Clinical diagnosis and treatment recommendations for immune checkpoint inhibitor-related hematological adverse events

Grade ≥ 3 hematologic adverse events of immunotherapy in advanced NSCLC patients: a systematic review and meta-analysis

BACKGROUND

The impact of incorporating immune checkpoint inhibitors (ICIs) into standard chemotherapy on the severity and risk of myelosuppression in advanced non-small cell lung cancer (NSCLC) patients remains uncertain.

METHODS

We conducted a systematic review and meta-analysis of phase 3 randomized controlled trials (RCTs) that evaluated ICIs in people with NSCLC. A comprehensive search of four databases, PubMed, Web of Science, Embase, and the Cochrane Library, was carried out from inception to 30 October 2023. Pooled analyses assessed the risk ratios (RR) for treatment-related hematological adverse events greater than or equal to grade 3. The protocol is registered with PROSPERO and has the CRD42024500056 registration number.

FINDINGS

Twenty-three phase 3 RCTs were contained, involving 15,844 people with NSCLC receiving ICIs with or without chemotherapy. Compared with chemotherapy alone, ICI monotherapy or dual immunotherapy reduced treatment-associated leukopenia (relative risk (RR) 0.03, 95% CI 0.01-0.08), neutropenia (RR 0.02, 95% CI 0.01-0.03), thrombocytopenia (RR 0.05, 95% CI 0.02-0.14), and anemia (RR 0.09, 95% CI 0.05-0.15), with a pooled incidence of 0.07%, 0.08%, 0.14%, and 9.07%. Compared with chemotherapy alone, ICIs in combination with chemotherapy increased the risk of developing treatment-related thrombocytopenia (RR 1.35, 95% CI 1.04-1.77), with a pooled incidence rate of 6.83%; it did not increase leukopenia (RR 0.97, 95% CI 0.70-1.35), neutropenia (RR 1.05, 95% CI 0.90-1.23), and anemia (RR 1.10, 95% CI 0.85-1.43), with pooled incidence rates of 4.47%, 14.67%, and 13.36%, respectively.

INTERPRETATION

For patients with advanced or metastatic NSCLC, severe hematological adverse events are uncommon when ICIs are used alone, as opposed to chemotherapy. However, when used in conjunction with chemotherapy, these side effects may be intensified, particularly in the form of an elevated incidence of thrombocytopenia of grade 3 or higher.

A Case Report of Severe Thrombocytopenic Purpura during Neoadjuvant Pembrolizumab Administration for Triple-Negative Breast Cancer

INTRODUCTION

Immune thrombocytopenic purpura (ITP) is one of the immune-related adverse events (irAEs) related to immune checkpoint inhibitors (ICIs). Here, we report a case of a 51-year-old woman with triple-negative breast cancer (TNBC) who experienced severe thrombocytopenic purpura during the neoadjuvant chemotherapy (NAC), including pembrolizumab.

CASE PRESENTATION

A 51-year-old woman was diagnosed with Stage II B TNBC and underwent NAC using pembrolizumab + paclitaxel + carboplatin. Her blood test on cycle 4, day 15 (C4D15) showed a significant decrease in platelets to <2000/μL accompanied by overt bleeding tendency. She was hospitalized for further investigation and treatment. Her platelet count recovered after platelet concentrate transfusion and corticosteroid administration. Her bone marrow examination showed normal cellularity, and she was judged as ITP. Due to the event and good clinical response to NAC, she underwent a right partial mastectomy and axillary lymph node dissection without completion of the planned NAC. The surgical specimen showed a complete pathological response.

CONCLUSIONS

Thrombocytopenia is known as one of the hematologic irAEs; however, severe thrombocytopenia with a bleeding tendency is rarely reported. Sufficient explanations to patients and appropriate referral to other related departments are important for earlier detection and treatment of irAE.

Mitigation of checkpoint inhibitor-induced autoimmune hemolytic anemia through modulation of purinergic signaling

ABSTRACT

Immune checkpoint inhibitors (ICPis) have revolutionized cancer immunotherapy but also can induce autoimmune hemolytic anemia (AIHA), a severe disease with high mortality. However, the cellular and molecular mechanism(s) of AIHA secondary to ICPi therapy (ICPi-AIHA) are unclear, other than being initiated through decreased checkpoint inhibition. Herein, we report ICPi-AIHA in a novel mouse model that shows similar characteristics of known human ICPi-AIHA (eg, autoantibodies, hemolysis, and increased mortality). During ICPi-AIHA, there is the simultaneous reduction of 2 regulatory T-cell populations (FoxP3+ and Tr1 [type 1 regulatory cells]) and an increase in inflammatory T helper cell 17 (TH17). Moreover, a novel CD39+CD73-FoxP3-CD25- CD4+ T-cell subset (ie, CD39 single positive [CD39SP]) emerges, and early increases in CD39SP predict AIHA development; CD39 is an ectonuclease that breaks down adenosine triphosphate (ATP). Additionally, we found that boosting ATPase activity by injecting recombinant apyrase mitigates AIHA development and significant CD39SP reductions, both suggesting a functional role for CD39 and demonstrating a novel therapeutic approach. Importantly, CD39SP are detectable in multiple mouse models developing AIHA and in patients with AIHA, demonstrating applicability to idiopathic and secondary AIHA. Highlighting broader autoimmunity relevance, ICPi-treated NZB mice experienced accelerated onset and severity of lupus, including AIHA. Moreover, ICPi treatment of healthy B6 animals led to detectable CD39SP and development of autoantibodies against multiple autoantigens including those on red blood cells and platelets. Together, our findings provide further insight into the cellular and molecular mechanisms of ICPi-AIHA, leading to novel diagnostic and therapeutic approaches with translational potential for use in humans being treated with ICPi.

Evaluation of emergency department visits and immune-related adverse effects (irAEs) in patients treated with nivolumab

INTRODUCTION

The development of immune checkpoint inhibitors (ICIs) represents one of the most significant advancements in cancer treatment over the past decade. Nivolumab, a widely used ICI, has been incorporated into the therapeutic regimens for various cancers. As with any drug, this drug also has side effects, including class-specific immune-related adverse effects (irAEs). Although irAEs are not rare, their diagnosis can be challenging. This study examines the emergency department (ED) visits of patients undergoing nivolumab therapy, focusing on diagnostic challenges, evaluating the management, and outcomes of irAEs in the ED setting.

MATERIAL AND METHODS

A retrospective cohort study was conducted on adult patients who received nivolumab therapy for any cancer between April 1, 2018, and March 31, 2023, at a large, urban tertiary care center. In this study, we evaluated the ED visits of patients receiving nivolumab. In addition to previous studies, we evaluated irAEs in detail (percentage, recognizability, risk factors, reasons for late recognition, and outcome). Patient data were collected from electronic medical records and patient's medical files. The anamnesis, laboratory, and imaging results, ED management, and consultation notes were examined separately for each ED visit. Logistic regression models were employed to identify significant univariable predictors of ED visits and irAEs.

RESULTS

A total of 199 patients were included in the study, all of whom had metastatic cancer. Of these, 154 patients (77.4%) received nivolumab therapy for non-small cell lung cancer. Most patients (71.9%, n = 143) had at least one additional comorbidity. One hundred and eleven patients (55.8%) presented to the ED. Hypertension (OR: 2.425, 95% CI: 1.226-4.795, p = 0.011) and chronic obstructive pulmonary disease (OR: 2.489, 95% CI: 1.133-5.468, p = 0.023) were identified as risk factors for ED visits. A total of 21 irAEs were diagnosed (14 in ED, 6 in the oncology clinic, and 1 in the inpatient ward). Univariate analysis found no significant association between irAE diagnosis and any specific factors.

CONCLUSION

A significant proportion of the patients treated with nivolumab for advanced cancer present to ED for ICI-related adverse events, although most cases were not attributable to irAEs. Due to the vague symptomatology of irAEs, their recognition and diagnosis in the ED can be challenging. Close collaboration between ED physicians and oncologists is paramount to the management of patients with cancer in the ED.

The Potential Adverse Impact of Post-Treatment Thrombocytopenia on Clinical Outcomes in Cancer Patients Treated With Immune Checkpoint Inhibitors

BACKGROUND

The main goal of this study is to explore the prognostic and predictive implications of post-treatment thrombocytopenia on treatment efficacy and clinical outcomes in advanced-stage cancer treated with immune checkpoint inhibitors (ICIs).

METHODS

This retrospective study included 102 patients with advanced-stage cancer who were treated with ICIs. The simultaneous administration of chemotherapy and ICIs was omitted; nevertheless, the selection of chemotherapy agents employed in different treatment lines was left to the discretion of the attending clinician. Patients were stratified into distinct cohorts based on their post-treatment platelet counts (evaluated for up to four to six months after the completion of ICI). The primary endpoint of interest was progression-free survival (PFS), and overall survival (OS) was the secondary endpoint.

RESULTS

Patients with superior Eastern Cooperative Oncology Group (ECOG) performance status and those who received ICI as second-line treatment displayed markedly elevated incidences of grade 1 thrombocytopenia (p < 0.05). Kaplan-Meier survival analysis confirmed that patients with high-grade thrombocytopenia had significantly shorter PFS (six vs. 13 vs. 19 months, p < 0.0001) and OS (10 vs. 21 vs. 25 months, p < 0.0001) than those with lower grades or without thrombocytopenia, respectively. Multivariate analysis revealed that decreased platelet levels were a negative independent prognostic factor for both PFS and OS in patients with advanced-stage cancer who received ICIs.

CONCLUSION

The results of this retrospective study suggest that a decline in platelet levels after treatment represents a dependable adverse prognostic biomarker for clinical outcomes. Moreover, a decrease in platelet levels has been linked to reduced treatment efficacy in advanced-stage cancer patients receiving ICIs, thereby providing valuable prognostic insights for the implementation of personalized treatment strategies in cancer immunotherapy.

A Case of Immune Aplastic Anemia during Combined Treatment with Atezolizumab and Chemotherapy for Non-Small Cell Lung Cancer

Immune check point inhibitors (ICIs) have durable antitumor effects. However, autoimmune toxicities, termed immune-related adverse events, occur in some patients. We report a case of severe immune aplastic anemia (AA) in a patient with non-small cell lung cancer who was receiving atezolizumab with bevacizumab/carboplatin/paclitaxel. Although the cancer has not recurred, his bone marrow is depleted and he did not respond to immunosuppressive therapy. He has survived for 1.5 years with blood transfusions and infection control. Immune AA associated with ICIs is rare, and a treatment has not yet been established. This case report provides information on the management and treatment response of patients with AA caused by ICIs. Further studies should investigate the mechanism and pathogenesis of immune AA caused by ICIs.

Efficacy and Safety of Hetrombopag for Thrombocytopenia in Patients with Advanced Solid Tumors: A Retrospective Study

Objective. To analyze and evaluate the clinical value of hetrombopag in cancer therapy-induced thrombocytopenia (CTIT) caused by antitumor therapy for malignant tumors and to provide scientific evidence support for clinical application in the real-world setting. Methods. The clinical data of CTIT patients with advanced solid tumors who received hetrombopag were analyzed retrospectively. The proportion of patients with different characteristics who recovered platelet count to ≥75 × 109/L at day 14 and the effective rate of platelet elevation was compared by the χ2 test or Fisher exact probability method. $P<0.05$ was considered statistically significant. Results. A total of 60 CTIT patients who received hetrombopag at our site from July 2021 to October 2022 were finally included in this study. The proportion of patients who achieved therapeutic effect within (7 ± 2) days after treatment was 26.7% (16/60), among which 20.0% (12/60) patients had platelet count recovered to ≥100 × 109/L, and 25.0% (15/60) patients had platelet count increase from baseline ≥50 × 109/L. Within (14 ± 2) days of treatment with hetrombopag, 66.7% (40/60) of patients achieved treatment response, of whom 56.7% (34/60) had platelet counts ≥100 × 109/L and 53.3% (32/60) had platelet counts ≥50 × 109/L increase from baseline. In addition, no treatment-related adverse events occurred during the treatment period. Conclusion. This retrospective study provides preliminary evidence that hetrombopag increases platelets in CTIT patients receiving antitumor therapy for advanced solid tumors.

Immune Checkpoint Inhibitor-Induced Pure Red Cell Aplasia: A Review of 2 Cases in Metastatic Melanoma

BACKGROUND Immunotherapy is a novel treatment offering an alternative to traditional chemotherapeutic agents for different malignancies. Hematologic adverse reactions (HARs) related to immune checkpoint inhibitors (ICIs) are uncommon. Pure red cell aplasia (PRCA) is a rare hematologic complication of ICI therapy in metastatic melanoma with significant mortality risk despite treatment with steroids or immunosuppressive therapy. For unexplained acute anemia after exclusion of other causes, performing bone marrow biopsy is imperative to diagnose PRCA and rule out involvement of bone marrow by primary tumor. HARs can occur during ICI therapy or even after ICI therapy is stopped. ICI rechallenge, even after the development of HARs, is considered in some patients with good response to treatment of HARs from ICIs. Recurrence of HARs with the same or different type of reaction is seen in some patients. CASE REPORT Two cases of ICI-induced PRCA were confirmed on bone marrow biopsy after dual ICI treatment with nivolumab and ipilimumab in metastatic melanoma. In case 2, PRCA was successfully treated with steroids and later rechallenged with single-agent nivolumab, causing mild ICI-induced immune thrombocytopenia, which did not require treatment with steroids. CONCLUSIONS It is crucial to increase clinician awareness of the possibility of PRCA development not only during treatment with ICI but also after finishing treatment with ICI; there is high mortality associated with missing an opportunity to diagnose and treat PRCA on time with favorable results. ICI rechallenge can be considered in patients who showed response to immunotherapy, especially those with limited alternative therapeutic options.

Immune checkpoint inhibitor-induced aplastic anaemia: Case series and large-scale pharmacovigilance analysis

Introduction: Impressive advances in immunotherapy especially immune checkpoint inhibitors have made great progress in treating multiple cancers but can also cause serious even incurable immune-related adverse events, mostly found in colitis, dermatitis, hepatitis, and thyroiditis patients. Rare autoimmune hematologic toxicities have been reported in the literature, but are poorly described. Aplastic anaemia induced by immune checkpoint inhibitors is a life-threatening autoimmune disease; however, only a few cases have been reported in the literature. Objective: To characterize and evaluate Aplastic anaemia associated with different ICI regimens in public database and review the literature. Methods: We described a case series of patients experiencing Aplastic anaemia while on immune checkpoint inhibitors. We also mined the Food and Drug Administration's Adverse Event Reporting System and used reporting odds ratio, the proportional reporting ratio, the Bayesian confidence propagation neural network and the multi-item gamma Poisson shrinker algorithms to achieve the data of the suspected adverse events of Aplastic anaemia-induced by immune checkpoint inhibitors between January 2011 and June 2022. Results: Thirteen patients with Aplastic anaemia events while on immune checkpoint inhibitors were included in our case series, and seven of them had a fatal outcome. In FAERS, a total of 38 individual case safety reports (immune checkpoint inhibitors) with different ICI regimens were retrieved, of which 25 (65.79%) were reported as monotherapy and 13 (34.2%) had a fatal outcome. The reporting odds ratio was significant for nivolumab (reporting odds ratio 3.05, 95%CI 1.73-5.38), pembrolizumab (reporting odds ratio 2.33, 95%CI 1.16-4.67), avelumab (reporting odds ratio 12.63, 95%CI 3.15-50.62) and ipilimumab/nivolumab (ROR 2.57, 95%CI 1.15-5.72). Conclusion: There is a significant reporting signal of Aplastic anaemia with several ICI agents. Clinicians should raise awareness and monitor this potentially fatal adverse event.

Immune checkpoint inhibitor-induced pure red cell aplasia: Case series and large-scale pharmacovigilance analysis

INTRODUCTION

Impressive advances in immunotherapy, especially immune checkpoint inhibitors (ICIs), have made great progress in treating multiple cancers. However, ICIs can also cause serious, even incurable, immune-related adverse events (irAEs), most often in patients with colitis, dermatitis, hepatitis, and thyroiditis. Rare autoimmune hematologic toxicities have been reported in the literature but are poorly described. Pure red cell aplasia (PRCA) induced by ICIs is a life-threatening autoimmune disease; however, only a few cases have been reported in the literature.

OBJECTIVE

To characterize and evaluate PRCA associated with different ICI regimens in a public database and to review the relevant literature.

METHODS

We described a case series of patients experiencing PRCA while on ICIs. We also mined the Food and Drug Administration's Adverse Event Reporting System (FAERS) and used reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network (BCPNN), and multi-item gamma Poisson shrinker (MGPS) algorithms to analyze the data of the suspected adverse events of PRCA induced by ICIs between January 2011 and June 2022.

RESULTS

Fifteen patients with PRCA events while on ICIs were included in our case series. In FAERS, a total of 41 individual case safety reports (ICSRs) with different ICI regimens were retrieved, among which 28 (68.3%) were related to monotherapy and three (7.3%) involved a fatal outcome. Signals of PRCA for all four ICI monotherapies (nivolumab, pembrolizumab, durvalumab, and atezolizumab) and ICI combination therapy (ipilimumab/nivolumab) were detected. Ipilimumab/nivolumab presented a higher reporting signal than nivolumab.

CONCLUSIONS

There is a significant reporting signal of PRCA with several ICI agents. Clinicians should be aware of and monitor this potentially fatal adverse event.

Immune Checkpoint Inhibitor-Related Cytopenias: About 68 Cases from the French Pharmacovigilance Database

Simple Summary

Data on immune checkpoint inhibitor (ICI)-related cytopenias are scarce. The aim of the study was to further characterize grade ≥ 2 ICI-related cytopenias using the French pharmacovigilance database. Immune thrombocytopenia and autoimmune hemolytic anemia were the most frequently reported ICI-related cytopenias (50.7% and 25.3%, respectively). Nearly half were grade ≥ 4, and 4.4% of patients died from cytopenia-related complications. Using the French pharmacovigilance database, this study provides a comprehensive analysis of ICI-related cytopenias that are rare but potentially life-threatening adverse drug reactions. Early recognition and timely initiation of appropriate treatment are key in their management in clinical practice.

Abstract

Immune checkpoint inhibitor (ICI)-related cytopenias have been poorly described. This study aimed to further characterize ICI-related cytopenias, using the French pharmacovigilance database. All grade ≥ 2 hematological adverse drug reactions involving at least one ICI coded as suspected or interacting drug according to the World Health Organization criteria and reported up to 31 March 2022, were extracted from the French pharmacovigilance database. Patients were included if they experienced ICI-related grade ≥ 2 cytopenia. We included 68 patients (75 ICI-related cytopenias). Sixty-three percent were male, and the median age was 63.0 years. Seven patients (10.3%) had a previous history of autoimmune disease. Immune thrombocytopenia (ITP) and autoimmune hemolytic anemia (AIHA) were the most frequently reported (50.7% and 25.3%, respectively). The median time to onset of ICI-related cytopenias was 2 months. Nearly half were grade ≥ 4, and three patients died from bleeding complications of refractory ITP and from thromboembolic disease with active AIHA. Out of 61 evaluable responses, complete or partial remission was observed after conventional treatment in 72.1% of ICI-related cytopenias. Among the 10 patients with ICI resumption after grade ≥ 2 ICI-related cytopenia, three relapsed. ICI-related cytopenias are rare but potentially life-threatening. Further studies are needed to identify risk factors of ICI-related cytopenias.

Sintilimab treatment for ureteral carcinoma following bladder cancer leads to leukopenia: a case report

Herein, we present a case report of sintilimab treatment for a patient with ureteral cancer reoccurring after bladder cancer, and exploration of the mechanism of adverse reactions from the aspects of intestinal flora and immunity. We have reported a case of leukopenia in a patient with recurrent ureteral cancer after bladder cancer who was treated with sintilimab. A 52-year-old Chinese man with a history of hypertension and diabetes presented with lower urinary tract symptoms, including painless hematuria, frequent and urgent urination, and micturition without pain. Computed tomography (CT) and 3-dimensional (3D) reconstruction suggested bladder space occupation, bladder cancer was pathologically confirmed after laser resection of the bladder tumor, which then recurred and was subject to reoperation. After 8 months, B-mode ultrasonography indicated left ureter occupation, and the patient began sintilimab immunotherapy according to the outcome of immunohistochemistry (IHC) and immune checkpoint inhibitor (ICI) evaluation. The patient was treated with sintilimab a total of 6 times. After the first treatment, the patient was in stable condition. The second treatment was discontinued due to renal insufficiency. The patient was then treated with renal and liver protection for 1.5 months, followed by 5 rounds of immunotherapy. After the sixth round of immunotherapy, the patient presented with leukopenia. In order to determine the causes of adverse reactions, we analyzed the changes of intestinal flora of patients before and after immunotherapy, and summarized the immune function indicators of patients during immunotherapy. The leucopenia induced by sintilimab may be related to intestinal flora and immunity.

Understanding neutropenia secondary to intrinsic or iatrogenic immune dysregulation

As a key member of the innate and adaptive immune response, neutrophils provide insights into the hematopoietic and inflammatory manifestations of inborn errors of immunity (IEI) and the consequences of immunotherapy. The facile recognition of IEI presenting with neutropenia provides an avenue for hematologists to facilitate early diagnosis and expedite biologically rationale care. Moreover, enhancing the understanding of the molecular mechanisms driving neutropenia in IEI-decreased bone marrow reserves, diminished egress from the bone marrow, and decreased survival-offers an opportunity to further dissect the pathophysiology driving neutropenia secondary to iatrogenic immune dysregulation, eg, immune checkpoint inhibitors and chimeric antigen receptor T-cell therapy.

Pembrolizumab-induced autoimmune haemolytic anemia in a patient with chronic lymphocytic leukaemia successfully treated with ibrutinib

We present a unique case of a patient with a long-standing history of indolent chronic lymphocytic leukaemia (CLL) who suddenly developed autoimmune haemolytic anaemia after starting immune checkpoint inhibitor therapy for bladder cancer. He had no clear indication to start CLL-directed treatment based on current clinical practice guidelines; however, targeted treatment of CLL with ibrutinib proved to be effective in treating the haemolytic anaemia.

Immune checkpoint inhibitors: An emergency medicine focused review

INTRODUCTION

Several novel cancer therapies have been developed, many of which focused on immune system modulation. These include immune checkpoint inhibitors, modulators, T-cell therapy, monoclonal antibodies, cytokines, oncolytic viruses, and vaccines. Although many of these therapies are well tolerated, significant adverse reactions can occur as a result of these novel drugs.

OBJECTIVE

This narrative review discusses complications associated with immune based cancer therapies, specifically immune checkpoint inhibitors, for emergency clinicians.

DISCUSSION

Novel cancer therapies including immune checkpoint inhibitors can improve the care of patients with malignancy. However, these therapies have a number of potential complications, known as immune-related adverse events (irAEs). Complications can involve the neurologic, cardiac, pulmonary, dermatologic, renal, gastrointestinal, hepatic, and hematologic systems. IrAEs most commonly occur in the first several months following treatment initiation. These complications can be graded based on severity of clinical and laboratory findings. While most of these irAEs are mild, patients may present with critical illness. Treatment commonly includes immune checkpoint inhibitor discontinuation, steroids, and evaluation for other immunosuppressant medications.

CONCLUSIONS

Knowledge of this novel cancer therapy class and its potential complications can improve the care of patients on immune checkpoint inhibitors in the emergency department setting.

The role of CD71+ erythroid cells in the regulation of the immune response

Complex regulation of the immune response is necessary to support effective defense of an organism against hostile invaders and to maintain tolerance to harmless microorganisms and autoantigens. Recent studies revealed previously unappreciated roles of CD71⁺ erythroid cells (CECs) in regulation of the immune response. CECs physiologically reside in the bone marrow where erythropoiesis takes place. Under stress conditions, CECs are enriched in some organs outside of the bone marrow as a result of extramedullary erythropoiesis. However, the role of CECs goes well beyond the production of erythrocytes. In neonates, increased numbers of CECs contribute to their vulnerability to infectious diseases. On the other side, neonatal CECs suppress activation of immune cells in response to abrupt colonization with commensal microorganisms after delivery. CECs are also enriched in the peripheral blood of pregnant women as well as in the placenta and are responsible for the regulation of feto-maternal tolerance. In patients with cancer, anemia leads to increased frequency of CECs in the peripheral blood contributing to diminished antiviral and antibacterial immunity, as well as to accelerated cancer progression. Moreover, recent studies revealed the role of CECs in HIV and SARS-CoV-2 infections. CECs use a full arsenal of mechanisms to regulate immune response. These cells suppress proinflammatory responses of myeloid cells and T-cell proliferation by the depletion of ʟ-arginine by arginase. Moreover, CECs produce reactive oxygen species to decrease T-cell proliferation. CECs also secrete cytokines, including transforming growth factor β (TGF-β), which promotes T-cell differentiation into regulatory T-cells. Here, we comprehensively describe the role of CECs in orchestrating immune response and indicate some therapeutic approaches that might be used to regulate their effector functions in the treatment of human conditions.

Two cases of lung cancer with hemophagocytic lymphohistiocytosis caused by immune checkpoint inhibitors

We report the cases of two patients with secondary hemophagocytic lymphohistiocytosis caused by immune checkpoint inhibitors, who were diagnosed using the recently developed HScore. The first patient presented with fever, cytopenia, and elevated liver enzyme levels at 46 days post‐pembrolizumab administration. The HScore was 175. The second patient developed an immune‐related adverse event at 30 days after the final pembrolizumab dose. The HScore was 185. Hemophagocytic lymphohistiocytosis was confirmed in both patients, and corticotherapy improved their condition. It is challenging to diagnose hemophagocytic lymphohistiocytosis, particularly after development at a late stage. Our patients developed hemophagocytic lymphohistiocytosis late after immune checkpoint inhibitor administration. However, the HScore enabled us to diagnose both cases precisely and in a timely manner.

Autoimmune Complications in Hematologic Neoplasms

Autoimmune cytopenias (AICy) and autoimmune diseases (AID) can complicate both lymphoid and myeloid neoplasms, and often represent a diagnostic and therapeutic challenge. While autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP) are well known, other rarer AICy (autoimmune neutropenia, aplastic anemia, and pure red cell aplasia) and AID (systemic lupus erythematosus, rheumatoid arthritis, vasculitis, thyroiditis, and others) are poorly recognized. This review analyses the available literature of the last 30 years regarding the occurrence of AICy/AID in different onco-hematologic conditions. The latter include chronic lymphocytic leukemia (CLL), lymphomas, multiple myeloma, myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML), myeloproliferative neoplasms, and acute leukemias. On the whole, AICy are observed in up to 10% of CLL and with higher frequencies in certain subtypes of non-Hodgkin lymphoma, whilst they occur in less than 1% of low-risk MDS and CMML. AID are described in up to 30% of myeloid and lymphoid patients, including immune-mediated hemostatic disorders (acquired hemophilia, thrombotic thrombocytopenic purpura, and anti-phospholipid syndrome) that may be severe and fatal. Additionally, AICy/AID are found in about 10% of patients receiving hematopoietic stem cell transplant or treatment with new checkpoint inhibitors. Besides the diagnostic difficulties, these AICy/AID may complicate the clinical management of already immunocompromised patients.

Hematological immune related adverse events after treatment with immune checkpoint inhibitors

INTRODUCTION

With the increasing use of checkpoint inhibitors, rare immune-related adverse events (irAE) are being identified. Haematological irAE (hem-irAE) are difficult to treat and have shown high mortality rates. In order to improve side-effect management for these potentially life-threatening events, we analysed frequency, severity and outcomes.

PATIENTS AND METHODS

Patients who developed hem-irAE while being treated with immune checkpoint inhibitors (ICI) therapy were retrospectively identified from 18 international cancer centres.

RESULTS

In total, more than 7626 patients treated with ICI were screened, and 50 patients with hem-irAE identified. The calculated incidence amounts to 0.6% and median onset was 6 weeks after the ICI initiation (range 1-128 weeks). Thrombocytopenia and leucopaenia were the most frequent hem-irAE with 34% (17/50) and 34% (17/50), respectively, followed by anaemia 28% (14/50), hemophagocytic lymphohistiocytosis (4% (2/50)), aplastic anaemia (2% (1/50)), acquired haemophilia A (2% (1/50)) and coagulation deficiency (2% (1/50)). Simultaneous thrombocytopenia and neutropenia occurred in two patients, concurrent anaemia and thrombocytopenia in one patient. Other than cessation of ICI (in 60%) and corticosteroids (in 78%), treatment included second-line immunosuppression in 24% of cases. Events resolved in 78% (39/50), while 18% (9/50) had persistent changes, and 2% (1/50) had fatal outcomes (agranulocytosis).

CONCLUSION

Hem-irAE can affect all haematopoietic blood cell lineages and may persist or even be fatal. Management may require immunosuppression beyond corticosteroids. Although these irAE are rare, treating physicians should be aware, monitor blood counts regularly and promptly act upon detection.

Difficult Cases of Autoimmune Hemolytic Anemia: A Challenge for the Internal Medicine Specialist

Autoimmune hemolytic anemia (AIHA) is diagnosed in the presence of anemia, hemolysis, and direct antiglobulin test (DAT) positivity with monospecific antisera. Many confounders of anemia and hemolytic markers should be included in the initial workup (i.e., nutrients deficiencies, chronic liver or kidney diseases, infections, and cancers). Besides classical presentation, there are difficult cases that may challenge the treating physician. These include DAT negative AIHA, diagnosed after the exclusion of other causes of hemolysis, and supported by the response to steroids, and secondary cases (infections, drugs, lymphoproliferative disorders, immunodeficiencies, etc.) that should be suspected and investigated through careful anamnesis physical examination, and specific tests in selected cases. The latter include autoantibody screening in patients with signs/symptoms of systemic autoimmune diseases, immunoglobulins (Ig) levels in case of frequent infections or suspected immunodeficiency, and ultrasound/ computed tomography (CT) studies and bone marrow evaluation to exclude hematologic diseases. AIHA occurring in pregnancy is a specific situation, usually manageable with steroids and intravenous (iv) Ig, although refractory cases have been described. Finally, AIHA may complicate specific clinical settings, including intensive care unit (ICU) admission, reticulocytopenia, treatment with novel anti-cancer drugs, and transplant. These cases are often severe, more frequently DAT negative, and require multiple treatments in a short time.

Cancer and Immune Checkpoint Inhibitor Treatment in the Era of SARS-CoV-2 Infection

Simple Summary

The introduction of immune checkpoint inhibitors (ICI) in 2011 revolutionized the management of many solid cancers and hematological malignancies. However, there are concerns regarding the use of ICI in the era of COVID-19. We present currently available information on the pros and cons of using ICI in cancer patients with respect to the risk of acquiring an infection by SARS-CoV2 and mortality from COVID-19. By means of the present paper, clinicians and researchers may update their knowledge on a highly topical clinical question—is the use of ICI in cancer patients with SARS-CoV2 infection harmful with respect to COVID-19 outcome?

Abstract

Whether cancer patients receiving immune checkpoint inhibitors (ICI) are at an increased risk of severe infection and mortality during the corona pandemic is a hotly debated topic that will continue to evolve. Here, we summarize and discuss current studies regarding COVID-19 and anti-cancer treatment with an emphasis on ICI. Importantly, several lines of evidence suggest that patients currently treated with ICI do not display an increased vulnerability to infection with SARS-CoV-2. Data regarding morbidity and mortality associated with COVID-19 in cancer patients receiving ICI are less clear and often conflicting. Although mostly based on experimental data, it is possible that ICI can promote the exacerbated immune response associated with adverse outcome in COVID-19 patients. On the other hand, mounting evidence suggests that ICI might even be useful in the treatment of viral infections by preventing or ameliorating T cell exhaustion. In this context, the right timing of treatment might be essential. Nevertheless, some cancer patients treated with ICI experience autoimmune-related side effects that require the use of immunosuppressive therapies, which in turn may promote a severe course of infection with SARS-CoV-2. Although there is clear evidence that withholding ICI will have more serious consequences, further studies are urgently needed in to better evaluate the effects of ICI in patients with COVID-19 and the use of ICI during the corona pandemic in general.

Anti-angiogenic Agents in Combination With Immune Checkpoint Inhibitors: A Promising Strategy for Cancer Treatment

Advances in cancer immunity have promoted a major breakthrough in the field of cancer therapy. This is mainly associated with the successful development of immune checkpoint inhibitors (ICIs) for multiple types of human tumors. Blockade with different ICIs, including programmed cell death 1 (PD-1), programmed cell death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors, may activate the immune system of the host against malignant cells. However, only a subgroup of patients with cancer would benefit from immune checkpoint blockade. Some patients experience primary resistance to initial immunotherapy, and a majority eventually develop acquired resistance to ICIs. However, the mechanisms involved in the development of drug resistance to immune checkpoint blockade remain unclear. Recent studies supported that combination of ICIs and anti-angiogenic agents could be a promising therapeutic strategy for overcoming the low efficacy of ICIs. Moreover, through their direct anti-cancer effect by inhibiting tumor growth and metastasis, anti-angiogenic drugs reprogram the tumor milieu from an immunosuppressive to an immune permissive microenvironment. Activated immunity by immune checkpoint blockade also facilitates anti-angiogenesis by downregulating the expression of vascular endothelial growth factor and alleviating hypoxia condition. Many clinical trials showed an improved anti-cancer efficacy and prolonged survival following the addition of anti-angiogenic agents to ICIs. This review summarizes the current understanding and clinical development of combination therapy with immune checkpoint blockade and anti-angiogenic strategy.

On the use of immune checkpoint inhibitors in patients with viral infections including COVID-19

The present review summarizes up-to-date evidence addressing the frequently discussed clinical controversies regarding the use of immune checkpoint inhibitors (ICIs) in cancer patients with viral infections, including AIDS, hepatitis B and C, progressive multifocal leukoencephalopathy, influenza, and COVID-19. In detail, we provide available information on (1) safety regarding the risk of new infections, (2) effects on the outcome of pre-existing infections, (3) whether immunosuppressive drugs used to treat ICI-related adverse events affect the risk of infection or virulence of pre-existing infections, (4) whether the use of vaccines in ICI-treated patients is considered safe, and (5) whether there are beneficial effects of ICIs that even qualify them as a therapeutic approach for these viral infections.

The Changing Landscape of Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia (AIHA) is a greatly heterogeneous disease due to autoantibodies directed against erythrocytes, with or without complement activation. The clinical picture ranges from mild/compensated to life-threatening anemia, depending on the antibody's thermal amplitude, isotype and ability to fix complement, as well as on bone marrow compensation. Since few years ago, steroids, immunesuppressants and splenectomy have been the mainstay of treatment. More recently, several target therapies are increasingly used in the clinical practice or are under development in clinical trials. This has led to the accumulation of refractory/relapsed cases that often represent a clinical challenge. Moreover, the availability of several drugs acting on the different pathophysiologic mechanisms of the disease pinpoints the need to harness therapy. In particular, it is advisable to define the best choice, sequence and/or combination of drugs during the different phases of the disease. In particular relapsed/refractory cases may resemble pre-myelodysplastic or bone marrow failure syndromes, suggesting a careful use of immunosuppressants, and vice versa advising bone marrow immunomodulating/stimulating agents. A peculiar setting is AIHA after autologous and allogeneic hematopoietic stem cell transplantation, which is increasingly reported. These cases are generally severe and refractory to standard therapy, and have high mortality. AIHAs may be primary/idiopathic or secondary to infections, autoimmune diseases, malignancies, particularly lymphoproliferative disorders, and drugs, further complicating their clinical picture and management. Regarding new drugs, the false positivity of the Coombs test (direct antiglobulin test, DAT) following daratumumab adds to the list of difficult diagnosis, together with the passenger lymphocyte syndrome after solid organ transplants. Diagnosis of DAT-negative AIHAs and evaluation of disease-related risk factors for relapse and mortality, notwithstanding improvement in diagnostic approach, are still an unmet need. Finally, AIHA is increasingly described following therapy of solid cancers with inhibitors of immune checkpoint molecules. On the whole, the double-edged sword of new pathogenetic insights and therapies has changed the landscape of AIHA, both providing enthusiastic knowledge and complicating the clinical management of this disease.