A promising immunosuppressive strategy of cyclosporine alternately combined with levamisole is highly effective for moderate aplastic anemia

Levamisole Suppresses CD4+ T-Cell Proliferation and Antigen-Presenting Cell Activation in Aplastic Anemia by Regulating the JAK/STAT and TLR Signaling Pathways

Aplastic anemia (AA) is a life-threatening disease primarily caused by a metabolic disorder and an altered immune response in the bone marrow (BM) microenvironment, where cytotoxic immune cells attack resident cells and lead to hematopoietic failure. We previously reported an efficient strategy by applying cyclosporin (CSA) combined with levamisole (CSA+LMS-based regimen) in the treatment of AA, but the immunoregulatory mechanism of LMS was still unclear. Here, the therapeutic effects of LMS were examined in vivo using the BM failure murine model. Meanwhile, the proportion and related function of T cells were measured by flow cytometry in vivo and in vitro. The involved signaling pathways were screened by RNA-seq and virtual binding analysis, which were further verified by interference experiments using the specific antagonists on the targeting cells by RT-PCR in vitro. In this study, the CSA+LMS-based regimen showed a superior immune-suppressive response and higher recession rate than standard CSA therapy in the clinical retrospective study. LMS improved pancytopenia and extended the survival in an immune-mediated BM failure murine model by suppressing effector T cells and promoting regulatory T-cell expansion, which were also confirmed by in vitro experiments. By screening of binding targets, we found that JAK1/2 and TLR7 showed the highest docking score as LMS targeting molecules. In terms of the underlying molecular mechanisms, LMS could inhibit JAK/STAT and TLR7 signaling activity and downstream involved molecules. In summary, LMS treatment could inhibit T-cell activation and downregulate related molecules by the JAK/STAT and TLR signaling pathways, supporting the valuable clinical utility of LMS in the treatment of AA.

Eltrombopag for patients with moderate aplastic anemia or uni-lineage cytopenias

There is no standard or widely effective treatment of patients with moderate aplastic anemia (MAA) or hypo-productive uni-lineage cytopenias (UC). Eltrombopag (EPAG), a small molecule thrombopoietin mimetic, has previously been shown to result in durable multi-lineage hematologic responses with low toxicity in patients with refractory severe aplastic anemia (SAA). Its safety and efficacy in MAA are unknown. This prospective phase 2 study enrolled previously untreated and treated MAA and UC patients with clinically relevant cytopenias. EPAG was administered at doses escalating from 50 to 300 mg/d. Hematologic responses were assessed at 16 to 20 weeks. Responding patients were continued on EPAG until reaching defined robust or stable blood counts. EPAG was reinstituted for relapse. Thirty-four patients were enrolled between 2012 and 2017, including 31 with MAA and 3 with UC. Seventeen patients responded in at least 1 eligible lineage by the primary end point. A striking improvement in anemia was observed in a patient with Diamond-Blackfan anemia. EPAG was well tolerated, and it was discontinued for robust or stable blood counts in 12 of 17 patients after a median of 8 months. A majority required re-initiation of EPAG for declining counts, and all regained response. Two of 34 patients developed non-chromosome 7 bone marrow cytogenetic abnormalities while taking EPAG, without dysplasia or increased blasts. Somatic mutation allele frequencies in cancer genes did not increase overall on EPAG. EPAG is a well-tolerated oral treatment of cytopenias in patients with MAA/UC. This trial was registered at www.clinicaltrials.gov as #NCT01328587.

Small PNH clones detected by fluorescent aerolysin predict a faster response to immunosuppressive therapy in patients with severe aplastic anaemia

Objectives: To clear the obscure conclusion on the prediction value of paroxysmal nocturnal haemoglobinuria (PNH) clones in severe aplastic anaemia (SAA) patients treated with immunosuppressive therapy (IST). Methods: We retrospectively analyzed 219 consecutive SAA patients treated with IST from October 2008 to October 2015 and evaluated the haematological responses to IST. Results: The presence of a PNH clone was detected in 55 (25.1%) patients prior to IST [37/88 by flow cytometry (FCM) and 18/131 by fluorescent aerolysin (FLAER)] and 27 disappeared after IST (23/37 in initial FCM group, 4/18 in initial FLAER group, p = 0.005). In patients without an initial clone, 12 (30.0%) cases in FCM and 17 (19.5%) in FLAER groups presented a PNH clone at least once after IST (p < 0.001). In patients with a pre-treatment PNH clone detected by FCM, the 3-, 6- and 12-month response rates were higher than patients without (p = 0.006; 0.002 and 0.002, respectively). And in FLAER group, the 3-month response rate was significantly higher in those with a prior clone (p = 0.017), however, the 6- and 12-month response rates showed no differences (p = 0.105, p = 0.144, respectively). By multivariate analysis, a shorter interval between diagnosis and treatment is associated with a better response and survival. Conclusions: A more reliable FLAER method allows us to draw a conclusion that PNH clone predicts a faster response but not a higher response rate to IST. Once a diagnosis is confirmed, the IST should be initiated as soon as possible.

A fatal case of levamisole induced bone marrow failure

A 20-year-old college student presented with high grade, intermittent fever for 10 days associated with blood stained loose stools after taking tablet levamisole for 17 days for vitiligo vulgaris. He was febrile, had a toxic appearance and appeared pale. Investigations showed neutropaenia with thrombocytopaenia. Blood cultures were sterile and stool cultures did not grow any enteric pathogens. His bone marrow examination was suggestive of an aplastic anaemia. He was administered empirical antibiotics, granulocyte colony stimulating factor and platelet transfusions. However, his fever and blood stained stools persisted. A repeat bone marrow examination after 2 weeks still revealed a hypoplastic marrow. Hence, a diagnosis of a levamisole induced bone marrow failure was made. While being worked up for an allogeneic stem cell transplantation, he developed neutropaenic enterocolitis and refractory septic shock with carbapenem resistant Klebsiella pneumoniae and succumbed to his illness.

Levamisole suppresses adipogenesis of aplastic anaemia-derived bone marrow mesenchymal stem cells through ZFP36L1-PPARGC1B axis

Aplastic anaemia (AA) is a life‐threatening hematopoietic disorder characterized by hypoplasia and pancytopenia with increasing fat cells in the bone marrow (BM). The BM‐derived mesenchymal stem cells (MSCs) from AA are more susceptible to be induced into adipogenic differentiation compared with that from control, which may be causatively associated with the fatty BM and defective hematopoiesis of AA. Here in this study, we first demonstrated that levamisole displayed a significant suppressive effect on the in vitro adipogenic differentiation of AA BM‐MSCs. Mechanistic investigation revealed that levamisole could increase the expression of ZFP36L1 which was subsequently demonstrated to function as a negative regulator of adipogenic differentiation of AA BM‐MSCs through lentivirus‐mediated ZFP36L1 knock‐down and overexpression assay. Peroxisome proliferator‐activated receptor gamma coactivator 1 beta (PPARGC1B) whose 3′‐untranslated region bears adenine‐uridine‐rich elements was verified as a direct downstream target of ZFP36L1, and knock‐down of PPARGC1B impaired the adipogenesis of AA BM‐MSCs. Collectively, our work demonstrated that ZFP36L1‐mediated post‐transcriptional control of PPARGC1B expression underlies the suppressive effect of levamisole on the adipogenic differentiation of AA BM‐MSCs, which not only provides novel therapeutic targets for alleviating the BM fatty phenomenon of AA patients, but also lays the theoretical and experimental foundation for the clinical application of levamisole in AA therapy.

Diagnosis and Treatment of Aplastic Anemia

OPINION STATEMENT

Acquired aplastic anemia (AA) is a rare, life-threatening bone marrow failure (BMF) disorder that affects patients of all ages and is caused by lymphocyte destruction of early hematopoietic cells. Diagnosis of AA requires a comprehensive approach with prompt evaluation for inherited and secondary causes of bone marrow aplasia, while providing aggressive supportive care. The choice of frontline therapy is determined by a number of factors including AA severity, age of the patient, donor availability, and access to optimal therapies. For newly diagnosed severe aplastic anemia, bone marrow transplant should be pursued in all pediatric patients and in younger adult patients when a matched sibling donor is available. Frontline therapy in older adult patients and in all patients lacking a matched sibling donor involves immunosuppressive therapy (IST) with horse antithymocyte globulin and cyclosporine A. Recent improvements in upfront therapy include encouraging results with closely matched unrelated donor transplants in younger patients and the emerging benefits of eltrombopag combined with initial IST, with randomized studies underway. In the refractory setting, several therapeutic options exist, with improving outcomes of matched unrelated donor and haploidentical bone marrow transplantation as well as the addition of eltrombopag to the non-transplant AA armamentarium. With the recent appreciation of frequent clonal hematopoiesis in AA patients and with the growing use of next-generation sequencing in the clinic, utmost caution should be exercised in interpreting the significance of somatic mutations in AA. Future longitudinal studies of large numbers of patients are needed to determine the prognostic significance of somatic mutations and to guide optimal surveillance and treatment approaches to prevent long-term clonal complications.

Cyclosporine Combined with Levamisole for Lower-Risk Myelodysplastic Syndromes

Clinical and experimental evidence suggests an immune-mediated pathophysiology in subjects with lower-risk myelodysplastic syndromes (MDS) in whom immunosuppressive therapy may be effective. The novel immunosuppressive strategy of cyclosporine A (CsA) alternately combined with levamisole (LMS; CsA + LMS regimen) can dramatically improve the response rate and survival in aplastic anemia from those of our previous study. Herein, we retrospectively analyzed the data of 89 lower-risk MDS patients who received the CsA + LMS regimen. A total of 63 patients (70.8%) achieved either complete remission or hematological improvement at 4 months. Overall, 51, 41 and 19 patients had erythroid, platelet and neutrophil responses, respectively. Following the CsA + LMS regimen, 6 patients progressed to more advanced MDS at a median interval of 5 months (range, 3-42 months). The estimated 24-month progression-free survival was 82.2% (95% CI, 72.84-91.56) for all patients. Within the median follow-up of 18.5 months (range, 7.0-61.0), 6 patients died. In conclusion, the CsA + LMS regimen alleviated cytopenias and improved survival and freedom from evolution, suggesting that it could be reserved as an alternative choice for lower-risk MDS.

[Aplastic anemia: Current state of diagnosis and treatment]

Aplastic anemia (AAI) is a rare life-threatening disorder which is characterized by bi- or tricytopenia and hypoplastic or aplastic bone marrow. AA can present as an acquired or congenital disorder. In recent years it was noted that a subgroup of patients with seemingly acquired AA with onset in adulthood carry mutations which cause or at least predispose to bone marrow failure, e.g. mutations in the genes of the telomerase complex. Options for first-line treatment are allogeneic stem cell transplantation or immunosuppression. The decision depends on severity of the disease, age and comorbidity of the patient and availability of a matched stem cell donor. Probability of survival after HLA-identical sibling transplantation exceeds 90% in young patients with bone marrow as the stem cell source and conditioning with an ATG-containing regimen. Results of matched unrelated donor transplantation have improved substantially over the last 10 years. Matched unrelated donor transplantation is increasingly considered as the first-line treatment for very young patients who are candidates for transplantation, but lack an HLA-identical sibling donor. The gold standard for immunosuppression is the combination of antithymocyte globulin (ATG) and cyclosporine A (CsA). ATG, a polyvalent antibody preparation, is obtained from animals after immunization with human thymocytes. Response rate and overall survival after horse ATG treatment are significantly higher compared to rabbit ATG. Recent trials reported a surprisingly high rate of bi- and trilinear response to treatment with the thrombopoietin receptor agonist eltrombopag in patients refractory to immunosuppression. Ongoing trials now address the potential role of eltrombopag as an adjunct to immunosuppression in first-line treatment.

Immunosuppressive therapy for transplant-ineligible aplastic anemia patients

Aplastic anemia is a rare life-threatening bone marrow failure that is characterized by bicytopenia or pancytopenia in the peripheral blood and a hypoplastic or aplastic bone marrow. The patients are at risk of infection and hemorrhage due to neutropenia and thrombocytopenia and suffer from symptoms of anemia. The main treatment approaches are allogeneic stem cell transplantation and immunosuppression. Here, we review current standard immunosuppression and the attempts that have been made in the past two decades to improve results: review of recent developments also reveals that sometimes not only the advent of new drugs, good ideas and well-designed clinical trials decide the progress in the field but also marketing considerations of pharmaceutical companies. Aplastic anemia experts unfortunately had to face the situation that efficient drugs were withdrawn simply for marketing considerations. We will discuss the current options and challenges in first-line treatment and management of relapsing and refractory patients with an emphasis on adult patients. Some promising new approaches are currently under investigation in prospective, randomized trials.

Outcome of a novel immunosuppressive strategy of cyclosporine, levamisole and danazol for severe aplastic anemia

Treatment options for patients with severe aplastic anemia (SAA) in developing countries are limited. A cohort of 261 patients with SAA received a novel immunosuppressive strategy of cyclosporine alternately combined with levamisole plus danazol (CSA&LMS-based regimen), which included 70 VSAA and 191 moderate SAA [initial absolute neutrophil count (ANC) >200/μL] cases. The CSA&LMS-based regimen was administrated orally with an initial dose of CSA 3 mg/kg in adults and 5 mg/kg in children every other day, LMS 150 mg in adults and 2.5 mg/kg in children every other day, and danazol (5.0-10.0) mg/kg daily, continued for 12 more months, followed by slow tapering. The 6-month response rates were 24.3 and 52.9 % for VSAA and moderate SAA (P < 0.001), respectively. Univariate and multivariate analyses demonstrated that younger age, higher pretreatment absolute reticulocyte count and ANC were favorable factors for achieving response at 6 months. The estimated 5-year overall survival rates were 33.8 % (95 % CI 20.6-47 %) and 80.5 % (95 % CI 69.7-91.3 %) for VSAA and moderate SAA, respectively (P < 0.001). To date, nine patients relapsed, and six patients evolved to clonal disorders. Thus, CSA&LMS-based regimen may represent a promising immunosuppressive strategy for moderate SAA.

Evolution of iron burden in acquired aplastic anemia: a cohort study of more than 3-year follow-up

Acquired aplastic anemia (AA) is the most common condition linked to transfusion dependence. We conducted a cohort study to explore patterns of the dynamic evolution of iron burden, and to identify the risk factors for iron overload (IO) in 550 AA patients. Of the participants, 13 % presented with IO when diagnosed, including 7 % of patients without a history of transfusion and 22 % of those receiving transfusions. Male patients [hazard ratio (HR) = 3.85, 95 % confidence interval (CI) 1.77-8.36], adults (HR = 3.04, 95 % CI 1.21-7.63), and patients with high transfusion burdens (more than eight units; HR = 11.30, 95 % CI 4.45-28.70) experienced a significantly higher risk of IO. Furthermore, we found a sharply increasing risk of IO within the first 2 years, especially in males, patients with large number of lifetime transfusions, and patients not responding to treatment. More interestingly, after transfusion independence, a significant seesaw effect between erythropoiesis and iron burden was not noted until 6 months later, which continued over 3 years. In contrast to female patients, children, and patients with lower transfusion burdens, male subjects, adults, and subjects with high transfusion burdens experienced a pattern of slow decline in iron burden. AA incurred a high risk of progression to IO and showed distinct patterns in the evolution of iron burden. In light of these data, we offer suggestions for decision-making regarding who should undergo iron chelation and when.

Nephrotoxic effects of common and emerging drugs of abuse

The kidneys can be injured in diverse ways by many drugs, both legal and illegal. Novel associations and descriptions of nephrotoxic effects of common and emerging drugs of abuse have appeared over the past several years. Anabolic androgenic steroids, illicitly used by athletes and others for decades to increase muscle mass and decrease body fat, are emerging as podocyte toxins given recent descriptions of severe forms of FSGS in long-term abusers. Synthetic cannabinoids, a new group of compounds with marijuana-like effects, recently became popular as recreational drugs and have been associated with an atypical form of AKI. 3,4-Methylenedioxymethamphetamine, commonly known as ecstasy, is a widely used synthetic recreational drug with mood-enhancing properties and a constellation of toxicities that can result in death. These toxic effects include hyperthermia, hypotonic hyponatremia due to its arginine vasopressin secretagogue-like effects, rhabdomyolysis, and cardiovascular collapse. Cocaine, a serotonin-norepinephrine-dopamine reuptake inhibitor that serves as an illegal stimulant, appetite suppressant, and anesthetic, also causes vasoconstriction and rhabdomyolysis. Recent adulteration of much of the world's supply of cocaine with levamisole, an antihelminthic agent with attributes similar to but distinct from those of cocaine, appears to have spawned a new type of ANCA-associated systemic vasculitis. This review discusses the nephrotoxic effects of these common and emerging drugs of abuse, of which both community and health care providers should become aware given their widespread abuse. Future investigation into pathogenetic mechanisms associated with these drugs is critical and may provide a window into ways to lessen and even prevent the nephrotoxic effects of these drugs of abuse and perhaps allow a deeper understanding of the nephrotoxicities themselves.

The polymorphisms of human leukocyte antigen loci may contribute to the susceptibility and severity of severe aplastic anemia in Chinese patients

The human leukocyte antigen (HLA) system has been reported to be involved in the development of aplastic anemia (AA). We compared and analyzed HLA-A, B, C, DRB1 and DQB1 alleles in 96 Chinese severe AA (SAA) patients to those in 600 healthy people chosen randomly from the China Marrow Donor Program to investigate the association of HLA class I and II allele polymorphisms with disposition of SAA and its severity degree in Chinese population. The DNA of patients was extracted and HLA high-resolution genotyping was conducted using polymerase chain reaction-sequence based typing technique. The gene frequencies of A(∗)02:01, A(∗)02:06, B(∗)13:01, DRB1(∗)07:01, DRB1(∗)09:01, DRB1(∗)15:01 and DQB1(∗)06:02 in SAA patients were significantly higher than in controls (all P<0.05), while the allelic frequencies of A(∗)02:07, A(∗)11:01 and B(∗)40:01 were notably lower in SAA patients than those in the controls (P = 0.001, 0.002, 0.005, respectively). Comparison among different severity of SAA groups exhibited significant increases of DRB1(∗)15:01 (P = 0.027) and DQB1(∗)06:02 (P = 0.013), but obviously lower frequencies of B(∗)46:01 (P = 0.023) and DRB1(∗)09:01 (P = 0.020) in non-VSAA patients than in VSAA patients. Thus, our results identified several risk and protective HLA alleles for Chinese SAA patients. Moreover, DRB1(∗)15:01, DQB1(∗)06:02, B(∗)46:01 and DRB1(∗)09:01 may be associated with severity of SAA.