Anemia of chronic disease in rheumatoid arthritis is associated with increased apoptosis of bone marrow erythroid cells: improvement following anti-tumor necrosis factor-alpha antibody therapy

Inhibition of alternative complement system and prolyl hydroxylase ameliorates anaemia of inflammation

Chronic diseases associated with inflammation cause early destruction of RBCs. Complement system, part of innate immunity, is involved in such RBC destruction. Persistent inflammation causes kidney injury, leading to reduced erythropoietin release and functional iron deficiency, causing anaemia. We have investigated effect of iptacopan, a factor B inhibitor, and desidustat, a prolyl hydroxylase inhibitor in anaemia induced by peptidoglycan polysaccharide (PGPS) treatment in rats. Inflammation, haemolysis and its diagnostic markers (LDH, total bilirubin, and RBC lifespan) were evaluated after three days of PGPS challenge. Haemoglobin, RBC, iron homeostasis, and RBC destruction were evaluated fourteen days after PGPS challenge. Desidustat (15 mg/kg) and iptacopan (20 mg/kg) were given along with PGPS and continued for two weeks. Iptacopan and its combination with desidustat prevented LDH, total bilirubin, complement protein-C3a and haemolysis. Combination treatment caused an early normalization of haemoglobin and RBC. Combination also reduced WBC, alkaline phosphatase, aspartate aminotransferase, and rat paw volume. Serum iron was increased by desidustat and its combination treatment. Spleen weight, tissue iron, and serum hepcidin were reduced by combination treatment. Effect of desidustat alone was prominent on iron (serum and tissue) and hepcidin. Thus, combination of iptacopan and desidustat can be a potentially useful therapeutic option for treatment of anaemia of inflammation.

Anemia as an indicator of a higher retention rate for tocilizumab versus tumor necrosis factor inhibitors in patients with rheumatoid arthritis from a Korean multi-center registry

Objective

To examine whether simple laboratory tests can guide selection between tocilizumab (TCZ) and tumor necrosis factor inhibitors (TNFi) in biologic-naive patients with rheumatoid arthritis (RA), by investigating their influence on drug retention.

Methods

Data of RA patients prescribed TCZ or TNFi as the initial biologics from March 2013 to December 2021 were obtained from the KOrean College of Rheumatology BIOlogics and Targeted Therapy (KOBIO) registry. Propensity score matching was performed to adjust for baseline confounding factors. Hazards of drug discontinuation for TCZ were calculated compared to those for TNFi. Interaction analyses with a Bonferroni-corrected p-value threshold were conducted to determine whether the hemoglobin level, C-reactive protein level, erythrocyte sedimentation rate, and platelet count affected the hazards of drug discontinuation.

Results

Overall, 893 patients were analyzed, of whom 315 and 578 were treated with TCZ and TNFi, respectively. The hazards of drug discontinuation in all patients were lower for TCZ than for TNFi (hazard ratio [HR] 0.53, 95% confidence interval [CI] 0.44~0.66). Notably, only the presence of anemia indicated a significant interaction (p for interaction=0.010); the HRs for drug discontinuation were 0.41 (95% CI 0.30~0.55) and 0.70 (95% CI 0.53~0.92) in the anemic and non-anemic groups, respectively. In the anemic subgroup, biologics were discontinued because of a lack of efficacy in 35.0% of TNFi initiators and 7.4% of TCZ initiators.Conclusion The drug discontinuation rate in biologic-naïve patients with RA was significantly lower for TCZ than for TNFi, particularly in those with anemia.

Akkermansia muciniphila induces slow extramedullary hematopoiesis via cooperative IL-1R/TLR signals

Bacterial infections can activate and mobilize hematopoietic stem and progenitor cells (HSPCs) from the bone marrow (BM) to the spleen, a process termed extramedullary hematopoiesis (EMH). Recent studies suggest that commensal bacteria regulate not only the host immune system but also hematopoietic homeostasis. However, the impact of gut microbes on hematopoietic pathology remains unclear. Here, we find that systemic single injections of Akkermansia muciniphila (A. m.), a mucin-degrading bacterium, rapidly activate BM myelopoiesis and slow but long-lasting hepato-splenomegaly, characterized by the expansion and differentiation of functional HSPCs, which we term delayed EMH. Mechanistically, delayed EMH triggered by A. m. is mediated entirely by the MYD88/TRIF innate immune signaling pathway, which persistently stimulates splenic myeloid cells to secrete interleukin (IL)-1α, and in turn, activates IL-1 receptor (IL-1R)-expressing splenic HSPCs. Genetic deletion of Toll-like receptor-2 and -4 (TLR2/4) or IL-1α partially diminishes A. m.-induced delayed EMH, while inhibition of both pathways alleviates splenomegaly and EMH. Our results demonstrate that cooperative IL-1R- and TLR-mediated signals regulate commensal bacteria-driven EMH, which might be relevant for certain autoimmune disorders.

Serum Raman spectroscopy can be used to screen patients with early rheumatoid arthritis

In this study, Raman spectroscopy was used to analyze the serum of patients with early rheumatoid arthritis (RA), and to explore the screening value of Raman spectroscopy in patients with early RA. A total of 216 patients were included in the study. Fasting venous blood was collected for routine biochemical detection, and the remaining samples were tested by serum Raman spectroscopy. Support vector machine was used for model building and training. The area under the curve (AUC) values of the model were as follows: (1) healthy group versus early RA group: 0.860, (2) healthy group versus non-early RA group: 0.903, and (3) early RA group versus non-early RA group: 0.918. This study shows that serum Raman spectroscopy has a good ability to screen RA and can be staged according to the course of the disease, which can provide new ideas and technical support for the diagnosis or screening of early RA.

More complications and higher transfusion rate in patients with rheumatoid arthritis than osteoarthritis undergoing total hip arthroplasty

PURPOSE

Total hip arthroplasty (THA) in patients with rheumatoid arthritis (RA) has been associated with an increased risk of periprosthetic joint infection, periprosthetic fractures, dislocations, and post-operative blood transfusion. However, higher post-operative blood transfusion is unclear whether it reflects peri-operative blood loss or is characteristic of RA. This study aimed to compare the complications, allogenic blood transfusion, albumin use, and peri-operative blood loss between patients who underwent THA because of RA or osteoarthritis (OA).

METHODS

Patients undergoing cementless THA for hip RA (n = 220) or hip OA (n = 261) at our hospital between 2011 and 2021 were retrospectively enrolled. Deep vein thrombosis, pulmonary embolism, myocardial infarction, calf muscular venous thrombosis, wound complications, deep prosthetic infection, hip prosthesis dislocation, periprosthetic fractures, 30-day mortality, 90-day readmission, allogeneic blood transfusion, and albumin infusions were considered as primary outcomes, while secondary outcomes included the number of perioperative anaemia patients as well as total, intra-operative, and hidden blood loss.

RESULTS

Compared to the OA group, patients with hip RA showed significantly higher rates of wound aseptic complications, hip prosthesis dislocation, homologous transfusion, and albumin use. RA patients also showed a significantly higher prevalence of pre-operative anemia. However, no significant differences were observed between the two groups in total, intra-operative, or hidden blood loss.

CONCLUSIONS

Our study suggests that RA patients undergoing THA are at a higher risk of wound aseptic complications and hip prosthesis dislocation than patients with hip OA. Pre-operative anaemia and hypoalbuminaemia in patients with hip RA place them at a significantly higher risk of post-operative blood transfusion and use of albumin.

Anaemia of acute inflammation: a higher acute systemic inflammatory response is associated with a larger decrease in blood haemoglobin levels in patients with COVID-19 infection

AIMS

The study tests the hypothesis that a higher acute systemic inflammatory response was associated with a larger decrease in blood hemoglobin levels in patients with Coronavirus 2019 (COVID-19) infection.

METHODS

All patients with either suspected or confirmed COVID-19 infection admitted to a busy UK hospital from February 2020 to December 2021 provided data for analysis. The exposure of interest was maximal serum C-reactive protein (CRP) level after COVID-19 during the same admission.

RESULTS

A maximal serum CRP >175mg/L was associated with a decrease in blood haemoglobin (-5.0 g/L, 95% confidence interval: -5.9 to -4.2) after adjustment for covariates, including the number of times blood was drawn for analysis.Clinically, for a 55-year-old male patient with a maximum haemoglobin of 150 g/L who was admitted for a 28-day admission, a peak CRP >175 mg/L would be associated with an 11 g/L decrease in blood haemoglobin, compared with only 6 g/L if the maximal CRP was <4 mg/L.

CONCLUSIONS

A higher acute systemic inflammatory response is associated with larger decreases in blood haemoglobin levels in patients with COVID-19. This represents an example of anaemia of acute inflammation, and a potential mechanism by which severe disease can increase morbidity and mortality.

Pathogenesis of Extraarticular Manifestations in Rheumatoid Arthritis-A Comprehensive Review

Rheumatoid arthritis (RA) is among the most prevalent and debilitating autoimmune inflammatory chronic diseases. Although it is primarily characterized by destructive peripheral arthritis, it is a systemic disease, and RA-related extraarticular manifestations (EAMs) can affect almost every organ, exhibit a multitude of clinical presentations, and can even be asymptomatic. Importantly, EAMs largely contribute to the quality of life and mortality of RA patients, particularly substantially increased risk of cardiovascular disease (CVD) which is the leading cause of death in RA patients. In spite of known risk factors related to EAM development, a more in-depth understanding of its pathophysiology is lacking. Improved knowledge of EAMs and their comparison to the pathogenesis of arthritis in RA could lead to a better understanding of RA inflammation overall and its initial phases. Taking into account that RA is a disorder that has many faces and that each person experiences it and responds to treatments differently, gaining a better understanding of the connections between the joint and extra-joint manifestations could help to create new treatments and improve the overall approach to the patient.

Role of Macrophages in Sickle Cell Disease Erythrophagocytosis and Erythropoiesis

Sickle cell disease (SCD) is an inherited blood disorder caused by a β-globin gene point mutation that results in the production of sickle hemoglobin that polymerizes upon deoxygenation, causing the sickling of red blood cells (RBCs). RBC deformation initiates a sequence of events leading to multiple complications, such as hemolytic anemia, vaso-occlusion, chronic inflammation, and tissue damage. Macrophages participate in extravascular hemolysis by removing damaged RBCs, hence preventing the release of free hemoglobin and heme, and triggering inflammation. Upon erythrophagocytosis, macrophages metabolize RBC-derived hemoglobin, activating mechanisms responsible for recycling iron, which is then used for the generation of new RBCs to try to compensate for anemia. In the bone marrow, macrophages can create specialized niches, known as erythroblastic islands (EBIs), which regulate erythropoiesis. Anemia and inflammation present in SCD may trigger mechanisms of stress erythropoiesis, intensifying RBC generation by expanding the number of EBIs in the bone marrow and creating new ones in extramedullary sites. In the current review, we discuss the distinct mechanisms that could induce stress erythropoiesis in SCD, potentially shifting the macrophage phenotype to an inflammatory profile, and changing their supporting role necessary for the proliferation and differentiation of erythroid cells in the disease. The knowledge of the soluble factors, cell surface and intracellular molecules expressed by EBI macrophages that contribute to begin and end the RBC’s lifespan, as well as the understanding of their signaling pathways in SCD, may reveal potential targets to control the pathophysiology of the disease.

Age-related mechanisms in the context of rheumatic disease

Ageing is characterized by a progressive loss of cellular function that leads to a decline in tissue homeostasis, increased vulnerability and adverse health outcomes. Important advances in ageing research have now identified a set of nine candidate hallmarks that are generally considered to contribute to the ageing process and that together determine the ageing phenotype, which is the clinical manifestation of age-related dysfunction in chronic diseases. Although most rheumatic diseases are not yet considered to be age related, available evidence increasingly emphasizes the prevalence of ageing hallmarks in these chronic diseases. On the basis of the current evidence relating to the molecular and cellular ageing pathways involved in rheumatic diseases, we propose that these diseases share a number of features that are observed in ageing, and that they can therefore be considered to be diseases of premature or accelerated ageing. Although more data are needed to clarify whether accelerated ageing drives the development of rheumatic diseases or whether it results from the chronic inflammatory environment, central components of age-related pathways are currently being targeted in clinical trials and may provide a new avenue of therapeutic intervention for patients with rheumatic diseases.

Longitudinal multi-omics analysis identifies early blood-based predictors of anti-TNF therapy response in inflammatory bowel disease

Background and aims

Treatment with tumor necrosis factor α (TNFα) antagonists in IBD patients suffers from primary non-response rates of up to 40%. Biomarkers for early prediction of therapy success are missing. We investigated the dynamics of gene expression and DNA methylation in blood samples of IBD patients treated with the TNF antagonist infliximab and analyzed the predictive potential regarding therapy outcome.

Methods

We performed a longitudinal, blood-based multi-omics study in two prospective IBD patient cohorts receiving first-time infliximab therapy (discovery: 14 patients, replication: 23 patients). Samples were collected at up to 7 time points (from baseline to 14 weeks after therapy induction). RNA-sequencing and genome-wide DNA methylation data were analyzed and correlated with clinical remission at week 14 as a primary endpoint.

Results

We found no consistent ex ante predictive signature across the two cohorts. Longitudinally upregulated transcripts in the non-remitter group comprised TH2- and eosinophil-related genes including ALOX15, FCER1A, and OLIG2. Network construction identified transcript modules that were coherently expressed at baseline and in non-remitting patients but were disrupted at early time points in remitting patients. These modules reflected processes such as interferon signaling, erythropoiesis, and platelet aggregation. DNA methylation analysis identified remission-specific temporal changes, which partially overlapped with transcriptomic signals. Machine learning approaches identified features from differentially expressed genes cis-linked to DNA methylation changes at week 2 as a robust predictor of therapy outcome at week 14, which was validated in a publicly available dataset of 20 infliximab-treated CD patients.

Conclusions

Integrative multi-omics analysis reveals early shifts of gene expression and DNA methylation as predictors for efficient response to anti-TNF treatment. Lack of such signatures might be used to identify patients with IBD unlikely to benefit from TNF antagonists at an early time point.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-022-01112-z.

Association between low hemoglobin, clinical measures, and patient-reported outcomes in patients with rheumatoid arthritis: results from post hoc analyses of three phase III trials of sarilumab

Background

Anemia is common in patients with rheumatoid arthritis (RA). Higher hemoglobin (Hb) levels may be associated with better clinical outcomes and patient-reported outcomes (PROs). To assess this hypothesis, we conducted two post hoc analyses in three sarilumab phase III studies: TARGET, MOBILITY, and MONARCH.

Methods

Pooled data from combination therapy from placebo-controlled MOBILITY (sarilumab + methotrexate) and TARGET (sarilumab + conventional synthetic disease-modifying antirheumatic drugs [csDMARDs]) and monotherapy data from active-controlled MONARCH (sarilumab vs. adalimumab) studies were included. Associations between Hb levels and clinical measures and PROs were assessed over 24 weeks. The mean changes from baseline in clinical outcomes and PROs (to week 24) and radiographic outcomes (to week 52) were evaluated between low and normal Hb levels (based on the World Health Organization [WHO] criteria).

Results

From TARGET, MOBILITY, and MONARCH, 546, 1197, and 369 patients, respectively, were stratified according to Hb levels (low vs. normal). Over 24 weeks, higher Hb levels were found to be consistently associated with better clinical outcomes and PROs in combination therapy and monotherapy groups and were more pronounced among the patients treated with sarilumab than those treated with placebo and adalimumab. The mean change from baseline to week 24 in clinical efficacy measures and PROs was similar in patients with low vs. normal Hb at baseline. Differences between sarilumab and/or adalimumab, for all outcomes, were larger for low Hb subgroups. In MOBILITY, by week 52, the inhibition of progression of structural damage (assessed via Modified Total Sharp Score [mTSS]) was 84% (sarilumab 200 mg) and 68% (sarilumab 150 mg) vs. placebo in patients with low Hb and 97% (sarilumab 200 mg) and 68% (sarilumab 150 mg) vs. placebo in patients with normal Hb. Similar results were observed for other radiographic outcomes.

Conclusions

In these post hoc analyses, a consistent relationship was observed between higher Hb levels and better clinical outcomes and PROs in patients with RA. Irrespective of the baseline Hb levels, sarilumab treatment was associated with improvements in clinical measures and PROs over 24 weeks (improvements were more pronounced than those with adalimumab treatment) and mitigation of joint damage progression over 52 weeks.

Trial registration

ClinTrials.gov NCT01061736, NCT01709578, and NCT02332590

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02891-x.

Bridging Insights From Lymph Node and Synovium Studies in Early Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease of unknown etiology characterized by inflammation of the peripheral synovial joints leading to pannus formation and bone destruction. Rheumatoid Factor (RF) and anti-citrullinated protein antibodies (ACPA) are present years before clinical manifestations and are indicative of a break in tolerance that precedes chronic inflammation. The majority of studies investigating disease pathogenesis focus on the synovial joint as target site of inflammation while few studies explore the initial break in peripheral tolerance which occurs within secondary lymphoid organs such as lymph nodes. If explored during the earliest phases of RA, lymph node research may provide innovative drug targets for disease modulation or prevention. RA research largely centers on the role and origin of lymphocytes, such as pro-inflammatory T cells and macrophages that infiltrate the joint, as well as growing efforts to determine the role of stromal cells within the synovium. It is therefore important to explore these cell types also within the lymph node as a number of mouse studies suggest a prominent immunomodulatory role for lymph node stromal cells. Synovium and proximal peripheral lymph nodes should be investigated in conjunction with one another to gain understanding of the immunological processes driving RA progression from systemic autoimmunity toward synovial inflammation. This perspective seeks to provide an overview of current literature concerning the immunological changes present within lymph nodes and synovium during early RA. It will also propose areas that warrant further exploration with the aim to uncover novel targets to prevent disease progression.

GM-CSF impairs erythropoiesis by disrupting erythroblastic island formation via macrophages

Anemia is a significant complication of chronic inflammation and may be related to dysregulated activities among erythroblastic island (EBI) macrophages. GM-CSF was reported to be upregulated and attracted as a therapeutic target in many inflammatory diseases. Among EBIs, we found that the GM-CSF receptor is preferentially and highly expressed among EBI macrophages but not among erythroblasts. GM-CSF treatment significantly decreases human EBI formation in vitro by decreasing the adhesion molecule expression of CD163. RNA-sequence analysis suggests that GM-CSF treatment impairs the supporting function of human EBI macrophages during erythropoiesis. GM-CSF treatment also polarizes human EBI macrophages from M2-like type to M1-like type. In addition, GM-CSF decreases mouse bone marrow (BM) erythroblasts as well as EBI macrophages, leading to a reduction in EBI numbers. In defining the molecular mechanism at work, we found that GM-CSF treatment significantly decreases the adhesion molecule expression of CD163 and Vcam1 in vivo. Importantly, GM-CSF treatment also decreases the phagocytosis rate of EBI macrophages in mouse BM as well as decreases the expression of the engulfment-related molecules Mertk, Axl, and Timd4. In addition, GM-CSF treatment polarizes mouse BM EBI macrophages from M2-like type to M1-like type. Thus, we document that GM-CSF impairs EBI formation in mice and humans. Our findings support that targeting GM-CSF or reprogramming EBI macrophages might be a novel strategy to treat anemia resulting from inflammatory diseases.

Reduced exercise capacity in patients with systemic sclerosis is associated with lower peak tissue oxygen extraction: a cardiovascular magnetic resonance-augmented cardiopulmonary exercise study

BACKGROUND

Exercise intolerance in systemic sclerosis (SSc) is typically attributed to cardiopulmonary limitations. However, problems with skeletal muscle oxygen extraction have not been fully investigated. This study used cardiovascular magnetic resonance (CMR)-augmented cardiopulmonary exercise testing (CMR-CPET) to simultaneously measure oxygen consumption and cardiac output. This allowed calculation of arteriovenous oxygen content gradient, a recognized marker of oxygen extraction. We performed CMR-CPET in 4 groups: systemic sclerosis (SSc); systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH); non-connective tissue disease pulmonary hypertension (NC-PAH); and healthy controls.

METHODS

We performed CMR-CPET in 60 subjects (15 in each group) using a supine ergometer following a ramped exercise protocol until exhaustion. Values for oxygen consumption, cardiac output and oxygen content gradient, as well as ventricular volumes, were obtained at rest and peak-exercise for all subjects. In addition, T1 and T2 maps were acquired at rest, and the most recent clinical measures (hemoglobin, lung function, 6-min walk, cardiac and catheterization) were collected.

RESULTS

All patient groups had reduced peak oxygen consumption compared to healthy controls (p < 0.022). The SSc and SSc-PAH groups had reduced peak oxygen content gradient compared to healthy controls (p < 0.03). Conversely, the SSc-PAH and NC-PH patients had reduced peak cardiac output compared to healthy controls and SSc patients (p < 0.006). Higher hemoglobin was associated with higher peak oxygen content gradient (p = 0.025) and higher myocardial T1 was associated with lower peak stroke volume (p = 0.011).

CONCLUSIONS

Reduced peak oxygen consumption in SSc patients is predominantly driven by reduced oxygen content gradient and in SSc-PAH patients this was amplified by reduced peak cardiac output. Trial registration The study is registered with ClinicalTrials.gov Protocol Registration and Results System (ClinicalTrials.gov ID: 100358).

Physiology and Inflammation Driven Pathophysiology of Iron Homeostasis-Mechanistic Insights into Anemia of Inflammation and Its Treatment

Anemia is very common in patients with inflammatory disorders. Its prevalence is associated with severity of the underlying disease, and it negatively affects quality of life and cardio-vascular performance of patients. Anemia of inflammation (AI) is caused by disturbances of iron metabolism resulting in iron retention within macrophages, a reduced erythrocyte half-life, and cytokine mediated inhibition of erythropoietin function and erythroid progenitor cell differentiation. AI is mostly mild to moderate, normochromic and normocytic, and characterized by low circulating iron, but normal and increased levels of the storage protein ferritin and the iron hormone hepcidin. The primary therapeutic approach for AI is treatment of the underlying inflammatory disease which mostly results in normalization of hemoglobin levels over time unless other pathologies such as vitamin deficiencies, true iron deficiency on the basis of bleeding episodes, or renal insufficiency are present. If the underlying disease and/or anemia are not resolved, iron supplementation therapy and/or treatment with erythropoietin stimulating agents may be considered whereas blood transfusions are an emergency treatment for life-threatening anemia. New treatments with hepcidin-modifying strategies and stabilizers of hypoxia inducible factors emerge but their therapeutic efficacy for treatment of AI in ill patients needs to be evaluated in clinical trials.

Erythroferrone Expression in Anemic Rheumatoid Arthritis Patients: Is It Disordered Iron Trafficking or Disease Activity?

Purpose

Erythroferrone (ERFE) is well acknowledged for its inhibitory function on hepcidin synthesis in the liver during stress erythropoiesis, thereby ensuring sufficient iron supply to bone marrow erythroblasts. Hepcidin plays an indispensable role in the pathogenesis of anemia of chronic disease (ACD). Thus, ERFE was suggested to protect against ACD in various diseases. Rheumatoid arthritis (RA) is commonly involved with ACD and high hepcidin levels, with a further increase of the latter in active states. The present study is a case-control study that aimed to determine the pattern of ERFE expression in RA patients with concomitant ACD and study its relationship with hepcidin, erythropoietin (EPO) and disease activity.

Patients and Methods

Fifty-five RA patients with ACD were categorized into active and inactive RA using the disease activity score (DAS28); 15 healthy subjects were included as control subjects. ERFE was measured for patients and control subjects using quantitative real-time polymerase chain reaction, in addition to testing for CBC, ESR, CRP, iron profile parameters and hepcidin. EPO was assessed for patients of both active and inactive RA groups.

Results

ERFE and hepcidin showed the highest levels in active RA; ERFE values were similar in control subjects and inactive RA patients, while hepcidin was significantly higher in inactive RA than control subjects. Patients with high ERFE levels had higher RBC, Hct, MCV, hepcidin and EPO levels. Stepwise regression analysis has identified DAS28 and disease duration as the best predictors of ERFE values, whereas ERFE and hepcidin were independent predictors of disease activity.

Conclusion

We introduce ERFE as a novel marker of RA activity. Although the inhibitory effect of ERFE on hepcidin is not evident, our results still indicate that ERFE may have a beneficial erythropoietic effect in the context of ACD in RA disease activity.

Iron deficiency anemia in IBD: an overlooked comorbidity

Introduction: Iron Deficiency Anemia (IDA) is a leading cause of anemia in Inflammatory Bowel disease (IBD). IDA affects quality of life (QoL) and lead to developmental and cognitive abnormalities. Diagnosis of IDA in IBD is complicated as biochemical tests available at present cannot help distinguish between IDA and anemia of chronic disease. Soluble transferrin receptor ferritin index has been gaining popularity as it can diagnose IDA in presence of chronic inflammation. ECCO guidelines recommend a Hb increase of >2 g/dL and a TfS of >30% within 4 weeks as adequate therapeutic response. IV iron is preferred over oral iron as it bypasses gastrointestinal tract, rapidly increases haemoglobin, and is not associated with intestinal inflammation. Our aim in this review is to provide apathway for physicians to help them diagnose and appropriately treat IDA in IBD.Areas covered: In this review article, we have discussed current diagnosis and treatment in detail and have proposed new directions on how future research can help manage IDA in IBD effectively.Expert opinion: Understanding the pathogenesis of IDA in IBD will further lead to exploring new potential diagnostic tests and treatment regimens for effective management of IDA in IBD.

Inflammation as a regulator of hematopoietic stem cell function in disease, aging, and clonal selection

Inflammation is an evolutionarily selected defense response to infection or tissue damage that involves activation and consumption of immune cells in order to reestablish and maintain organismal integrity. In this process, hematopoietic stem cells (HSCs) are themselves exposed to inflammatory cues and via proliferation and differentiation, replace mature immune cells in a demand-adapted fashion. Here, we review how major sources of systemic inflammation act on and subsequently shape HSC fate and function. We highlight how lifelong inflammatory exposure contributes to HSC inflamm-aging and selection of premalignant HSC clones. Finally, we explore emerging areas of interest and open questions remaining in the field.

Tumor Immune Evasion Induced by Dysregulation of Erythroid Progenitor Cells Development

Cancer cells harness normal cells to facilitate tumor growth and metastasis. Within this complex network of interactions, the establishment and maintenance of immune evasion mechanisms are crucial for cancer progression. The escape from the immune surveillance results from multiple independent mechanisms. Recent studies revealed that besides well-described myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs) or regulatory T-cells (Tregs), erythroid progenitor cells (EPCs) play an important role in the regulation of immune response and tumor progression. EPCs are immature erythroid cells that differentiate into oxygen-transporting red blood cells. They expand in the extramedullary sites, including the spleen, as well as infiltrate tumors. EPCs in cancer produce reactive oxygen species (ROS), transforming growth factor β (TGF-β), interleukin-10 (IL-10) and express programmed death-ligand 1 (PD-L1) and potently suppress T-cells. Thus, EPCs regulate antitumor, antiviral, and antimicrobial immunity, leading to immune suppression. Moreover, EPCs promote tumor growth by the secretion of growth factors, including artemin. The expansion of EPCs in cancer is an effect of the dysregulation of erythropoiesis, leading to the differentiation arrest and enrichment of early-stage EPCs. Therefore, anemia treatment, targeting ineffective erythropoiesis, and the promotion of EPC differentiation are promising strategies to reduce cancer-induced immunosuppression and the tumor-promoting effects of EPCs.

Appraisal of the Antiarthritic Potential of Prazosin via Inhibition of Proinflammatory Cytokine TNF-α: A Key Player in Rheumatoid Arthritis

Prazosin, a selective α₁ adrenergic receptor antagonist, with documented anti-inflammatory potential, was evaluated for its antiarthritic efficacy by targeting specifically TNF-α. The antiarthritic attribute of prazosin validated through in vitro screening comprised thermally provoked denaturation of bovine serum albumin (BSA) and egg albumin along with membrane stabilization evaluation at a concentration of 100-6400 μg/mL, while in vivo screening comprised formaldehyde-instigated arthritis at the doses of 5, 10, and 20 mg/kg and complete Freund's adjuvant (CFA)-induced arthritis at 20 mg/kg dose. Paw swelling, body weight, arthritic score, hematological parameters, and histological and radiographic examination of ankle joints were assessed for a period of 28 days after CFA immunization. Moreover, the proinflammatory cytokine TNF-α level was also assessed through quantitative real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Prazosin revealed significant antiarthritic effect evident through protein denaturation inhibition in the egg albumin and the BSA model, stabilization of red blood cell membrane in the membrane stabilizing assay, and reduction in paw volume in formaldehyde-induced arthritis. Likewise, prazosin exhibited propitious antiarthritic effects in the CFA-provoked arthritis model manifested by paw volume and arthritic score alleviation, substantial weight loss prevention, and preservation of the normal hematological and biochemical profile. Histological and X-ray investigation unveiled no substantive structural alterations in treated rat's ankle joints. The TNF-α expression level was also reduced. Thus, the current study is suggestive that prazosin exhibits a strong antiarthritic potential possibly through inhibition of TNF-α.

Traditional and modern management strategies for rheumatoid arthritis

Rheumatoid arthritis (RA) is a serious disorder of the joints affecting 1 or 2% of the population aged between 20 and 50 years worldwide. RA is the foremost cause of disability in developing and Western populations. It is an autoimmune disease-causing inflammation and pain involving synovial joints. Pro-inflammatory markers, including cytokines, such as interleukin -1 (IL-1), IL-6, IL-7, IL-8, and tumor necrosis factor-α (TNF-α) are involved in RA. RA treatment involves TNF-α blockade, B cell therapy, IL-1 and IL-6 blockade, and angiogenesis inhibition. Synthetic drugs available for the treatment of RA include disease-modifying anti-rheumatic drugs (DMARD), such as cyclophosphamide, sulfasalazine, methotrexate, nonsteroidal anti-inflammatory drugs (NSAIDs), and intramuscular gold. These agents induce adverse hepatorenal effects, hypertension, and gastric ulcers. We found that patients diagnosed with chronic pain, as in RA, and those refractory to contemporary management are most likely to seek traditional medicine. Approximately 60-90% of patients with arthritis use traditional medicines. Therefore, the efficacy and safety of these traditional medicines need to be established. The treatment for RA entails a comprehensive multidisciplinary strategy to reduce pain and inflammation and to restore the activity of joints. The potential medicinal plants exhibiting anti-arthritic and anti-rheumatic pharmacological activity are reviewed here.

Stress erythropoiesis in atherogenic mice

Bone marrow erythropoiesis is mainly homeostatic and a demand of oxygen in tissues activates stress erythropoiesis in the spleen. Here, we show an increase in the number of circulating erythrocytes in apolipoprotein E-/- mice fed a Western high-fat diet, with similar number of circulating leukocytes and CD41+ events (platelets). Atherogenic conditions increase spleen erythropoiesis with no variations of this cell lineage in the bone marrow. Spleens from atherogenic mice show augmented number of late-stage erythroblasts and biased differentiation of progenitor cells towards the erythroid cell lineage, with an increase of CD71+CD41CD34-CD117+Sca1-Lin- cells (erythroid-primed megakaryocyte-erythroid progenitors), which is consistent with the way in which atherogenesis modifies the expression of pro-erythroid and pro-megakaryocytic genes in megakaryocyte-erythroid progenitors. These data explain the transiently improved response to an acute severe hemolytic anemia insult found in atherogenic mice in comparison to control mice, as well as the higher burst-forming unit-erythroid and colony forming unit-erythroid capacity of splenocytes from atherogenic mice. In conclusion, our work demonstrates that, along with the well stablished enhancement of monocytosis during atherogenesis, stress erythropoiesis in apolipoprotein E-/- mice fed a Western high fat diet results in increased numbers of circulating red blood cells.

Efficacy of iron supplementation in patients with inflammatory bowel disease treated with anti-tumor necrosis factor-alpha agents

BACKGROUND

Anemia is a common extraintestinal manifestation of inflammatory bowel disease (IBD). However, data on the influence of anti-tumor necrosis factor-alpha (anti-TNF-α) agents and iron supplementation on anemia in patients with IBD are sparse. We assessed the effect of iron supplementation in patients with IBD initially treated with an anti-TNF-α agent.

METHODS

Data from 79 IBD patients who started anti-TNF-α treatment at a tertiary hospital were analyzed. The patients were divided into the anti-TNF-α (n = 52) and anti-TNF-α with iron supplementation (n = 27) groups. Effects on laboratory parameters, the prevalence of anemia, and disease activity were evaluated at baseline (year 0) and 1 year later.

RESULTS

The hemoglobin (Hb) level significantly increased between years 0 and 1 in both groups [12.0 ± 1.8-13.3 ± 2.0 g/dL in the anti-TNF-α group (p < 0.001) and 9.8 ± 2.4-11.7 ± 2.3 g/dL in the anti-TNF-α and iron supplementation group (p = 0.004)]. In a subgroup analysis of severely anemic patients with IBD, iron supplementation increased the magnitude of the improvement in Hb level (8.5 ± 1.5-11.4 ± 2.1 g/dL; p = 0.001) compared with the anti-TNF-α group (9.3 ± 0.8-11.4 ± 2.7 g/dL; p = 0.081). Disease activity was significantly improved in both groups at year 1 compared with year 0. Persistent anemia was significantly correlated with severe anemia at baseline (p = 0.017).

CONCLUSION

In anemic patients with IBD, anti-TNF-α agents led to clinically meaningful improvements in anemia independent of iron supplementation. Also, iron supplementation could be helpful in severely anemic patients with IBD.

Stress erythropoiesis: definitions and models for its study

Steady-state erythropoiesis generates new erythrocytes at a constant rate, and it has enormous productive capacity. This production is balanced by the removal of senescent erythrocytes by macrophages in the spleen and liver. Erythroid homeostasis is highly regulated to maintain sufficient erythrocytes for efficient oxygen delivery to the tissues, while avoiding viscosity problems associated with overproduction. However, there are times when this constant production of erythrocytes is inhibited or is inadequate; at these times, erythroid output is increased to compensate for the loss of production. In some cases, increased steady-state erythropoiesis can offset the loss of erythrocytes but, in response to inflammation caused by infection or tissue damage, steady-state erythropoiesis is inhibited. To maintain homeostasis under these conditions, an alternative stress erythropoiesis pathway is activated. Emerging data suggest that the bone morphogenetic protein 4 (BMP4)-dependent stress erythropoiesis pathway is integrated into the inflammatory response and generates a bolus of new erythrocytes that maintain homeostasis until steady-state erythropoiesis can resume. In this perspective, we define the mechanisms that generate new erythrocytes when steady-state erythropoiesis is impaired and discuss experimental models to study human stress erythropoiesis.

Inflammatory anemia may be an indicator for predicting disease activity and structural damage in Chinese patients with rheumatoid arthritis

OBJECTIVES

This study aimed to investigate the relationship of serum hemoglobin (HB) level with disease activity and structural damage in Chinese patients with rheumatoid arthritis (RA).

METHODS

A total of 890 RA patients and 890 normal subjects were enrolled in the case-control study. A HB threshold of< 110 g/L (women) and < 120 g/L (men) was used to determine anemia. All the patients were divided into three groups: non-anemia group (HB ≥ 120 g/L (male) or 110 g/L (female)), mild anemia group ((90 g/L < HB < lower limit of normal), and medium to severe anemia group (HB ≤ 90 g/L). Serum HB level and anemia prevalence between RA patients and normal subjects were compared. Associations of HB level with disease activity, structural damage, and function of joint in different groups were also investigated.

RESULTS

The average of HB level in RA was (109.08 ± 17.96)g/l, which was lower than that in controls (136.75 ± 14.57)g/l (P < 0.001). Anemia was observed in 47% of the RA patients, while prevalence of anemia in control group was only 4.4%. In RA group, percentages of non-anemia, mild anemia, and medium to severe anemia were 47%, 38%, and 15%. Compared with non-anemia RA patients, RA patients with anemia had higher disease activity, severer structural damage and worse function of joint (P < 0.001). With the increase of anemia, the disease activity, structural damage, and dysfunction of joints increased significantly (P < 0.05-0.001). Linear regression analysis showed that HB level was negatively correlated with disease activity parameters, degree of joint destruction, and function (P < 0.05-0.001). Logistic regression indicated that serum HB level was protective factors for disease activity and structural damage in RA (P < 0.001).

CONCLUSION

HB level was significantly related to disease activity and structural damage in RA patients.Key Points• Inflammatory anemia was popular (about a half) in patients with RA.• HB level was related to disease activity and structural damage in RA patients.

Effects of anti-TNF-alpha therapy on hemoglobin levels and anemia in patients with inflammatory bowel disease

BACKGROUND

Tumor necrosis factor-α (TNF-α) is involved in inducing inflammatory anemia. The potential effect of anti-TNF-α agents on anemia in inflammatory bowel diseases (IBD) is still unknown.

METHODS

Analytical data and disease characteristics from 362 IBD patients [271 CD/91UC) treated with anti-TNF-α drugs were retrospectively collected. Effects on disease activity, blood markers and prevalence of anemia were assessed after 6 and 12 months of therapy.

RESULTS

29.3% patients presented anemia at baseline, and significantly reduced to 14.4% and 7.8% after 6 and 12 months of therapy, respectively. Mean ± SD Hb levels increased significantly at month 6, and this increase was sustained at 12 months. Serum markers of iron metabolism increased significantly compared to baseline, as disease activity measured by C-reactive protein (CRP) was reduced. All these effects were observed independently for CD and UC, and were independent of iron supplementation during treatment. Anemia at baseline (OR 4.09; 95%CI 1.98-8.45) and elevated CRP (OR 3.45; 95CI 1.29-9.22) were independently associated with risk of persistent anemia, as well as iron replacement during therapy (OR 4.36; 95%CI 2.07-9.16).

CONCLUSIONS

Controlling disease activity with anti-TNF- α therapy significantly and independently associated with resolution of anemia in IBD, with no relevant role for iron replacement therapy.

Stress Erythropoiesis is a Key Inflammatory Response

Bone marrow medullary erythropoiesis is primarily homeostatic. It produces new erythrocytes at a constant rate, which is balanced by the turnover of senescent erythrocytes by macrophages in the spleen. Despite the enormous capacity of the bone marrow to produce erythrocytes, there are times when it is unable to keep pace with erythroid demand. At these times stress erythropoiesis predominates. Stress erythropoiesis generates a large bolus of new erythrocytes to maintain homeostasis until steady state erythropoiesis can resume. In this review, we outline the mechanistic differences between stress erythropoiesis and steady state erythropoiesis and show that their responses to inflammation are complementary. We propose a new hypothesis that stress erythropoiesis is induced by inflammation and plays a key role in maintaining erythroid homeostasis during inflammatory responses.

GM-CSF drives dysregulated hematopoietic stem cell activity and pathogenic extramedullary myelopoiesis in experimental spondyloarthritis

Dysregulated hematopoiesis occurs in several chronic inflammatory diseases, but it remains unclear how hematopoietic stem cells (HSCs) in the bone marrow (BM) sense peripheral inflammation and contribute to tissue damage in arthritis. Here, we show the HSC gene expression program is biased toward myelopoiesis and differentiation skewed toward granulocyte-monocyte progenitors (GMP) during joint and intestinal inflammation in experimental spondyloarthritis (SpA). GM-CSF-receptor is increased on HSCs and multipotent progenitors, favoring a striking increase in myelopoiesis at the earliest hematopoietic stages. GMP accumulate in the BM in SpA and, unexpectedly, at extramedullary sites: in the inflamed joints and spleen. Furthermore, we show that GM-CSF promotes extramedullary myelopoiesis, tissue-toxic neutrophil accumulation in target organs, and GM-CSF prophylactic or therapeutic blockade substantially decreases SpA severity. Surprisingly, besides CD4+ T cells and innate lymphoid cells, mast cells are a source of GM-CSF in this model, and its pathogenic production is promoted by the alarmin IL-33.

The emerging role of red blood cells in cytokine signalling and modulating immune cells

For many years red blood cells have been described as inert bystanders rather than participants in intercellular signalling, immune function, and inflammatory processes. However, studies are now reporting that red blood cells from healthy individuals regulate immune cell activity and maturation, and red blood cells from disease cohorts are dysfunctional. These cells have now been shown to bind more than 50 cytokines and have been described as a sink for these molecules, and the loss of this activity has been correlated with disease progression. In this review, we summarise what is currently understood about the role of red blood cells in cytokine signalling and in modulating the activity of immune cells. We also discuss the implications of these findings for transfusion medicine and in furthering our understanding of anaemia of chronic inflammation. By bringing these disparate units of work together, we aim to shine a light on an area that requires significantly more investigation.

Inhibitory effects of 4-hydroperoxy-2-decenoic acid ethyl ester on phorbol ester- and TGF-β1-induced MMPs expression

Matrix metalloproteinases (MMPs), zinc-containing proteinases, play a critical role in tumour progression by degrading extracellular matrix components. MMP2 and MMP9 are secreted from tumour-associated macrophages as well as tumour cells and have been implicated in the formation of the tumour microenvironment. Therefore, the inhibition of these MMPs may suppress tumour progression and metastasis. 4-Hydroperoxy-2-decenoic acid ethyl ester (HPO-DAEE) is known to cause apoptosis in the human lung cancer cell line A549 by inducing endoplasmic reticulum (ER) stress. However, the effects of HPO-DAEE on tumour progression remain unclear. HPO-DAEE pre-treatment significantly suppressed phorbol 12-myristate 13-acetate (TPA)-triggered MMP activation in human monocytic THP-1 cells. It also enhanced the expression of haem oxygenase-1, an antioxidant enzyme, and suppressed the TPA-triggered intracellular accumulation of reactive oxygen species (ROS). Furthermore, HPO-DAEE suppressed transforming growth factor-β1-triggered human prostate cancer PC3 cell migration and this was accompanied by the inhibition of MMP expression and activities. The present results indicate that HPO-DAEE may exert inhibitory effects on tumour progression by suppressing MMP expression and activities.

Inflammation induces stress erythropoiesis through heme-dependent activation of SPI-C

Inflammation alters bone marrow hematopoiesis to favor the production of innate immune effector cells at the expense of lymphoid cells and erythrocytes. Furthermore, proinflammatory cytokines inhibit steady-state erythropoiesis, which leads to the development of anemia in diseases with chronic inflammation. Acute anemia or hypoxic stress induces stress erythropoiesis, which generates a wave of new erythrocytes to maintain erythroid homeostasis until steady-state erythropoiesis can resume. Although hypoxia-dependent signaling is a key component of stress erythropoiesis, we found that inflammation also induced stress erythropoiesis in the absence of hypoxia. Using a mouse model of sterile inflammation, we demonstrated that signaling through Toll-like receptors (TLRs) paradoxically increased the phagocytosis of erythrocytes (erythrophagocytosis) by macrophages in the spleen, which enabled expression of the heme-responsive gene encoding the transcription factor SPI-C. Increased amounts of SPI-C coupled with TLR signaling promoted the expression of Gdf15 and Bmp4, both of which encode ligands that initiate the expansion of stress erythroid progenitors (SEPs) in the spleen. Furthermore, despite their inhibition of steady-state erythropoiesis in the bone marrow, the proinflammatory cytokines TNF-α and IL-1β promoted the expansion and differentiation of SEPs in the spleen. These data suggest that inflammatory signals induce stress erythropoiesis to maintain erythroid homeostasis when inflammation inhibits steady-state erythropoiesis.

Persistent anemia and hypoalbuminemia in rheumatoid arthritis patients with low serum triiodothyronine level

Objectives: To determine the clinical characteristics of rheumatoid arthritis (RA) patients with low serum triiodothyronine (T3) levels.Methods: We evaluated serum free T3 (fT3), free T4, and thyroid-stimulating hormone (TSH) levels in 338 RA patients. After excluding patients taking anti-thyroid drugs or having anti-thyroid antibodies, we compared the clinical characteristics of the RA patients with low fT3 to those with normal/high fT3, before and after RA treatment.Results: Six percent of RA patients had low fT3 levels. Patients with low fT3 were older and had higher disease activity scores (DAS28), higher Steinbrocker stage, higher health assessment questionnaire scores, lower body mass index, and lower hemoglobin and albumin levels compared with normal/high-fT3 patients. After RA treatment, fT3 levels normalized in half of the low-fT3 patients and remained low in the other half. Although DAS28 scores were similarly improved in both subgroups of the low-fT3 patients, anemia and hypoalbuminemia did not normalize in the persistently low-fT3 subgroup.Conclusion: Low serum fT3 levels represent the profound wasting seen in RA patients that is characterized by anemia and hypoalbuminemia and that cannot be evaluated by DAS28 scores alone.

Hepcidin

Dysregulation of metabolism and utilization of iron can lead to the development and maintenance of anemia of CKD. Anemia is prevalent among patients with CKD. The markers of iron sufficiency or availability of iron are far from perfect which results in inaccurate diagnosis and treatment of anemia with poor outcomes. Hepcidin, a 25 amino acid peptide produced by the hepatocytes, has emerged as the key regulator of uptake and release of iron in the tissues to maintain a steady supply of iron to erythron and other tissues while avoiding higher levels of iron that could be detrimental to the organs. Hepcidin itself is regulated by the supply of iron, the need for erythropoiesis, and the state of inflammation. Alterations in hepcidin levels are associated with restricted erythropoiesis, anemia, and iron overload. Discovery of hepcidin and elucidation of its mechanism of action and consequences of its upregulation and suppression have unraveled important insight into many hematologic disorders including anemia of CKD. This knowledge has also unlocked unique opportunities to modulate hepcidin via agonists and antagonists of hepcidin and its feedback pathways to treat clinical conditions. Many such agents are being developed and have potential therapeutic utility in future.

Pro-inflammatory cytokine blockade attenuates myeloid expansion in a murine model of rheumatoid arthritis

Rheumatoid arthritis (RA) is a debilitating autoimmune disease characterized by chronic inflammation and progressive destruction of joint tissue. It is also characterized by aberrant blood phenotypes including anemia and suppressed lymphopoiesis that contribute to morbidity in RA patients. However, the impact of RA on hematopoietic stem cells (HSC) has not been fully elucidated. Using a collagen-induced mouse model of human RA, we identified systemic inflammation and myeloid overproduction associated with activation of a myeloid differentiation gene program in HSC. Surprisingly, despite ongoing inflammation, HSC from arthritic mice remain in a quiescent state associated with activation of a proliferation arrest gene program. Strikingly, we found that inflammatory cytokine blockade using the interleukin-1 receptor antagonist anakinra led to an attenuation of inflammatory arthritis and myeloid expansion in the bone marrow of arthritic mice. In addition, anakinra reduced expression of inflammation-driven myeloid lineage and proliferation arrest gene programs in HSC of arthritic mice. Altogether, our findings show that inflammatory cytokine blockade can contribute to normalization of hematopoiesis in the context of chronic autoimmune arthritis.

Established and Emerging Concepts to Treat Imbalances of Iron Homeostasis in Inflammatory Diseases

Inflammation, being a hallmark of many chronic diseases, including cancer, inflammatory bowel disease, rheumatoid arthritis, and chronic kidney disease, negatively affects iron homeostasis, leading to iron retention in macrophages of the mononuclear phagocyte system. Functional iron deficiency is the consequence, leading to anemia of inflammation (AI). Iron deficiency, regardless of anemia, has a detrimental impact on quality of life so that treatment is warranted. Therapeutic strategies include (1) resolution of the underlying disease, (2) iron supplementation, and (3) iron redistribution strategies. Deeper insights into the pathophysiology of AI has led to the development of new therapeutics targeting inflammatory cytokines and the introduction of new iron formulations. Moreover, the discovery that the hormone, hepcidin, plays a key regulatory role in AI has stimulated the development of several therapeutic approaches targeting the function of this peptide. Hence, inflammation-driven hepcidin elevation causes iron retention in cells and tissues. Besides pathophysiological concepts and diagnostic approaches for AI, this review discusses current guidelines for iron replacement therapies with special emphasis on benefits, limitations, and unresolved questions concerning oral versus parenteral iron supplementation in chronic inflammatory diseases. Furthermore, the review explores how therapies aiming at curing the disease underlying AI can also affect anemia and discusses emerging hepcidin antagonizing drugs, which are currently under preclinical or clinical investigation.

Anemia of inflammation

Anemia of inflammation (AI), also known as anemia of chronic disease (ACD), is regarded as the most frequent anemia in hospitalized and chronically ill patients. It is prevalent in patients with diseases that cause prolonged immune activation, including infection, autoimmune diseases, and cancer. More recently, the list has grown to include chronic kidney disease, congestive heart failure, chronic pulmonary diseases, and obesity. Inflammation-inducible cytokines and the master regulator of iron homeostasis, hepcidin, block intestinal iron absorption and cause iron retention in reticuloendothelial cells, resulting in iron-restricted erythropoiesis. In addition, shortened erythrocyte half-life, suppressed erythropoietin response to anemia, and inhibition of erythroid cell differentiation by inflammatory mediators further contribute to AI in a disease-specific pattern. Although the diagnosis of AI is a diagnosis of exclusion and is supported by characteristic alterations in iron homeostasis, hypoferremia, and hyperferritinemia, the diagnosis of AI patients with coexisting iron deficiency is more difficult. In addition to treatment of the disease underlying AI, the combination of iron therapy and erythropoiesis-stimulating agents can improve anemia in many patients. In the future, emerging therapeutics that antagonize hepcidin function and redistribute endogenous iron for erythropoiesis may offer additional options. However, based on experience with anemia treatment in chronic kidney disease, critical illness, and cancer, finding the appropriate indications for the specific treatment of AI will require improved understanding and a balanced consideration of the contribution of anemia to each patient's morbidity and the impact of anemia treatment on the patient's prognosis in a variety of disease settings.

Immunosuppressive therapy in myelodysplastic syndromes: a borrowed therapy in search of the right place

INTRODUCTION

Myelodysplastic syndromes (MDS) encompass a heterogenous collection of clonal hematopoietic stem cell disorders defined by dysregulated hematopoiesis, peripheral cytopenias, and a risk of leukemic progression. Increasing data support the role of innate and adaptive immune pathways in the pathogenesis and disease course of MDS. The role of immunosuppressive therapy has an established role in the treatment of other hematologic diseases, such as aplastic anemia whose pathogenesis is postulated to reflect that of MDS with regards to many aspects of immune activation. Areas covered: This paper discusses the current understanding of immune dysregulation as it pertains to MDS, the clinical experience with immunosuppressive therapy in the management of MDS, as well as future prospects which will likely improve therapeutic options and outcomes for patients with MDS. Expert commentary: Though limited by paucity of high quality data, immunomodulatory and immunosuppressive therapies for the treatment of MDS have shown meaningful clinical activity in selected patients. Continued clarification of the immune pathways that are dysregulated in MDS and establishing predictors for clinical benefit of immunosuppressive therapy are vital to improve the use and outcomes with these therapies.

Low Hemoglobin and Radiographic Damage Progression in Early Rheumatoid Arthritis: Secondary Analysis From a Phase III Trial

OBJECTIVE

To study low blood hemoglobin concentrations as a predictor of radiographic damage progression in patients with rheumatoid arthritis (RA).

METHODS

Post hoc analyses were performed in patients from the PREMIER trial with early RA undergoing 2 years of adalimumab (ADA), methotrexate (MTX), or ADA + MTX combination therapy. Low disease activity was defined as a score <3.2 on the 28-joint Disease Activity Score using the C-reactive protein level (DAS28-CRP), and clinical response by the American College of Rheumatology criteria for 20% improvement at week 24. Baseline or mean hemoglobin concentrations over time, or anemia as defined using sex-specific World Health Organization criteria, were analyzed in mixed-effects models for longitudinal data in men and women as predictors of progressive joint damage, as measured by the modified total Sharp/van der Heijde score (ΔSHS). Data were adjusted for treatment and other patient characteristics, including the DAS28-CRP.

RESULTS

Baseline hemoglobin was inversely associated with ΔSHS in adjusted analyses (P < 0.05 for both sexes). Baseline anemia predicted greater ΔSHS in MTX-treated patients over 104 weeks, and in ADA- and combination-treated patients over 26 weeks. Lower hemoglobin concentrations over time, as well as time with anemia, were associated with greater damage progression (P < 0.001). The effect of low hemoglobin concentrations on joint damage progression remained significant, even in patients achieving low disease activity.

CONCLUSION

Low hemoglobin is a DAS28-CRP-independent predictor of radiographic joint damage progression in MTX-treated patients with early RA. This effect decreases over time in ADA- and combination-treated patients, and in clinical responders irrespective of treatment modality.

Erythropoiesis: insights into pathophysiology and treatments in 2017

Erythropoiesis is a tightly-regulated and complex process originating in the bone marrow from a multipotent stem cell and terminating in a mature, enucleated erythrocyte.Altered red cell production can result from the direct impairment of medullary erythropoiesis, as seen in the thalassemia syndromes, inherited bone marrow failure as well as in the anemia of chronic disease. Alternatively, in disorders such as sickle cell disease (SCD) as well as enzymopathies and membrane defects, medullary erythropoiesis is not, or only minimally, directly impaired. Despite these differences in pathophysiology, therapies have traditionally been non-specific, limited to symptomatic control of anemia via packed red blood cell (pRBC) transfusion, resulting in iron overload and the eventual need for iron chelation or splenectomy to reduce defective red cell destruction. Likewise, in polycythemia vera overproduction of red cells has historically been dealt with by non-specific myelosuppression or phlebotomy. With a deeper understanding of the molecular mechanisms underlying disease pathophysiology, new therapeutic targets have been identified including induction of fetal hemoglobin, interference with aberrant signaling pathways and gene therapy for definitive cure. This review, utilizing some representative disorders of erythropoiesis, will highlight novel therapeutic modalities currently in development for treatment of red cell disorders.

A Gain-of-Function Mutation in EPO in Familial Erythrocytosis

Familial erythrocytosis with elevated erythropoietin levels is frequently caused by mutations in genes that regulate oxygen-dependent transcription of the gene encoding erythropoietin ( EPO). We identified a mutation in EPO that cosegregated with disease with a logarithm of the odds (LOD) score of 3.3 in a family with autosomal dominant erythrocytosis. This mutation, a single-nucleotide deletion (c.32delG), introduces a frameshift in exon 2 that interrupts translation of the main EPO messenger RNA (mRNA) transcript but initiates excess production of erythropoietin from what is normally a noncoding EPO mRNA transcribed from an alternative promoter located in intron 1. (Funded by the Gebert Rüf Foundation and others.).

Terminal Maturation of Orthochromatic Erythroblasts Is Impaired in Burn Patients

Mechanisms of erythropoietin (Epo)-resistant anemia in burn patients are poorly understood. We have recently found that administering a nonselective beta 1,2-adrenergic blocker propranolol (PR) was effective in reversing myelo-erythroid commitment through MafB regulation and increase megakaryocyte erythrocyte progenitors in burn patients' peripheral blood mononuclear cell (PBMC)-derived ex vivo culture system. Having known that Epo-dependent proliferation of early erythroblasts is intact after burn injury, here we inquired whether or not Epo-independent maturation stage of erythropoiesis is affected by burn injury and the relative role of PR on late-stage erythropoiesis. While majority of erythropoiesis occurs in the bone marrow, maturation into reticulocytes is crucial for their release into sinusoids to occupy the peripheral circulation for which enucleation is vital. peripheral blood mononuclear cells (PBMCs) from burn patients were extended beyond commitment and proliferation stages to late maturation stage in ex vivo culture to understand the role of PR in burn patients. Burn impedes late maturation of orthochromatic erythroblasts into reticulocytes by restricting the enucleation step. Late-stage erythropoiesis is impaired in burn patients irrespective of PR treatment. Further, substituting the microenvironment with control plasma (homologous) in place of autologous plasma rescues the conversion of orthochromatic erythroblasts to reticulocytes. Results show promise in formulating interventions to regulate late-stage erythropoiesis, which can be used in combination with PR to reduce the number of transfusions.

Changes in Hepcidin and Hemoglobin After Anti-TNF-alpha Therapy in Children and Adolescents With Crohn Disease

OBJECTIVES

Anemia is the most common systemic complication of inflammatory bowel disease, is more common in affected children than in adults, and is mediated in large part by chronic inflammation. Inflammation increases levels of the iron-regulatory protein hepcidin, which have been elevated in adults with Crohn disease.

METHODS

We measured serum hepcidin-25 and hemoglobin (Hgb) in 40 children and adolescents with Crohn disease at baseline and 10 weeks after initiation of anti-tumor necrosis factor (TNF)-α therapy. Measures of disease activity, inflammatory markers, and cytokines were obtained in all subjects. Anemia was defined by World Health Organization criteria.

RESULTS

At baseline hepcidin and C-reactive protein levels were correlated, and 95% of subjects were anemic. After anti-TNF-α therapy, median (interquartile range) hepcidin concentrations decreased significantly and the distribution narrowed (27.9 [16.2, 52.9] vs 23.2 [11.1, 37.7] ng/mL, P = 0.01). Mean (standard deviation) Hgb also increased significantly (10.6 ± 1.2 to 10.9 ± 1.1 g/dL, P = 0.02), and the increase was sustained at 12 months, although 90% of participants continued to meet anemia criteria at 10 weeks. Disease activity and markers of inflammation also decreased and albumin levels increased. In generalized estimating equation analyses, higher TNF-α, interleukin 6, erythrocyte sedimentation rate, and C-reactive protein were associated with higher hepcidin concentrations (P = 0.04, P = 0.03, P = 0.003, and P < 0.001, respectively), and increased levels of disease activity were associated with higher hepcidin.

CONCLUSIONS

In children with Crohn disease, anti-TNF-α therapy is associated with decreased levels of hepcidin and increased Hgb 10 weeks after induction. Improvement in anemia may be a secondary benefit for children who receive this therapy.

Caspase-3/-7-Specific Metabolic Precursor for Bioorthogonal Tracking of Tumor Apoptosis

Apoptosis is one of the most important intracellular events in living cell, which is a programmed cell death interrelated with caspase enzyme activity for maintaining homeostasis in multicellular organisms. Therefore, direct apoptosis imaging of living cells can provide enormous advantages for diagnosis, drug discovery, and therapeutic monitoring in various diseases. However, a method of direct apoptosis imaging has not been fully validated, especially for live cells in in vitro and in vivo. Herein, we developed a new apoptosis imaging technology via a direct visualization of active caspase-3/-7 activity in living cells. For this, we synthesized a caspase-3/-7-specific cleavable peptide (KGDEVD) conjugated triacetylated N-azidoacetyl-D-mannosamine (Apo-S-Ac₃ManNAz), wherein the Apo-S-Ac₃ManNAz can be cleaved by the active caspase-3/-7 in live apoptotic cells and the cleaved Ac₃ManNAz molecules can further generate targetable azido groups (N₃) on the living cell surface. Importantly, the azido groups on the apoptotic tumor cells could be visualized with Cy5.5-conjugated dibenzylcyclooctyne (DBCO-Cy5.5) via bioorthogonal click chemistry in vitro cell culture condition and in vivo tumor-bearing mice. Therefore, our Apo-S-Ac₃ManNAz can be utilized for the further applications in tumor therapy as a monitoring tool for anticancer efficacy and optimization of anticancer new drugs in cell culture system and in tumor-bearing mice.

Zytopenien

Hematological alterations can often be observed during rheumatic diseases. The effects can be clinically severe, ranging from anemia of different grades of severity, through increased risk of hemorrhage due to thrombocytopenia up to severe infections as a result of high-grade leukocytopenia. The clinical sequelae for patients are predominantly determined by the extent of cytopenia. The underlying disease itself can initially be considered as the cause. Examples are anemia as a result of chronic inflammation, antibody-mediated thrombocytopenia as in systemic lupus erythematosus (SLE) or granulocytopenia within the framework of Felty's syndrome. Immunosuppressive treatment also often leads to alterations in the blood constituents. Although some substances, such as cyclophosphamide can suppress all three cell types, there are also selective effects, such as isolated thrombocytopenia under treatment with tocilizumab and JAK inhibitors. The differential diagnostic clarification of cytopenia can be difficult and necessitates a systematic work-up of the course of the disease and the subsequent treatment. The reviews of anemia, leukocytopenia and thrombocytopenia presented here summarize the most important components of the differentiation of hematological alterations in patients with rheumatic diseases.

Anti-TNF-α effects on anemia in rheumatoid and psoriatic arthritis

A key role in the pathogenesis of rheumatoid arthritis (RA) and psoriatic arthritis (PsA) is played by inflammatory cytokines, including tumor necrosis factor-α (TNF-α), which are also involved in inducing inflammatory anemia. We have followed 67 RA patients and 64 PsA patients for 1 year to evaluate the effects of TNF-α inhibitors on disease activity and on inflammatory anemia. Patients were divided into three different treatment groups, according to a randomized assignment to receive therapy with etanercept, adalimumab, or infliximab. Treatment with anti-TNF-α resulted in a significant reduction in disease activity score-28 (DAS28) values both in RA and PsA patients, already from the third month of treatment ( P = 0.01). In both populations, there was an increase in hemoglobin (HB) levels already after 3 months of treatment ( P = 0.001), and HB levels were inversely proportional to the disease activity, regardless of the type of medication used. The increased HB values and the reduction of DAS28 values during the observation period suggest the existence of a negative correlation between them both in RA and PsA, regardless of the type of anti-TNF-α used. Our data suggest a pleiotropic action of anti-TNF-α, such as the well-known action on the activity of the disease, and the improvement in inflammatory anemia.