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V Perfetti

Publications and source records attributed to V Perfetti.

At least 19 recordsLinked to original sources
PubMed1996

Human cytomegalovirus early infection, acute rejection, and major histocompatibility class II expression in transplanted lung. Molecular, immunocytochemical, and histopathologic investigations.

The present study aimed to investigate the relationship between acute rejection and human cytomegalovirus (HCMV) infection, as well as the coexpression of HLA-DR and immediate-early (IE) viral antigens, in 143 transbronchial biopsies and bronchoalveolar lavage fluids of 32 lung transplant recipients. We investigated the occurrence of morphologically overt viral infection with conventional histopathology, the expression of IE antigens with single labeling immunohistochemistry, the coexpression of IE antigens and HLA-DR molecules with double labeling techniques, and the presence of viral IE genes with polymerase chain reaction. Histopathologic study showed overt viral infections (12.6%) in 18 of the 143 biopsies; 8 were in a context of pneumonia and 10 were localizations without surrounding inflammatory cells; immunohistochemistry showed IE viral antigen expression in 31 (21.67%); PCR detected viral IE genes in 73/143 lavage fluids and biopsies (51%). The double labeling immunohistochemical technique showed that most IE antigen-expressing, noncytopathic cells were either HLA-DR negative in areas without infiltrates, or HLA-DR positive in those areas where inflammatory infiltrates were consistent, in the absence of viral cytopathy, with acute rejection. The results indicate that, in transplanted lung, the frequency of morphologically occult HCMV infection (as detected by immunohistochemically and/or PCR) is much higher than that of morphologically overt viral infection. The occurrence of inflammatory infiltrates (consistent with acute rejection) around morphologically occult infected cells and the possible lack of inflammation around both early- and late-infected cells suggest that in biopsies with occult infection the infiltrates should be attributed to allograft reaction. This conclusion would be in keeping with the coexpression of HLA-DR and HCMV IE in infiltrate-rich biopsies that are consistent with acute rejection, as well as with the absence of HLA-DR expression in IE antigen-positive cells in infiltrate-free-areas.

Acute Disease↗
PubMed1996

Saporin, a ribosome-inactivating protein used to prepare immunotoxins, induces cell death via apoptosis.

The plant toxin saporin is a ribosome-inactivating protein which inhibits protein synthesis and growth of both normal and tumour cells. Its cytotoxic activity can be increased by coupling with antibodies recognizing cell surface antigens. In this work we performed experiments to test the hypothesis that saporin induces cell death via apoptosis. Exposure to saporin induced apoptosis in different cellular models, such as human peripheral blood B lymphocytes and neutrophils, in the Daudi B-cell line, and in the haemopoietic cell lines HL-60 and TF-1. This was indicated by: (a) the appearance of typical morphological features such as chromatin condensation, nuclear fragmentation and blebbing of plasma membranes: (b) DNA degradation into oligonucleosomal fragments: (c) the appearance of apoptotic cells on DNA flow cytometry as a cell population with reduced DNA content (A0 region). The fraction of cells showing features of apoptosis ranged from 19 +/- 5% for TF-1 cells to 35 +/- 8% for neutrophils. In experiments with normal peripheral blood B lymphocytes or with Daudi cells, we compared the activity of native saporin with that of an immunotoxin hybrid molecule obtained by binding the toxin to two bispecific antibodies recognizing both saporin and the B lymphocyte-specific antigen CD22 (Sap/BsAb complexes). Saporin bound to the antibodies was 2-3 logs more effective than native saporin in inducing apoptosis, with maximal inhibitions being observed at concentrations of 10(-6) M for native saporin and 10(-9)-10(-8) M for the hybrid molecules. These findings indicate that treatment with saporin results in apoptosis of target cells and suggest that this may be relevant to the therapeutic use of saporin-containing immunotoxins. In fact, if used in vivo as an immunotoxin, its cytotoxic activity could be devoid of more extensive and non-specific tissue damaging effects as would be the case if saporin induced necrosis of target cells.

Antibodies, Monoclonal↗
PubMed1995

Interaction of the anthracycline 4'-iodo-4'-deoxydoxorubicin with amyloid fibrils: inhibition of amyloidogenesis.

All types of amyloidosis are structurally characterized by the cross beta-pleated sheet conformation of the fibrils, irrespective of their biochemical composition. The clinical observation that the anthracycline 4'-iodo-4'-deoxy-doxorubicin (IDOX) can induce amyloid resorption in patients with immunoglobulin light chain amyloidosis was the starting point for this investigation of its possible mechanism of action. IDOX binds strongly to all five types of natural amyloid fibrils tested: immunoglobulin light chains, amyloid A, transthyretin (methionine-30 variant), beta-protein (Alzheimer), and beta 2-microglobulin. Quantitative binding studies showed that IDOX, but not doxorubicin, binds strongly to amyloid fibrils. This binding is saturable and involves two apparently distinct binding sites with Kd values of 5.9 x 10(-11) M and 3.4 x 10(-9) M. IDOX inhibited in vitro insulin amyloid fibrillogenesis. In vivo studies using the experimental amyloid murine model confirmed the specific targeting of IDOX to amyloid deposits. Preincubation of amyloid enhancing factor with IDOX significantly reduced the formation of amyloid deposits. It is hypothesized that IDOX exerts its beneficial effects through the inhibition of fibril growth, thus increasing the solubility of existing amyloid deposits and facilitating their clearance. IDOX may represent the progenitor of a class of amyloid-binding agents that could have both diagnostic and therapeutic potential in all types of amyloidoses.

Amyloid↗
PubMed1994

Reversal of nephrotic syndrome due to reactive amyloidosis (AA-type) after excision of localized Castleman's disease.

The patient (TAL), a chronic asymptomatic HBV carrier with HBsAg-anti-HBsAg circulating immune complexes, was admitted to our hospital because of a nephrotic syndrome due to renal amyloidosis. There was no family history of hereditary amyloidosis. Recurrent arthralgias, asthenia, and weight loss were the prominent clinical features. Laboratory test results showing that severe chronic inflammatory activity had been present for 6 years. Interleukin-6 (IL-6) serum concentration was 10 times normal and C-reactive protein was 1.9 mg/ml. A complex immunological picture was also present (immune complex formation, exuberant B-cell reactivity, and decrease in the number of CD4 T cells). A localized form of Castleman's disease (CD) (plasma-cell type) was diagnosed by surgical excision of a giant axillary lymph node. AA amyloid was present in the blood vessels. Within 60 days after excision of the mass, the systemic symptoms subsided, laboratory signs of inflammatory activity disappeared and IL-6 serum concentration returned to normal, thus establishing a causal relationship between the localized Castleman's disease, elevated IL-6 concentration and the chronic inflammation responsible for AA amyloidosis. At 10 months of follow-up, the nephrotic syndrome has reversed, kidney function has slowly ameliorated, and the patient has gained 12 kg. Abdominal fat aspirates drawn to search for amyloid, positive before surgery, were subsequently negative. The latter finding, and the remission of the nephrotic syndrome, provided strong evidence for regression of the amyloid deposits. However, the HBsAg-anti-HBsAg immune complexes and depression of T-helper cell activity persist. This immunological derangement is therefore not a consequence of CD. Chronic stimulation of the immune system due to the patient's inability to eliminate HBV, in the contest of perturbed immunity, may have favored the genesis of the lymphadenopathy.

Adult↗
PubMed1994

AL amyloidosis. Characterization of amyloidogenic cells by anti-idiotypic monoclonal antibodies.

BACKGROUND: AL amyloidosis is characterized by systemic tissue deposition of monoclonal Ig light chains synthesized by a bone marrow plasma cell (PC) clone whose biologic characteristics remain undetermined. EXPERIMENTAL DESIGN: Anti-idiotypic (anti-Id) monoclonal antibodies (MoAbs) were used as specific probes to identify and study amyloidogenic cells in two patients by means of immunofluorescence methods. These MoAbs recognized populations of bone marrow pre-PC, PC, and peripheral blood lymphocytes. To test whether the circulating Id+ lymphocytes were capable of PC differentiation, peripheral blood lymphocytes were incubated with the differentiation-inducing agents, interleukin-3 and interleukin-6 in liquid culture. Preincubation with the anti-Id MoAb and complement was used to inhibit formation of Id+PC in vitro. RESULTS: The anti-Id MoAb identified three types of cells in the bone marrow with cytoplasmic Ig having the same isotype as the monoclonal component: a) lymphoid cells, that were slightly larger than common peripheral blood lymphocytes (47% CD45RA+, 28% CD45R0+, 97% CD38-, 100% CD10-, 100% mu-chain-); b) lymphoplasmacytoid cells with more abundant cytoplasm and Id+ Ig (CD45RA-, CD45RO-, CD10-, 53% CD38+); 3) mature PC that were very similar to normal PC in morphology and antigenic profile (CD38+, PCA1+, CD56-). A different picture was seen when anti-Id MoAb were used to detect peripheral blood Id+ elements: analysis revealed a population of mature resting surface Ig+ B lymphocytes. Circulating Id+ lymphocytes differentiated in vitro to PC and lymphoplasmacytoid cells that were very similar to those present in the bone marrow. A significant reduction in the number of Id+ PC was obtained after incubation with the anti-Id MoAb and complement. CONCLUSIONS: This study shows that the amyloidogenic cell clone is constituted by at least the following cell populations: a fraction of bone marrow cells (lymphoid, lymphoplasmacytoid cells and PC) and a subset of peripheral blood post-switched B lymphocytes. The results suggest a relationship among these cells, indicating that circulating Id+ lymphocytes may be the possible precursors of the more differentiated bone marrow population.

Amyloidosis↗
PubMed1993

Acute phase proteins and prognosis in multiple myeloma.

Serum IL-6 levels have been shown to correlate with disease severity and prognosis in patients with plasma cell dyscrasias. Among its pleiotropic actions, IL-6 is also the major regulator of the acute phase response in humans. The possible impact on survival of the major serum acute phase proteins (s.APP) [C-reactive protein (s.CRP), alpha-1-antitrypsin (s.AAT), haptoglobin, acid alpha-1-glycoprotein and alpha-2-macroglobulin (used as control)] was assessed on a population of 103 consecutive, previously untreated myeloma patients. Univariate analysis showed that among the acute phase proteins only s.AAT (P = 0.015) and s.CRP (P = 0.027) were significantly correlated with survival. The multivariate Cox proportional hazard model applied to s.APP and other common parameters showed that s.beta-2-microglobulin (s.b2M), s.calcium, s.creatinine, BM plasma cell percentage, age and s.AAT correlated significantly with survival. Combining s.b2M and s.AAT allowed stratification of myeloma patients: those with low levels of s.b2M (< or = 3 mg/l) and of s.AAT (< or = 3 g/l) presented an excellent prognosis (median survival exceeding 10 years) while those presenting higher values of the two parameters presented a median survival of 2.5 years (P = 0.002).

Acute-Phase Proteins↗
PubMed1993

Application of monoclonal anti-idiotypes in the study of AL amyloidosis: therapeutic implications.

A monoclonal anti-idiotyped antibody (IgG1k MAb 3B11D4) has been raised against the lambda-chain dimers isolated from the urine of a patient (DEP) with AL amyloidosis. This antibody binds a conformational idiotope present on the monoclonal DEP IgA, but does not recognize the reduced and alkylated lambda-chain monomers, nor the 15- to 17-kDa light chain fragments obtained from the amyloid fibrils, which have the same N-terminal sequence as the urinary light chains. The nonreactivity of this MAb with amyloid fibrils was confirmed by immunohistochemical examination of cryostatic sections of an amyloidoma surgically removed from the patient's subcutaneous tissue. Our data demonstrate that the deletion of about 70 amino acid residues of the C-terminus of the lambda chain prevents the formation of the self-limiting dimer and may facilitate the deposition of fragments into amyloid fibrils. With regard to the amyloidogenic clone, MAb 3B11D4 recognizes the plasma cell clone in bone marrow and 9% of circulating B lymphocytes. Panning and cytotoxicity experiments demonstrate that this antibody has the capability of selectively eliminating the idiotype-positive cells from peripheral blood. Antibodies with these properties could find application in a new therapeutic strategy which provides high-dose chemotherapy, total body irradiation, and rescue with circulating stem cells. These antibodies could be used in two distinct phases: first, in the purging of the stem cells to be infused from the amyloidogenic clone and, secondly, in an attempt to eliminate residual disease by intravenous infusion.

Amyloid↗
PubMed1992

Use of an anti-idiotypic monoclonal antibody in studying amyloidogenic light chains in cells, urine and fibrils: pathophysiology and clinical implications.

A monoclonal anti-idiotype antibody (IgG1k MoAb 3B11D4) raised against the amyloidogenic DEP lambda chain dimer binds a conformational idiotope also present on the monoclonal DEP IgA immunoglobulin. MoAb 3B11D4 does not recognize the reduced and alkylated lambda chain monomers, nor the 15-17-kDa fibrillar light chain fragments which have the same N-terminal sequence of the urinary light chains. The lack of about 70 amino acid residues of the C terminal of the protein prevents the formation of the self-limiting dimer and may facilitate the deposition of the fragments into amyloid fibrils. MoAb 3B11D4 recognizes the plasma cell clone in bone marrow and 9% of circulating B lymphocytes. Panning experiments demonstrate that this antibody has the capability to selectively eliminate the idiotype positive cells from peripheral blood. Antibodies with these characteristics could become a useful tool for better understanding the pathogenesis of the disease and for new therapeutic options.

Amino Acid Sequence↗
PubMed1991

Expression of housekeeping genes in Hodgkin's disease lymph nodes.

Housekeeping genes, particularly actin, tubulin, and the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH), are widely used to estimate the amount and integrity of RNA in Northern blotting. In this work, the most reliable housekeeping gene for gene expression analysis of Hodgkin's disease (HD) lymph nodes was determined by comparing the conventional housekeeping genes, beta-actin, beta-tubulin, GAPDH, and the mouse gene LLRep3, that had been used previously in gene expression studies. It was found that the amounts of mRNA in these genes are very heterogeneous in HD lymph nodes. In contrast, their expression was relatively constant in tonsils undergoing a chronic inflammatory process. It is concluded that none of the housekeeping genes tested is suitable for the fine quantitative analysis of gene expression in HD lymph nodes.

Actins↗
PubMed1990

Relevance of class, molecular weight and isoelectric point in predicting human light chain amyloidogenicity.

The ability to predict the amyloidogenicity of certain light chains may facilitate an earlier diagnosis of AL amyloidosis and, possibly, lead to more effective treatment. Using current methods, available in clinical chemistry laboratories, we assessed the class, the relative molecular mass (Mr) and the isoelectric point of urinary monoclonal light chains from 35 patients with AL amyloidosis (A+) and 51 without amyloidosis (A-). The light chain class (LCC) was lambda in 77% and 45% of A+ and A- patients, respectively. Light chain fragments (LCF) with low Mr (12-18 x 10(3) were detected in the urine of 30/35 A+ patients and in 15/51 A- ones. The mean (SD) isoelectric point (pI) of A+ light chains was 4.8 (1.1) while in A- patients it was 6.2 (1.6). Univariate analysis showed significant differences between the two groups for the three parameters. Discriminant analysis gave a function which allowed a correct allocation of 81% of the cases between the two groups.

Amyloidosis↗
PubMedDate not supplied

Specificity and variable region cDNA sequence of an isogeneic monoclonal antiidiotype to an anti-alpha(1----6)dextran.

We have characterized a monoclonal isogeneic antiidiotype, IdB5.7, from a BALB/c mouse immunized with the anti-alpha(1----6)dextran C57BL/6 45.21.1. It defined a hapten-inhibitable idiotope expressed on four of the 2 myeloma and 37 hybridoma anti-alpha(1----6)dextrans tested. Sequence comparison of Id+ and Id- anti-alpha(1----6)dextrans suggested that two extra amino acids at VH 100A and 100B and different residues at VH 101 abolish the expression of the idiotope in the Id- anti-alpha(1----6)dextrans. Sequence analysis of the VH of IdB5.7 showed a CDR1 longer than usual and a D segment in CDR3 formed by the fusion of two D minigenes. The IdB5.7 V kappa uses the V kappa 1 germline gene K5.1 with a few substitutions. The D-D fusion in VH CDR3 is a feature which has been reported in several other antiidiotypic antibodies.

Amino Acid Sequence↗
PubMedDate not supplied

Gene expression of pyrogenic cytokines in Hodgkin's disease lymph nodes.

BACKGROUND: Inflammatory cytokines released by either the neoplastic or reactive cells in Hodgkin's disease (HD) might mediate its peculiar clinical and histopathological features. We investigated by Northern blotting the gene expressions of the pyrogenic and inflammation-associated cytokines IL-1 alpha, IL-1 beta, TNF-alpha, TNF-beta (lymphotoxin) and IL-6 in 14 HD lymph nodes and studied their relation to systemic symptoms (B symptoms). METHODS: Two ug of poly(A)+RNA from 14 HD lymph nodes (8 from symptomatic and 6 from asymptomatic patients, of different histological type and disease stage) were subjected to agarose electrophoresis, Northern blotted and hybridized to the various cytokine cDNA probes. RESULTS: The inflammatory cytokines were expressed very heterogenously in HD, even in lymph nodes with the same histological type and with similar stromal inflammatory reactions. IL-1 beta was increased about 2 to 10 times in 5 of 8 lymph nodes from patients with B symptoms, whereas the other cytokines were heterogenously expressed in both symptomatic and asymptomatic patients. Statistical analysis on densitometric values demonstrated that the difference in IL-1 beta expression between symptomatic and asymptomatic patients was significant (p less than 0.02). CONCLUSIONS: These results support the hypothesis of increased IL-1 levels in tumoral lymph nodes from symptomatic HD patients.

Cytokines↗