Giacomo Lucivero

Cytotoxic and immunotoxic effects of Fusarium mycotoxins using a rapid colorimetric bioassay

A colorimetric MTT (tetrazolium salt) cleavage test was used to evaluate cytotoxicity of twenty-three Fusarium mycotoxins on two cultured human cell lines (K-562 and MIN-GL1) as well as their inhibitory effect on proliferation of phytohemagglutinin-stimulated human peripheral blood lymphocytes. The values of 50% inhibition of lymphocyte blastogenesis were very close to the 50% cytotoxic doses observed with the more sensitive cell line (MIN-GL1). T-2 toxin was the most cytotoxic with CD50 and ID50 values less than 1 ng/ml. Type A trichothecenes were the most cytotoxic followed by the type B trichothecenes; the non-trichothecenes were the least cytotoxic. The MTT cleavage test, in conjunction with cell culture, is a simple and rapid bioassay to evaluate cytotoxicity and immunotoxicity of Fusarium mycotoxins.

Primary cardiac T-cell lymphoma

Primary cardiac lymphoma (PCL), defined as a lymphoma clinically mimicking cardiac disease, with the bulk of the tumor located intrapericardially, is extremely rare in immunocompetent patients. Clinical manifestations vary depending on sites of involvement in the heart and include chest pain, arrhythmias, pericardial effusion, and heart failure. Diagnosis is often difficult and may require invasive procedures; in some cases, diagnosis is not made until autopsy. Histologically, nearly all cases of PCL reported thus far have been of B-cell origin. In this report, we describe a case of PCL of T-cell origin in an adult immunocompetent patient, the second reported in the literature to the best of our knowledge, and provide a brief overview of the features of previously published PCL cases.

Behavior of Circulating CD4+CD25+Foxp3+ Regulatory T Cells in Colon Cancer Patients Undergoing Surgery

CD4+CD25+Foxp3+ regulatory T cells (Treg) specialize in suppressing immune responses. In this study, 47 consecutive colon cancer patients were subjected to circulating Treg frequency assessment by flow cytometry before and after cancer resection. Thirty-two healthy subjects served as controls. Circulating Treg frequencies were significantly higher in colon cancer patients with respect to healthy controls. When patients were subgrouped according to Dukes stages, a linear relationship was observed between Dukes stages and Treg frequencies. In radically resected patients, Treg frequencies were shown to have significantly dropped down. Patients with advanced colon cancer were more likely to have significantly higher proportions of circulating Treg frequencies than Dukes A and B patients when compared to healthy subjects. Of note, nonradically resected patients were found to display reductions in—but not normalization of—Treg frequencies. These results suggest that cancer itself may be able to drive Treg recruitment as a strategy of immunoevasion.

Effects of preactivated autologous T lymphocytes on CD80, CD86 and CD95 expression by chronic lymphocytic leukemia B cells.

Profound immune dysfunction is a constant feature in B-cell chronic lymphocytic leukemia (B-CLL) patients. Immunological abnormalities include hypogammaglobulinemia, impaired immunoglobulin class switching and diminished germinal center formation. This state of immune suppression renders B-CLL patients highly susceptible to infections, which contribute greatly to morbidity and mortality in this disease. Impaired T cell function in B-CLL is well-documented and has been suggested to result from inhibitory effects exerted by malignant B lymphocytes. Because the presence of leukemic cells may represent a major obstacle to efficient T cell activation, T lymphocytes were separated from CLL B cells, stimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin for 4 h, and then cocultured with autologous leukemic B cells both at a 1:1 ratio or at the same ratio as in vivo for 24-40 h. CLL B cell expression of CD86 and CD95 was markedly upregulated using this approach, whereas CD80 expression was augmented only in a minority of patients; these effects were partially preserved even when preactivated T cells were rechallenged with CLL B cells at the same low T/B cell ratio as that observed in vivo. Finally, CD80 upregulation on CLL B cells appeared to be mainly dependent on CD40L-mediated stimulation, whereas CD86 and CD95 expression was efficiently augmented by soluble factors released by preactivated T lymphocytes. In conclusion, efficient activation of T lymphocytes in B-CLL may be achieved which, in turn, may result in enhanced antigen-presenting capacity and susceptibility to apoptosis of leukemic cells via CD86 and CD95 upregulation, respectively.

Clinical and phenotypic features of CD5-negative B cell chronic lymphoproliferative disease resembling chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) B cells are phenotypically identified by surface expression of CD5 and CD23 antigens. Infrequently, patients with a monoclonal B cell lymphocytosis clinically resembling classic B-CLL have been found to harbor leukemic B cells lacking expression of the CD5 antigen. Little information is available concerning such CLL-like lymphoproliferative syndromes. Here, we provide phenotypic and clinical characteristics of 13 patients with CD5-negative chronic lymphoproliferative disorders selected from among 400 B-CLL patients followed up at a single academic center. Phenotypic analysis was carried out by flow cytometry using a broad panel of monoclonal antibodies including activation, costimulatory, adhesion, and growth factor receptor molecules. Moreover, intracellular staining and stimulation experiments were performed to investigate whether CD5 antigen was either retained in the cytoplasm of clonal B cells or not expressed due to defective cellular activation, respectively. Overall, CD5-negative leukemic cells were found to express significantly different levels of several membrane molecules, including CD95, CD69, CD23, CD25, CD80, and CD20, compared to “classic” CLL B cells. CD5 antigen was not detected in the cytoplasm of CD5-negative clonal B cells, nor could it be induced following in vitro activation. CD3+ T cell proportions were found to be less affected in CD5-negative patients than in classic B-CLL. Although these data suggest that CD5-negative clonal B cells are phenotypically different from classic B-CLL, clinical outcomes were similar to those shown by B-CLL patients, with most of the patients experiencing a long-lasting disease requiring chemotherapeutic intervention at some time during the disease course.

Granulomatous lobular mastitis: another manifestation of systemic lupus erythematosus?

Granulomatous lobular mastitis (GLM) is a benign disease of the breast generally affecting women of child-bearing age. Diagnosis is based on findings of noncaseating granulomatous inflammation at histologic evaluation of biopsy. GLM has been reported in association with infectious diseases (tuberculosis, bacterial, fungal, or parasitic infections), vasculitis (Wegener’s granulomatosis, sarcoidosis, giant cell arteritis, polyarteritis nodosa), foreign body reaction (e.g., breast implants), and oral contraceptive usage. When an apparent etiology cannot be found, GLM is defined as idiopathic. Pathogenesis is unknown, although an abnormal immune response has been hypothesized to underlie the development of this condition. Accordingly, we report here a case of GLM associated with a serological profile indicative of combined systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS), clinically mimicking multifocal breast cancer (Fig. 1). A 65-year-old woman was referred to our Institution because of multiple nodular lesions in both breasts resembling multifocal cancer. Her past medical history was remarkable for a non-ST-elevation myocardial infarction (NSTEMI) occurred at age 40. Relevant laboratory tests included positivity for both ANA (1:1280, homogeneous + nucleolar pattern) and anti-dsDNA (indirect immunofluorescence on Crithidia luciliae), prolonged aPTT (67.7′′), detection of both anticardiolipin IgG (271 GPL U/mL; n.v.: <10) and anti-b2-glycoprotein I IgG (177 UA/mL; n.v.: <10), and consumed complement C4 (8 mg/dL; n.v.: 12– 52). Both patients’ breasts were subjected to excisional biopsy. However, contrary to the initial diagnostic suspicion, the patient was diagnosed as having granulomatous lobular mastitis (Fig. 2). The patient denied clinical complaints attributable to SLE/APS. No pregnancy morbidity/losses were reported during childbearing age. Physical examination was normal, apart from breast involvement. Cultures of breast tissue for bacterial, mycobacterial, and fungal pathogens were negative. Intradermal PPD was negative at a 72-hour

A scleroderma-like cutaneous syndrome associated with a marked Th2-type immune response occurring after a prosthetic joint implant.

A scleroderma-like cutaneous syndrome, occurring after implantation of a prosthetic knee joint in an elderly woman, is reported. This case did not seem to typically fit into any of the known scleroderma-like disorders of the skin described to date. The patient was shown to be sensitized to metals contained in the prosthesis and to mount a Th2-type immune response concomitantly with development of skin fibrosis. In particular, eosinophilia, markedly elevated serum IgE levels, in vitro spontaneous production of interleukin (IL)-4 by T lymphocytes, and elevated serum levels of Th2 cytokines (namely, IL-4, IL-5, and IL-13) were observed during the acute phase of illness. Since eosinophils and such Th2 cytokines as IL-13 also have recognized fibrogenic properties, it is speculated that the pathogenesis of skin fibrosis in this case could have been the direct and/or indirect consequence of the coexisting Th2-type immune response.