Ring sideroblasts show abnormal mitochondrial iron accumulation, and their emergence in the bone marrow is a characteristic of sideroblastic anemias (SAs). SAs are a group of heterogeneous congenital and acquired disorders. Congenital SA is a rare disease caused by gene mutations involved in heme biosynthesis, iron-sulfur cluster biosynthesis, and mitochondrial protein synthesis. SAs can also occur after exposure to certain drugs or alcohol and due to copper deficiency (secondary SA). Furthermore, SAs are associated with myelodysplastic syndrome (idiopathic SA), strongly correlating with specific somatic mutations in splicing factor 3b subunit 1 (SF3B1), which is involved in the RNA splicing machinery. https://www.selleckchem.com/products/e1210.html Recent reports have indicated that common defects in iron/heme metabolism underlie in the mechanisms of ring sideroblast formation in congenital and acquired SAs. Current understanding of SA pathophysiology, including the mechanisms of ring sideroblast formation, is discussed in this review.Anemia remains an important complication of patients with chronic kidney disease (CKD). Relative erythropoietin deficiency was assumed to be the main cause of anemia in CKD. In contrast, it is possible that iron dysregulation for erythropoiesis in CKD patients also affects not only anemia but also cardiovascular event or survival of these patients. A prospective observational study was conducted for 3 years on 1,000 maintenance hemodialysis patients. In time-dependent cox hazard analysis, we found the higher risks of cardiovascular disease (HR 4.45, p less then 0.001) and all-cause mortality (HR 5.8, p less then 0.001) in patients with low transferrin saturation (TSAT) ( less then 20%) and high ferritin levels (≥100 ng/ml) who are suspected to have iron dysregulation for erythropoiesis compared with patients with high TSAT and low ferritin level. From these results, we hypothesized that iron dysregulation in CKD patients is closely associated with various complications and survival. Moreover, iron administration should be approached with caution in patients who present with iron dysregulation for erythropoiesis.Iron is essential to maintain cellular homeostasis, such as hemoglobin synthesis, mitochondrial respiratory chain formation, DNA replication, DNA demethylation, and histone demethylation. In addition, iron acts as a catalyst to produce reactive oxygen species, including hydroxyl radicals, which induce 8-OHdG production and DNA double strand breaks. Hence, the total body iron level should be strictly regulated. Recently, hepatic hepcidin was found to inhibit iron absorption from the gastrointestinal tract, and hepcidin production is reduced by erythroid factors, such as growth differentiation factor 15 (GDF15) and erythroferrone. Systemic iron kinetics seem to be regulated by cooperation among the liver, gastrointestinal tract, and hematopoietic tissues. However, this cooperation could be disturbed in bone marrow failure syndrome (BMFS). In some anemic disorders, such as β-thalassemia, and some categories of MDS, GDF15 or erythroferrone were overproduced and promoted iron absorption. Frequent blood transfusions rapidly increase iron accumulation in the body and eventually result in irreversible organ damage, such as heart failure. Therefore, the introduction of an early intervention to improve iron overload in BMFS is necessary. In recent years, oral chelators have been introduced for clinical use. Erythropoiesis-stimulating agents and thrombopoietin receptor agonists could also improve refractory anemia or BMFS and improve iron overload.A 72-year-old man with ileocecal lymphadenopathy was found to have Epstein-Barr virus-positive diffuse large B-cell lymphoma using open biopsy, and an ileostoma was created. R-CHOP-like chemotherapy was initiated, but his malnutrition did not improve. After 3 cycles of chemotherapy, a 2-m-long Cestoda was removed from the stoma and was identified as Diphyllobothrium nihonkaiense using mitochondria cytochrome c oxidase subunit 1 targeted polymerase chain reaction analysis. Although D. nihonkaiense infections are asymptomatic, the ileostomy was thought to have exacerbated the malabsorption in this patient. Parasitic infections are rare; however, they should be added to the differential diagnosis of malnutrition of unknown cause during chemotherapy for hematological malignancies.A 56-year-old woman was referred to our hospital with symptoms of swelling, purpura, and pain in her limbs. Prior to referral, bleeding in her limbs had spontaneously appeared and disappeared several times. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) were prolonged, and the factor II level was 17%. The plasma-mixing test indicated lupus anticoagulant (LA), which was confirmed using aPTT-LA and dilute Russell's viper venom time (dRVVT). Therefore, she was diagnosed with lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS). During screening for underlying disorders, chest computed tomography (CT) revealed a retrosternal mass. Biopsy was not performed because the administration of freshly frozen plasma failed to correct her coagulopathy. Prednisolone (PSL) treatment (1 mg/kg) was initiated, which normalized the coagulation tests. The retrosternal mass also disappeared. PSL was tapered without LAHPS recurrence; however, the follow-up CT revealed systemic lymphadenopathy. Follicular lymphoma was diagnosed using lymph-node biopsy. Considering the subsequent LAHPS recurrence, six cycles of bendamustine + rituximab were administered. Complete response with no LAHPS recurrence was observed at the time of drafting this report. LAHPS is rare and distinct from antiphospholipid syndrome because it can cause severe bleeding. Underlying disorders should be evaluated in cases of LAHPS.A 58-year-old man was admitted with shortness of breath in September 2019. He had a severe hemolytic anemia with a high cold agglutinin (CA) titer. He also had arthralgia and finger deformation. He was diagnosed with cold agglutinin syndrome (CAS) secondary to rheumatoid arthritis (RA) based on the clinical course. Occasionally, CAS has been reported to occur in parallel with collagen disease, infectious disease, or malignant tumor. CAS developing secondary to collagen disease occurs less frequently than that to infectious disease or malignant tumors. Furthermore, CAS caused by RA is very rare, even among patients with collagen diseases. Our patient was effectively treated with immunosuppressive therapy including abatacept, which attenuated the symptoms of CAS and RA.