Initiation of extracorporeal photopheresis in lung transplant patients with mild to moderate refractory BOS: A single-center real-life experience.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) is the main limitation to long-term survival following lung transplantation. Several studies generated promising results regarding the efficacy of extracorporeal photopheresis (ECP) in BOS management. We aimed to compare FEV1 evolution in ECP-treated versus non-ECP treated patients among BOS recipients. METHODS: Overall, 25 BOS patients were included after receiving optimized treatment. Data were collected retrospectively. Twelve patients with moderate and refractory BOS received ECP treatment. RESULTS: Among non-ECP treated control patients (n = 13), six experienced persistent decline without undergoing ECP for various reasons. ECP stabilized pre-ECP lung function during the subsequent 6 to 24 months (repeated measures one-way Anova, p = 0.002), without any significant impact observed by either FEV1 decline speed prior to ECP or time between BOS diagnosis and ECP onset. ECP-treated patients displayed a similar risk of an additional permanent 20% or higher drop in FEV1 after BOS onset compared to controls, but a lower risk compared to control decliners (p = 0.05). ECP quickly stabilized FEV1 decline in refractory BOS patients compared to non-treated decliners. CONCLUSIONS: We confirmed that this therapeutic option against refractory BOS can be managed in a medium-size LTx center, with a satisfactory efficacy and an acceptable tolerance.

Impact of rituximab on stem cell mobilization following ACVBP regimen in poor-risk patients with diffuse large B-cell lymphoma: results from a large cohort of patients.

BACKGROUND: The ACVBP regimen is an efficient induction regimen for poor-risk patients with diffuse large B-cell lymphoma (DLBCL) before consolidative autologous stem cell transplantation. Adjunction of the monoclonal anti-CD20 antibody rituximab (R-ACVBP) was recently found to be superior to ACVBP alone. This study assessed the impact of rituximab on stem cell mobilization in two similar consecutive groups of patients treated with ACVBP in two prospective, controlled trials. STUDY DESIGN AND METHODS: The first trial (LNH-98B-3) involved 137 patients treated with ACVBP alone. In the second trial (LNH-03-3B), 91 patients received an R-ACVBP regimen. Stem cell mobilization was performed after a course of (R)-ACVBP. RESULTS: The median peak numbers of blood CD34+ cell counts recorded before the first apheresis procedure in the ACVBP and R-ACVBP groups were 69×10(6) and 63×10(6) /L, respectively (p=0.55). The median numbers of CD34+ cells collected were 7.1×10(6) and 6.0×10(6) CD34+ cells/kg for the ACVBP and R-ACVBP groups, respectively (p=0.13). The median number of apheresis procedures required for gathering the minimum amount of CD34+ cells (2×10(6) /kg) was the same in the two groups. CONCLUSION: When compared with ACVBP alone, adjunction of rituximab does not impair stem cell mobilization.

Involvement of Fc gamma RI (CD64) in the mechanism of HIV-1 inhibition by polyclonal IgG purified from infected patients in cultured monocyte-derived macrophages.

The aim of this study was to investigate the mechanism of HIV-1 neutralization using monocyte-derived macrophages (MDM) in comparison to PBMC as target cells. For this purpose, we analyzed neutralizing activities of different human polyclonal IgG samples purified from sera of HIV-1-infected individuals using a single cycle infection assay. We found an increase of the neutralizing titer when macrophages vs PBMC were used as target cells. Moreover, polyclonal IgG from HIV-1-infected patients that are not able to neutralize virus when PBMC are used as target cells strongly inhibit MDM infection. Similar results were obtained with neutralizing mAbs. To explore the participation of FcgammaRs in HIV-1 inhibition, F(ab')(2) and Fab of these Igs were produced. Results indicated that both F(ab')(2) and Fab are less effective to inhibit virus replication in MDM. Moreover, competition experiments with Fc fragments of IgG from healthy donors or with purified monoclonal anti-human FcgammaRs Ab strengthen the participation of the FcgammaRs, and in particular of FcgammaRI (CD64) in HIV-1 inhibition on MDM. Mechanisms by which HIV-specific IgG inhibit virus replication in cultured macrophages are proposed and the benefit of inducing such Abs by vaccination is discussed.

Activation of human macrophages by allogeneic islets preparations: inhibition by AOP-RANTES and heparinoids.

During transplantation, pancreatic islets release chemokines which promote macrophage attraction, hampering engraftment of islets. The aim of this study was to modulate chemotaxis and the immune response of human macrophages induced by islets. Human monocyte-derived macrophages of healthy subjects were exposed to supernatants of human islets. Chemotaxis, tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) release were evaluated. To modulate migration, human macrophages were incubated in the presence of aminooxypentane-regulated on activation, normal, T-cell expressed, and secreted (AOP-RANTES), a potent antagonist of CCR5. Chemotactic activity of islets supernatant was modulated by the addition of heparin or heparinoids [pentosan and calix[8S]arene (C8S)]. AOP-RANTES significantly reduced, in a dose-dependent manner, macrophage chemotaxis and cytokine release induced by islets supernatant. The chemotactic index was reduced from 3.05 +/- 0.27 to 0.71 +/- 12, TNF-alpha from 1205 +/- 52 to 202 +/- 12 pg/ml, and IL-1beta from 234 +/- 12 to 10 +/- 6 pg/ml. The trapping of chemokines by heparinoids reduced the chemotactic activity of islets supernatant from 3.05 +/- 0.27 to 1.2 +/- 0.1 with heparin or pentosan and to 1.72 +/- 0.22 with C8S, and also decreased the TNF-alpha release by human macrophages from 1205 +/- 35 to 1000 +/- 26 (C8S), 250 +/- 21 (heparin) and 320 +/- 19 (pentosan) pg/ml, and IL-1beta from 234 +/- 13 to 151 +/- 5 (C8S), 50 +/- 3 (heparin) and 57 +/- 4 (pentosan) pg/ml. In conclusion, AOP-RANTES and heparinoids inhibit human macrophage activation and migration induced by islets supernatant.

Dendritic cell susceptibility to hepatitis C virus genotype 1 infection.

In vitro infection of human monocyte-derived dendritic cells was carried out to study their susceptibility to hepatitis C virus (HCV) infection. Immature dendritic cells and mature dendritic cells were incubated overnight at 37 degrees C with HCV-positive (genotype 1) serum samples; the presence of the viral genome associated with the production of its replicative intermediate was used as evidence of infection. In immature dendritic cells, HCV RNA was detectable from days 1-10 post-infection (p.i.), and de novo synthesis of negative-strand HCV RNA could be demonstrated by a strand-specific rTth reverse transcription-polymerase chain reaction at day 2. In mature dendritic cells, the positive-strand form was detectable from days 1-5 p.i., while the negative-strand HCV RNA appeared at days 1 and 2 p.i. Quasispecies present in the inoculum and 6 days p.i. were analyzed by sequencing hypervariable region 1 of the E2 protein. Only two of seven HVR variants present in the inoculum were found in HCV-infected immature dendritic cells. Another two HVR variants not found in the inoculum were recovered from infected immature dendritic cells, suggesting serum minor variants selection or virus evolution during in vitro replication. Analysis by single-strand conformation polymorphism assay of 5' untranslated region of HCV sequences showed that the patterns obtained from the inoculum and infected immature dendritic cells and mature dendritic cells differed slightly. These findings indicate that both immature dendritic cells and mature dendritic cells are susceptible to HCV genotype 1 infection, supporting at least HCV RNA replication. This model should be a valuable tool for the study of modulation of dendritic cell functions in HCV infection.

Heat shock proteins 70 and 60 share common receptors which are expressed on human monocyte-derived but not epidermal dendritic cells.

Priming of CTL by means of heat shock proteins (hsp) is dependent on antigen-presenting cells (APC), which present the hsp-associated peptides, via their cell surface MHC class I molecules, toCD8(+) T cells. It has not yet been established how human (hu) hsp70 interacts with the major (hu)APC, the dendritic cells (DC). Here we show that (hu)hsp70 is specifically internalized intoCD14(-), Toll-like receptor 4(-) monocyte-derived (hu)DC by receptor-mediated endocytosis. We further demonstrate that (hu)hsp70 and (hu)hsp60 share the same receptors on (hu)monocyte-derived DC. Both molecules as well as MHC class I molecules are spontaneously internalized and reach the MHC class II-enriched compartments. Finally, freshly isolated (hu) epidermal Langerhans cells (LC), the DC of the skin, as well as CD34(+)-derived LC do not bind hsp60 or hsp70. Given the likely importance of the internalization of hsp70 by APC in the induction of the immune responses, the finding that hsp60 and hsp70 are internalized through the same receptor(s) may explain why microbial hsp60 represents a major T cell antigen. This may rationalize the use of microbial hsp60 to prime immune responses against microbes. The lack of hsp60/70 receptors on epidermal LC raises the crucial question as to whether absence of priming of the skin and mucosal immune systems by hsp-polypeptide complexes could account for some tissue-specific diseases. This work also points to a potential advantage of using monocyte-derived DC in human immunotherapeutic applications of hsp60/70.