Anti-B-cell monoclonal antibody therapy seems to be effective in PTLD, even in monoclonal B-cell forms, but other approaches will be necessary to improve survival further.

Sezary syndrome is a cutaneous T cell lymphoma characterized by infiltration of the skin by CD4+ cells. These cells generally respond poorly to mitogens and T cell activators. We have studied the action of ILl to IL4, IL6, and IL7 on the proliferation of Sezary cells from 12 patients. With the exception of IL2 and IL7, the cytokines studied had no proliferative effect on these cells. Whereas IL2 had only a low proliferative capacity (twoto threefold increase) on peripheral blood mononuclear cells, recombinant IL7 constantly induced a very significant (340-fold increase) proliferative response, and was used successfully to generate cell lines in three out of eight cases. Growth of Sezary cell lines was shown to be strictly dependent on IL7, and after 2-5 wk of culture presented a switch to a homogeneous phenotype CD3+4+8-7-(except for one line that remained CD7+), with a typical morphology of Sezary cells. Their tumoral origin was demonstrated by the expression of the same T cell receptor-13 gene rearrangement as the patients' T cells. Importantly, cultured normal epidermal keratinocyte supernatants could support the growth of our Sezary lines. Furthermore, the proliferative activity contained in these supernatants was completely blocked by a monoclonal anti-IL7 antibody. These results suggest that IL7 may, therefore, represent an important cytokine in the physiopathology of cutaneous T cell lymphoma. (J. Clin. Invest. 1992. 90:1054-1060

The recombination events of the gamma and beta T-cell receptor (TCR) loci were analysed in a series of 39 peripheral T-cell lymphomas (PTCLs) in association with the expression of TCR chains. In TCR alpha beta PTCLs, 22/23 cases showed a gamma-gene rearrangement while only 18/23 showed a concomitant beta-gene rearrangement. The germline configuration of the beta locus was found in angiommunoblastic lymphadenopathy and lymphoepithelioid lymphomas. Three gamma delta PTCLs rearranged both gamma and beta genes. TCR silent PTCLs showed three different patterns of gamma- and beta-gene rearrangements. Three cases were in germline configuration for both loci; five cases had a rearranged gamma and a germline beta locus; and five cases had the two loci rearranged. Regarding the variable genes in the gamma-rearranged alleles, members of the V gamma I subgroup were the most frequently presented (39/50), followed by V gamma II, V gamma III, and V gamma IV (9/50, 1/50, and 1/50, respectively). Joining segment usage was as follows: J1 or J2 (32/50), JP1 or JP2 (17/50), and JP (1/50). Taken together, these data demonstrate that the gamma locus is more frequently rearranged whatever the TCR expression. The gamma-locus analysis provides a better diagnostic yield than the beta locus in the study of PTCL clonality.

The haematology analyser Coulter GEN.S gives a set of data -'positional parameters'- defining white blood cell (WBC) populations by mean of index values (mean and standard deviation of volume, conductivity and scatter, used to identify the WBC populations). The volume and conductivity parameters related to the lymphocytes were analysed at diagnosis in patients suffering from chronic B-lymphocytic leukaemia (B-CLL), other non-CLL lymphoproliferative disorders (OLPD) and viral diseases. The standard deviation of volume index (SDVI) is significantly higher in the three groups, whereas the mean volume index (MVI) is significantly lower in B-CLL, and increased in OLPD and viral diseases. These two groups could be distinguished by their mean conductivity index (MCI), which is significantly lower in viral disease group. Cut-offs were calculated for each parameter by the mean of Receiver Operating Characteristic (ROC) analysis. The study of the detection performances showed that the combination of lymphocyte count with SDVI, MVI and MCI could be used with a good sensitivity and specificity to discriminate between the most frequent lymphocyte pathologies, even in patients with normal lymphocyte count.

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