chain gene rearrangements at the single-cell level in lymphomas with dual genotype

By prospectively studying immunoglobulin heavy chain gene (IgH) and T cell receptor gamma (TCRgamma) gene rearrangements in 398 lymphoma cases, a dual genotype was observed in 13% of B cell and 11% of T cell lymphomas. According to histological subtype, the highest incidence was observed for mantle cell lymphomas (32%) and lymphoplasmacytic lymphoma (21%) among B cell lymphomas, and for angioimmunoblastic lymphoma (AILT) (46%) and Sézary syndrome (SS) (50%) among T cell lymphomas. To determine whether the dual genotype corresponds to the presence of two distinct monoclonal populations or to the presence of both rearrangements within the same lymphoma cells, single-cell microdissection was used after immunohistochemistry and a single-cell combined IgH and TCRgamma gene analysis was designed after a whole-genome amplification step. This protocol was applied to the study of two nodal B cell lymphomas (one diffuse large B cell lymphoma and one mantle cell lymphoma) and two cutaneous T cell lymphomas (one AILT and one SS). Two cases (SS and mantle cell lymphoma) were true bigenotypic lymphomas, as both IgH and TCRgamma monoclonal rearrangements were detected in the same cells. Conversely, in the diffuse large B cell lymphoma and AILT cases, large CD22+ single cells exhibited only the monoclonal IgH rearrangement but not the TCRgamma gene that was detected in CD3+ single cells. Such an approach allows the identification of true bigenotypic lymphoma among dual genotypic lymphoma. Specific genetic alterations may be further amplified from microdissected cryopreserved material, such as the t(11;14) breakpoint detected in bigenotypic B cells of the mantle cell lymphoma case.

Microanatomical compartments of clonal and reactive T cells in mycosis fungoides: molecular demonstration by single cell polymerase chain reaction of T cell receptor gene rearrangements

Mycosis fungoides (MF) is a cutaneous T cell lymphoma, clinically characterized by patches, plaques and tumors occurring in successive stages of the disease. In early MF, an infiltrate consisting of mainly reactive T cells is seen in the papillary dermis while tumor cells are mostly confined to the epidermis. By contrast, later stages show nodular infiltrates formed mostly of tumor cells in the dermis while the epidermis is relatively devoid of tumor cells; however, knowledge of the localization of clonal T cells has been based on histomorphologic features and immunohistochemical stainings visualizing certain V-beta subfamilies of the T cell receptor (TCR). As these techniques do not allow for an unequivocal identification of clonal tumor cells, we used micromanipulation and single cell PCR amplifying the TCR chain gene rearrangement. A total number of 387 single T cells was isolated from six skin biopsies in five patients in patch, plaque, and tumor stages. Of these, 180 T cells were picked from the epidermis and 207 from the dermal infiltrate. The rearranged TCR-gamma DNA could be sequenced from 181 of 387 T cells. In three of six patients representing all three stages, epidermal T cells with a clonal rearrangement could be amplified. In early plaque stage a higher degree of epidermal T lymphocytes was found than in initial patch, later plaque, and tumor stages with an inverse distribution found for reactive T lymphocytes. In two patients a biallelic rearrangement was demonstrated that had not been detected in prior PCR analysis from blood and skin samples. These data show that clonal (neoplastic) and non-clonal (reactive) T lymphocytes in MF preferentially infiltrate different microanatomical compartments of the skin, depending on the stage of disease. The microanatomically distinct localization of reactive and clonal T cells suggests that the absence of direct contact between tumor and host-defense lymphocytes may contribute to tumor persistence and progression in epidermis, peripheral blood, and deep dermal tumor cell nests, respectively.

Hodgkin's disease: immunoglobulin heavy and light chain gene rearrangements revealed in single Hodgkin/Reed-Sternberg cells

AIM

To corroborate and investigate the nature of Hodgkin/Reed-Sternberg cells (H/R-S) of various subtypes of Hodgkin's disease.

METHOD

Single H/R-S cells were micro-picked from frozen sections of tissues affected by Hodgkin's disease. The DNA from these cells was amplified by the polymerase chain reaction (PCR) with immunoglobulin heavy chain (IgH) gene FRIIIa/JH primers and light chain gene family specific primers.

RESULTS

Fifty two of 135 isolated cells gave specific reaction products (36%). IgH and V kappa 4 gene rearrangements were found repeatedly in many H/R-S cells from one case of lymphocyte predominant Hodgkin's disease. Repeated V kappa 4 and individual IgH/V kappa 4,2 rearrangements were seen in one case, and individual IgH and V lambda 3/V kappa 4 rearrangements were seen in another case of nodular sclerosis-type Hodgkin's disease. Repeated IgH/V lambda 3 and individual V lambda 2,4 rearrangements, repeated V kappa 4 and individual IgH/V kappa 3 rearrangements, and repeated IgH and individual V kappa 3/V kappa 4 rearrangement were detected, respectively, in three cases of mixed cellularity-type Hodgkin's disease. Repeated and individual IgH rearrangements were found in another two cases of mixed cellularity-type Hodgkin's disease.

CONCLUSION

The H/R-S cells isolated from lymphocyte predominant Hodgkin's disease had IgH and V kappa 4 gene rearrangements, which supports the conclusion that this disease results from a proliferation of neoplastic B cells. The IgH and kappa and/or lambda gene rearrangements seen in H/R-S cells isolated from classic Hodgkin's disease (mixed cellularity-type and nodular sclerosis-type) support the theory that these cells derive from B lineage cells at various stages of differentiation. To our knowledge, this is first time that lambda gene rearrangements have been detected in H/R-S cells.

t(2;5) positive lymphoma with peripheral blood involvement

We report two cases of CD30 and t(2;5) positive lymphomas with peripheral blood (PB) involvement. Case one demonstrated the histological appearance of a diffuse large cell lymphoma with disease in the bone marrow (BM) and PB. Immunoperoxidase stains of the BM for CD30 proved to be of value in detecting disease. RT-PCR for the t(2;5) translocation product was positive in the PB, BM and lymph node. Case two had a typical anaplastic large cell lymphoma (ALCL) morphology, with a suboptimal BM biopsy, but abnormal circulating cells in the PB showing the presence of the NPM/ALK fusion product demonstrated by RT-PCR. The first case demonstrates that not all CD30 positive and t(2;5)-associated lymphomas have an anaplastic appearance. Routine staining for CD30 and EMA in BM biopsies is useful for pathological staging. The significance of the t(2;5) in defining a specific histological subtype is unclear. RT-PCR for the t(2;5) is a more sensitive test to detect disease in PB and BM as compared with light microscopy. The clinical significance of molecular staging for patients with ALCL using RT-PCR needs to be evaluated.