CALR mutations are a revolutionary discovery and represent an important hallmark of myeloproliferative neoplasms (MPN), especially essential thrombocythemia and primary myelofibrosis. To date, several CALR mutations were identified, with only frameshift mutations linked to the diseased phenotype. It is of diagnostic and prognostic importance to properly define the type of CALR mutation and subclassify it according to its structural similarities to the classical mutations, a 52-bp deletion (type 1 mutation) and a 5-bp insertion (type 2 mutation), using a statistical approximation algorithm (AGADIR). Today, the knowledge on the pathogenesis of CALR-positive MPN is expanding and several cellular mechanisms have been recognized that finally cause a clonal hematopoietic expansion. In this review, we discuss the current basis of the cellular effects of CALR mutants and the understanding of its implementation in the current diagnostic laboratorial and medical practice. Different methods of CALR detection are explained and a diagnostic algorithm is shown that aids in the approach to CALR-positive MPN. Finally, contemporary methods joining artificial intelligence in accordance with molecular-genetic biomarkers in the approach to MPN are presented.

Introduction: Hypoparathyroidism is a chronic condition which requires a lifelong substitution with vitamin D analogues and careful monitoring. This is especially true for older patients and older compounds as dihydrotachysterol with longer half-life that might lead to long-lasting hypercalcemic episodes. Case presentation: A 74-year old male patient with postsurgical hypoparathyroidism who has been successfully supplemented with dihydrotachysterol (1.7 ml/day) for over 50 years presented with neuropsychiatric disturbances, constipation, renal insufficiency and polyuria. Laboratory investigation demonstrated serum calcium 3.7 mmol/L, serum creatinine 180 micromol/L, urine calcium excretion 1.1 mmol/mmol of the creatinine, normal 25 OH vitamin D₃ and low parathormone and 1,25 di OH vitamin D₃. Careful history revealed that he has been erroneously taking 2.5 ml of dihydrotachysterol per day for at least 6 to 8 weeks that caused vitamin D intoxication and symptomatic hypercalcemia. He was treated with intravenous saline infusion, prednisolone and 60 mg of intravenous sodium pamidronate. On the fourth day after admission serum calcium dropped rapidly within the reference range. The treatment for hypoparathyroidism had to be reinstituted 10 days after dihydrotachysterol had been discontinued when the patient was switched to shorter acting calcitriol. Conclusions: Here we reported that the immediate use of pamidronate in addition to classic treatment of dihydrotachysterol intoxication with intravenous saline, diuretics and glucocorticoids is an effective treatment choice that leads to rapid resolution of hypercalcemia.

Chimeric antigen receptor (CAR) T cell therapy has emerged as a powerful therapeutic approach against a range of hematologic malignancies. While the incorporation of CD28 or 4-1BB costimulatory signaling domains into CARs revolutionized immune responses, there is an exciting prospect of further enhancing CAR functionality. Here, we investigated the design of CD19 CARs enriched with distinct Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), or Toll/IL-1 domain-containing adaptor-inducing interferon (IFN)-β (TRIF) costimulatory domains. Screening of various designs identified several candidates with no tonic activity but with increased CD19 target cell-dependent interleukin (IL)-2 production. Human T cells transduced with the selected CAR construct exhibited augmented hIL-2 and hIFN-γ induction and cytotoxicity when cocultured with CD19-positive lymphoma and solid-tumor cell lines. RNA sequencing (RNA-seq) analysis demonstrated the upregulation of some genes involved in the innate immune response and T cell activation and proliferation. In experiments on a xenogeneic solid-tumor mice model, MyD88 and TLR4 CAR T cells exhibited prolonged remission. This study demonstrates that the integration of a truncated TLR4 signaling costimulatory domain could provide immunotherapeutic potential against both hematologic malignancies and solid tumors.

(1) Background: Relapsed/refractory (r/r) and secondary acute myeloid leukemia are highlighted by chemoresistance and poor outcomes. The aim of the study was to assess the efficacy and toxicity of fludarabine, cytarabine, and granulocyte-colony stimulation factor (FLAG) with or without idarubicin (-Ida) and to discuss novel therapies in this setting. (2) Methods: Clinical and cytogenetic data on 130 consecutive patients with r/r and secondary AML treated at our center were retrospectively analyzed. (3) Results: There were 48, 56, and 26 patients with relapsed, refractory, and secondary AML, respectively. The median age was 60 years. The overall response was achieved in 70% of patients. The median overall survival (OS) time for the whole group was 9.4 months. In total, 47% of patients proceeded to allogeneic hematopoietic stem cell transplantation (aHSCT) and these patients had significantly prolonged OS compared to the others (63 months vs. 4.2 months; p < 0.001). Among the variables, including age, FLT3 mutation status, European LeukemiaNet (ELN) 2022 classification risk, FLAG vs. FLAG-Ida, and aHSCT, a multivariate analysis revealed that only aHSCT significantly influenced overall survival. (4) Conclusions: FLAG(-Ida) chemotherapy remains an effective salvage chemotherapy for patients with r/r and secondary AML with a plan of proceeding to aHSCT.

The association of systemic mastocytosis (SM) with a non-mast cell haematological neoplasm represents a specific subtype of mastocytosis termed systemic mastocytosis with associated haematological non-mast cell disease (SM-AHNMD). The overwhelming majority of the associated neoplasms are of myeloid origin, while lymphoid neoplasms associated with SM have been reported rarely. Association of SM with Hodgkin’s lymphoma (HL) is exceedingly rare; so far, only two cases of HL as associated hematological non-mast cell disease in systemic mastocytosis have been published in the recent English literature. We present a case of a 37-year-old otherwise healthy male who was referred to our institution because of a one-month lasting dysphagia of both hard and liquid food. Physical examination showed tumour in the left jugular area measuring 2 cm in the largest diameter while computer tomography of the thorax revealed a 5.2 cm large, hypodense, soft tissue tumour between the trachea and left arteria carotis communis. On the basis of FNAB findings, the diagnosis of a “neutrophil-rich” Hodgkin’s lymphoma was established. Excisional biopsy of mediastinal tumor showed lymphoid neoplasm with morphology and immunophenotype consistent with nodular sclerosis classical Hodgkin’s lymphoma (NScHL). Bone marrow trephine biopsy and the MGG-stained smear of the bone marrow aspirate performed for lymphoma staging revealed an existence of systemic mastocytosis which was unexpected and incidental finding. Mast cells were highlighted by CD117 and tryptase immunostainings while CD25 positivity of mast cells was consistent with their neoplastic phenotype.There were no HL infiltrates present in the bone marrow. We report a very rare combination of systemic mastocytosis with Hodgkin’s lymphoma as associated clonal haematological non-mast cell lineage disease. Systemic mastocytosis was an unexpected finding. The diagnosis of SM in bone marrow in our case was straight-forward, but it can be difficult in the case of reactive lymphoid aggregates or a difficult distinction between SM and HL infiltration. In particular, distinction can be challenging from the immunohistochemical point of view in the case of high-grade mast cell disease which can be CD30 positive.

Immune thrombocytopenia (ITP) is an autoimmune blood disorder characterised by isolated severe thrombocytopenia. Arterial thrombotic events, such as acute ischaemic stroke (AIS), are rare complications. A 56-year-old woman with chronic ITP on eltrombopag and dexamethasone therapy presented to the emergency department due to AIS in the vertebrobasilar territory, and lower abdominal pain. The computed tomography (CT) scan of the head was unremarkable, whereas CT angiography revealed left vertebral artery occlusion. As the platelet count was sufficient, intravenous thrombolysis (IVT) was initiated. However, after 15 min, an anaphylactic reaction occurred, which was appropriately solved. Although the IVT was prematurely stopped, the NIHSS score improved from 7 to 2, and the follow-up head CT scan remained unremarkable. CT angiography of the thoracoabdominal aorta revealed multiple thrombi in the infrarenal aorta, inferior mesenteric artery (IMA), and left renal artery. The abdominal pain subsided after IVT, but recurred within 24 h. Repeated CT angiography showed ischaemia of the descending colon, with persistent IMA occlusion. After the hemicolectomy condition stabilised. Discrete left-sided ataxia and impaired sensation were the only neurological sequelae. We found two articles reporting only three patients with ITP who suffered AIS and were treated with IVT. A favourable outcome was observed in two cases, while one patient suffered an intracranial haemorrhage (ICH) and died. A review of AIS cases with undefined thrombocytopenia treated with IVT reported ICH in up to 6.8% of patients. Our case suggests that IVT for AIS may be effective in patients with ITP. Further data are needed to better clarify this issue.