Humoral immune failure defined by immunoglobulin class and immunoglobulin G subclass deficiency is associated with shorter treatment-free and overall survival in Chronic Lymphocytic Leukaemia

Cross-talk between leukemic and immune cells at the tumor microenvironment in chronic lymphocytic leukemia: An update review

Chronic lymphocytic leukemia (CLL) is a mature-type B cell malignancy correlated with significant changes and defects in both the innate and adaptive arms of the immune system, together with a high dependency on the tumor microenvironment. Overall, the tumor microenvironment (TME) in CLL provides a supportive niche for leukemic cells to grow and survive, and interactions between CLL cells and the TME can contribute to disease progression and treatment resistance. Therefore, the increasing knowledge of the complicated interaction between immune cells and tumor cells, which is responsible for immune evasion and cancer progression, has provided an opportunity for the development of new therapeutic approaches. In this review, we outline tumor microenvironment-driven contributions to the licensing of immune escape mechanisms in CLL patients.

Improved Innate Immune Function in Patients with Chronic Lymphocytic Leukemia Treated with Targeted Therapy in Clinical Trials

PURPOSE

Patients with chronic lymphocytic leukemia (CLL) have increased risk of severe infections. Although adaptive immune dysfunction is well described, clinical tools for identifying patients at risk are lacking, warranting investigation of additional immune components. In contrast to chemotherapy, targeted agents could spare or even improve innate immune function. Therefore, we investigated innate immune phenotypes and function in patients with CLL before and during targeted treatment.

EXPERIMENTAL DESIGN

Baseline and consecutive blood samples were collected from patients with CLL treated with acalabrutinib (n = 17) or ibrutinib+venetoclax (n = 18) in clinical trials. Innate immune function was assessed by TruCulture, a whole-blood ligand-stimulation assay quantifying cytokine release in response to standardized stimuli. Innate immune phenotypes were characterized by flow cytometry. As a proxy for infections, we mapped antimicrobial use before and during treatment.

RESULTS

At baseline, patients with CLL displayed impaired stimulated cytokine responses to the endotoxin lipopolysaccharide (LPS) along with deactivated monocytes, enrichment of myeloid-derived suppressor cells and metamyelocytes, and elevated (unstimulated) proinflammatory cytokines. Two/three cycles of acalabrutinib or ibrutinib normalized LPS-stimulated responses, in parallel with decreased duration of infections. Innate immune profiles and elevated proinflammatory cytokines further normalized during longer-term acalabrutinib or ibrutinib+venetoclax, paralleled by decreased infection frequency.

CONCLUSIONS

Innate immune impairment and infection susceptibility in patients with CLL were restored in parallel during targeted therapy. Thus, targeted treatment may reduce the risk of infections in CLL, as currently under investigation in the PreVent-ACaLL phase 2 trial of acalabrutinib+venetoclax for high-risk CLL (NCT03868722).

Immunoglobulin replacement vs prophylactic antibiotics for hypogammaglobulinemia secondary to hematological malignancy

ABSTRACT

Immunoglobulin replacement and prophylactic antibiotics are commonly used to prevent infections in patients with secondary hypogammaglobulinemia due to hematological malignancies but have never been directly compared. In this randomized controlled feasibility trial conducted in 7 hospitals in Australia and New Zealand, we enrolled patients with secondary hypogammaglobulinemia with either a history of recurrent/severe infection or an immunoglobulin G level <4 g/L. Participants were randomized in a 1:2 ratio to immunoglobulin (0.4 g/kg per 4 weeks IV) or daily antibiotics (trimethoprim-sulfamethoxazole 160 mg/800 mg or, if contraindicated, 100 mg doxycycline) for 12 months. Participants allocated to antibiotics were allowed to crossover after grade ≥3 infections. The primary outcome was proportion of patients alive on the assigned treatment 12 months after randomization. Between August 2017 and April 2019, 63 patients were randomized: 42 to antibiotics and 21 to immunoglobulin. Proportion of participants alive on allocated treatment at 12 months was 76% in the immunoglobulin and 71% in the antibiotic arm (Fisher exact test P=.77; odds ratio, 0.78; 95% CI, 0.22-2.52). The lower quartile for time to first major infection (median, not reached) was 11.1 months for the immunoglobulin and 9.7 months for the antibiotic arm (log-rank test, P=.65). Three participants in the immunoglobulin and 2 in the antibiotic arm had grade ≥3 treatment-related adverse events. A similar proportion of participants remained on antibiotic prophylaxis at 12 months to those on immunoglobulin, with similar rates of major infections. Our findings support the feasibility of progressing to a phase 3 trial. Trial registration #ACTRN12616001723471.

Pathogenesis and management of immune dysfunction secondary to B cell haematological malignancies

Malignancies of the B-lymphocyte lineage are among the most diagnosed haematological malignancies in clinical practice. In our community, multiple myeloma (MM) and its precursor condition monoclonal gammopathy of undetermined significance are the commonest, accounting for ~12% of diagnoses, followed by chronic lymphocytic leukaemia (CLL) and its precursor condition monoclonal B lymphocytosis, ~9%. Along with diffuse large B cell lymphoma, follicular lymphoma and marginal zone lymphoma, these conditions comprise around a third of all haematological malignancies diagnosed. Infection remains an important cause of mortality and morbidity in the management of patients with these conditions. This is in part treatment-related but also reflective of disease-related immune dysfunction. Infectious complications account for up to 50% of early mortality in patients with myeloma and up to 50% of all mortality in patients with CLL. A variety of strategies are available to decrease the morbidity and mortality of infectious complications; however, practices vary between countries and often between treating physicians. Treatment options have evolved significantly over the last decade, with the introduction of monoclonal antibodies, small molecule inhibitors, second- and third-generation immunomodulatory agents and CAR-T cell therapy. Much of the data that inform clinical practice in infection management predates current therapeutic approaches. This is in part because of the rapid development of new therapies but also reflective of the long natural history of many of these diseases and the need for prolonged periods of observation. In this article, we review the aspects of disease and treatment that contribute to immune dysfunction in MM, CLL and B-cell non-Hodgkin lymphoma and review the current strategies used to manage immune dysfunction and infection.

Immune Dysfunction and Infection - Interaction between CLL and Treatment: A Reflection on Current Treatment Paradigms and Unmet Needs

BACKGROUND

Chronic lymphocytic leukemia (CLL) is a hematological malignancy characterized by immune dysfunction, which significantly contributes to increased morbidity and mortality due to infections.

SUMMARY

Advancement in therapeutic strategies based on combination chemoimmunotherapy and targeted treatment have increased life expectancy for patients affected by CLL. However, mortality and morbidity due to infection showed no improvement over the last decades. Although therapy options are highly efficient in targeting leukemic cells, several studies highlighted the interactions of different treatments with the tumor microenvironment immune components, significantly impacting their clinical efficacy and fostering increased risk of infections.

KEY MESSAGES

Given the profound immune dysfunction caused by CLL itself, treatment can thus represent a double-edged sword. Thus, it is essential to increase our understanding and awareness on how conventional therapies affect the disease-microenvironment-infection axis to ensure the best personalized strategy for each patient. This requires careful consideration of the advantages and disadvantages of efficient treatments, whether chemoimmunotherapy or targeted combinations, leading to risk of infectious complications. To this regard, our machine learning-based algorithm CLL Treatment-Infection Model, currently implemented into the local electronic health record system for Eastern Denmark, aims at early identification of patients at high risk of serious infections (PreVent-ACaLL; NCT03868722). We here review strategies for management of immune dysfunction and infections in CLL.

Multiple COVID-19 vaccine doses in CLL and MBL improve immune responses with progressive and high seroconversion

Patients with chronic lymphocytic leukemia (CLL) or monoclonal B-lymphocytosis (MBL) have impaired response to COVID-19 vaccination. A total of 258 patients (215 with CLL and 43 with MBL) had antispike antibody levels evaluable for statistical analysis. The overall seroconversion rate in patients with CLL was 94.2% (antispike antibodies ≥50 AU/mL) and 100% in patients with MBL after multiple vaccine doses. After 3 doses (post-D3) in 167 patients with CLL, 73.7% were seropositive, 17.4% had antispike antibody levels between 50 and 999 AU/mL, and 56.3% had antispike antibody levels ≥1000 AU/mL, with a median rise from 144.6 to 1800.7 AU/mL. Of patients who were seronegative post-D2, 39.7% seroconverted post-D3. For those who then remained seronegative after their previous dose, seroconversion occurred in 40.6% post-D4, 46.2% post-D5, 16.7% post-D6, and 0% after D7 or D8. After seroconversion, most had a progressive increase in antispike antibody levels. Neutralization was associated with higher antispike antibody levels, more vaccine doses, and earlier severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants; neutralizing antibody against early clade D614G was detected in 65.3%, against Delta in 52.0%, and against Omicron in 36.5%. SARS-CoV-2-specific T-cell production of interferon γ and interleukin 2 occurred in 73.9% and 60.9%, respectively, of 23 patients tested. After multiple vaccine doses, by multivariate analysis, immunoglobulin M ≥0.53 g/L, immunoglobulin subclass G3 ≥0.22 g/L and absence of current CLL therapy were independent predictors of positive serological responses. Multiple sequential COVID-19 vaccination significantly increased seroconversion and antispike antibody levels in patients with CLL or MBL.

Comprehensive analysis of immune responses in CLL patients after heterologous COVID-19 vaccination

Patients with chronic lymphocytic leukemia (CLL) treated with B-cell pathway inhibitors and anti-CD20 antibodies exhibit low humoral response rate (RR) following SARS-CoV-2 vaccination. To investigate the relationship between the initial transcriptional response to vaccination with ensuing B and T cell immune responses, we performed a comprehensive immune transcriptome analysis flanked by antibody and T cell assays in peripheral blood prospectively collected from 15 CLL/SLL patients vaccinated with heterologous BNT162b2/ChAdOx1 with follow up at a single institution. The two-dose antibody RR was 40% increasing to 53% after booster. Patients on BTKi, venetoclax ± anti-CD20 antibody within 12 months of vaccination responded less well than those under BTKi alone. The two-dose T cell RR was 80% increasing to 93% after booster. Transcriptome studies revealed that seven patients showed interferon-mediated signaling activation within 2 days and one at 7 days after vaccination. Increasing counts of COVID-19 specific IGHV genes correlated with B-cell reconstitution and improved humoral RR. T cell responses in CLL patients appeared after vaccination regardless of treatment status. A higher humoral RR was associated with BTKi treatment and B-cell reconstitution. Boosting was particularly effective when intrinsic immune status was improved by CLL-treatment.

Immunoglobulin replacement therapy in chronic lymphocytic leukaemia patients with hypogammaglobulinaemia and infection

OBJECTIVES

To analyse total national utilisation of immunoglobulin (Ig) replacement therapy (IgRT) for Chronic Lymphocytic Leukaemia patients with acquired hypogammaglobulinaemia and severe and/or recurrent bacterial infections.

METHODS

In 2007, the National Blood Authority first published Criteria for the clinical use of intravenous immunoglobulin in Australia. The Australian Red Cross Lifeblood assessed, approved, and recorded all supply with patient demographics, distribution data, intravenous Ig (IVIg) volumes and treatment episodes. IVIg was the sole product used in Australia from 2008-2013 inclusive.

RESULTS

From 2008 to 2013 across Australia, 2734 individual CLL patients received 48,870 treatment episodes using a total 1,324,926 g of IVIg therapy. Six IVIg products were available, with domestically manufactured Intragam^® P accounting for 89.7% of supply. The average age for first dose was 74 years. Males received 60.6% of the total treatment episodes representing 20% more than females. The average pre-treatment IgG level was 4.03 ± 2.03 g/L (range 0.30-10.50 g/L). A sustained average annual increased IVIg utilisation of 5.5% was observed. There was significant regional variation consistent with differences in prescriber preferences across states and territories.

CONCLUSION

This study provides a globally unique insight into IgRT supply and demand in CLL patients by analysis of total national use in Australia over a 6-year period.

Managing the Risk of Infection in Chronic Lymphocytic Leukemia in the Era of New Therapies

Purpose of Review

Patients diagnosed with CLL have an increased susceptibility to infections. Over the years, there has been a shift of the treatment arsenal to an increasing use of chemotherapy-free regimens, particularly small molecule inhibitors. These therapies have proven to be effective and have a favorable toxicity profile. Infections continue to represent a significant complication in the era of novel therapies.

Recent Findings

Recent studies continue to bring new insights into the effects of modern therapies on the immune system. Evidence supporting infection prevention strategies is scarce. We will review the available recommendations to prevent infections in patients with CLL treated with novel therapies.

Summary

New CLL therapies are broadly adopted in routine practice, requiring optimization of their side effects. Timely prevention, recognition, and treatment of infections should remain an important aspect of the standard management of a patient with CLL.

Effects of Multispecies Probiotic on Intestinal Microbiota and Mucosal Barrier Function of Neonatal Calves Infected With E. coli K99

Altered gut microbiota are implicated in inflammatory neonatal calf diarrhea caused by E. coli K99. Beneficial probiotics are used to modulate gut microbiota. However, factors that mediate host-microbe interactions remain unclear. We evaluated the effects of a combination of multispecies probiotics (MSP) on growth, intestinal epithelial development, intestinal immune function and microbiota of neonatal calves infected with E. coli K99. Twelve newborn calves were randomly assigned as follows: C (control, without MSP); D (E. coli O78:K99 + gentamycin); and P (E. coli O78:K99 + supplemental MSP). All groups were studied for 21 d. MSP supplementation significantly (i) changed fungal Chao1 and Shannon indices of the intestine compared with group D; (ii) reduced the relative abundance of Bacteroides and Actinobacteria, while increasing Bifidobacteria, Ascomycetes, and Saccharomyces, compared with groups C and D; (iii) improved duodenal and jejunal mucosal SIgA and total Short Chain Fatty Acids (SCFA) concentrations compared with group D; (iv) increased relative ZO-1 and occludin mRNA expression in jejunal mucosa compared with group D; and (v) enhanced intestinal energy metabolism and defense mechanisms of calves by reducing HSP90 expression in E. coli K99, thereby alleviating the inflammatory response and promoting recovery of mucosal function. Our research may provide direct theoretical support for future applications of MSP in ruminant production.

Second primary malignancies in chronic lymphocytic leukaemia: Skin, solid organ, haematological and Richter's syndrome

Chronic lymphocytic leukaemia (CLL) is invariably accompanied by some degree of immune failure, and CLL patients have a high rate of second primary malignancy (SPM) compared to the general population. We comprehensively documented the incidence of all forms of SPM including skin cancer (SC), solid organ malignancy (SOM), second haematological malignancy (SHM) and separately Richter's syndrome (RS) across all therapy eras. Among the 517 CLL/small lymphocytic lymphoma (SLL) patients, the overall incidence of SPMs with competing risks was SC 31.07%, SOM 25.99%, SHM 5.19% and RS 7.55%. Of the 216 treated patients, 106 (49.1%) had at least one form of SPM, and 63 of 106 (29.2% of treated patients) developed an SPM 1.5 years (median) after treatment for their CLL. Melanoma accounted for 30.3% of SC. Squamous cell carcinoma (SCC), including eight metastatic SCCs, was 1.8 times more than basal cell carcinoma (BCC), a reversal of the typical BCC:SCC ratio. The most common SOMs were prostate (6.4%) and breast (4.5%). SHM included seven acute myeloid leukaemia (AML) and five myelodysplasia (MDS) of which eight (four AML, four MDS) were therapy-related. Any SPM occurred in 32.1% of 53 Monoclonal B-lymphocytosis (MBL) patients. Age-adjusted standardised rates of SPM (per 100,000) for CLL, MBL and the general Australian population were 2648, 1855 and 486.9, respectively. SPMs are a major health burden with 44.9% of CLL patients with having at least one SPM, and apart from SC, associated with significantly reduced overall survival. Dramatic improvements in CLL treatment and survival have occurred with immunochemotherapy and targeted therapies, but mitigating SPM burden will be important to sustain further progress.

Artificial intelligence models in chronic lymphocytic leukemia - recommendations toward state-of-the-art

Artificial intelligence (AI), machine learning and predictive modeling are becoming enabling technologies in many day-to-day applications. Translation of these advances to the patient's bedside for AI assisted interventions is not yet the norm. With specific emphasis on CLL, here, we review the progress of prognostic models in hematology and highlight sources of stagnation that may be limiting significant improvements in prognostication in the near future. We discuss issues related to performance, trust, modeling simplicity, and prognostic marker robustness and find that the major limiting factor in progressing toward state-of-the-art prognostication within the hematological community, is not the lack of able AI algorithms but rather, the lack of their adoption. Current models in CLL still deal with the 'average' patient while the use of patient-centric approaches remains absent. Using lessons from research areas where machine learning has become an enabling technology, we derive recommendations and propose methods for achieving state-of-the-art predictions in modeling health data, that can be readily adopted by the CLL modeling community.

Impact of Immune Parameters and Immune Dysfunctions on the Prognosis of Patients with Chronic Lymphocytic Leukemia

Simple Summary

In chronic lymphocytic leukemia (CLL), immune alterations—affecting both the innate and adaptive immunity—are very common. As a clinical consequence, patients with CLL frequently present with autoimmune phenomena, increased risk of infections and second malignancies. The aim of this review article is to present available data on CLL-associated alterations of immune parameters that correlate with known prognostic markers and with clinical outcome. Also, data on the impact of immune-related clinical manifestations on the prognosis of patients with CLL will be discussed.

Abstract

Chronic lymphocytic leukemia (CLL) is characterized by a wide spectrum of immune alterations, affecting both the innate and adaptive immunity. These immune dysfunctions strongly impact the immune surveillance, facilitate tumor progression and eventually affect the disease course. Quantitative and functional alterations involving conventional T cells, γδ T cells, regulatory T cells, NK and NKT cells, and myeloid cells, together with hypogammaglobulinemia, aberrations in the complement pathways and altered cytokine signature have been reported in patients with CLL. Some of these immune parameters have been shown to associate with other CLL-related characteristics with a known prognostic relevance or to correlate with disease prognosis. Also, in CLL, the complex immune response dysfunctions eventually translate in clinical manifestations, including autoimmune phenomena, increased risk of infections and second malignancies. These clinical issues are overall the most common complications that affect the course and management of CLL, and they also may impact overall disease prognosis.

Effect of a Multispecies Probiotic Mixture on the Growth and Incidence of Diarrhea, Immune Function, and Fecal Microbiota of Pre-weaning Dairy Calves

The effects of different doses of a multispecies probiotic (MSP) mixture on growth performance, the incidence of diarrhea rate and immune function, and fecal microbial diversity and structure were evaluated in pre-weaning Holstein dairy calves at WK2, WK4, WK6, and WK8. Forty Chinese Holstein female newborn calves were randomly assigned to four treatments with 10 calves in each group, C (control group), T1 (0.5 g MSP/calf/day, T2 (1 g MSP/calf/day), and T3 (2 g MSP/calf/day) groups. The experimental period was 56 days. Feed intake and health scoring were recorded every day until the end of the experiment. Fecal contents and blood samples were sampled at WK2, WK4, WK6, and WK8. Growth performance, incidence of diarrhea, and total serum concentrations (IgA, IgG, and IgM) were analyzed. Bacterial 16S rRNA and fungal ITS genes were high-throughput sequenced for fecal microbiota. The relationships among the populations of the principal fecal microbiota at WK2 and the growth performance or serum immunoglobulin concentrations were analyzed using Pearson's rank correlation coefficients. The MSP supplementation reduced the incidence of diarrhea in the first 4 weeks of life, and serum IgA, IgG, and IgM concentrations increased between WK2 and WK8 in the T3 group. There was an increase in growth performance and reduction in the incidence of diarrhea until WK4 after birth in T3 group, compared with the control, T1, and T2 groups. The results of fecal microbiota analysis showed that Firmicutes and Bacteroides were the predominant phyla, with Blautia, Ruminococcaceae_UCG-005, norank_f__Muribaculaceae, Bacteroides, Subdoligranulum, and Bifidobacterium being the dominant genera in calf feces. Aspergillus, Thermomyces, and Saccharomyces were the predominant fungal phyla. Compared with the control, in T1 and T2 groups, the MSP supplementation reduced the relative abundance of Bacteroidetes and increased the relative abundance of Bifidobacterium, Lactobacillus, Collinsella, and Saccharomyces at WK2 in group T3. Thus, the fecal microbial composition and diversity was significantly affected by the MSP mixture during the first 2 weeks of the calves' life. MSP mixtures reduced the incidence of diarrhea in pre-weaning calves (during the first 4 weeks of life). There was a significant improvement in growth performance, reduction in calf diarrhea, balance in the fecal microbiota, and an overall improvement in serum immunity, compared with the control group. We, therefore, recommend adding 2 g/day of multispecies probiotic mixture supplementation in diets of dairy calves during their first 4 weeks of life before weaning.

Longitudinal study of intravenous versus subcutaneous immunoglobulin replacement therapy in hematological malignancy

AIM

To present findings from a longitudinal study on infection risk, mortality, and patient perspective of intravenous immunoglobulin (IVIg) and subcutaneous immunoglobulin (SCIg) treatment for patients with hypogammaglobulinemia secondary to hematological malignancy or its treatment (abbreviated as SID).

METHODS

Observational study period included final year of IVIg (13 patients) and of the first 3 years of SCIg (17 patients) with SID. Data were collected on clinical outcomes from medical records and patient perception via study specific questionnaire.

RESULTS

The median age was 63 years (53-76 years), and for 82.4% of patients their hematological malignancy was in complete remission. The annual mean serum IgG trough levels remained stable over the 4 years and were 7.0 g/L (±2.77 g/L) with IVIg, and 8.0 g/L (±1.75 g/L), 8.7 g/L (±2.75 g/L), and 7.6 g/L (±2.89 g/L) (year 1, 2, and 3, respectively) with SCIg. While the annual infection rate was similar, the rate of hospitalization due to infection fluctuated, with 37%, 9%, 15%, and 32% in year 1, 2, 3, and 4 respectively. There were no systemic adverse events with IVIg or SCIg. Patients reported a strong preference for SCIg. One patient died due to progression of underlying disease and infection within the study period.

CONCLUSION

SCIg was the preferred treatment mode over IVIg in our cohort, but both were well tolerated without any systemic adverse events in 4-year follow up. The dosage and serum IgG levels were stable throughout. However, the number of infections requiring hospitalization fluctuated. It is anticipated that these findings encourage more hospitals to offer SCIg for SID patients.

A nationwide study on inpatient opportunistic infections in patients with chronic lymphocytic leukemia in the pre-ibrutinib era

OBJECTIVE

Opportunistic infections in chronic lymphocytic leukemia (CLL) have been described in clinical trials, single-center studies, and case reports. We performed a nationwide study to estimate the incidence and impact of inpatient opportunistic infections.

METHODS

The incidence rate (IR) and incidence rate ratio (IRR) for Swedish CLL patients diagnosed 1994-2013, and matched controls were calculated, as well as the case-fatality ratio (CFR).

RESULTS

Among 8989 CLL patients, a total of 829 opportunistic infections were registered (IR 16.6 per 1000 person-years) compared with 252 opportunistic infections in 34 283 matched controls (IR 0.99). The highest incidence in the CLL cohort was for Pneumocystis pneumonia (200 infections, IR 4.03); Herpes zoster (146 infections, IR 2.94), and Pseudomonas (83 infections, IR 1.66) infections. The highest risk relative to matched controls was observed for Pneumocystis pneumonia (IRR 114, 95% confidence interval 58.7-252). The 60-day CFR for CLL patients with opportunistic infections was 23% (188/821), highest for progressive multifocal encephalopathy (5/7, 71%) and aspergillosis (25/60, 42%).

CONCLUSION

We have uniquely depicted the incidence of rare and serious infections in CLL patients and found a relatively high incidence of Pneumocystis pneumonia. Of the most common opportunistic infections, CLL patients with aspergillosis had the poorest prognosis.

Immune Dysfunctions and Immune-Based Therapeutic Interventions in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is a B-cell malignancy characterized by a wide range of tumor-induced alterations, which affect both the innate and adaptive arms of the immune response, and accumulate during disease progression. In recent years, the development of targeted therapies, such as the B-cell receptor signaling inhibitors and the Bcl-2 protein inhibitor venetoclax, has dramatically changed the treatment landscape of CLL. Despite their remarkable anti-tumor activity, targeted agents have some limitations, which include the development of drug resistance mechanisms and the inferior efficacy observed in high-risk patients. Therefore, additional treatments are necessary to obtain deeper responses and overcome drug resistance. Allogeneic hematopoietic stem cell transplantation (HSCT), which exploits immune-mediated graft-versus-leukemia effect to eradicate tumor cells, currently represents the only potentially curative therapeutic option for CLL patients. However, due to its potential toxicities, HSCT can be offered only to a restricted number of younger and fit patients. The growing understanding of the complex interplay between tumor cells and the immune system, which is responsible for immune escape mechanisms and tumor progression, has paved the way for the development of novel immune-based strategies. Despite promising preclinical observations, results from pilot clinical studies exploring the safety and efficacy of novel immune-based therapies have been sometimes suboptimal in terms of long-term tumor control. Therefore, further advances to improve their efficacy are needed. In this context, possible approaches include an earlier timing of immunotherapy within the treatment sequencing, as well as the possibility to improve the efficacy of immunotherapeutic agents by administering them in combination with other anti-tumor drugs. In this review, we will provide a comprehensive overview of main immune defects affecting patients with CLL, also describing the complex networks leading to immune evasion and tumor progression. From the therapeutic standpoint, we will go through the evolution of immune-based therapeutic approaches over time, including i) agents with broad immunomodulatory effects, such as immunomodulatory drugs, ii) currently approved and next-generation monoclonal antibodies, and iii) immunotherapeutic strategies aiming at activating or administering immune effector cells specifically targeting leukemic cells (e.g. bi-or tri-specific antibodies, tumor vaccines, chimeric antigen receptor T cells, and checkpoint inhibitors).

Early Intervention with Lenalidomide in Patients with High-risk Chronic Lymphocytic Leukemia

PURPOSE

Infectious complications constitute a leading cause of morbidity and mortality in chronic lymphocytic leukemia (CLL). Patients respond poorly to vaccines, particularly pneumococcal polysaccharide and influenza vaccines. In addition, patients with genetically high-risk disease are at increased risk for early disease progression and death. Lenalidomide, an oral immunomodulatory agent with demonstrated clinical activity in CLL, can potentially restore immune system dysfunction associated with CLL while improving disease outcomes.

PATIENTS AND METHODS

Phase II study randomized 49 patients with genetically high-risk CLL or small lymphocytic lymphoma [SLL; defined as unmutated Ig heavy chain variable region, deletion(17p) or (11q), and/or complex abnormal karyotype], to receive lenalidomide either concurrent (arm A) or sequential to (arm B) two doses of 13-valent protein-conjugated pneumococcal vaccine (PCV13) administered 2 months apart, in patients not meeting International Workshop on Chronic Lymphocytic Leukemia treatment criteria.

RESULTS

Four serotypes (3, 4, 5, 6B) achieved the additional seroprotection definition of a fourfold increase in arm A, and six serotypes (3, 4, 5, 6B, 19A, 19F) in arm B. All patients achieved the defined concentration of 0.35 μg/mL for at least one serotype tested. No significant difference was observed with the addition of lenalidomide. At median time on treatment of 3.6 years, median progression-free survival (PFS) was 5.8 years [95% confidence interval (CI), 3.1-not reached]. PFS at 1, 2, and 3 years was 85% (95% CI, 72-93), 79% (95% CI, 64-88), and 72% (95% CI, 57-83), respectively.

CONCLUSIONS

Lenalidomide is efficacious with manageable toxicities as an early intervention strategy in patients with high-risk CLL, but did not enhance humoral response to PCV13 vaccine.

Monoclonal gammopathy and serum immunoglobulin levels as prognostic factors in chronic lymphocytic leukaemia

The relationship between chronic lymphocytic leukaemia (CLL) and qualitative/quantitative gammaglobulin abnormalities is well established. Nevertheless, in order to better understand this kind of connection, we examined 1505 patients with CLL and divided them into four subgroups on the basis of immunoglobulin (Ig) aberrations at diagnosis. A total of 73 (4·8%), 149 (10%), 200 (13·2%) and 1083 (72%) patients were identified with IgM monoclonal gammopathy (IgM/CLL), IgG monoclonal gammopathy (IgG/CLL), hypogammaglobulinaemia (hypo-γ) and normal Ig levels (γ-normal) respectively. IgM paraprotein was significantly associated with a more advanced Binet/Rai stage and del(17p)/TP53 mutation, while IgG abnormalities correlated with a higher occurrence of trisomy 12. Patients with any type of Ig abnormality had shorter treatment-free survival (TFS) but no significant impact affecting overall survival (OS) compared to those with normal Ig levels.

IgA levels at diagnosis predict for infections, time to treatment, and survival in chronic lymphocytic leukemia

To better understand the relationship between baseline immunoglobulin measurements and subsequent clinical outcomes in chronic lymphocytic leukemia (CLL), we performed a retrospective analysis on 660 patients with CLL (72%), monoclonal B-cell lymphocytosis (MBL) (13%), and small lymphocytic lymphoma (SLL) (14%), diagnosed between 2005 and 2014 at CancerCare Manitoba. Of 511 patients who had their first immunoglobulin level determined within 3 months of diagnosis, abnormal (either increased or decreased) immunoglobulin M (IgM), IgG, and IgA values were observed in 58% of patients with CLL, 27% of patients with MBL, and 20% of patients with SLL. Immunoglobulin deviances were similar for MBL and CLL Rai stage 0 and for SLL and Rai stages I and II; for CLL, IgG and IgA abnormalities occurred with increasing frequency with advancing Rai stage. In contrast, the frequency of IgM abnormalities was similar in all patient groups. IgA abnormalities significantly correlated with high β2-microglobulin (B2M) expression, whereas abnormal IgG and IgA levels were associated with the use of IGHV1-69, 3-21, and 3-49 subtypes. Increases in IgG or IgM were commonly associated with the presence of a CLL-type M-band, whereas oligoclonal bands were frequently observed with increased IgA levels. Although abnormal levels of IgG and IgA at diagnosis were independent predictors for future immunoglobulin replacement, only abnormal IgA levels were associated with shorter time to first treatment and overall survival. These findings indicate that both reduced and elevated levels of IgG and IgA at diagnosis are important and independent prognostic markers for infection in CLL, with IgA being more relevant as a marker of disease progression and survival.

Low Humoral Immune Response and Ineffective Clearance of SARS-Cov-2 in a COVID-19 Patient With CLL During a 69-Day Follow-Up

Background: A recent outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), which began in Wuhan, China, with a high level of human-to-human transmission has been reported. There are limited data available on Coronavirus Disease 2019 (COVID-19) patients with hematological malignancies with more than 60 days of follow-up. This study describes the clinical characteristics, including multiple recurrences of COVID-19, in a patient with chronic lymphocytic leukemia (CLL) during 69 days of follow-up.

Case Presentation: A 72-year-old female was admitted to hospital isolation after being infected with COVID-19 as part of a family cluster on January 30, 2020. Apart from SARS-Cov-2 virus infection, laboratory results revealed lymphocytosis of uncertain etiology and abnormal distribution of T lymphocytes. On blood smears, small blue lymphocytes with scant cytoplasm were observed, and the presence of high levels of circulating clonal B cells was also demonstrated by flow cytometry. The patient was diagnosed with COVID-19 and CLL. Among her family members, she had the highest viral loads and the fastest progression on lung injury and developed severe pneumonia. Serological results showed she had both 2019-nCoV-specific IgM and IgG antibodies; however, only IgG antibodies were detected in her husband's plasma.

Results: A combination regimen of antiviral therapy and high-dose intravenous immunoglobulin (IVIG) in the early stage seemed to be effective for treating CLL and SARS-Cov-2 infection. Because of the low humoral immune response, the CLL patient could not effectively clear the SARS-Cov-2 infection and suffered from recurrence twice during the 69-day follow-up.

Conclusion: In CLL, a neoplastic antigen-specific B-cell clone proliferates, and the progeny cells accumulate and outgrow other B cells, leading to immune deficiency. Considering the low humoral immune response and ineffective clearance of SARS-Cov-2 in CLL patients, the follow-up and home quarantine period should be extended. We need further studies to clarify suspending or continuing CLL therapy during COVID infection. For those patients who are prone to progression to severe disease, administering humoral immunity therapies can help to prevent disease progression and quickly meet the cure criteria.

Immunological Role of IgG Subclasses

The loss of tolerance to self-antigens is the unequivocal "red line" of autoimmunity: both development of autoreactive T and B cells and production of polyclonal autoantibodies represent seminal keys to the pathogenesis of protean autoimmune diseases. Most of these autoantibodies are immunoglobulins G (IgG), functionally distinguished in four subclasses named IgG1, IgG2, IgG3, and IgG4, due to structural differences in the hinge and heavy chain constant regions. Different studies analyzed serum levels of IgG subclasses in the course of different disorders, showing that they might have a pathogenic role by regulating interactions among immunoglobulins, Fc-gamma receptors, and complement. To date, the mechanisms promoting different IgG subclasses distribution during the natural history of most autoimmune diseases remain somewhat unclear. Evidence from the medical literature shows that the serum IgG profile is peculiar for many autoimmune diseases, suggesting that different subclasses could be specific for the underlying driving autoantigens. A better knowledge of IgG subsets may probably help to elucidate their pathological task, but also to define their relevance for diagnostic purposes, patients' personalized management, and prognosis assessment.

Effects of different types of zinc supplement on the growth, incidence of diarrhea, immune function, and rectal microbiota of newborn dairy calves

Neonatal diarrhea in dairy calves causes huge economic and productivity losses in the dairy industry. Zinc is an effective anti-diarrheal agent, but high doses may pose a threat to the environment. Therefore, we aimed to evaluate the effects of low-dose zinc supplementation on the growth, incidence of diarrhea, immune function, and rectal microbiota of newborn Holstein dairy calves. Thirty newborn calves were allocated to either a control group (without extra zinc supplementation), or groups supplemented with either 104 mg of zinc oxide (ZnO, equivalent to 80 mg of zinc/d) or 457 mg of zinc methionine (Zn-Met, equivalent to 80 mg of zinc/d) and studied them for 14 d. The rectal contents were sampled on d 1, 3, 7, and 14, and blood samples were collected at the end of the study. Supplementation with ZnO reduced the incidence of diarrhea during the first 3 d of life, and increased serum IgG and IgM concentrations. The Zn-Met supplementation increased growth performance and reduced the incidence of diarrhea during the first 14 d after birth. The results of fecal microbiota analysis showed that Firmicutes and Proteobacteria were the predominant phyla, and Escherichia and Bacteroides were the dominant genera in the recta of the calves. As the calves grew older, rectal microbial diversity and composition significantly evolved. In addition, dietary supplementation with ZnO reduced the relative abundance of Proteobacteria in 1-d-old calves, and increased that of Bacteroidetes, Lactobacillus, and Faecalibacterium in 7-d-old calves, compared with the control group. Supplementation with Zn-Met increased the relative abundance of the phylum Actinobacteria and the genera Faecalibacterium and Collinsella on d 7, and that of the genus Ruminococcus after 2 wk, compared with the control group. Thus, the rectal microbial composition was not affected by zinc supplementation but significantly evolved during the calves' early life. Zinc supplementation reduced the incidence of diarrhea in young calves. In view of their differing effects, we recommend ZnO supplementation for dairy calves during their first 3 d of life and Zn-Met supplementation for the subsequent period. These findings suggest that zinc supplementation may be an alternative to antibacterial agents for the treatment of newborn calf diarrhea.

Machine learning can identify newly diagnosed patients with CLL at high risk of infection

Infections have become the major cause of morbidity and mortality among patients with chronic lymphocytic leukemia (CLL) due to immune dysfunction and cytotoxic CLL treatment. Yet, predictive models for infection are missing. In this work, we develop the CLL Treatment-Infection Model (CLL-TIM) that identifies patients at risk of infection or CLL treatment within 2 years of diagnosis as validated on both internal and external cohorts. CLL-TIM is an ensemble algorithm composed of 28 machine learning algorithms based on data from 4,149 patients with CLL. The model is capable of dealing with heterogeneous data, including the high rates of missing data to be expected in the real-world setting, with a precision of 72% and a recall of 75%. To address concerns regarding the use of complex machine learning algorithms in the clinic, for each patient with CLL, CLL-TIM provides explainable predictions through uncertainty estimates and personalized risk factors.

Chronic lymphocytic leukemia is an indolent disease, and many patients succumb to infection rather than the direct effects of the disease. Here, the authors use medical records and machine learning to predict the patients that may be at risk of infection, which may enable a change in the course of their treatment.

Basic Research and Clinical Reports Associated with Low Serum IgG4 Concentrations

Elevated IgG4 concentrations in serum have received a great deal of attention recently, whereas the significance of decreased IgG4 levels was frequently neglected in spite of its close relation with infectious and noninfectious inflammations. In this review, based on the structural and functional characteristics of IgG4, we bring together case reports and research related to low levels of IgG4 and try to scratch the importance of decreased IgG4 concentrations in serum. As with elevated IgG4 levels, low serum IgG4-related diseases can be involved in multiple systems such as infection in the respiratory system, stroke in the circulatory system, and glomerulonephritis in the urinary system. Both genetic and immune dysregulation can contribute to decreased IgG4 levels. In the light of animal experiments, we believe that the mystery of low IgG4 can be revealed as long as enough attention is acquired.

Risk of Infection Associated With Ibrutinib in Patients With B-Cell Malignancies: A Systematic Review and Meta-analysis of Randomized Controlled Trials

INTRODUCTION

B-cell malignancies confer an increased risk of infection due to associated immune defects. Conflicting evidence exists on the risk of infection in patients receiving ibrutinib. We conducted a systematic review and meta-analysis to estimate relative risk of infection with ibrutinib in B-cell malignancies.

METHODS

A systematic search of Embase, Medline, Web of Science, Scopus, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, European Union Clinical Trials Register, and ClinicalTrials.gov was performed through January 15, 2019, to identify randomized controlled trials comparing ibrutinib with other agents or placebo in B-cell malignancies. We pooled point estimates using the Der Simonian and Laird random-effects model. Statistical analyses were performed by Stata/SE 15.1.

RESULTS

Seven studies randomizing 2167 patients were included in the final analysis. Treatment duration in studies ranged from 9.4 to 38.7 months. Ibrutinib was associated with a significantly increased risk of infection (any grade and grade 3-5) in patients with B-cell malignancies [pooled risk ratio (RR) = 1.34, 95% confidence interval [CI], 1.06-1.69, P = .015; and RR = 1.35, 95% CI, 1.05-1.74, P = .018, respectively]. In patients with chronic lymphocytic leukemia, a significantly increased risk of grade 3-5 infection was noted in the ibrutinib group [pooled RR = 1.24, 95% CI, 1.02-1.50, P = .028]. Incidences of pneumonia and upper respiratory tract infection were not significantly different between groups.

CONCLUSION

Our meta-analysis found that ibrutinib was associated with significantly higher risk of infections in patients with B-cell malignancies. Occurrence of major individual subtypes was not different between groups, possibly as a result of inconsistent reporting across studies.

A new risk model to predict time to first treatment in chronic lymphocytic leukemia based on heavy chain immunoparesis and summated free light chain

BACKGROUND

Chronic lymphocytic leukemia (CLL) is frequently accompanied by immune dysregulation.

AIMS

In this multicenter prospective study, we investigated whether heavy + light chains (HLC: IgGκ, IgGλ, IgAκ, IgAκ, IgMκ, IgMλ) and IgG subclasses (IgG1, IgG2, IgG3, and IgG4) could be used as novel prognostic markers of immunoparesis in 105 treatment-naïve patients with CLL.

RESULTS

Heavy + light chains immunoparesis of ≥1, ≥2, and ≥3 isotypes was evident in 74 (70%), 58 (55%), and 36 (34%) patients, respectively. Severe HLC immunoparesis was identified in 40 (38%) patients. Of the IgG subclasses, IgG1 and IgG2 were most frequently suppressed, affecting 46 (44%) and 36 (34%) patients, respectively; 63 (60%) patients had low levels of at least one IgG subclass. In multivariate analysis, severe HLC immunoparesis (hazard ratio [HR]: 36.5; P = .010) and ΣFLC ≥ 70 mg/L (HR: 13.2; P = .004) were the only factors independently associated with time to first treatment (TTFT). A risk model including these variables identified patients with 0, 1, and 2 risk factors and significantly different TTFT (P < .001). Patients with two factors represented an ultra-high-risk group with a median TTFT of only 1.3 months.

CONCLUSION

The above findings demonstrate the potential for the use of HLC immunoparesis, together with sFLC measurements, as future prognostic biomarkers in CLL.

Cost-utility analysis comparing hospital-based intravenous immunoglobulin with home-based subcutaneous immunoglobulin in patients with secondary immunodeficiency

BACKGROUND AND OBJECTIVE

Immunoglobulin replacement therapy (IRT) is often used to support patients with primary immunodeficiency disease (PID) and secondary immunodeficiency disease (SID). Home-based subcutaneous immunoglobulin (SCIg) is reported to be a cheaper and more efficient option compared to hospital-based intravenous immunoglobulin (IVIg) for PID. In contrast, there is little information on the cost-effectiveness of IRT in SID. However, patients who develop hypogammaglobulinaemia secondary to other conditions (SID) have different clinical aetiology compared to PID. This study assesses whether SCIg provides a good value-for-money treatment option in patients with secondary immunodeficiency disease (SID).

METHODS

A Markov cohort simulation model with six health states was used to compare cost-effectiveness of IVIg with SCIg from a healthcare system perspective. The costs of treatment, infection and quality-adjusted life years (QALYs) for IVIg and SCIg treatment options were modelled with a time horizon of 10 years and weekly cycles. Deterministic and probabilistic sensitivity analyses were performed around key parameters.

RESULTS

The cumulative cost for IVIg was A$151 511 and for SCIg A$144 296. The QALYs with IVIg were 3·07 and with SCIg 3·51. Based on the means, SCIg is the dominant strategy with better outcomes and at lower cost. The probabilistic sensitivity analysis shows that 88·3% of the 50 000 iterations fall below the nominated willingness to pay threshold of A$50 000 per QALY. Therefore, SCIg is a cost-effective treatment option.

CONCLUSION

For SID patients in Queensland (Australia), the home-based SCIg treatment option provides better health outcomes and cost savings.

Epidemiology of bloodstream infections in patients with chronic lymphocytic leukemia: a longitudinal nation-wide cohort study

Patients with chronic lymphocytic leukemia (CLL) have a high risk of bloodstream infections (BSI). BSI cause significant morbidity and mortality among CLL patients; approximately one-third of fatalities in CLL list infections as cause of death. All CLL patients in Denmark diagnosed between 2008 and 2016 were followed through registries for the event of a BSI. Patient characteristics and bacterial findings were analyzed separately for treatment-naive and treated patients. A total of 3677 and 1020 patients with CLL were followed as treatment-naive and treated patients, respectively. We identified 145 cases of Gram-positive bacteremia. Streptococcus pneumoniae accounted for 32 (22%) cases, while Staphylococcus aureus was found 30 times (21%). Gram-negative microorganisms were found in 166 (46%) cases. Escherichia coli accounted for 77 (46%) cases. Lastly, we identified six episodes of candidemia of which five (83%) were fatal within 30 days of the infection. Based on increased frequency of S. pneumoniae and Pseudomonas aeruginosa and the high mortality of candidemia in CLL, empirical antibiotics with double coverage for S. pneumoniae and P. aeruginosa is recommended; upon suspected or proven candidemia, treatment with broad-spectrum fungicidal agents are recommended.