Chronic lymphocytic leukemia cells bind and present the erythrocyte protein band 3: possible role as initiators of autoimmune hemolytic anemia

Unusual complications in the management of chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a common, indolent disease that typically presents with a proliferation of mature, immunologically dysfunctional CD5+ B-cells which preferentially occupy the bone marrow, peripheral blood and lymphoid organs. Immune dysfunction leads to an increase in autoimmune diseases which occur in approximately 10% of patients with CLL. Autoimmune cytopenias are the most common, but other organs may be affected as well. The treatment of these conditions typically depends on the extent of CLL and severity of symptoms, but generally consists of CLL-directed therapies, immunosuppression or both. CLL may also infiltrate extranodal sites in the body. Symptomatic extranodal CLL or extranodal disease which threatens normal organ function is an indication for initiation of CLL-directed therapy. The following review summarizes autoimmune and extranodal complications that can occur in patients with CLL and our suggested approach to their treatment.

Autoimmune Cytopenia in CLL: Prognosis and Management in the Era of Targeted Therapies

ABSTRACT

Chronic lymphocytic leukemia (CLL) is frequently associated with autoimmune hemolytic anemia and immune thrombocytopenia and, less frequently, with pure red cell aplasia and immune neutropenia. The emergence of these complications is related to an intertwined and complex relationship between patient, disease, and treatment characteristics. The prognostic repercussion of autoimmune cytopenia (AIC) in patients with CLL mainly depends on its response to therapy. For patients with AIC and nonactive CLL, treatment is as in primary, uncomplicated AIC, keeping in mind that no response is an indication for CLL therapy. The success of treating active CLL-related AIC widely relies on a flexible strategy that should include initial therapy with corticosteroids and a rapid shift to effective CLL therapy in nonresponding patients. Targeted therapies (e.g., ibrutinib) that have already demonstrated to be effective in CLL-related AIC will likely offer a unique possibility of treating both AIC and CLL as a single target.

Autoimmune Complications in Chronic Lymphocytic Leukemia in the Era of Targeted Drugs

Autoimmune phenomena are frequently observed in patients with chronic lymphocytic leukemia (CLL) and are mainly attributable to underlying dysfunctions of the immune system. Autoimmune cytopenias (AIC) affect 4-7% of patients with CLL and mainly consist of autoimmune hemolytic anemia and immune thrombocytopenia. Although less common, non-hematological autoimmune manifestations have also been reported. Treatment of CLL associated AIC should be primarily directed against the autoimmune phenomenon, and CLL specific therapy should be reserved to refractory cases or patients with additional signs of disease progression. New targeted drugs (ibrutinib, idelalisib and venetoclax) recently entered the therapeutic armamentarium of CLL, showing excellent results in terms of efficacy and became an alternative option to standard chemo-immunotherapy for the management of CLL associated AIC. However, the possible role of these drugs in inducing or exacerbating autoimmune phenomena still needs to be elucidated. In this article, we review currently available data concerning autoimmune phenomena in patients with CLL, particularly focusing on patients treated with ibrutinib, idelalisib, or venetoclax, and we discuss the possible role of these agents in the management of AIC.

Autoimmune Cytopenias in Chronic Lymphocytic Leukemia: Focus on Molecular Aspects

Autoimmune cytopenias, particularly autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP), complicate up to 25% of chronic lymphocytic leukemia (CLL) cases. Their occurrence correlates with a more aggressive disease with unmutated VHIG status and unfavorable cytogenetics (17p and 11q deletions). CLL lymphocytes are thought to be responsible of a number of pathogenic mechanisms, including aberrant antigen presentation and cytokine production. Moreover, pathogenic B-cell lymphocytes may induce T-cell subsets imbalance that favors the emergence of autoreactive B-cells producing anti-red blood cells and anti-platelets autoantibodies. In the last 15 years, molecular insights into the pathogenesis of both primary and secondary AIHA/ITP has shown that autoreactive B-cells often display stereotyped B-cell receptor and that the autoantibodies themselves have restricted phenotypes. Moreover, a skewed T-cell repertoire and clonal T cells (mainly CD8+) may be present. In addition, an imbalance of T regulatory-/T helper 17-cells ratio has been involved in AIHA and ITP development, and correlates with various cytokine genes polymorphisms. Finally, altered miRNA and lnRNA profiles have been found in autoimmune cytopenias and seem to correlate with disease phase. Genomic studies are limited in these forms, except for recurrent mutations of KMT2D and CARD11 in cold agglutinin disease, which is considered a clonal B-cell lymphoproliferative disorder resulting in AIHA. In this manuscript, we review the most recent literature on AIHA and ITP secondary to CLL, focusing on available molecular evidences of pathogenic, clinical, and prognostic relevance.

Inflammatory myopathies and lymphoma

The inflammatory myopathies comprise a group of immune-mediated muscle diseases. Lymphoma is a term for a variety of lymphatic system malignancies. Autoimmune diseases and lymphoproliferative malignancies share a complex bidirectional relationship. A causal relationship between inflammatory mypathies and lymphoma has not been established. The diagnosis/treatment of inflammatory myopathy usually precedes the detection/diagnosis of lymphoma. Immune system dysregulation presumably underlies the evolution of lymphoma in patients with inflammatory myopathies. Inflammatory activity with chronic B-cell activation and/or antigen stimulation is deemed the major risk factor for lymphoma in patients with autoimmunity. A "paraneoplastic" phenomenon or the effects of immunosuppressive therapy may be alternative immune-based mechanisms. In chronic lymphocytic leukemia immune system disturbance rarely results in non-hematological autoimmune disease, including inflammatory myopathies.

Desiccating stress-induced disruption of ocular surface immune tolerance drives dry eye disease

Dry eye is an allegedly autoimmune disorder for which the initiating mechanisms and the targeted antigens in the ocular surface are not known, yet there is extensive evidence that a localized T helper type 1 (Th1)/Th17 effector T cell response is responsible for its pathogenesis. In this work, we explore the reconciling hypothesis that desiccating stress, which is usually considered an exacerbating factor, could actually be sufficient to skew the ocular surface's mucosal response to any antigen and therefore drive the disease. Using a mouse model of dry eye, we found that desiccating stress causes a nuclear factor kappa B (NF-κB)- and time-dependent disruption of the ocular surface's immune tolerance to exogenous ovalbumin. This pathogenic event is mediated by increased Th1 and Th17 T cells and reduced regulatory T cells in the draining lymph nodes. Conversely, topical NF-κB inhibitors reduced corneal epithelial damage and interleukin (IL)-1β and IL-6 levels in the ocular surface of mice under desiccating stress. The observed effect was mediated by an augmented regulatory T cell response, a finding that highlights the role of mucosal tolerance disruption in dry eye pathogenesis. Remarkably, the NF-κB pathway is also involved in mucosal tolerance disruption in other ocular surface disorders. Together, these results suggest that targeting of mucosal NF-κB activation could have therapeutic potential in dry eye.

Lymphoma-associated dysimmune polyneuropathies

Lymphoma consists of a variety of malignancies of lymphocyte origin. A spectrum of clinical peripheral neuropathy syndromes with different disease mechanisms occurs in about 5% of lymphoma patients. There exists a complex inter-relationship between lymphoproliferative malignancies and autoimmunity. An imbalance in the regulation of the immune system presumably underlies various immune-mediated neuropathies in patients with lymphoma. This article reviews lymphoma and more-or-less well-defined dysimmune neuropathy subgroups that are caused by humoral and/or cell-mediated immune disease mechanisms directed against known or undetermined peripheral nerve antigens.

Bendamustine and rituximab combination in the management of chronic lymphocytic leukemia-associated autoimmune hemolytic anemia: a multicentric retrospective study of the French CLL intergroup (GCFLLC/MW and GOELAMS)

We report our experience on bendamustine and rituximab (BR) combination in 26 patients with chronic lymphocytic leukemia (CLL) complicated by autoimmune hemolytic anemia (AIHA). At the time of BR initiation, 88% of the patients had already been treated for AIHA and CLL was progressive regardless of AIHA in all patients but one. Overall response rates were 81% for AIHA and 77% for CLL. Median time to next treatment was 28.3 months and 26.2 months for AIHA and CLL, respectively. BR therapy may represent a good and safe therapeutic option in this setting where adequate control of CLL seems important for long-term AIHA response.

Semaphorin 3A controls allergic and inflammatory responses in experimental allergic conjunctivitis

AIM

To assess the efficacy of topical Semaphorin-3A (SEMA3A) in the treatment of allergic conjunctivitis.

METHODS

Experimental allergic conjunctivitis (EAC) mice model induced by short ragweed pollen (SRW) in 4-week-old of BALB/c mice, mice were evaluated using haematoxylin and eosin (H&E) staining, immunofluorescence and light microscope photographs. Early phase took the samples in 24h after instillation and late phase took the samples between 4 to 14d after the start of treatment. The study use of topical SEMA3A (10 U, 100 U, 1000 U) eye drops and subconjunctival injection of SEMA3A with same concentration. For comparison, five types of allergy eyedrops were quantified using clinical characteristics.

RESULTS

Clinical score of composite ocular symptoms of the mice treated with SEMA3A were significantly decreased both in the immediate phase and the late phase compared to those treated with commercial ophthalmic formulations and non-treatment mice. SEMA3A treatment attenuates infiltration of eosinophils entering into conjunctiva in EAC mice. The score of eosinophil infiltration in the conjunctiva of SEMA3A 1000 U-treated group were significantly lower than low-concentration of SEMA3A treated groups and non-treated group. SEMA3A treatment also suppressed T-cell proliferation in vitro and decreased serum total IgE levels in EAC mice. Moreover, Treatment of SEMA3A suppressed Th2-related cytokines (IL-5, IL-13 and IL-4) and pro-inflammatory cytokines (IFN-γ, IL-17 and TNF-α) release, but increased regulatory cytokine IL-10 concentration in the conjunctiva of EAC mice.

CONCLUSIONS

SEMA3A as a biological agent, showed the beneficial activity in ocular allergic processes with the less damage to the intraocular tissue. It is expected that SEMA3A may be contributed in patients with a more severe spectrum of refractory ocular allergic diseases including allergic conjunctivitis in the near future.

Old DAT and new data: positive direct antiglobulin test identifies a subgroup with poor outcome among chronic lymphocytic leukemia stage A patients

Only a minority of chronic lymphocytic leukemia (CLL) patients harboring a positive direct antiglobulin test (DAT) will develop autoimmune hemolytic anemia (AIHA). In a single institution cohort of 378 CLL patients, 56 patients (14.8%) had at least one positive DAT during the course of the disease, either at diagnosis or later. We found no relationship between the time of the first positive DAT and overall survival (OS). However, patients with a positive DAT who did not develop AIHA had the same adverse outcome as patients who developed AIHA. Of the patients who were in Binet stage A at diagnosis, those with a positive DAT had a significantly shorter OS, regardless of their IGHV mutational status, however, there was a strong association with VH1-69. By multivariate analysis, a positive DAT was found to be an independent adverse prognostic factor for OS. Thus, DAT represents a strong adverse prognostic factor and its determination should be repeated during follow-up.

Autoimmune cytopenias in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is frequently complicated by secondary autoimmune cytopenias (AIC) represented by autoimmune hemolytic anemia (AIHA), immune thrombocytopenia (ITP), pure red cell aplasia, and autoimmune granulocytopenia. The distinction of immune cytopenias from cytopenias due to bone marrow infiltration, usually associated with a worse outcome and often requiring a different treatment, is mandatory. AIHA and ITP are more frequently found in patients with unfavorable biological risk factors for CLL. AIC secondary to CLL respond less favorably to standard treatments than their primary forms, and treating the underlying CLL with chemotherapy or monoclonal antibodies may ultimately be necessary.

CXCL12 is a costimulator for CD4+ T cell activation and proliferation in chronic lymphocytic leukemia patients

Activated T cells from patients with chronic lymphocytic leukemia (CLL) provide survival and proliferative signals to the leukemic clone within lymphoid tissues. Recruitment of both, CLL cells and T lymphocytes, to this supportive microenvironment greatly depends on CXCL12 production by stromal and myeloid cells. CXCL12 also supplies survival stimuli to leukemic B cells, but whether it exerts stimulatory effects on T lymphocytes from CLL patients is unknown. In order to evaluate the capacity of CXCL12 to increase CD4(+) T cell activation and proliferation in CLL patients, peripheral blood mononuclear cells were cultured with or without recombinant human CXCL12 or autologous nurse-like cells, and then T cell activation was induced by anti-CD3 mAb. CXCL12 increases the proliferation and the expression of CD25, CD69, CD154, and IFNγ on CD3-stimulated CD4(+) T cells from CLL patients, similarly in T cells from ZAP-70(+) to ZAP-70(-) patients. Autologous nurse-like cells establish a close contact with CD4(+) T cells and increase their activation and proliferation partially through a CXCR4-dependent mechanism. In addition, we found that activated T cells in the presence of CXCL12 enhance the activation and proliferation of the leukemic clone. In conclusion, CXCL12 production by lymphoid tissue microenvironment in CLL patients might play a key dual role on T cell physiology, functioning not only as a chemoattractant but also as a costimulatory factor for activated T cells.

Benzalkonium chloride breaks down conjunctival immunological tolerance in a murine model

The impact of topical eye drops with benzalkonium chloride (BAK) as a preservative could involve more than the reported toxic effects on the ocular surface epithelium and ultimately affect the immune balance of the conjunctiva. We found that BAK not only impairs tolerance induction in a murine model, but leads to mild systemic immunization. Contrasting with antigen only-treated mice, there was no induction of interleukin 10-producing antigen-specific CD4(+) cells in BAK-treated animals. Moreover, the tolerogenic capacity of migrating dendritic cells (DCs) was reduced, apparently involving differential conditioning by soluble epithelial factors. Accordingly, epithelial cells exposed in vitro to BAK were less suppressive and failed to induce tolerogenic DCs in culture. As this effect of BAK was dependent on epithelial nuclear factor κB pathway activation, our findings may provide new therapeutic targets. Thus, tolerance breakdown by BAK should be considered an important factor in the management of glaucoma and immune-mediated ocular surface disorders.

Storage-induced changes in erythrocyte membrane proteins promote recognition by autoantibodies

Physiological erythrocyte removal is associated with a selective increase in expression of neoantigens on erythrocytes and their vesicles, and subsequent autologous antibody binding and phagocytosis. Chronic erythrocyte transfusion often leads to immunization and the formation of alloantibodies and autoantibodies. We investigated whether erythrocyte storage leads to the increased expression of non-physiological antigens. Immunoprecipitations were performed with erythrocytes and vesicles from blood bank erythrocyte concentrates of increasing storage periods, using patient plasma containing erythrocyte autoantibodies. Immunoprecipitate composition was identified using proteomics. Patient plasma antibody binding increased with erythrocyte storage time, while the opposite was observed for healthy volunteer plasma, showing that pathology-associated antigenicity changes during erythrocyte storage. Several membrane proteins were identified as candidate antigens. The protein complexes that were precipitated by the patient antibodies in erythrocytes were different from the ones in the vesicles formed during erythrocyte storage, indicating that the storage-associated vesicles have a different immunization potential. Soluble immune mediators including complement factors were present in the patient plasma immunoprecipitates, but not in the allogeneic control immunoprecipitates. The results support the theory that disturbed erythrocyte aging during storage of erythrocyte concentrates contributes to transfusion-induced alloantibody and autoantibody formation.

Chronic lymphocytic leukemia and autoimmunity: a systematic review

Chronic lymphocytic leukemia is frequently associated with immune disturbances. The relationship between chronic lymphocytic leukemia and autoimmune cytopenias, particularly autoimmune hemolytic anemia and immune thrombocytopenia, is well established. The responsible mechanisms, particularly the role of leukemic cells in orchestrating the production of polyclonal autoantibodies, are increasingly well understood. Recent studies show that autoimmune cytopenia is not necessarily associated with poor prognosis. On the contrary, patients with anemia or thrombocytopenia due to immune mechanisms have a better outcome than those in whom these features are due to bone marrow infiltration by the disease. Moreover, fears about the risk of autoimmune hemolysis following single agent fludarabine may no longer be appropriate in the age of chemo-immunotherapy regimens. However, treatment of patients with active hemolysis may pose important problems needing an individualized and clinically sound approach. The concept that autoimmune cytopenia may precede the leukemia should be revisited in the light of recent data showing that autoimmune cytopenia may be observed in monoclonal B-cell lymphocytosis, a condition that can only be detected by using sensitive flow cytometry techniques. On the other hand, there is no evidence of an increased risk of non-hemic autoimmune disorders in chronic lymphocytic leukemia. Likewise, there is no epidemiological proof of an increased risk of chronic lymphocytic leukemia in patients with non-hemic autoimmunity. Finally, since immune disorders are an important part of chronic lymphocytic leukemia, studies aimed at revealing the mechanisms linking the neoplastic and the immune components of the disease should help our understanding of this form of leukemia.

IGHV gene rearrangements as outcome predictors for CLL patients: experience of Ukrainian group

Important characteristics of chronic lymphocytic leukaemia (CLL) cells are biased immunoglobulin variable heavy chain (IGHV) gene repertoire and expression of stereotyped B-cell receptors (BCRs); however, their prognostic value (in contrast to the impact of IGHV gene mutational status) is less clear. To evaluate the impact of separate IGHV gene usage and expression of stereotyped BCRs in CLL prognosis. Clinical data and IGHV gene configuration were analysed in 319 consecutive patients with CLL. We found that the majority of clinical parameters of patients were defined by IGHV mutational status. Our data also provided new evidence supporting the prognostic relevance of separate IGHV genes or stereotyped BCR in CLL, namely: (a) a restricted non-mutated (UM) IGHV gene repertoire in CLL patients with autoimmune haemolytic anaemia (AIHA) (more frequent expression of UM IGHV1-69, IGHV3-11 and IGHV4-59 genes, P = 0.001), a shorter period of AIHA development for expressors of these genes (P = 0.001) and a tendency towards expression of a stereotypic HCDR3 (P = 0.029), (b) a high incidence of second solid tumour development in IGHV3-21-expressing patients (P = 0.005) and (c) differences in overall survival (OS) of UM CLL patients depending on the BCR structure. Further research of specific IGHV gene usage and subsets of stereotyped BCRs in CLL may be helpful in more precise prediction of CLL prognosis in individual patients.

Autoimmune cytopenia in chronic lymphocytic leukemia: prevalence, clinical associations, and prognostic significance

We analyzed prevalence, characteristics, clinical correlates, and prognostic significance of autoimmune cytopenia in patients with chronic lymphocytic leukemia. Seventy of 960 unselected patients (7%) had autoimmune cytopenia, of whom 19 were detected at diagnosis, 3 before diagnosis, and 48 during the course of the disease. Forty-nine patients had autoimmune hemolytic anemia, 20 had immune thrombocytopenic purpura, and 1 had both conditions. A clear association was observed between autoimmune cytopenia and poor prognostic variables (ie, high blood lymphocyte count, rapid blood lymphocyte doubling time, increased serum β-2 microglobulin level, and high expression of ζ-associated protein 70 and CD38). Nevertheless, the outcome of patients with autoimmune cytopenia as a whole was not significantly different from that of patients without this complication. Furthermore, no differences were observed according to time at which cytopenia was detected (ie, at diagnosis, during course of disease). Importantly, patients with advanced (Binet stage C) disease because of an autoimmune mechanism had a significantly better survival than patients in advanced stage related to a massive bone marrow infiltration (median survivals: 7.4 years vs 3.7 years; P = .02). These results emphasize the importance of determining the origin of cytopenia in patients with chronic lymphocytic leukemia for both treatment and prognostic purposes.

Autoimmune complications in chronic lymphocytic leukaemia (CLL)

Patients with B-chronic lymphocytic leukaemia /small lymphocytic lymphoma (CLL) have a 5-10% risk of developing autoimmune complications, which primarily cause cytopaenia. These autoimmune cytopaenias can occur at any stage of CLL and do not have independent prognostic significance. The most common autoimmune complication is autoimmune haemolytic anaemia with a lower frequency of immune thrombocytopaenia and pure red blood cell aplasia and only rarely, autoimmune granulocytopaenia (AIG). Autoimmune cytopaenia should always be considered in the differential diagnosis of cytopaenia in patients with CLL. Patients with CLL can also have more than one form of autoimmune cytopaenia, which can occur together with bone-marrow failure. Treatment is usually effective but rarely curative for autoimmune cytopaenia complicating CLL. Optimal therapy will depend on a timely and accurate diagnosis of autoimmune cytopaenia and should be individualised according to the severity of the cytopaenia and the presence or absence of concomitant progressive CLL requiring therapy.

Autoimmunity and lymphomagenesis

For more than 50 years, links between autoimmunity and lymphomas have been described based on human and animal studies. Over the last 3 decades, many studies have addressed specific hypotheses about these associations using population level data. This has been accomplished by assessing previous autoimmune history in case-control studies of patients with lymphoma (mainly non-Hodgkin lymphoma) and myeloma, and by following cohorts of patients with various autoimmune diseases for subsequent development of lymphoma and multiple myeloma. In this article, we review our recently published series of association studies based on data from Scandinavia and from US Veterans and other relevant findings. We also discuss what these associations have revealed about the mechanisms and pathways underlying both autoimmunity and lymphoma. Finally, we discuss the future directions involving a combination of population and molecular studies that are needed to better define underlying biological mechanisms.