Splenic marginal zone lymphoma--a clinicopathological study in a series of 16 patients.

Splenic marginal zone lymphoma (SMZL), characterized in the WHO classification of lymphoid tumors, is a rare disorder comprising less than 1% of lymphoid neoplasms; only a few series concerning this entity have been published. Although this type of lymphoma is well defined histologically, its histogenesis remains obscure. Moreover, specific biological markers are still lacking and immunophenotype profile is not specific. These and other reasons, such as the existence of cytogenetic subtypes, have led to some authors to suspect that SMZL constitutes a heterogeneous entity. We have analyzed a series of sixteen SMZL cases from four hospitals in our community, from a clinical, biological and pathological point of view. When compared with those reported in the literature, our findings show three main differences: our patients less frequently showed an intrasinusoidal bone marrow infiltration pattern; the presence of a serum monoclonal component was rarely seen; and CD5-positive SMZL cases appear to be more common than previously thought.

Successful response to rituximab in two cases of acquired haemophilia refractory to standard-therapy.

Acquired autoantibodies against coagulation factors (acquired haemophilia) frequently constitute a life-threatening bleeding situation requiring a prompt therapeutic intervention, including control of bleeding and secondarily an attempt of eradication of the inhibitor by prolonged immunosuppressive therapy. The combination of oral corticosteroids and cyplophosphamide seems to be effective to eradicate the autoantibody, but some patients may be resistant. Another therapeutic approach, recently described, observes treatment with the chimeric anti-CD20 monoclonal antibody rituximab. We report two consecutively treated patients whose acquired FVIII inhibitors did not respond to standard immunosuppressive regimens, and only when rituximab was added to therapy, complete response and prolonged remission were obtained.

Effect of prenatal stress on the hormonal response to acute and chronic stress and on immune parameters in the offspring.

The effect of prenatal stress on the time course of the corticosterone response to acute and chronic stress and on hematological and immunological parameters in the offspring were analized in the present study. Pregnant Sprague-Dawley rats were stressed daily for 2 hours during the last week of gestation, and female and male off-spring were studied during adulthood. Corticosterone response to acute immobilization stress was not significantly different in either control or prenatally stressed rats. However, after 10 days of immobilization stress the corticosterone response completely disappeared in the control animals but not in the prenatally stressed group: high levels of corticosterone were found during the first hour of stress, although they were lower than those found in acutely stressed rats. Adrenal hypertrophy in response to prenatal stress was observed in females but not in male offspring, and chronic stress only increased adrenal weights in the male control group. Prenatal stress decreased the total peripheral leukocyte count, altered its diferential count decreasing lymphocytes and increasing neutrophil and eosinhophil counts, and significantly reduced the percentage of peripheral lymphocyte T CD8+ subset in male offspring. Chronic stress also reduced the percentage of the peripheral T CD8+ lymphocyte subset in the control group but not in the prenatally stressed group. These results suggest that the exposure to stress during pregnancy alters the adaptative response of the hypothalamus-pituitary-adrenocortical axis to chronic stress and presumably the immune competence in the offspring.