A Revised Classification of Primary Iron Overload Syndromes.

Background and Aims: The clinical introduction of hepcidin25 (Hep25) has led to a more detailed understanding of its relationship with ferroportin (FP) and divalent metal transporter1 in primary iron overload syndromes (PIOSs). In 2012, we proposed a classification of PIOSs based on the Hep25/FP system, which consists of prehepatic aceruloplasminemia, hepatic hemochromatosis (HC), and posthepatic FP disease (FP-D). However, in consideration of accumulated evidence on PIOSs, we aimed to renew the classification. Methods: We reviewed the 2012 classification and retrospectively renewed it according to new information on PIOSs. Results: Iron-loading anemia was included in PIOSs as a prehepatic form because of the newly discovered erythroferrone-induced suppression of Hep25, and the state of traditional FP-D was remodeled as the BIOIRON proposal. The key molecules responsible for prehepatic PIOSs are low transferrin saturation in aceruloplasminemia and increased erythroferrone production by erythroblasts in iron-loading anemia. Hepatic PIOSs comprise four genotypes of HC, in each of which the synthesis of Hep25 is inappropriately reduced in the liver. Hepatic Hep25 synthesis is adequate in posthepatic PIOSs; however, two mutant FP molecules may resist Hep25 differently, resulting in SLC40A1-HC and FP-D, respectively. PIOS phenotypes are diagnosed using laboratory tests, including circulating Hep25, followed by suitable treatments. Direct sequencing of the candidate genes may be outsourced to gene centers when needed. Laboratory kits for the prevalent mutations, such as C282Y, may be the first choice for a genetic analysis of HC in Caucasians. Conclusions: The revised classification may be useful worldwide.

Methotrexate-induced subacute myelopathy: a serious but treatable complication.

Subacute myelopathy is a rare but serious complication of methotrexate (MTX) that may cause paraplegia. Although its underlying mechanisms have not been fully elucidated, homocysteine is thought to play a role in the pathogenesis of this adverse effect. Herein, we report the case of a 34-years old female patient with diffuse large B-cell lymphoma who developed progressive paraplegia accompanied by dysfunctional bladder and bowel movements after treatment with a modified CODOX-M/IVAC regimen, including high-dose intravenous MTX and intrathecal (IT-) MTX. Neurological symptoms gradually improved to almost normal levels within 4.5 months of onset following treatment with a combination of S-adenosylmethionine, methionine, cyanocobalamin, and folate. During chemotherapy, including high-dose MTX and IT-MTX for hematological malignancies, MTX-induced subacute neuronal damage should be carefully evaluated, and appropriate treatment should be initiated as early as possible.

Low-grade B cell lymphoma in the perirenal space of the left kidney associated with high titer cold agglutinin disease.

Cold agglutinin disease (CAD) is a subgroup of autoimmune hemolytic anemia caused by monoclonal cold agglutinins produced by clonally expanded B lymphocytes. In primary CAD, lymphoproliferative bone marrow disorder is noted, while as one of the secondary cold agglutinin syndromes (CAS), the initial manifestation of CAD is followed by development of lymphoma. Here, we report a case of low-grade B cell lymphoma developed 3 months after an initial CAD diagnosis. The patient had an extremely high serum cold agglutinin titer (1:16,384) and slightly elevated serum IgM (452 mg/dL; reference, 31-200) with positive monoclonal IgM-kappa chain. After diagnosis of lymphoma-associated CAS, he was managed successfully with six cycles of a BR (bendamustine and rituximab) regimen. Cold agglutinin titers fell rapidly to 1:2048 at 5 months and to 1:512 at 10 months after chemotherapy, and the patient has been in a complete remission for 34 months.

Chronic Nonbacterial Osteomyelitis of the Jaw in a 3-Year-Old Girl.

Differential diagnosis of bacterial osteomyelitis (BOM) and chronic nonbacterial osteomyelitis (CNO) is challenging. Pediatric CNO can be diagnosed at around 10 years of age and when CNO cases involve only the jaw, it is difficult to make a diagnosis in a young child. A 3-year-old female developed CNO at the jaw alone. She presented with no fever, right jaw pain, mild trismus, and a preauricular facial swelling around the right mandible. Computed tomography (CT) revealed a hyperostotic right mandible, with osteolytic and sclerotic changes associated with periosteal reaction. At first, we suspected BOM and antibiotics were administered. Subsequently, CNO was diagnosed, and the patient received flurbiprofen (a nonsteroidal anti-inflammatory drug (NSAIDs)). Lack of a sufficient response led to successful treatment with a combination of oral alendronate and flurbiprofen. Physicians should be aware of CNO, a rare autoinflammatory noninfectious bone disease of unknown etiology, even in young children, although the disease mostly affects older children and adolescents.

Juvenile Hemochromatosis With Non-transfused Hemolytic Anemia Caused by a De Novo PIEZO1 Gene Mutation.

Differential diagnosis of juvenile hemochromatosis along with hemolytic anemia is often difficult. We report a 23-year-old woman with macrocytic hemolytic anemia with iron overload. The patient showed high serum ferritin and transferrin saturation and low serum transferrin and ceruloplasmin. We also noticed stomatocytes in her blood smear, which was confirmed by scanning electron microscopy. Target gene sequencing identified a mutation in PIEZO1 (heterozygous c.6008C>A: p.A2003D). This mutation was reported previously in a family with dehydrated hereditary stomatocytosis (DHS1, [OMIM 194380]), but in the current case, it was identified to be a de novo mutation. We underscore DHS1 in the differential diagnosis of iron overload associated with non-transfused hemolytic anemia in children and young adults.

Relapses of multisystem/multifocal bone Langerhans cell histiocytosis in paediatric patients: Data analysis from the JLSG-96/02 study.

We assessed relapse patterns in paediatric patients with relapsed Langerhans cell histiocytosis (LCH) who were initially treated with the JLSG-96/02 protocol. We analysed 187 relapse events in 101 relapsed LCH patients [31 with multifocal bone (MFB) and 70 with multisystem (MS) at LCH diagnosis] among a total 317 patients enrolled in JLSG-96/-02 studies. Relapse of LCH was defined as an exacerbation of the non-active disease (NAD) condition. Of the 317 patients, 101 (31.9%) had the first relapse at 1.5 years after initiation of therapy. The first relapse and subsequent relapses did not differ between patients with MFB and MS disease. Of the 187 relapse events, relapse occurred as a single-system disease (n = 159; 85%), in which isolated bone relapse (n = 104; 55%) was the most common. Relapse at MS disease with the risk of organ involvement is extremely rare. After relapse(s), most patients underwent chemotherapy (122/187; 65%) and 87% of them achieved NAD status again. The incidence of permanent consequences was significantly higher in patients with relapses than in those without relapses. In the JLSG cohort, bone relapse most occurred in both MFB and MS patients. Most relapses could be effectively controlled by repeated administration of the initial chemotherapy.

Acute abdomen due to anaphylactic intestinal edema associated with systematic mastocytosis: a case report.

BACKGROUND: Among various anaphylactic conditions resulting in acute abdomen, mast cell activation disorders, although rare, are included in the differential diagnosis. CASE PRESENTATION: This report describes a 63-year-old Caucasian man who was brought to the emergency room with sudden onset abdominal pain, vomiting, and diarrhea, with breathing difficulty, and with facial swelling after quarrelling with an acquaintance. Computed tomography showed edematous and swollen intestines, consistent with splenomegaly. Physical findings included maculopapular cutaneous mastocytosis. He also had a long history of repeated episodes of anaphylaxis requiring occasional epinephrine auto-injector administration; however, the precise cause of anaphylaxis was previously undetermined. Blood tests showed high serum concentrations of soluble IL-2R and tryptase, suggesting mast cell-related disease. Subsequent biopsies of his bone marrow and cutaneous rash confirmed the diagnosis of systemic mastocytosis (SM). CONCLUSION: SM was diagnosed in a patient with acute abdomen who visited the emergency room.

Bone lesions of Langerhans cell histiocytosis triggered by trauma in children.

BACKGROUND: Bone lesions of Langerhans cell histiocytosis (LCH) may be triggered by trauma. METHODS: The characteristics of pediatric patients in the JLSG-02 study cohort who developed a bone lesion at the trauma site at diagnosis of LCH were analyzed retrospectively. RESULTS: Of the 261 pediatric patients with LCH, 12 (4.6%), of median age 4.9 years, had trauma-triggered bone LCH lesions at diagnosis, making them significantly older than the remaining patients (P = 0.006). Trauma sites included the craniofacial regions in 10 patients and the lumbar spine and pelvis in one patient each. At the time of trauma, six patients had a bump at the site, whereas none had extradural hematomas or bone fractures. The median time from trauma to onset was 4 weeks. Of these 12 patients, three had isolated bone (IB) disease; four had multifocal bone (MFB) disease, including the bone lesion at the trauma site; and five had multisystem disease, including four with lesions in neighboring tissue and one with polyuria (posterior pituitary lesion) more than 1 year before the trauma-triggered bone lesion. Treatment responses were good in all 12 patients and none died, but relapses were observed in two patients, one each with IB and MFB disease. CONCLUSIONS: About 5% of pediatric patients with LCH developed new trauma-triggered bone lesions at a relatively old age. These lesions can manifest as IB, or, in patients with underlying LCH diseases, as MFB or multisystem. Good clinical outcomes were observed in these patients.

Puzzling (IRIDA-Like and Hemolytic) Anemia in a Child With Idiopathic Pulmonary Hemosiderosis.

Before the diagnosis of idiopathic pulmonary hemosiderosis (IPH), unexplained or puzzling anemia may precede and delay in the diagnosis of pediatric IPH is common. A 5.8 years old female child initiated with iron-refractory iron deficiency anemia-like iron deficiency and hemolytic anemia and at 6.8 years of age IPH was materialized, when the patient showed the triad signs of IPH with hemosiderin-laden alveolar macrophages in gastric aspirate. Although time to the diagnosis was previously reported to be ranged from 16 to 30 months, in our case it took 12 months from the initial anemia to IPH diagnosis.

Hyperhomocysteinemia-related lung disease and hemolytic anemia with bone marrow features masquerading as myelodysplasia.

Hyperhomocysteinemia is linked to TMA-related clinical symptoms such as apparent thromboembolism, microangiopathic hemolytic anemia (MAHA), and various types of end-organ damage due to microvascular thrombi; this is because high plasma levels of homocysteine impair the vascular endothelium. However, the association between hyperhomocysteinemia and pulmonary involvement is unclear. Here, we describe a 63-year-old male who was hospitalized with respiratory failure and MAHA with MDS-like features in the bone marrow. Plasma homocysteine levels were elevated significantly with 199.4 µmol/L (reference: 6.3-18.9) due to a homozygous (T/T) polymorphism for the 677C>T mutation within the MTHFR gene associated with chronic alcoholism-induced folate deficiency. Pulmonary lesions showed ground-glass opacity and there was pleural effusion. The patient was managed successfully with a combination of folate/mecobalamin supplementation, plasma exchange, and a methylprednisolone pulse, followed by oral prednisolone. Clinical symptoms, lung disease, MAHA, and bone marrow abnormalities improved as plasma homocysteine levels normalized.

Virus-triggered secondary hemophagocytic lymphohistiocytosis.

Primary (familial/hereditary) and secondary (non-familial/hereditary) hemophagocytic lymphohistiocytosis (HLH) are hyperinflammatory and hypercytokinemic syndromes. Secondary HLH includes infection- (eg viral/bacterial/fungal/parasitic) and non-infection- (eg collagen disease or malignancy) related diseases. Viral HLH is the major type among all age groups. Secondary viral HLH and primary HLH must be differentiated carefully because primary HLH can be associated with viral infection(s), and the outcome is dismal without a timely diagnosis and hematopoietic stem cell transplantation (HSCT). Epstein-Barr virus (EBV)-related HLH (EBV-HLH) is the most common type of viral HLH in childhood. For non-EBV-HLH, appropriate treatment of viral infection, followed by immunomodulatory agent(s) such as corticosteroids, intravenous immunoglobulin or cyclosporine A, is usually successful; however, recent SARS-CoV-2-related HLH may become life-threatening. EBV-HLH may occur heterogeneously associated with the primary infection, with chronic active EBV infection or with underlying primary HLH. Although immunomodulatory agent(s) are effective in the majority of EBV-HLH cases, management differs from that of non-EBV-HLH because severe and refractory cases may require etoposide-containing HLH-1994/2004 regimens or other experimental agents. The novel agent, emapalumab (an anti-IFN-γ monoclonal antibody) can be used to treat EBV-HLH cases to avoid the risk of secondary malignancy due to etoposide. Finally, HSCT is required for refractory EBV-HLH cases and can also be curative in some other cases.

Protein C Gene Mutation in an Older Adult Patient with Clostridium perfringens Septicemia-Related Visceral Vein Thrombosis.

A 78-year-old Japanese male with Clostridium perfringens septicemia and cholecystitis was found to have thrombosis in the left branch of intrahepatic portal vein as well as superior mesenteric vein. Visceral vein thrombosis (VVT) in this case was associated with protein C deficiency, due to a heterozygous mutation, p. Arg185Met. Our experience emphasizes that VVT, or other thromboembolic events, may occur in later life, triggered by environmental thrombosis risk factors, together with underlying hereditary protein C gene mutation.

Congenital Hypofibrinogenemia in a Neonate with a Novel Mutation in the FGB Gene.

Detection of severe hypofibrinogenemia (<50 mg/dL) in a neonate soon after birth is alarming because of the risk of hemorrhage. A female neonate was noted to be hypofibrinogenemic (<50 mg/dL) on day 0 of birth; she showed no thrombocytopenia/coagulopathy or hemorrhagic symptoms. Considering the possibility of afibrinogenemia, which may cause bleeding, fresh frozen plasma (FFP) was initiated twice a week to maintain her plasma fibrinogen level at 50-100 mg/dL. Thereafter, we found hypofibrinogenemia in her father and elder sister and plasma fibrinogen levels, determined by clot formation and immunological methods, showed similarly reduced values in both the neonate (proband) and her father. Based on a presumed diagnosis of congenital hypofibrinogenemia, sequencing of the fibrinogen genes was performed, revealing a novel heterozygous mutation of FGB (Genbank NG008833); a p.403Try>Stop. The neonate was treated with repeat FFP infusions until two months of age, when treatment was stopped because she remained asymptomatic.

Long-term complications in uniformly treated paediatric Langerhans histiocytosis patients disclosed by 12 years of follow-up of the JLSG-96/02 studies.

Langerhans cell histiocytosis (LCH) is a rare inflammatory myeloid neoplasia derived from immature myeloid dendritic cells with the mitogen-activated protein kinase (MAPK) pathway gene mutation. LCH is rarely fatal, but patients develop various permanent consequences (PCs). We report the frequencies of LCH-related PCs in paediatric patients (n = 317) treated by the JLSG-96/02 AraC-containing regimens. One-third of LCH patients had at least one PC at a median follow-up of 12 years. Central nervous system (CNS)-related PCs (neurological and endocrinological) accounted for 21·5%, non-CNS-related 16·7%. We require novel therapeutic measures to further reduce the frequency of LCH-related PCs.