Pembrolizumab-induced agranulocytosis

INTRODUCTION

With the widespread use of anti-programmed death-1 monoclonal antibodies, such as pembrolizumab, rare side effects appear in clinical practice.

CASE REPORT

We report the case of a man diagnosed with non-keratinizing squamous lung carcinoma stage IVB with programmed death-ligand 1 70% who developed agranulocytosis 10 days after a single dose of pembrolizumab as monotherapy.

MANAGEMENT AND OUTCOME

Pembrolizumab was discontinued immediately. Grade 4 neutrophil decrease is mentioned in the product information sheet as a rare side effect. The patient was admitted in poor physical condition with grade 4 neutropenic fever, mucositis and anemia. Agranulocytosis did not improve despite treatment with granulocyte colony-stimulating factor, intravenous corticosteroids and intravenous immunoglobulins. He experienced a rapid worsening and died 3 weeks after admission. The causal relationship between pembrolizumab and the appearance of agranulocytosis was determined as possible according to Naranjo's modified Karch and Lasagna's imputability algorithm.

DISCUSSION

Hematologic immune-related adverse events are uncommon but important side effects among patients treated with immune checkpoint inhibitors. Agranulocytosis and neutropenia are infrequently reported but can be life-threatening. The main approach for agranulocytosis consists of intravenous corticosteroids, granulocyte colony-stimulating factors and blood products. Depending on bone marrow characteristics, treatments for refractory patients include intravenous immunoglobulins or cyclosporine. After an immune-related adverse event, benefits and risks must be considered before continuation with an immune checkpoint inhibitor. Detection and communication of adverse drug reactions to the Pharmacovigilance Systems have special relevance for rare side effects.

'Double whammy': An Unusual Co-occurrence of Idiosyncratic phenytoin-induced agranulocytosis and acute liver failure in a child

Idiosyncratic adverse events to phenytoin therapy, such as agranulocytosis and acute liver failure, though rare, may be life-threatening. Simultaneous occurrence of both adverse events is exceedingly rare; only two cases have been reported in the literature to date. We describe such a case in a 15-year-old girl. Prompt haematological and hepatic recovery occurred after discontinuation of the drug. Given the widespread use of phenytoin in seizure disorders, clinicians prescribing this drug should be aware of its potential complications. Early recognition can considerably improve outcomes.

Agranulocytosis Associated With Psychiatric Polypharmacy: Lessons Learned From a Clinical Case

Psychiatric polypharmacy involves the use of two or more psychotropic medications to manage a mental and emotional condition. The prevalence of psychotropic polypharmacy has been increasing since the 1990s and has been attributed to the rise in multiple psychiatric conditions presenting in one patient. However, as the prevalence of polypharmacy increases to maximize therapeutic advantages, so does the adverse effect profile of those drugs used in combination, leading to very life-threatening effects such as agranulocytosis. Thus, we report a case of agranulocytosis secondary to polypharmacy in a patient with a history of multiple complex psychiatric conditions.  The patient is a 20-year-old female with a past medical history of major depressive disorder, borderline personality disorder, post-traumatic stress disorder, anxiety disorder, hypothyroidism, and ulcerative colitis. Her psychiatric conditions were managed with multiple medications including chlorpromazine, and clozapine was recently added a month prior to admission. Upon admission, the patient was hemodynamically stable and febrile, with complaints of generalized body aches and myalgia. Laboratory results showed profound leukopenia with a white blood cell count of 1.0x103/uL and a neutrophil number of 0.02x103/uL. The patient was admitted to the hospital for neutropenic sepsis and was aggressively treated with intravenous antibiotics. Her clozapine and chlorpromazine were discontinued. In this report, we discuss the association between chlorpromazine and clozapine use and agranulocytosis, emphasizing the importance of regular monitoring and heightened awareness for patients on these medications. This case also underscores the necessity for cautious polypharmacy medication management in individuals with complex psychiatric conditions, highlighting the potential life-threatening consequences of polypharmacy in this population.

Gingival Necrosis Related to Sepsis-Induced Agranulocytosis Due to Pseudomonas aeruginosa Bacteraemia: A Case Report

Background: There have been no reports of sepsis-induced agranulocytosis causing gingival necrosis in otherwise medically healthy patients to the authors' best knowledge. Even though there are several case reports of gingival necrosis secondary to medication-induced agranulocytosis, they have not systematically described the natural progression of agranulocytosis-related gingival necrosis. Methods: This paper presents a case report of a 29-year-old female Indian patient with generalised gingival necrosis and constitutive signs of intermittent fever, nausea, and vomiting. She also complained of abdominal pains. Blood counts showed agranulocytosis, and the patient was admitted for a workup of the underlying cause. Parenteral broad-spectrum antibiotics were administered, which brought about clinical resolution. Results: Her gingival necrosis was attributed to sepsis-induced agranulocytosis triggered by Pseudomonas aeruginosa bacteraemia, and upon clinical recovery, spontaneous exfoliation left behind exposed bone. Secondary healing over the exposed alveolar bone was noted after a year-long follow-up, albeit with some residual gingival recession. Conclusions: Oral manifestations of gingival necrosis, when present with concomitant constitutive symptoms, could indicate a serious underlying systemic condition that could be potentially life-threatening if left untreated. Dentists should be cognizant of this possibility so that timely intervention is not delayed.

Comparison of agranulocytosis and anti-neutrophil cytoplasmic antibody-associated vasculitis caused by two antithyroid drugs: A pharmacovigilance study using the WHO international database

BACKGROUND

Methimazole (MMI) and propylthiouracil (PTU) are commonly used for patients with thyrotoxicosis. Agranulocytosis and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is associated with high morbidity and mortality, requiring appropriate interventions. In this study, we compared adverse drug effects associated with MMI and PTU using a real-world large pharmacovigilance database.

METHODS

We searched all Individual Case Safety Reports reported to be associated with MMI and PTU, from VigiBase between 1967 and June 2, 2021. We conducted disproportionality analysis (case/non-case analysis) to analyze the difference in reported adverse drug reactions (ADRs) between antithyroid drugs (case) and the entire database (non-cases). We further analyzed information for the cases of agranulocytosis and AAV.

RESULTS

Among 11 632 cases of ADRs reported after MMI intake, agranulocytosis occurred in 1633 cases and AAV occurred in 41 cases. For 5055 cases of ADRs reported after PTU intake, agranulocytosis occurred in 459 cases and AAV occurred in 110 cases. Agranulocytosis occurred after a median of 28 days after PTU intake and 33 days after MMI intake. More than 95% of the agranulocytosis cases were classified as serious, but most of them (65.1% for PTU and 70.4% for MMI) were reported to have recovered after dechallenge actions; mostly drug withdrawal. AAV occurred after a median of 668 days after PTU intake, and 1162 days after MMI intake.

CONCLUSIONS

This is a pharmacoepidemiological study investigating agranulocytosis and AAV caused by MMI and PTU. Through this research, we could provide more specific insights into a safe prescription of antithyroid drugs in a real-world setting.

Identifying causative medications for agranulocytosis: A case report of an older adult with cerebral infarction

Key Clinical Message

Most drugs that cause adverse events are difficult to identify in critically ill patients undergoing polypharmacy. We share our experience in identifying the causative drug among four suspect drugs administered during emergency treatment.

Abstract

We present the case of a 93-year-old man who was admitted for the treatment of cerebrovascular events. The patient was initially prescribed dual antiplatelet therapy with aspirin and clopidogrel along with lansoprazole, Hange-koboku-toh, and elobixibat. On day 36 after admission, the patient was found to have developed agranulocytosis. To improve his cerebrovascular prognosis, we first discontinued medications other than the anticoagulant medicines and initiated filgrastim. We discontinued clopidogrel 9 days after the discontinuation of the other medicines considering his low white blood cell count. One day after the discontinuation of clopidogrel, the agranulocytosis was alleviated. Considering the time course, clopidogrel, lansoprazole, Hange-koboku-toh, and elobixibat were suspected as the culprit medicines. This case highlights the considerable challenges encountered in clinical practice when attempting to identify the drugs responsible for agranulocytosis, particularly in patients on intensive medication therapy.

Agranulocytosis Associated With Use of Sulfamethoxazole/Trimethoprim in a Healthy Adult

Purpose: A case of sulfamethoxazole/trimethoprim-induced agranulocytosis is reported. Summary: A 53-year-old healthy male presented to the emergency room with a fever of 102.7°F and was found to have a white blood cell (WBC) count of 0.6 × 103 cells/μL with an absolute neutrophil count (ANC) of 0.0 x 103 cells/μL. He had recently completed a 10-day course of sulfamethoxazole/trimethoprim for left lower extremity cellulitis. During admission, a bone marrow biopsy was performed which was not concerning for malignancy and no cause for the agranulocytosis other than the sulfamethoxazole/trimethoprim was identified. The agranulocytosis resolved after 6 days of hospitalization with a WBC count of 8.9 × 103 cells/μL and an ANC of 4.1 x 103cells/μL on the day of discharge. Conclusion: A 53-year-old male developed agranulocytosis after 10 days of sulfamethoxazole/trimethoprim therapy for the treatment of a skin and soft tissue infection. His neutropenia resolved after sulfamethoxazole/trimethoprim discontinuation.

Agranulocytosis and secondary infection related to JAK inhibitors and IL-6 receptor blockers: a disproportionality analysis using the US Food and drug administration adverse event reporting system

Background: Given that the fight against coronavirus disease 2019 (COVID-19) is not over, we aimed to explore the occurrence of agranulocytosis and infectious complications in patients with and without COVID-19 following immunoregulatory therapy based on real-world data. Methods: This was a retrospective disproportionality analysis based on the US Food and Drug Administration Adverse Event Reporting System (FAERS). All cases reported between the first quarter of 2004 and the fourth quarter of 2022 about Janus kinase inhibitors (baricitinib, tofacitinib, ruxolitinib) and interleukin-6 receptor blockers (tocilizumab, sarilumab) were collected. Disproportionality analyses were conducted by reporting odds ratio (ROR) and information component (IC). Results: A total of 211,363 cases were recognized from the FDA Adverse Event Reporting System database. Data analysis showed that tocilizumab (reporting odds ratio: 3.18, 95% CI: 3.18-3.29; information component: 1.37, 95% CI: 1.31-1.42), sarilumab (ROR: 1.64, 95% CI: 1.55-1.73; IC: 0.61, 95% CI: 0.43-0.79), baricitinib (ROR: 3.42, 95% CI: 3.19-3.67; IC: 1.43, 95% CI: 1.21-1.65), tofacitinib (ROR: 2.53, 95% CI: 2.49-2.57; IC: 1.11, 95% CI: 1.05-1.16), and ruxolitinib (ROR: 1.87, 95% CI: 1.83-1.91; IC: 0.77, 95% CI: 0.70-0.84) were all associated with secondary infection. The association in the combination group was higher than that in the monotherapy group (ROR: 4.69, 95% CI: 4.53-4.86; IC: 1.73, 95% CI: 1.62-1.84). As for agranulocytosis, tocilizumab (ROR: 1.61, 95% CI: 1.53-1.69; IC: 0.67, 95% CI: 0.50-0.84) and ruxolitinib (ROR: 2.32, 95% CI: 2.21-2.43; IC: 1.18, 95% CI: 1.02-1.33) showed the significant signals. The association was higher in the combination group than in the monotherapy group (ROR: 2.36, 95% CI: 2.15-2.58; IC: 1.20, 95% CI: 0.90-1.51). Secondary infection after treatment with tofacitinib (ROR: 1.37, 95% CI: 1.02-1.84), tocilizumab (ROR: 1.46, 95% CI: 1.01-2.09), and sarilumab (ROR: 2.46, 95% CI: 1.10-5.50) was reported more frequently in COVID-19 than in non-COVID-19 patients. Conclusion: Both Janus kinase inhibitors and interleukin-6 receptor blockers are significantly associated with secondary infection and agranulocytosis, and the combined treatment further increases the association. The correlation with secondary infection in patients treated with tofacitinib, tocilizumab, and sarilumab is higher in COVID-19 than in non-COVID-19 patients.

Pure White Cell Aplasia Associated With Long-Term Unprotected Exposure to High Concentrations of Benzalkonium Chloride and 2-Phenoxyethanol

Pure white cell aplasia (PWCA) is a very rare hematological disorder with a nearly total absence of granulocytes and their precursor cells. While the disease is rarely diagnosed incidentally in otherwise asymptomatic individuals, most patients suffer from sometimes life-threatening infections. Due to its very low incidence, the precise pathomechanism of PWCA still needs to be elucidated. While most cases reported in the literature have been associated with an underlying thymic or autoimmune disease, some other factors including the intake of certain drugs such as antimicrobial agents or immune checkpoint inhibitors have been identified as potential triggers. Since PWCA is commonly refractory to treatment with granulocyte colony-stimulating factors (G-CSF), the main focus lies in identifying and eliminating the underlying trigger. Here, we report a unique case where the development of PWCA in a 56-year-old man with an upper respiratory tract infection has to be attributed to the long-term unprotected exposure to an industrial detergent containing high concentrations of the preservatives benzalkonium chloride (BAC) and 2-phenoxyethanol (2-PE). As a matter of fact, certain hematotoxic potential has been described in the literature for both BAC and 2-PE.

Antithyroid Drug-Induced Agranulocytosis: A Case Report

Agranulocytosis is a rare but life-threatening complication of methimazole and propylthiouracil, antithyroid drugs (ATDs) prescribed for the treatment of hyperthyroidism. We report the case of a 41-year-old female who presented to our institution with complaints of fevers, chills, sore throat, myalgias, and generalized weakness one month after treatment initiation with methimazole. A complete blood count at admission revealed agranulocytosis with an absolute neutrophil count of 0/μl. After discontinuation of the medication, she was treated with granulocyte-colony stimulating factor and intravenous broad-spectrum antibiotics, which improved her condition on day seven of hospitalization. Although agranulocytosis is a rare complication of antithyroid drugs, providers must maintain a high index of clinical suspicion as prompt diagnosis and treatment are essential. After the diagnosis is confirmed with an absolute neutrophil count <500/μl, management involves discontinuation of the offending agent and initiation of intravenous broad-spectrum antibiotics. Granulocyte-colony stimulating factor, commonly employed in addition to antibiotics, is a controversial treatment option and more research demonstrating its efficacy is necessitated. Preventing mortality associated with antithyroid drug-induced agranulocytosis is achieved through patient education at the time of ATD initiation.

Early Achromobacter xylosoxidans Endocarditis After the Valvular Mitral Replacement Complicated by an Agranulocytosis on B-lactams: A Case Report

An immunocompetent 82-year-old woman developed endocarditis caused by an atypical organism called Achromobacter xylosoxidans, after a first valvular surgery. The intravenous antibiotic therapy with ceftazidime - 2 g every 8 hours during five weeks - a key part of the treatment, induced agranulocytosis as an adverse event. Cross-reactivity between antibiotics was suspected. Finally, the patient's cure was the result of a coordinated effort between medical and surgical professionals. Postoperative follow-up is six years.

Clinical impact of reducing the frequency of clozapine monitoring: controlled mirror-image cohort study

BACKGROUND

To minimise infection during COVID-19, the clozapine haematological monitoring interval was extended from 4-weekly to 12-weekly intervals in South London and Maudsley NHS Foundation Trust.

AIMS

To investigate the impact of this temporary policy change on clinical and safety outcomes.

METHOD

All patients who received clozapine treatment with extended (12-weekly) monitoring in a large London National Health Service trust were included in a 1-year mirror-image study. A comparison group was selected with standard monitoring. The proportion of participants with mild to severe neutropenia and the proportion of participants attending the emergency department for clozapine-induced severe neutropenia treatment during the follow-up period were compared. Psychiatric hospital admission rates, clozapine dose and concomitant psychotropic medication in the 1 year before and the 1 year after extended monitoring were compared. All-cause clozapine discontinuation at 1-year follow-up was examined.

RESULTS

Of 569 participants, 459 received clozapine with extended monitoring and 110 controls continued as normal. The total person-years were 458 in the intervention group and 109 in the control group, with a median follow-up time of 1 year in both groups. During follow-up, two participants (0.4%) recorded mild to moderate neutropenia in the intervention group and one (0.9%) in the control group. There was no difference in the incidence of haematological events between the two groups (IRR = 0.48, 95% CI 0.02-28.15, P = 0.29). All neutropenia cases in the intervention group were mild, co-occurring during COVID-19 infection. The median number of admissions per patient during the pre-mirror period remained unchanged (0, IQR = 0) during the post-mirror period. There was one death in the control group, secondary to COVID-19 infection.

CONCLUSIONS

There was no evidence that the incidence of severe neutropenia was increased in those receiving extended monitoring.

Clozapine rechallenge or continuation despite neutropenia or agranulocytosis using colony-stimulating factor: A systematic review

OBJECTIVES

Rechallenge/continuation of clozapine in association with colony-stimulating factors (CSFs) following neutropenia/agranulocytosis has been reported, but many questions remain unanswered about efficacy and safety. This systematic review aims to assess the efficacy and safety of rechallenging/continuing clozapine in patients following neutropenia/agranulocytosis using CSFs.

METHODS

MEDLINE, Embase, PsycInfo, and Web of Science databases were searched from inception date to July 31, 2022. Articles screening and data extraction were realized independently by two reviewers, according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 systematic review guidance. Included articles had to report on at least one case where clozapine was rechallenged/continued using CSFs despite previous neutropenia/agranulocytosis.

RESULTS

Eight hundred forty articles were retrieved; 34 articles met the inclusion criteria, totaling 59 individual cases. Clozapine was successfully rechallenged/continued in 76% of patients for an average follow-up period of 1.9 years. There was a trend toward better efficacy reported in case reports/series, compared with consecutive case series (overall success rates of 84% and 60%, respectively, p-value = 0.065). Two administration strategies were identified, "as-needed" and prophylactic, both yielding similar success rates (81% and 80%, respectively). Only mild and transient adverse events were documented.

CONCLUSIONS

Although limited by the relatively small number of published cases, factors such as time of onset to first neutropenia and severity of the episode did not seem to impact the outcome of a subsequent clozapine rechallenge using CSFs. While the efficacy of this strategy remains to be further adequately evaluated in more rigorous study designs, its long-term innocuity warrants considering its use more proactively in the management of clozapine hematological adverse events as to maintain this treatment for as many individuals as possible.

A Case Report on Metamizole-Induced Agranulocytosis: Is the Benefit Worth the Risk?

Metamizole is a drug with analgesic and antipyretic properties widely available in Portugal. Its use is highly controversial because of the risk of agranulocytosis, a rare but serious adverse event. A 70-year-old female patient with a recent history of treatment with metamizole for post-surgery fever and pain presented to the ED with sustained fever, diarrhea, and painful mouth ulcers. Laboratory tests revealed agranulocytosis. The patient was placed under protective isolation and started treatment with granulocyte-colony stimulating factor (G-CSF) and empiric antibiotic therapy with piperacillin/tazobactam and vancomycin for neutropenic fever. After an extensive workup, no source of infection was identified. During hospitalization, infectious and neoplastic causes of agranulocytosis were investigated, but the results were negative. Metamizole-induced agranulocytosis was suspected. The patient completed a total of three days of G-CSF and eight days of empiric antibiotic therapy with sustained clinical improvement. She was discharged completely asymptomatic and remained clinically stable during follow-up without a resurgence of agranulocytosis. This case report is intended to increase awareness of metamizole-induced agranulocytosis. While this is a well-known side effect, it is also often overlooked. It is paramount that both physicians and patients know how to correctly manage metamizole to prevent and promptly treat agranulocytosis.

A single-tube multiplex real-time PCR for HLA-B*38:02 genotype by detecting highly specific SNPs

Purpose: HLA-B*38:02 is closely related to carbimazole/methimazole-induced agranulocytosis. This study aimed to develop and validate a rapid and economical method for HLA-B*38:02 genotyping. Methods: A single-tube multiplex real-time PCR detection system comprising amplification refractory mutation system primers and TaqMan probes was established for HLA-B*38:02 genotyping. Sequence-based typing was applied to validate the accuracy of the assay. Results: The accuracy of the assay was 100% for HLA-B*38:02 genotyping. The detection limit of the new method was 0.05 ng DNA. The positive rate of HLA-B*38:02 in the Han (8%, n = 100), Bouyei (17.8%, n = 90) and Tibetan (12.7%, n = 110) populations was significantly higher than that in the Uighur population (1%, n = 100) (p < 0.05). Conclusion: The proposed method is rapid and reliable for HLA-B*38:02 screening in a clinical setting.

Successful Steroid Treatment of Pembrolizumab-induced Agranulocytosis that Developed after Splenectomy in a Patient with Non-small-cell Lung Cancer: A Case Report

Neutropenia, a rare immune-related adverse event, affects patients receiving treatment with immune checkpoint inhibitors (ICIs). We herein report a case of pembrolizumab-induced agranulocytosis. An 83-year-old man was diagnosed with advanced-stage lung carcinoma concomitant with splenomegaly complicated by hypersplenism, causing pancytopenia. To avoid the risk of bone marrow suppression due to cytotoxic chemotherapy, pembrolizumab monotherapy was chosen. However, the patient developed agranulocytosis despite the resolution of pancytopenia through splenectomy performed after the fourth pembrolizumab cycle. Neutrophil counts improved after steroid treatment but not after granulocyte colony-stimulating factor treatment. This case demonstrated that neutropenia can sometimes develop abruptly after several ICI therapy cycles.

Morbidity and Mortality of Neutropenic Patients in Visceral Surgery: A Narrative Review

Leukocytes are essential for the function of the immune system and cell–cell interaction in the human body, but hematological diseases as well as chemotherapeutic treatments due to cancer lead to occasionally or even permanent leukocyte deficiency. Normally, more than 50% of leukocytes are neutrophilic granulocytes, and leukopenia is, therefore, mostly characterized by a decrease in neutrophilic granulocytes. The consequence of neutropenia is increased susceptibility to infection, but also healing disorders are suggestable due to the disturbed cell–cell interaction. While there is no surgical treatment for leucocyte disorders, patients suffering from neutropenia are sometimes in need of surgery for other reasons. Less is known about the morbidity and mortality of this patients, which is why this narrative review critically summarizes the results of recent research in this particular field. The results of this review suggest that neutropenic patients in need of emergency surgery have a higher mortality risk compared to non-neutropenic patients. In contrast, in elective surgery, there was not a clear tendency for a higher mortality risk of neutropenic patients. The role of neutrophilic granulocytes in inflammation and immunity in surgical patients is emphasized by the results, but most of the evaluated studies showed methodological flaws due to small sample sizes or risk of bias. Further research has to evaluate the risk for postoperative complications, particularly of infectious complications such as surgical site infections, in neutropenic patients undergoing elective surgery, and should address the role of neutrophilic function in postoperative morbidity and mortality.

Clozapine-specific proliferative response of peripheral blood-derived mononuclear cells in Japanese patients with clozapine-induced agranulocytosis

BACKGROUND

Although clozapine-induced granulocytopenia (CIG) is less severe than clozapine-induced agranulocytosis (CIA), and some patients with CIG may not go on to develop serious complications, clozapine is discontinued in cases of both CIA and CIG. Understanding the pathogenic mechanisms of CIA/CIG could provide better management of clozapine therapy. Recently, as a mechanistic insight into adaptive immune systems, European groups reported clozapine-specific proliferative responses and clozapine-specific T cells using blood taken from patients with CIA and/or CIG.

AIMS

The aims of our study are to support this mechanistic evidence and to investigate the difference in the lymphocyte response to clozapine between patients with CIG and those with CIA.

METHODS

Lymphocyte stimulation tests (LSTs) were conducted using CD25-positive cell-depleted peripheral blood-derived mononuclear cells (PBMCs) isolated from blood of four Japanese patients with CIA, four patients with CIG, and nine clozapine-tolerant subjects.

RESULTS

Three of four patients with CIA and one of four patients with CIG showed proliferative responses to clozapine with a stimulation index of greater than 2. In contrast, none of the nine clozapine-tolerant subjects showed any response to clozapine. Olanzapine did not stimulate PBMCs of patients with CIA, patients with CIG, or clozapine-tolerant subjects.

CONCLUSIONS

Clozapine- and CIA-specific lymphocyte reactions in a Japanese population provided supportive evidence that the pathogenesis of CIA is based on adaptive immune reactions. In addition, patients with CIG who show a positive response to an LST may at the very least not be chosen for clozapine-rechallenge and further prospective studies are desirable to verify this hypothesis.

Pure white cell aplasia an exceptional condition in the immunological conundrum of thymomas: Responses to immunosuppression and literature review

Thymomas are tumours frequently associated with autoimmune manifestations or immunodeficiencies like Good syndrome. In rare cases, pure white cells aplasia (PWCA) has been described in association with thymomas. PWCA is characterized by agranulocytosis of autoimmune background primary refractory to granulocyte colony-stimulating factor (G-CSF). It is necessary the use of immunosuppressor to allow granulocyte recovery. Without treatment, it could be fatal.

Case Report: High Doses of Intravenous Immunoglobulins as a Successful Treatment for Late Onset Immune Agranulocytosis After Rituximab Plus Bendamustine

Late onset neutropenia (LON) related to rituximab or rituximab plus chemotherapy is defined as an unexplained absolute neutrophil count of ≤1.5 × 10⁹/L starting at least four weeks after the last rituximab administration. LON is infrequent and its pathophysiology remains unknown. There are no guidelines or consensus strategies for the optimal management of patients developing LON. The majority of the patients recover promptly with no specific treatment and only some cases need to be managed with granulocytic colony stimulating factor (G-CSF), usually with a rapid response. Here, we describe a 69-year-old patient with Waldenström's macroglobulinemia who presented a septic event in the context of severe LON after rituximab plus bendamustine. The diagnosed of agranulocytosis was established by bone marrow examination. Interestingly, anti-neutrophil antibodies bound to the patient's granulocytes were found suggesting an autoimmune mechanism. The patient did not respond to G-CSF but achieved a rapid response after high doses of intravenous immunoglobulins with full white blood cell recovery.

The Long-Term Efficacy of Deferiprone in Thalassemia Patients With Iron Overload: Real-World Data from the Registry Database

Deferiprone (DFP) is an oral iron-chelating agent that is widely used in thalassemia patients with iron overload. This study aimed to investigate the long-term efficacy of DFP monotherapy on serum ferritin (SF) and adverse events. All thalassemia patients aged 15 years or older who received DFP monotherapy were identified from the thalassemia registry database between November 2008 and October 2019. After treatment, patients who achieved a target SF level, defined as <1000.0 ng/mL in transfusion-dependent thalassemia (TDT) and <800.0 ng/mL in non-TDT (NTDT) for two consecutive visits, were categorized as the achievable group. We used multivariate analysis to identify factors that contribute to differences between groups. One hundred and five patients were enrolled in the study with a median age of 28 (19-41) years and median initial SF level of 1399.0 (1141.0-2169.0) ng/mL. Of these, 61.0% carried Hb E (HBB: c.79G>A)/β-thalassemia (β-thal) and 60.0% were TDT patients. The median DFP dose was 63 (47-73) mg/kg/d and the median follow-up duration of treatment was 36 (20-54) months. A total of 58 (55.24%) patients were in the achievable group. The initial SF level <1350.0 ng/mL was significantly associated with achieving a targeted SF level (p = 0.002). Ten adverse events resulted in withholding DFP. The most common was gastrointestinal irritation in four patients and three patients with agranulocytosis. In conclusion, DFP is an effective iron chelator in thalassemia patients. Slightly more than half the patients (55.0%) achieved a target SF level. Lower SF levels at the beginning were an important factor.

Drug Reaction with Eosinophilia and Systemic Symptoms and Agranulocytosis Presenting as Cervical Lymphadenopathy

Objective: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare cause of cervical lymphadenopathy. It is a potentially life-threatening hypersensitivity reaction, commonly characterized by fever, rash, hematological abnormalities, and multi-organ involvement. Its association with agranulocytosis is even rarer, with fewer than 10 cases describing the coexistence of DRESS with agranulocytosis reported in the English literature. Case Summary: An otherwise well 40-year-old female presented with a sore throat and cervical lymphadenopathy, with investigations revealing DRESS and agranulocytosis secondary to carbamazepine. Conclusion: DRESS and agranulocytosis are serious, potentially life-threatening adverse drug reactions which can initially present as cervical lymphadenopathy. As carbamazepine is considered first-line therapy for certain chronic neuropathic conditions such as trigeminal neuralgia, clinicians should be aware of the varying clinical presentations of both conditions.

Clozapine and Neutropenia in Patients with Schizophrenia and SARS-CoV-2 Infection

BACKGROUND

Clozapine (CLZ) is used for treatment-resistant schizophrenia (TRS). Adverse reactions to clozapine include neutropenia. In March 2020, WHO declared the COVID-19 pandemic and after, psychiatrists raised concerns regarding continuation of clozapine, due to multiple restrictions. We aimed to provide a study on the association between neutropenia and clozapine in patients with schizophrenia and COVID-19.

AIM

To assess the neutrophil count in patients with schizophrenia treated with clozapine and infected with COVID-19.

METHODS

The study patients with schizophrenia, according to DSM-5, admitted to the Clinical Hospital of Psychiatry and Neurology Brasov, Romania, between April 2020 and October 2021. The inclusion criteria included positive RT-PCR (real-time PCR) test for COVID-19 and treatment with clozapine. We assessed three values of ANC (absolute neutrophil count): before COVID-19 infection (last ANC obtained at mandatory check), during infection and 1 month after resolution (first negative PCR test).

RESULTS

Of the 105 cases, 95 did not have neutropenia. Fifty-nine patients were males (62.1%), mean age was 43.5 years (SD = 12.1) with an average of clozapine treatment of 52.4 months (SD = 11.9). At baseline, they had a small reduction in the ANC mean value (4.41 × 109/l; SD = 2.22) which did not constitute a statistically significant decline from the prior to COVID-19 mean value of 4.66 × 109/l (SD = 2.34; p = 0.45). Values were also normal in the first month after negative PCR testing (4.45 × 109/l; SD = 2.35; p = 0.91). A total of 10 patients (9.5%) had neutropenia. The age, dose of clozapine and duration of treatment were not statistically different compared to the group without neutropenia.

CONCLUSION

Psychiatrists and other health professionals should keep in mind that neutrophil count may decrease during COVID-19 infection in patients taking clozapine and in some cases, neutropenia may even occur. We assumed that neutropenia could be caused by COVID-19 and clozapine interaction.

Acute antibiotically induced neutropenia: A systematic review of case reports

AIMS

Acute neutropenia induced by antibiotics is a rare side effect of this frequently prescribed class of drugs. We aim to find similarities and differences between reported cases.

METHODS

Through a database search (PubMed, 1968-2020), we identified published case reports and extracted, among other data, patient demographics, duration of treatment with the respective agent, and duration of recovery.

RESULTS

Overall, 83 cases were included. Neutropenia developed after a median (min-max) of 21 (17.5-28.5) days of treatment and was resolved after a median (min-max) of 6 (3.0-8.75) days. Vancomycin and ceftaroline emerged as the two most commonly described antibiotics. In 51.8% of cases, the suspected antibiotic was discontinued; in 37.4% of cases, it was substituted by another agent. Only three case reports mentioned death as a result of neutropenia. The use of granulocyte colony-stimulating growth factors (CSFs) shortened the duration of neutropenia and improved outcome for patients' health.

CONCLUSION

Neutropenia induced by antibiotics remains a rare or rarely reported side effect. Long-term and high-dose treatment regimens expose a higher risk of development. Thus, regular full blood counts are advised during therapy.

A puerperal patient with agranulocytosis during tazobactam / piperacillin administration : A case report

Tazobactam / piperacillin (TAZ / PIPC) is an injectable combination drug consisting of a broad-spectrum penicillin and a β-lactamase inhibitor. This antimicrobial has a wide spectrum of efficacy against both Gram-positive bacteria and anaerobes. Adverse events usually present as diarrhea or liver dysfunction ; agranulocytosis has not been reported in Japanese patients with puerperal disorders. However, we report a 32-year-old Japanese woman who received TAZ / PIPC to treat an intraperitoneal infection that developed after complications related to transvaginal delivery. Within 14 days of beginning TAZ / PIPC therapy, the patient developed agranulocytosis, indicated by a white blood cell count of 1900 cells / µL and a neutrophil count of 475 cells / µL. We discontinued TAZ / PIPC at this point and changed the antimicrobial to meropenem. Seven days later, her white blood cell count increased to 3700 cells / µL (neutrophil count : 1684 cells / µL), and the intraperitoneal infection resolved. Patients receiving TAZ / PIPC should be monitored periodically for agranulocytosis as well as for diarrhea and liver dysfunction. J. Med. Invest. 68 : 368-371, August, 2021.

Rothia aeria pneumonia in an immunocompetent patient: A novel case study

An 80-year-old woman with no lung disease or autoimmune disease presented with a productive cough, lasting for 2 months. Chest computed tomography revealed a transbronchial dispersal shadow in the left upper lobe, and sputum culture showed Gram-positive rods. The identified causative organism was Rothia aeria, and thus, she was treated with oral trimethoprim/sulfamethoxazole (TMP-SMX). Eleven days after initiating TMP-SMX treatment, she returned with a complaint of dyspnoea. While the sputum culture revealed normal flora, the patient's condition was diagnosed as bronchitis during R. aeria pneumonia treatment; therefore, she was hospitalized. Five days after admission, her laboratory findings revealed agranulocytosis, caused by an adverse event of TMP-SMX. Her neutrophil count increased after discontinuing TMP-SMX treatment. Bronchitis was alleviated with intravenous antibiotic administration, and she was discharged on Day 8. We report a rare case of R. aeria pneumonia in an immunocompetent patient.

Pre-treatment Neutropenia in Children and Adolescents with Autoimmune Hyperthyroidism

OBJECTIVE

Neutropenia can occur in untreated autoimmune hyperthyroidism (AIH) or in association with treatment with the anti-thyroid drug, methimazole (MMI). Starting MMI in children and adolescents with AIH and pre-existing neutropenia could thus be worrisome. The aim was to describe the prevalence of neutropenia in pediatric AIH, prior to antithyroid drug therapy and to assess the effect of antithyroid drugs on neutrophil count.

METHODS

Patients with AIH attending a pediatric endocrinology clinic were retrospectively reviewed. Absolute neutrophil count (ANC) data at presentation and during anti-thyroid treatment for up to 24 weeks was collected. AIH was defined as elevated free thyroxine (fT4) or free tri-iodothyronine (fT3), suppressed thyroid stimulating hormone, and positive thyroid autoantibodies. Neutropenia was defined as ANC <1500 cells/μL.

RESULTS

Thirty-one patients (71% female) were included with a median interquartile range (IQR) age of 14.71 (11.89-17.10) years. Neither fT4 nor fT3 levels correlated with ANC at presentation (r_s=0.22, p=0.24 and r_s=0.13, p=0.54, respectively). 26/31 (84%) had normal baseline ANC. None developed neutropenia with thionamides. 5/31 (16%) had baseline neutropenia (median ANC 1,200/μL; IQR 874-1200). Four of these five started MMI at diagnosis while one was started on propranolol only but MMI was started one week later. All five normalized ANC within 24 weeks.

CONCLUSION

In this cohort, 16% of AIH patients had neutropenia at presentation, but this resolved in the short term and did not worsen with thionamides. Thionamides may be used with caution in these patients with close monitoring of blood counts.

Therapeutic drug monitoring of clozapine in adults with schizophrenia: a review of challenges and strategies

INTRODUCTION

Clozapine (CLZ) is the superior drug in treatment of schizophrenia. Serum concentration of CLZ is associated with clinical response and dose-dependents side effects, where generalized tonic-clonic seizures are most critical. Thus, therapeutic drug monitoring (TDM) of CLZ may guide individual dosing to reach target exposure and prevent dose-dependent side effects. However, current TDM methods are not capable of predicting the risk of agranulocytosis, which is a dose-independent side effect restricting use of CLZ to treatment-resistant schizophrenia (TRS).

AREAS COVERED

The article provides an overview of clinical, pharmacological, and toxicological aspects of CLZ, and the role of TDM as a tool for dose titration and follow-up in patients with TRS. Main focus is on current challenges and strategies in CLZ TDM, including future perspectives on potential identification/analysis of CLZ metabolite biomarkers reflecting the risk of granulocyte toxicity.

EXPERT OPINION

The association between CLZ serum concentration, clinical response and risk of seizures is indisputable. TDM should therefore always guide CLZ dose titration. Development of advanced TDM methods, including biomarkers predicting the risk of granulocyte toxicity might extend TDM to be a tool for deciding which patients that can be treated safely with CLZ, potentially increasing its utility beyond TRS.

Azathioprine-induced severe myelosuppression accompanied by massive hair loss and painful oral ulcer in an autoimmune hepatitis patient with NUDT15 minor variant: A case report

This report highlights azathioprine-induced severe myelosuppression in the patient with NUDT15 minor variant. This case report is particularly instructive because several typical symptoms are the clues to this critical adverse drug reaction.

Thionamide-induced Agranulocytosis: A Retrospective Analysis of 36 Patients With Hyperthyroidism

OBJECTIVE

Agranulocytosis is a rare but serious adverse drug reaction (ADR) of thionamide antithyroid drugs (ATDs). We explored the characteristics of ADRs in patients with hyperthyroidism.

METHODS

This retrospective study included 3558 inpatients with Graves disease treated in a Class A Grade 3 hospital between 2015 and 2019. The clinical presentation and laboratory workup of patients with antithyroid drug (ATD)-induced agranulocytosis was analyzed.

RESULTS

Agranulocytosis was thought to be caused by ATDs in 36 patients. The hospital length of stay was 12 (10-16) days, and hospitalization costs were approximately $2810.89 ($2156.50-$4164.67). The median duration of ATD therapy prior to agranulocytosis development was 30 (20-40) days. Fever (83.33%) and sore throat (75%) were the most common symptoms as early signs of agranulocytosis. The lowest neutrophil counts were 0.01 (0.00-0.03) × 10⁹/L and 0.14 (0.02-0.29) × 10⁹/L in the methimazole and propylthiouracil groups, respectively (P = .037). The recovery times of agranulocytosis were 9.32 ± 2.89 days and 5.60 ± 4.10 days in the methimazole and propylthiouracil groups, respectively (P = .016). Patients with severe agranulocytosis required a longer time to recover (P < .001) and had closer to normal serum thyroxine and triiodothyronine levels. The interval between the first symptom of agranulocytosis and ATD withdrawal was 1 (0-3) day.

CONCLUSIONS

Patients with agranulocytosis needed a long hospital length of stay and incurred high costs. Methimazole was prone to causing a more serious agranulocytosis than propylthiouracil. High thyroid hormone was unlikely to play a role in adverse drug reactions. Patient education is important.

Clozapine-associated neutropenia following augmentation with sodium valproate

Clozapine is gold standard for the management of treatment-resistant schizophrenia. It can offer life-changing symptom reduction where other antipsychotics have failed, and for these patients, treatment with clozapine should be maintained, if in any possible way. However, treatment with clozapine comes with a risk of developing potentially fatal adverse reactions, for example, severe neutropenia or agranulocytosis, in which case, treatment must be discontinued. Here, we present a case of clozapine-related neutropenia that commenced after the addition of sodium valproate. A subsequent re-challenge to clozapine resulted in severe neutropenia and led to the permanent cessation of clozapine treatment. The patient had been tolerating clozapine for more than a year before the addition of sodium valproate. The awareness of an interaction between clozapine and sodium valproate could help reduce the risk of clozapine-induced neutropenia and subsequent clozapine discontinuation.

Naringin treatment improved main clozapine-induced adverse effects in rats; emphasis on weight gain, metabolic abnormalities, and agranulocytosis

Schizophrenia is one of the major neuropsychiatric disorders affecting people worldwide. Unfortunately, currently available antipsychotic medications possess several side effects. Among them, clozapine is one of the atypical antipsychotics prescribed in schizophrenia wing to its blocking effect on dopamine (D2) and serotonin (5-HT_1c ) receptors. However, it has been recently reserved for resistant schizophrenia due to its several side effects. The current research aimed at investigating potential naringin add-on benefit to cease the main side effects of clozapine in ketamine-induced psychosis in rats. In this study, schizophrenia was induced in rats via ketamine administration that could promote neuropathological patterns of schizophrenia. Afterwards, clozapine and naringin were administered to rats in order to improve such effects induced by ketamine. Clozapine administration promoted weight gain, hyperglycemia, dyslipidemia, and agranulocytosis. However, naringin was able to reduce such adverse effects when added to clozapine treatment. Naringin increased total leukocyte count preventing agranulocytosis either when administered alone or in combination with clozapine. In addition, via its metabolic activities, naringin treatment lowered serum total cholesterol and triglycerides levels. Moreover, naringin prevented weight gain when administered. Finally, naringin reduced serum glucose level preventing hyperglycemia associated with clozapine treatment. Collectively, these findings may suggest that naringin possesses a potential add-on benefit to clozapine in treatment of schizophrenia.

Clinical Analysis of Bloodstream Infections During Agranulocytosis After Allogeneic Hematopoietic Stem Cell Transplantation

Purpose

To explore the epidemiological characteristics and risk factors of bloodstream infections (BSI) in patients who develop agranulocytosis fever after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study also provides a basis for the clinical treatment of BSI.

Methods

A retrospective analysis of 397 allo-HSCT patients in the Department of Hematology of our hospital was conducted from January 2013 to December 2017 to analyze the incidence of BSI, the distribution and types of pathogenic bacteria, and drug resistance rates. We also determined whether various parameters are risk factors to BSI, including the patient age, gender, disease type, transplantation method, stem cell source, pre-treatment with anti-thymocyte globulin (ATG), and agranulocytosis time.

Results

Among the 397 allo-HSCT patients, 294 had a fever during the period of agranulocytosis, and 52 cases were found to have BSI. The incidence of BSI in patients with agranulocytosis fever was 17.7% (52/294). Among the 60 pathogens detected, 43 (71.67%), 10 (16.67%), and 7 (11.67%) were Gram negative strains, Gram positive strains, and fungi, respectively. The most common bacteria were Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The detection rate of extended-spectrum β-lactamase (ESBL) was 40.0%, and carbapenem-resistant Enterobacteriaceae (CRE) accounted for 17.9%. Single-factor and multi-factor analyses showed that pre-treatment with ATG, agranulocytosis time (≥21 days), and stem cell source were risk factors for BSI.

Conclusion

We found that in our hospital, BSIs in allo-HSCT patients are mainly caused by Gram-negative bacteria, and the resistance rate to carbapenem drugs is high. Pre-treatment with ATG, agranulocytosis time (≥21 days), and stem cell source are risk factors for BSI.

A possible increased risk of metamizole-associated neutropenia among COVID-19 patients

Metamizole is commonly used as analgesic and antipyretic drug. The use of metamizole is prohibited in several countries due to its rare side effect of neutropenia and even agranulocytosis. Among the many symptoms of COVID-19, fever and diffuse pain predominant and therefore it can be assumed that metamizole may be widely used in the current epidemic period. So far, there have been no reports on the safety of metamizole in COVID-19 patients. We describe a series of 3 patients who developed severe neutropenia under metamizole treatment, raising a concern of a possible increased risk of this side effect among COVID-19 patients.

Clozapine re-challenge and initiation following neutropenia: a review and case series of 14 patients in a high-secure forensic hospital

OBJECTIVE

Clozapine remains the most effective intervention for treatment resistant schizophrenia; however, its use is prohibited following neutropenias. We review neutrophil biology as applied to clozapine and describe the strategies to initiate clozapine following neutropenia used in a case series of 14 consecutive patients rechallenged in a United Kingdom (UK) high-secure psychiatric hospital. We examine outcomes including the use of seclusion and transfer.

METHODS

A case series of 14 male patients with treatment resistant schizophrenia treated with clozapine despite previous episodes of neutropenia between 2006 and 2015 is presented. Data were collected during 2015 and 2019. Using this routinely collected clinical data, we describe the patient characteristics, causes of neutropenia, the strategies used for rechallenging with clozapine and clinical outcomes.

RESULTS

Previous neutropenias were the result of benign ethnic neutropenia, clozapine, other medications and autoimmune-related. Our risk mitigation strategies included: granulocyte-colony stimulating factor (G-CSF), lithium and watch-and-wait. There were no serious adverse events; at follow up half of the patient's had improved sufficiently to transfer them to conditions of lesser security. There were dramatic reductions in the use of seclusion.

CONCLUSION

Even in this extreme group, clozapine can be safely and effectively re/initiated following neutropenias, resulting in marked benefits for patients. This requires careful planning based on an understanding of neutrophil biology and the aetiology of the specific episode of neutropenia.

The Clinical Characteristics of ARDS in Children With Hematological Neoplasms

In order to explore the clinical characteristics of pediatric patients admitted to the pediatric intensive care unit (PICU) who suffered from hematological neoplasms complicated with acute respiratory distress syndrome (ARDS), we retrospectively analyzed 45 ARDS children with hematological neoplasms who were admitted to the PICU of Shanghai Children's Medical Center from January 1, 2014, to December 31, 2020. The 45 children were divided into a survival group and a non-survival group, a pulmonary ARDS group and an exogenous pulmonary ARDS group, and an agranulocytosis group and a non-agranulocytosis group, for statistical analysis. The main clinical manifestations were fever, cough, progressive dyspnea, and hypoxemia; 55.6% (25/45) of the children had multiple organ dysfunction syndrome (MODS). The overall mortality rate was 55.6% (25/45). The vasoactive inotropic score (VIS), pediatric critical illness scoring (PCIS), average fluid volume in the first 3 days and the first 7 days, and the incidence of MODS in the non-survival group were all significantly higher than those in the survival group (P < 0.05). However, total length of mechanical ventilation and length of hospital stay and PICU days in the non-survival group were significantly lower than those in the survival group (P < 0.05). The PCIS (OR = 0.832, P = 0.004) and the average fluid volume in the first 3 days (OR = 1.092, P = 0.025) were independent risk factors for predicting death. Children with exogenous pulmonary ARDS were more likely to have MODS than pulmonary ARDS (P < 0.05). The mean values of VIS, C-reactive protein (CRP), and procalcitonin (PCT) in children with exogenous pulmonary ARDS were also higher (P < 0.05). After multivariate analysis, PCT was independently related to exogenous pulmonary ARDS. The total length of hospital stay, peak inspiratory pressure (PIP), VIS, CRP, and PCT in the agranulocytosis group were significantly higher than those in the non-agranulocytosis group (P < 0.05). Last, CRP and PIP were independently related to agranulocytosis. In conclusion, children with hematological neoplasms complicated with ARDS had a high overall mortality and poor prognosis. Children complicated with MODS, positive fluid balance, and high VIS and PCIS scores were positively correlated with mortality. In particular, PCIS score and average fluid volume in the first 3 days were independent risk factors for predicting death. Children with exogenous pulmonary ARDS and children with agranulocytosis were in a severely infected status and more critically ill.

Clozapine: An Updated Overview of Pharmacogenetic Biomarkers, Risks, and Safety-Particularities in the Context of COVID-19

Background: clozapine (CLZ) use is precarious due to its neurological, cardiovascular, and hematological side effects; however, it is the gold standard in therapy-resistant schizophrenia (TRS) in adults and is underused. Objective: to examine the most recent CLZ data on (a) side effects concerning (b) recent pharmacological mechanisms, (c) therapy benefits, and (d) the particularities of the COVID-19 pandemic. Data sources: a search was performed in two databases (PubMed and Web of Science) using the specific keywords “clozapine” and “schizophrenia”, “side effects”, “agranulocytosis”, “TRS”, or “bipolar affective disorder (BAF)” for the last ten years. Study eligibility criteria: clinical trials on adults with acute symptoms of schizophrenia or related disorders. Results: we selected 37 studies, randomized controlled trials (RCTs), and clinical case series (CCS), centered on six main topics in the search area: (a) CLZ in schizophrenia, (b) CLZ in bipolar disorder, (c) side effects during the clozapine therapy, (d) CLZ in pregnancy, (e) CLZ in early-onset schizophrenia, and (f) CLZ therapy and COVID-19 infection. Limitations: we considered RCTs and CCS from two databases, limited to the search topics. Conclusions and implications of key findings: (a) clozapine doses should be personalized for each patient based on pharmacogenetics testing when available; the genetic vulnerability postulates predictors of adverse reactions’ severity; patients with a lower genetic risk could have less frequent hematological monitoring; (b) a CLZ-associated risk of pulmonary embolism imposes prophylactic measures for venous thromboembolism; (c) convulsive episodes are not an indication for stopping treatment; the plasma concentration of clozapine is a better side effect predictor than the dosage; (d) COVID-19 infection may enhance clozapine toxicity, generating an increased risk of pneumonia. Therapy must be continued with the proper monitoring of the white blood count, and the clozapine dose decreased by half until three days after the fever breaks; psychiatrists and healthcare providers must act together.

Amiodarone-Induced Neutropenia: An Uncommon Side Effect of a Common Drug

Amiodarone is widely used as an antiarrhythmic agent for the treatment of both supraventricular and ventricular arrhythmias in various inpatient as well as outpatient settings. Classified as a class III antiarrhythmic agent, it acts mainly by inhibition of potassium channels in the cardiac muscle. Adverse effects are quite common and usually involve pulmonary, gastrointestinal, endocrine, dermatologic, or neuromuscular systems. Although hematologic side effects including thrombocytopenia have also been reported, amiodarone-induced neutropenia is quite rare. We present a case of amiodarone-induced neutropenia in a 66-year-old Caucasian gentleman. He presented to our hospital with cardiac arrest due to ventricular-fibrillation and had received amiodarone as a part of his therapy. His hospital course was complicated by neutropenia which was found to have a clear temporal relation with amiodarone. His initial white blood cell count was 6400/mm3 with an absolute neutrophil count (ANC) of 4800/mm3. His ANC started to downtrend and reached a nadir of 400/mm3 at day six of therapy. This improved significantly after stopping amiodarone, without any change in other medications. Given the rapid improvement of his neutropenia with the discontinuation of amiodarone, further workup with a bone marrow biopsy was not performed. Severe selective neutropenia, also known as agranulocytosis, is a life-threatening condition due to increased risk of severe infections. Antiarrhythmic agents such as tocainamide, procainamide, and flecainide are generally known to cause agranulocytosis. The mechanism of agranulocytosis or neutropenia is thought to be mediated by either immune-mediated destruction or direct and indirect toxicity to myeloid precursors. Although amiodarone has been in use for over 20 years in the management of tachyarrhythmias, agranulocytosis as a direct side effect of amiodarone therapy has been rarely reported. It is important to keep in mind this rare but potentially life-threatening adverse effect of amiodarone when initiating therapy.

Agranulocytosis-complicated DRESS with medullar HHV-6 replication

HHV-6B is the subtype most often involved in the systemic manifestations of the DRESS, but also in myelosuppression in bone marrow transplant. We report a new observation of its myelosuppressive effect: a case of DRESS complicated by agranulocytosis with detectable HHV-6 RNA in bone marrow.

Agranulocytosis Following COVID-19 Recovery

Clinicians have continued to report on the clinical behavior and characteristics of patients with coronavirus disease 2019 (COVID-19) as our knowledge of the virus continues to mature. Herein, we report the case of a 39-year-old male with multiple comorbidities who became critically ill with COVID-19 infection, requiring mechanical ventilation and vasopressors, and then developed agranulocytosis following clinical improvement and resolution of symptoms of COVID infection. The period of agranulocytosis coincided with the development of thrombocytosis, and following resolution of agranulocytosis, the platelet count also normalized, suggesting a possible related mechanism. Interestingly, the patient was treated with TBO-filgrastim 480 mcg daily with a rapid reconstitution of neutrophils. While the mechanism of agranulocytosis remains unknown, we report, to our knowledge, the first known case of agranulocytosis following COVID-19 infection and its successful treatment with granulocyte colony-stimulating factor.

Reactive Metamizole Metabolites Enhance the Toxicity of Hemin on the ATP Pool in HL60 Cells by Inhibition of Glycolysis

Metamizole is an analgesic, whose pharmacological and toxicological properties are attributed to N-methyl-aminoantipyrine (MAA), its major metabolite. In the presence of heme iron, MAA forms reactive metabolites, which are toxic for granulocyte precursors. Since decreased cellular ATP is characteristic for MAA-associated toxicity, we studied the effect of MAA with and without hemin on energy metabolism of HL60 cells, a granulocyte precursor cell line. The combination MAA/hemin depleted the cellular ATP stronger than hemin alone, whereas MAA alone was not toxic. This decrease in cellular ATP was observed before plasma membrane integrity impairment. MAA/hemin and hemin did not affect the proton leak but increased the maximal oxygen consumption by HL60 cells. This effect was reversed by addition of the radical scavenger N-acetylcysteine. The mitochondrial copy number was not affected by MAA/hemin or hemin. Hemin increased mitochondrial superoxide generation, which was not accentuated by MAA. MAA decreased cellular ROS accumulation in the presence of hemin. In cells cultured in galactose (favoring mitochondrial ATP generation), MAA/hemin had less effect on the cellular ATP and plasma membrane integrity than in glucose. MAA/hemin impaired glycolysis more than hemin or MAA alone, and N-acetylcysteine blunted this effect of MAA/hemin. MAA/hemin decreased protein expression of pyruvate kinase more than hemin or MAA alone. In conclusion, cellular ATP depletion appears to be an important mechanism of MAA/hemin toxicity on HL60 cells. MAA itself is not toxic on HL60 cells up to 100 µM but boosts the inhibitory effect of hemin on glycolysis through the formation of reactive metabolites.

Clozapine-induced agranulocytosis in Japan: Changes in leukocyte/neutrophil counts before and after discontinuation of clozapine

OBJECTIVE

To determine the prevalence, background factors, and progression of and recovery from clozapine-induced agranulocytosis in Japan.

METHODS

Data on treatment-resistant schizophrenia patients registered with the Clozaril Patient Monitoring Service (CPMS) between July 29, 2009 and January 20, 2016 were extracted. Patients with a neutrophil count <500/mm³ were defined as having agranulocytosis, and those with a leukocyte count <3,000/mm³ or a neutrophil count <1,500/mm³ but not meeting the criteria for agranulocytosis were defined as having leukopenia/neutropenia.

RESULTS

Of 3,746 patients, agranulocytosis and leukopenia/neutropenia were observed in 38 (1.0%) and 182 (4.9%) patients, respectively. Age was significantly higher in the agranulocytosis group (p < .001). Decreased leukocyte counts 1 week prior to discontinuation were observed only in the agranulocytosis group. The median number of days to recovery from agranulocytosis and leukopenia/neutropenia was 10 and 4, respectively, with more variation in the latter.

CONCLUSIONS

Although some patients with leukopenia/neutropenia might carry less pathologic significance, the results of this study reconfirmed the importance of regular blood monitoring for preventing agranulocytosis.

Effective Preoperative Plasmapheresis Treatment of Severe Hyperthyroidism in a Patient with Giant Toxic Nodular Goiter and Methimazole-Induced Agranulocytosis

Agranulocytosis is a rare but very serious complication of thyrostatic therapy. In severe hyperthyroidism, the removal of circulating thyroid hormones by plasmapheresis may be an effective therapeutic option. This report describes the therapeutic difficulties and successful preoperative treatment with plasmapheresis in a 63-year-old patient admitted to the Endocrinology Clinic with severe hyperthyroidism, during the course of giant toxic nodular goiter and agranulocytosis, which occurred after 2 weeks of taking methimazole. During hospitalization, methimazole treatment was discontinued and therapy with steroids, a beta blocker, propylthiouracil, Lugol’s solution, lithium carbonate, and antibiotics were initiated. Granulocyte colony growth stimulating factor was also used to resolve agranulocytosis. Due to the failure to achieve euthyreosis using this approach, we decided to conduct thyroid surgery, as a life-saving action, after preparation of the patient by plasmapheresis. Two plasmapheresis procedures were performed, resulting in a decrease in the concentration of free thyroid hormones. Total thyroidectomy was performed and there were no complications during surgery. We conclude that plasmapheresis may be considered as an effective alternative treatment option for the preparation of patients with hyperthyroidism for surgery, when the clinical situations prevent the use of conventional treatments for hyperthyroidism and when immediate life-saving surgery is necessary.

Idiosyncratic Drug-Induced Neutropenia and Agranulocytosis in Elderly Patients

Agranulocytosis is a rare, but serious and life-threatening hematologic disorder in elderly patients. Idiosyncratic drug-induced agranulocytosis (IDIA) has been classically defined by a neutrophil count below 0.5 × 10⁹/L. The annual incidence of IDIA in Europe is about 1.6–9.2 cases per million inhabitants. Increasing age and female sex have been considered as risk factors for the development of this condition. Besides, it is well known that older people take on average more drugs than younger people. This condition is most often associated with the intake of antibacterial agents, antiplatelets, antithyroids, antipsychotics, antiepileptics and nonsteroidal anti-inflammatory drugs (NSAIDs). Initially, agranulocytosis may present without symptoms, but may quickly progress to a severe infection and sepsis. The causative drug should be immediately stopped. In febrile patients, blood cultures and where indicated, site-specific cultures should be obtained and early treatment with empirical broad-spectrum antibiotics started. Even with adequate treatment, the mortality rate is higher in elderly patients reaching up to 20%. Hematopoietic growth factors have proven to be useful as they shorten the duration of neutropenia. However, data on neutropenia and agranulocytosis in the elderly meeting the criteria of evidence-based medicine are still poor in the literature. This review analyzes the results of our experience as well as other published studies of the universal literature.

Low-Dose Quetiapine Causing Agranulocytosis and Leucopenia in a Patient with Benign Neutropenia: A Case Report

Low white blood cell (WBC) counts and agranulocytosis are a relatively rare side effect of atypical antipsychotic treatment. Often, quetiapine is used as an adjunctive medication to help with sleep and mood in some patients. Many times, it is prescribed at lower doses when targeting this mechanism of action, especially when used in combination with antidepressants. The following case highlights the importance of understanding the potential risks in prescribing quetiapine in patients who have underlying genetic susceptibility towards low white blood cell counts.

Clozapine and hematologic adverse reactions: Impact of the Risk Evaluation and Mitigation Strategy program

Introduction

In October 2015, the Food and Drug Administration (FDA) instituted an update to the mandatory Risk Evaluation and Mitigation Strategy (REMS) program for clozapine to improve safety monitoring of hematologic events. However, the impact of the clozapine REMS program on reporting of hematologic adverse events has not been quantified.

Methods

We assessed adverse event reports for agranulocytosis, granulocytopenia, leukopenia, and neutropenia from the FDA Adverse Event Reporting System (FAERS) for a 1-year time period before (October 2014 to September 2015, pre-REMS) and after (October 2015 to September 2016, post-REMS) the implementation of the clozapine REMS program. The AERSMine platform was used to capture historical effect estimates (October 2004 to September 2014). Reporting odds ratios (ROR), proportional reporting ratios (PRR), and corresponding Taylor series 95% confidence intervals (CIs) were calculated for hematologic events with clozapine compared with all other medications using OpenEpi.

Results

Reporting rates for agranulocytosis, granulocytopenia, leukopenia, and neutropenia with clozapine all increased from the pre-REMS to post-REMS time frames, ranging from a 2-fold increase with leukopenia to a 40-fold increase with neutropenia; the composite measure of all hematologic reports had a 12-fold increase. During the post-REMS time frame, the ROR increased by 1691% (111.4, 95% CI 100.6-123.4) compared with the pre-REMS time frame (7.1, 95% CI 5.2-9.6), and the PRR increased by 1280% (83.1, 95% CI 76.8-90.0 vs 6.9, 95% CI 5.1-9.4) for the composite outcome.

Discussion

We observed significant increases in reports of hematologic adverse events with clozapine after the introduction of the clozapine REMS program. Future research should explore the impact of the less stringent exclusionary and discontinuation criteria on utilization (eg, expanded access) and clinical outcomes (eg, treatment effectiveness and adverse events).

Safety of antithyroid drugs in pregnancy: update and therapy implications

Introduction: The thionamide antithyroid drugs, methimazole (MMI), its pro-drug derivative carbimazole (CMZ), and propylthiouracil (PTU) are the mainstay of treatment for hyperthyroidism in pregnancy. However, antithyroid drugs carry risks of adverse effects that can affect fetal and maternal well-being.Areas covered: This review provides an update on the safety of antithyroid drugs in pregnancy, focusing on the most serious concerns of severe liver disease and congenital anomalies.Expert opinion: PTU-induced liver disease is uncommon but can run a catastrophic course in pregnancy with a risk of liver failure and threats to maternal or fetal survival. Acute pancreatitis is a relatively rare occurrence that has been linked to thionamide use in a handful of reports in non-pregnant individuals. Observational studies on the risk of birth defects with antithyroid drug exposure in pregnancy overall show an increase in birth defect risk with exposure to CMZ/MMI, and to a lesser extent, PTU. Further studies are required to determine whether the currently recommended approach of switching between thionamide drugs in pregnancy improves outcomes. Ultimately, a preventative strategy of offering definitive therapy to hyperthyroid women of childbearing potential offers the best approach to truly reduce the risks of antithyroid drug adverse effects in pregnancy.