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.

Associations of HLA genotypes with antithyroid drug-induced agranulocytosis: A systematic review and meta-analysis of pharmacogenomics studies.

AIMS: Antithyroid drug (ATD)-induced agranulocytosis is a life-threatening adverse drug reaction. Previous studies suggested that HLA genotypes may play an important role in ATD-induced agranulocytosis. To examine the associations between HLA genotypes and ATD-induced agranulocytosis, we conducted a systematic review and meta-analysis of pharmacogenomics studies. METHODS: We searched the MEDLINE, Embase and CENTRAL databases on 16 June 2018 for case-control studies on the associations between HLA genotypes with ATD-induced agranulocytosis. The Newcastle-Ottawa scale was used to evaluate the risk of bias of included studies. We conducted random-effects model meta-analysis to obtain pooled odds ratios (ORs) with 95% confidence intervals (CIs) to determine the associations between HLA genotypes and ATD-induced agranulocytosis. RESULTS: We included 5 studies with 142 ATD-induced agranulocytosis cases, 1529 matched ATD-tolerant controls and 5945 healthy controls. The risk of bias of included studies was generally low. ATD-induced agranulocytosis was associated with HLA-B*27:05 (OR 10.97; 95% CI 0.75-159.99), HLA-B*38:02 (OR 19.85; 95% CI 7.94-49.57) and HLA-DRB1*08:03 (OR 5.29; 95% CI 3.44-8.14). After excluding propylthiouracil, the associations of ATD-induced agranulocytosis with HLA-B*27:05 and HLA-B*38:02 were strengthened (OR being 20.61 (95% CI 5.21-81.58) and 40.59 (95% CI 13.24-124.47), respectively). The associations of ATD-induced agranulocytosis with HLA-B*27:05, HLA-B*38:02 and HLA-DRB1*08:03 remained significant when compared to population controls (OR being 7.37 (95% CI 3.86-14.07), 36.43 (95% CI 12.80-103.70) and 5.42 (95% CI 2.36-12.47), respectively). HLA-B*27:05, HLA-B*38:02, and HLA-DRB1*08:03 alleles were associated with ATD-induced agranulocytosis, especially in carbimazole/methimazole-induced agranulocytosis. CONCLUSIONS: HLA-B*27:05, HLA-B*38:02 and HLA-DRB1*08:03 alleles were associated with ATD-induced agranulocytosis, especially in carbimazole/methimazole-induced agranulocytosis.

Transient immune-mediated agranulocytosis following Mycoplasma pneumoniae infection.

Mycoplasma pneumoniae is a common respiratory pathogen which may cause haematological manifestations including haemolytic anaemia and thrombocytopaenia. Severe neutropaenia is rare with very few cases reported in the literature. An 85-year-old man was transferred to our facility with agranulocytosis in the context of an infective exacerbation of chronic obstructive pulmonary disease with positive serological testing for M. pneumoniae. No alternative infective, autoimmune or lymphoproliferative cause of the neutropaenia was identified. Granulocyte autoantibody testing was performed with a positive result for neutrophil-bound IgG and IgM autoantibodies and significant agglutination reactions. The patient was treated with azithromycin and granulocyte colony-stimulating factor which resulted in a sustained resolution of his neutropaenia.

Clozapine-induced agranulocytosis/granulocytopenia: mechanisms and monitoring.

PURPOSE OF REVIEW: Clozapine-induced agranulocytosis/granulocytopenia (CIAG) is an uncommon condition, but potentially fatal in consequences. The pathogenesis, despite multiple experiments, is not fully elucidated. The current theory suggests reactive oxygen species - nitrenium ion as the most important factor of CIAG. In this review, mechanism and monitoring of CIAG will be discussed. RECENT FINDINGS: The mechanism of CIAG seems to have an autoimmune background, rather than toxic. Clozapine has a high potential to undergo biochemical activation to nitrenium ion. The role of the primary metabolite of clozapine - N-desmethylclozapine - is in decline. Nitrenium ion is mainly synthesized by CYP3A4, CYP2D6, and myeloperoxidase system in leukocytes. An important component of CIAG pathogenesis is genetic aberration in human leukocyte antigen genes, and also genes associated with apoptosis and ubiquitination. Clozapine monitoring regimes differ between countries. US-derived clozapine Risk Evaluation and Mitigation Strategy is the most tolerant in the aspect of blood parameter thresholds. Therefore, it provides the opportunities for physician to continue the treatment and also to rechallenge the drug after the episode of CIAG. SUMMARY: Each patient with the episode of CIAG should be assessed individually, with special attention to risk factors and drug-drug interactions. Upon that, the decision about clozapine rechallenge or withdrawal should be made.

An Elderly Woman with Anti-neutrophil Antibody-positive Agranulocytosis Who Responded to High-dose Intravenous Methylprednisolone.

Although anti-neutrophil antibodies (ANAs) often exist and immunoreaction may be involved in agranulocytosis, few reports have so far described ANA-positive cases of agranulocytosis with an unknown etiology. We herein describe the case of a 69-year-old woman who presented with ANA-positive agranulocytosis. In this case, both the withdrawal of the drugs that had possibly caused neutropenia and the use of granulocyte-colony stimulating factor (G-CSF) were ineffective treatment measures. Approximately 2 weeks after the discontinuation of the suspected drugs, we initiated corticosteroid pulse therapy; the neutrophil count recovered by day 19 of steroid therapy. High-dose methylprednisolone therapy should thus be considered for patients demonstrating ANA-positive agranulocytosis with an unknown etiology that is refractory to G-CSF treatment.

Clozapine-induced agranulocytosis: Evidence for an immune-mediated mechanism from a patient-specific in-vitro approach.

Use of the atypical antipsychotic clozapine (CZP) is compromised by the risk of potentially fatal agranulocytosis/granulocytopenia (CIAG). To address this, we have established a simple, personalized cell culture-based strategy to identify CIAG-susceptible patients, hypothesizing that an immunogenic and possibly haptene-based mechanism underlies CIAG pathophysiology. To detect a putative haptene-induced response to CZP in vitro exposure, a traditional lymphocyte stimulation assay was adapted and applied to patient-specific peripheral blood-derived mononuclear cells (PBMC). 6 patients with a history of CIAG, 6 patients under CZP treatment (without CIAG) and 12 matched healthy controls were studied. In vitro CZP exposure, even at strikingly low levels, resulted in significantly increased proliferation rates only in CIAG patients' PBMC. Other parameters including cell viability and mitogen-induced proliferation were also affected by in vitro CZP exposure, yet there was no significant difference between the groups. This personalized approach is a starting point for further investigations into a putative haptene-based mechanism underlying CIAG development, and may facilitate the future development of predictive testing.

Exploring an animal model of amodiaquine-induced liver injury in rats and mice.

Amodiaquine (AQ) is associated with a relatively high incidence of idiosyncratic drug-induced liver injury (IDILI) and agranulocytosis. A previous study reported that a combination of high dose AQ and glutathione (GSH) depletion led to liver injury. However, the characteristics of this toxicity were very different from AQ-induced liver injury in humans. We developed a model of AQ-induced liver injury with characteristics similar to the injury in humans by treating mice with lower doses of AQ for several weeks. In this study we found that not only did GSH depletion not increase AQ covalent binding to hepatic proteins at this lower dose, but also it paradoxically prevented the liver injury. We extended the model to rats and found AQ treatment led to a mild delayed onset liver injury that resolved despite continued treatment with AQ. Immunohistochemistry indicated the presence of Kupffer cell activation, apoptosis and hepatocyte proliferation in the liver. There was also an increase in serum IL-2, IL-5, IL-9, IL-12, MCP-1 and TGFß, but a decrease in leptin. Coincident with the elevated serum ALT, the number of liver CD4(+) T-cells, IL-17 secreting cells and TH17/Treg cells increased at Week 3 and decreased during continued treatment. Increases in NK1.1+ cells and activated M2 macrophages were also observed during liver injury. These results suggest that the outcome of the liver injury was determined by the balance between effector and regulatory cells. Co-treatment with cyclosporin prevented AQ-induced liver injury, which supports an immune mechanism. Retinoic acid (RA), which has been reported to enhance natural killer (NK) cell activity, exacerbated AQ-induced liver injury. These results suggest that AQ-induced IDILI is immune mediated and the subsequent adaptation appears to represent immune tolerance.

Good's Syndrome Accompanied by Agranulocytosis Following a Rapid Clinical Course.

Good's syndrome is an immunodeficiency disease involving thymoma accompanied by hypogammaglobulinemia. We encountered a case of Good's syndrome accompanied by agranulocytosis that followed a rapid clinical course. A 72-year-old man visited our hospital with a two-week history of a sore throat. Candida albicans was detected in the pharynx, and hypogammaglobulinemia was detected in addition to granulocytopenia. The patient subsequently developed septic shock and followed a rapid clinical course which ended in death. Good's syndrome with agranulocytosis was diagnosed at autopsy. Good's syndrome accompanied by agranulocytosis can follow a rapid clinical course and some cases remain asymptomatic until old age. Its prompt treatment is crucial.

Agranulocytosis and mixed-type autoimmune hemolytic anemia in primary sjögren's syndrome: a case report and review of the literature.

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease that presents with sicca symptoms of the main mucosal surfaces. Patients with pSS have a broad spectrum of laboratory features, such as cytopenias and hypergammaglobulinemia. Although hematological abnormalities are usually seen in pSS patients, agranulocytosis and autoimmune hemolytic anemia (AIHA) are rare. Here we describe a 40-year-old woman with pSS who developed both agranulocytosis and mixed-type AIHA. An increased risk of malignancies has also been reported in pSS patients with hematological changes. Although there is no evidence of malignancies, this patient should be closely followed up in case of developing lymphoma.

A case of atypical Bartonella henselae infection in a patient with methimazole-induced agranulocytosis.

Antithyroid medications such as methimazole and propylthiouracil are commonly used to treat hyperthyroid disorders. Thionamide-induced agranulocytosis is a rare but life-threatening potential side effect of these medicines. In addition to routine monitoring of blood counts, healthcare workers caring for patients on such medication need to be mindful of atypical presentations of acute agranulocytosis throughout the treatment course. The manifestations of underlying infectious aetiologies can be mistaken for more common illness and result in delayed diagnosis. We present a case of a 41-year-old woman receiving methimazole for Grave's disease, who presented to outpatient care with high fever, pharyngitis, lymphadenopathy and jaundice. After failing to respond to empiric antibiotics, a diagnosis of neutropenia was made and the patient was admitted for inpatient care with eventual recovery following a course of granulocyte colony-stimulating factor. A diagnosis of atypical Bartonella henselae was eventually made and treated appropriately. The patient was later discharged and underwent radioactive iodine ablation.

Current understanding of the mechanisms of idiosyncratic drug-induced agranulocytosis.

INTRODUCTION: Idiosyncratic drug-induced agranulocytosis (IDIAG) is a life-threatening adverse reaction characterized by an absolute neutrophil count < 500 cells/µl of blood. It shares many of the characteristics of other idiosyncratic drug reactions (IDRs), and this presumably reflects mechanistic similarities. AREAS COVERED: This review describes the evidence for mechanistic hypotheses of IDIAG and new hypotheses are explored. EXPERT OPINION: The characteristics of IDIAG are most consistent with an immune mechanism. Where genetic studies have been done, the genes associated with an increased risk of IDIAG are either human leukocyte antigen genes or other genes associated with the immune response, which provides further evidence for an immune mechanism. There is evidence that the immune response leading to most IDRs is triggered by reactive metabolites of the offending drug, and most drugs that are associated with IDIAG are either known to be oxidized to a reactive metabolite by neutrophils or have a functional group that has the potential to be easily oxidized to a reactive metabolite. There is new evidence that drugs that cause IDRs including IDIAG can activate inflammasomes. Thus, the ability of a drug to be oxidized to a reactive metabolite by neutrophils and to activate inflammasomes may be useful biomarkers to predict IDIAG risk.

Development of a novel mouse model of amodiaquine-induced liver injury with a delayed onset.

Amodiaquine (AQ) treatment is associated with a high incidence of idiosyncratic drug-induced liver injury (IDILI) and agranulocytosis. Evidence suggests that AQ-induced IDILI is immune mediated. A significant impediment to mechanistic studies of IDILI is the lack of valid animal models. This study reports the first animal model of IDILI with characteristics similar to mild IDILI in humans. Treatment of female C57BL/6 mice with AQ led to liver injury with delayed onset, which resolved despite continued treatment. Covalent binding of AQ was detected in the liver, which was greater in female than in male mice, and higher in the liver than in other organs. Covalent binding in the liver was maximal by Day 3, which did not explain the delayed onset of alanine aminotransferase (ALT) elevation. However, coincident with the elevated serum ALT, infiltration of liver and splenic mononuclear cells and activation of CD8 T-cells within the liver were identified. By Week 7, when ALT levels had returned close to normal, down-regulation of several inflammatory cytokines and up-regulation of PD-1 on T-cells suggested induction of immune tolerance. Treatment of Rag1(-/-) mice with AQ resulted in higher ALT activities than C57BL/6 mice, which suggested that the adaptive immune response was responsible for immune tolerance. In contrast, depletion of NK cells significantly attenuated the increase in ALT, which implied a role for NK cells in mild AQ-induced IDILI. This is the first example of a delayed-onset animal model of IDILI that appears to be immune-mediated.

Hepatic effects of aminoglutethimide: a model aromatic amine.

Primary aromatic amine drugs are structural alerts in drug development because of their association with a high incidence of idiosyncratic drug reactions (IDRs). If biomarkers could be found that predict IDR risk, it would have a major impact on drug development. Previous attempts to do this through screening of hepatic gene expression profiles in rodents treated with aromatic amine drugs found limited changes. Of the drugs studied, aminoglutethimide (AMG) induced the most changes, and this led to a more comprehensive study of its effects on the liver. Brown Norway rats treated with AMG for up to 14 days showed only a transient elevation of glutamate dehydrogenase. Pathway-specific PCR arrays found few AMG-induced gene changes associated with an immune response and, of these changes, the majority were involved with innate immunity such as Tlr2, Ticam2, CD14, and C3. AMG treatment also led to significant changes in the apoptosis and mitochondrial panel of genes. It was recently found that AMG does induce significant changes in the bone marrow of rats, and agranulocytosis is a common IDR caused by AMG. In contrast, liver injury is not a common IDR associated with AMG. Therefore, the liver may be able to effectively deal with AMG reactive metabolites, and changes observed in this study may be involved in adaptation. Myeloperoxidase is also known to be able to oxidize aromatic amines to reactive metabolites, and these observations suggest that metabolism outside of the liver may be important for the mechanism of aromatic amine-induced IDRs.

Clozapine-induced agranulocytosis is associated with rare HLA-DQB1 and HLA-B alleles.

Clozapine is a particularly effective antipsychotic medication but its use is curtailed by the risk of clozapine-induced agranulocytosis/granulocytopenia (CIAG), a severe adverse drug reaction occurring in up to 1% of treated individuals. Identifying genetic risk factors for CIAG could enable safer and more widespread use of clozapine. Here we perform the largest and most comprehensive genetic study of CIAG to date by interrogating 163 cases using genome-wide genotyping and whole-exome sequencing. We find that two loci in the major histocompatibility complex are independently associated with CIAG: a single amino acid in HLA-DQB1 (126Q) (P=4.7 × 10(-14), odds ratio (OR)=0.19, 95% confidence interval (CI)=0.12-0.29) and an amino acid change in the extracellular binding pocket of HLA-B (158T) (P=6.4 × 10(-10), OR=3.3, 95% CI=2.3-4.9). These associations dovetail with the roles of these genes in immunogenetic phenotypes and adverse drug responses for other medications, and provide insight into the pathophysiology of CIAG.

Antithyroid drugs induced agranulocytosis and multiple myeloma: case report and general considerations.

Antithyroid drugs as thionamides are largely used in the treatment of the thyrotoxicosis. Side effects were reported in less than 10% of the cases, especially hematological, hepatic or skin allergies. One of the most severe manifestations is agranulocytosis, probably based on an immune mechanism that is exacerbated by the presence of the thyroid autoimmune disease itself. If the presence of the severe leucopenia is actually an epiphenomenon of a preexisting hematological disturbance as multiple myeloma is debated. The myeloma may also be correlated with an autoimmune predisposition. We present the case of a 56 years old female patient diagnosed with Graves' disease, who developed agranulocytosis after 8 months of therapy with thiamazole. Two months after antithyroid drug's withdrawal, the granulocytes number increased and she received therapy with radioiodine. Two years later she came back for diffuse bone pain that turned out to be caused by a multiple myeloma, confirmed by bone marrow biopsy. It might be a connection between the severe form of leucopenia that the patient developed and the medullar malignancy.

Analysis of 754 cases of antithyroid drug-induced agranulocytosis over 30 years in Japan.

BACKGROUND: Agranulocytosis is a rare but serious complication of antithyroid drug (ATD) therapy. Characteristics of agranulocytosis have been reported in only a small number of patients. METHOD: We studied 754 cases of ATD-induced agranulocytosis reported over 30 years. The age distribution and sex ratio were compared with those in 12 503 untreated Graves' patients at Kuma Hospital. The annual number of new Graves' patients in Japan was estimated from the Japan Medical Data Center Data Mart-Pharmacovigilance health insurance receipt database. RESULTS: Agranulocytosis developed within 90 days after starting ATD therapy in most patients (84.5%). The methimazole dose given at onset was 25.2 ± 12.8 mg/d (mean ± SD). The mean age was 43.4 ± 15.2 years, and the male to female ratio was 1:6.3. When compared with patients at Kuma Hospital, patients with agranulocytosis were older (P < .001) and more females (P < .0001). Of 211 patients with more than 1 granulocyte measurement before onset, 131 (62%) showed normal counts (>1000/µL) within 2 weeks before onset, demonstrating real sudden onset of agranulocytosis. In contrast, some of the 20 patients with more than 4 measurements showed gradual decreases in granulocyte counts. Analysis of physician reports for 30 fatal cases revealed that some deaths might have been prevented. The number of new Graves' patients treated with ATD was estimated at about 35 000 per year, and the incidence rate of agranulocytosis was 0.1% to 0.15% in Japan. CONCLUSION: This is the largest study of agranulocytosis. Agranulocytosis tends to occur abruptly within 3 months after initiation of ATD therapy, although it develops gradually in some patients. Providing every patient with sufficient information on agranulocytosis is critical.

Autoimmune cytopenias in chronic lymphocytic leukemia.

The clinical course of chronic lymphocytic leukemia (CLL) may be complicated at any time by autoimmune phenomena.The most common ones are hematologic disorders, such as autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP). Pure red cell aplasia (PRCA) and autoimmune agranulocytosis (AG) are, indeed, more rarely seen. However, they are probably underestimated due to the possible misleading presence of cytopenias secondary to leukemic bone marrow involvement or to chemotherapy cytotoxicity. The source of autoantibodies is still uncertain, despite the most convincing data are in favor of the involvement of resting normal B-cells. In general, excluding the specific treatment of underlying CLL, the managementof these complications is not different from that of idiopathic autoimmune cytopenias or of those associated to other causes. Among different therapeutic approaches, monoclonal antibody rituximab, given alone or in combination, has shown to be very effective.

Cocaine-induced vasculitis: clinical and immunological spectrum.

Levamisole-contaminated cocaine has recently been recognized in North America and Europe, and its use is associated with a variety of clinical and autoimmune abnormalities. The clinical characteristic seems to be the presence of a painful purpuric skin rash that predominantly affects the ear lobes and cheeks, often accompanied by systemic manifestations including fever, malaise, arthralgias, myalgias, and laboratory abnormalities, for example leukopenia, neutropenia, positive ANA, ANCA, and phospholipid antibodies. Most of these manifestations can be seen with the use of either drug, especially levamisole. There is no specific therapy, and discontinuation of its use is followed by improvement. Prednisone and immunosuppressive therapy may be needed at times. Further use of the drug is characterized by recurrence of most of the complaints.

Immune-mediated agranulocytosis caused by the cocaine adulterant levamisole: a case for reactive metabolite(s) involvement.

The United States Public Health Service Administration is alerting medical professionals that a substantial percentage of cocaine imported into the United States is adulterated with levamisole, a veterinary pharmaceutical that can cause blood cell disorders such as severe neutropenia and agranulocytosis. Levamisole was previously approved in combination with fluorouracil for the treatment of colon cancer; however, the drug was withdrawn from the U.S. market in 2000 because of the frequent occurrence of agranulocytosis. The detection of autoantibodies such as antithrombin (lupus anticoagulant) and an increased risk of agranulocytosis in patients carrying the human leukocyte antigen B27 genotype suggest that toxicity is immune-mediated. In this perspective, we provide an historical account of the levamisole/cocaine story as it first surfaced in 2008, including a succinct review of levamisole pharmacology, pharmacokinetics, and preclinical/clinical evidence for levamisole-induced agranulocytosis. Based on the available information on levamisole metabolism in humans, we propose that reactive metabolite formation is the rate-limiting step in the etiology of agranulocytosis associated with levamisole, in a manner similar to other drugs (e.g., propylthiouracil, methimazole, captopril, etc.) associated with blood dyscrasias. Finally, considering the toxicity associated with levamisole, we propose that the 2,3,5,6-tetrahydroimidazo[2,1-b]thiazole scaffold found in levamisole be categorized as a new structural alert, which is to be avoided in drug design.