African American Patients' Psychosocial Support Needs and Barriers to Treatment: Patient Needs Assessment.

This study assessed adult patient's psychosocial support needs and treatment barriers in an urban diverse cancer center. A needs assessment was conducted with a convenience sample of adult oncology patients (n = 113; 71.7 % African American). Most patients were parenting school-age children and worried about them (96 %); 86.7 % would attend a family support program. Among patients who were married or partnered (68 %), 63.7 % were concerned about communication, coping, and emotional support; 53.9 % would attend a couple support program. Patients identified similar treatment barriers: transportation, babysitting for younger children, convenience of time/place, and refreshments. Findings suggest that behavioral health care providers should be available to screen cancer patients and improve access to appropriate psychosocial oncology support programs.

The combination of bendamustine, bortezomib, and rituximab for patients with relapsed/refractory indolent and mantle cell non-Hodgkin lymphoma.

Given the significant activity and tolerability of bendamustine, rituximab, and bortezomib in patients with relapsed indolent and mantle cell non-Hodgkin lymphoma, and laboratory studies suggesting synergistic activity, we conducted a multicenter phase 2 study of the bendamustine/bortezomib/rituximab combination. Patients with relapsed or refractory indolent and mantle cell lymphoma with adequate organ function were treated with bendamustine 90 mg/m² days 1 and 4; rituximab 375 mg/m² day 1, and bortezomib 1.3 mg/m² days 1, 4, 8, 11. Six 28-day cycles were planned. Thirty patients (7 with mantle cell lymphoma) were enrolled and treated. Eight patients experienced serious adverse events, including one event of grade 5 sepsis. Common nonhematologic adverse events were generally grade 1 or grade 2 and included nausea (50%), neuropathy (47%), fatigue (47%), constipation (40%), and fever (40%). Of 29 patients evaluable for efficacy, 24 (83%) achieved an objective response (including 15 with complete response). With median follow-up of 24 months, 2-year progression-free survival is 47% (95% confidence interval, 25%-69%). On the basis of these promising results, the US cooperative groups have initiated randomized trials to evaluate this regimen in follicular and mantle cell lymphoma. This trial was registered at www.clinicaltrials.gov as #NCT00547534.

Rituximab immunotherapy results in the induction of a lymphoma idiotype-specific T-cell response in patients with follicular lymphoma: support for a "vaccinal effect" of rituximab.

The incorporation of rituximab, a chimeric anti-CD20 monoclonal antibody, into the therapeutic armamentarium for patients with follicular lymphoma (FL) has significantly improved treatment outcome for such patients. Despite the almost universal application of this therapy, however, its exact mechanism of action has not been completely defined. One proposed mechanism is that of a "vaccinal" effect, whereby FL cell kill by rituximab results in the elicitation of an FL-specific T-cell response. The demonstration that rituximab can even elicit such a response in patients has, to our knowledge, never been shown. We analyzed the response against the immunoglobulin expressed by the FL before and after rituximab monotherapy in 5 FL patients and found an increase in FL idiotype-specific T cells after rituximab in 4 of 5 patients. Our data thus provide "proof of principle" for the ability of passive immunotherapy with rituximab to elicit an active FL-specific cellular response.

Susceptibility to autoimmunity and B cell resistance to apoptosis in mice lacking androgen receptor in B cells.

Estrogens have been linked to a higher female incidence of autoimmune diseases. The role of androgen and the androgen receptor (AR) in autoimmune diseases, however, remains unclear. Here we report that the lack of AR in B cells in different strains of mice, namely general AR knockout, B cell-specific AR knockout, and naturally occurring testicular feminization mutation AR-mutant mice, as well as castrated wild-type mice, results in increased B cells in blood and bone marrow. Analysis of the targeted mice, together with bone marrow transplantation using Rag1(-/-) recipients, overexpression of retrovirally encoded AR-cDNA, and small interfering RNA-mediated AR mRNA knockdown approaches also show that the B cell expansion results from resistance to apoptosis and increased proliferation of bone marrow precursor B cells, accompanied by changes in several key modulators related to apoptosis, such as Fas/FasL signals, caspases-3/-8, nuclear factor-kappaB, and Bcl-2. We also show that the effects of AR loss are, in part, B cell intrinsic. Mice bearing AR-deficient B cells show increased levels of serum IgG2a and IgG3 as well as basal double-stranded DNA-IgG antibodies and are more vulnerable to development of collagen-induced arthritis. Together, these data indicate that androgen/AR play a crucial role in B cell homeostasis and tolerance. Therapies targeting AR might provide an alternative strategy with which to battle autoimmune diseases.

High-risk acute lymphoblastic leukemia cells with bcr-abl and INK4A/ARF mutations retain susceptibility to alloreactive T cells.

INK4A/ARF mutations are acquired in bcr/abl(+) lymphoid blast phase chronic myelogenous leukemia (CML) and bcr/abl(+) acute lymphoblastic leukemia (ALL). Donor lymphocyte infusion and graft-versus-leukemia (GVL) are generally ineffective in such ALLs, whereas GVL is highly active against bcr/abl(+) CML, which does not have a lesion in the INK4A/ARF locus. The mechanisms for the ineffectiveness of GVL are not fully known, and it is possible that intrinsic resistance of acute lymphoid leukemias to immune effectors associated with allogeneic GVL may contribute to ineffectiveness. This work tested the hypothesis that INK4A/ARF mutations that are associated with transformation of bcr/abl(+) CML to an ALL phenotype, and that are associated with increased resistance to apoptosis render ALL cells insensitive to allogeneic immune responses to minor histocompatibility antigens (mHA). Murine acute pre-B ALLs were induced by transfer of the human p210 bcr/abl gene into bone marrow of INK4A/ARF null mice. These ALL lines were then studied in a murine model of MHC-matched, mHA-mismatched allogeneic BMT. In vivo growth of these ALLs was inhibited in allogeneic transplants characterized by active allogeneic immune responses compared to their behavior in syngeneic transplants. In vitro ALLs with INK4A/ARF, p210 bcr/abl, or p190 bcr/abl mutations remained sensitive to anti-mHA cytolytic T cells. In addition, the ALLs were capable of inducing primary immune responses to mHAs in vivo. Thus, ALLs with INK4A/ARF or bcr/abl mutations are not intrinsically resistant to allogeneic T cell responses, suggesting that active immunotherapies against mHA have the potential to control such acute lymphoblastic leukemias.

Truncated immunoglobulin Dmu causes incomplete developmental progression of RAG-deficient pro-B cells.

Early stages of B cell development are dependent on the expression of a pre-B cell receptor (BCR), composed of a mu heavy chain (HC) in association with surrogate light chain (SLC) proteins and the signaling molecules, Igalpha and Igbeta. During the formation of the variable region of the mu chain by somatic gene rearrangement, a truncated form of the mu protein (called Dmu) is sometimes produced by the rearrangement of a D(H) segment to a J(H) segment using one of three reading frames (designated rf2). When a Dmu protein is formed, subsequent B cell development is blocked by down-regulation of further HC rearrangements, so that a full-length muHC cannot be formed. In this study, we demonstrate that in recombinase activating gene (RAG)-2-deficient B220(+) CD43(+) pro-B cells in which B lymphopoiesis has been arrested at fraction C, transgenic expression of Dmu promoted partial developmental progression to fraction C', but was unable to mediate the pro-B to pre-B cell transition to fraction D effected by full-length muHC protein. These data suggest that the intracellular signaling pathways engaged by the Dmu pre-BCR are insufficient to facilitate the expansion and/or survival of pre-B cells, and are distinct from those engaged by the pre-BCR-containing full-length muHC.

Analysis of lymphocyte development and function using the RAG-deficient blastocyst complementation system.

The RAG-deficient blastocyst complementation system (RBCS) represents a flexible and rapid method for the genetic analysis of lymphocyte function using a gene-targeting approach. In chimeras derived from manipulated embryonic stem cells injected into VDJ recombination-incapable, RAG-deficient blastocysts, any lymphoid cells past the prolymphocytic stage will be embryonic stem cell-derived. This approach can therefore bypass pitfalls such as pleiotropy and embryonic lethality to allow the analysis of targeted gene mutations with respect to lymphocyte development and function in a genetically uniform cell population. Thanks to recent advances in targeting techniques and in mouse embryo manipulation, this remarkably efficient technique has become a highly feasible and useful addition to any immunology research program. In this review, we discuss the technical aspects of the procedure, as well as its advantages and drawbacks compared to alternative approaches, and our practical experience in establishing the system at the University of Rochester.

9G4 autoreactivity is increased in HIV-infected patients and correlates with HIV broadly neutralizing serum activity.

The induction of a broadly neutralizing antibody (BNAb) response against HIV-1 would be a desirable feature of a protective vaccine. Vaccine strategies thus far have failed to elicit broadly neutralizing antibody responses; however a minority of HIV-infected patients do develop circulating BNAbs, from which several potent broadly neutralizing monoclonal antibodies (mAbs) have been isolated. The findings that several BNmAbs exhibit autoreactivity and that autoreactive serum antibodies are observed in some HIV patients have advanced the possibility that enforcement of self-tolerance may contribute to the rarity of BNAbs. To examine the possible breakdown of tolerance in HIV patients, we utilized the 9G4 anti-idiotype antibody system, enabling resolution of both autoreactive VH4-34 gene-expressing B cells and serum antibodies. Compared with healthy controls, HIV patients had significantly elevated 9G4+ serum IgG antibody concentrations and frequencies of 9G4+ B cells, a finding characteristic of systemic lupus erythematosus (SLE) patients, both of which positively correlated with HIV viral load. Compared to the global 9G4-IgD--memory B cell population, the 9G4+IgD--memory fraction in HIV patients was dominated by isotype switched IgG+ B cells, but had a more prominent bias toward "IgM only" memory. HIV envelope reactivity was observed both in the 9G4+ serum antibody and 9G4+ B cell population. 9G4+ IgG serum antibody levels positively correlated (r = 0.403, p = 0.0019) with the serum HIV BNAbs. Interestingly, other serum autoantibodies commonly found in SLE (anti-dsDNA, ANA, anti-CL) did not correlate with serum HIV BNAbs. 9G4-associated autoreactivity is preferentially expanded in chronic HIV infection as compared to other SLE autoreactivities. Therefore, the 9G4 system provides an effective tool to examine autoreactivity in HIV patients. Our results suggest that the development of HIV BNAbs is not merely a consequence of a general breakdown in tolerance, but rather a more intricate expansion of selective autoreactive B cells and antibodies.

Requirement for enhancer specificity in immunoglobulin heavy chain locus regulation.

The intronic Emicro enhancer has been implicated in IgH locus transcription, VDJ recombination, class switch recombination, and somatic hypermutation. How Emicro controls these diverse mechanisms is still largely unclear, but transcriptional enhancer activity is thought to play a central role. In this study we compare the phenotype of mice lacking the Emicro element (DeltaEmicro) with that of mice in which Emu was replaced with the ubiquitous SV40 transcriptional enhancer (SV40eR mutation) and show that SV40e cannot functionally complement Emu loss in pro-B cells. Surprisingly, in fact, the SV40eR mutation yields a more profound defect than DeltaEmicro, with an almost complete block in micro0 germline transcription in pro-B cells. This active transcriptional suppression caused by enhancer replacement appears to be specific to the early stages of B cell development, as mature SV40eR B cells express micro0 transcripts at higher levels than DeltaEmicro mice and undergo complete DNA demethylation at the IgH locus. These results indicate an unexpectedly stringent, developmentally restricted requirement for enhancer specificity in regulating IgH function during the early phases of B cell differentiation, consistent with the view that coordination of multiple independent regulatory mechanisms and elements is essential for locus activation and VDJ recombination.

The relationship of FcgammaRIIIa genotype to degree of B cell depletion by rituximab in the treatment of systemic lupus erythematosus.

OBJECTIVE: Despite wide use of the anti-CD20 monoclonal antibody rituximab in the treatment of B cell lymphomas, the mechanism by which it causes B cell depletion remains a subject of controversy. As part of an ongoing phase I/II trial of rituximab in the treatment of systemic lupus erythematosus (SLE), we sought to determine whether the effectiveness of B cell depletion was influenced by polymorphisms of Fc receptors (FcR) on effector cells. METHODS: During rituximab treatment of 12 SLE patients, B cell depletion was monitored as a function of the serum rituximab level and FcgammaRIIa and FcgammaRIIIa genotypes at baseline and at 1 month and 2 months after treatment. FcR genotypes were determined by polymerase chain reaction. Serum levels of rituximab were measured by enzyme-linked immunosorbent assay (ELISA). B lymphocyte percentages were assessed by flow cytometry. RESULTS: B cell depletion was highly variable in this patient cohort, with B cell percentages at the 1-2-month posttreatment nadir ranging from undetectable (<0.1 cell/microl) to 16% ( approximately 30 cells/microl) of the total peripheral blood lymphocytes. At 2 months posttreatment, B cell percentages were highly correlated with both the serum rituximab level and the FcgammaRIIIa genotype (R(2) = 0.75, P = 0.002). The FcgammaRIIIa genotype was a significant independent predictor of the efficacy of B cell depletion (P = 0.019). CONCLUSION: These results highlight the potential variability of B cell depletion by rituximab in the treatment of autoimmune disease and indicate that Fc receptors are an important determinant of that variability. The findings further suggest the importance of antibody-dependent cell-mediated cytotoxicity and/or apoptosis induction via FcgammaRIIIa-expressing effector cells in the mechanism of B cell depletion by this widely used monoclonal antibody.

A new murine model of humoral immuno-deficiency specifically affects class switching to T-independent antigens.

Immunoglobulin (Ig) isotype deficiencies are among the most common and least characterized humoral immunodeficiencies. A thorough understanding of their immunological and genetic features has been hampered by their extreme heterogeneity and the paucity of suitable animal models. Here, we report the initial characterization of a new mouse model with selective Ig deficiency. SENCARA mice display low serum IgG3 levels as well as severely deficient IgG3 responses to T cell-independent (TI) type 1 and 2 antigens. However, despite the significant block in class switching, expression of activation-induced deaminase and gamma3 germ-line transcription after TI antigen immunization are normal. IgG3 production in response to in vitro LPS stimulation was also normal, ruling out a specific defect in the Cgamma3 switch machinery. A decrease in the number of peritoneal B1a cells and enlarged splenic marginal zones were observed. The immunodeficiency is inherited as an autosomal, semi-dominant, essentially monogenic trait in SENCARA x C57BL/6 crosses. The SENCARA humoral immunodeficiency constitutes a novel immune phenotype, resembling human conditions such as IgG2 deficiency. This new mouse model will be of interest for the understanding of mechanisms involved in TI immune responses and may provide new insights into the molecular basis of human Ig deficiencies.

B cell depletion as a novel treatment for systemic lupus erythematosus: a phase I/II dose-escalation trial of rituximab.

OBJECTIVE: Safer and more effective therapies are needed for the treatment of systemic lupus erythematosus (SLE). B lymphocytes have been shown to play fundamental pathogenic roles in SLE, and therefore, elimination of B cells with the use of rituximab may represent a new therapy for SLE. METHODS: A phase I/II dose-escalation trial of rituximab added to ongoing therapy in SLE was conducted. Rituximab was administered as a single infusion of 100 mg/m2 (low dose), a single infusion of 375 mg/m2 (intermediate dose), or as 4 infusions (1 week apart) of 375 mg/m2 (high dose). CD19+ lymphocytes were measured to determine the effectiveness of B cell depletion. The Systemic Lupus Activity Measure (SLAM) score was used as the primary outcome for clinical efficacy. RESULTS: Rituximab was well tolerated in this patient population, with most experiencing no significant adverse effects. Only 3 serious adverse events, which were thought to be unrelated to rituximab administration, were noted. A majority of patients (11 of 17) had profound B cell depletion (to <5 CD19+ B cells/microl). In these patients, the SLAM score was significantly improved at 2 and 3 months compared with baseline (P = 0.0016 and P = 0.0022, respectively, by paired t-test). This improvement persisted for 12 months, despite the absence of a significant change in anti-double-stranded DNA antibody and complement levels. Six patients developed human antichimeric antibodies (HACAs) at a level > or =100 ng/ml. These HACA titers were associated with African American ancestry, higher baseline SLAM scores, reduced B cell depletion, and lower levels of rituximab at 2 months after initial infusion. CONCLUSION: Rituximab therapy appears to be safe for the treatment of SLE and holds significant therapeutic promise, at least for the majority of patients experiencing profound B cell depletion. Based on these results, controlled trials of rituximab appear to be warranted.