COVID-19 outcomes in haemopoietic stem cell transplant recipients in Western Australia: the value of vaccination and antiviral therapy.

Coronavirus-19 (COVID-19) mortality rates among haemopoietic stem cell transplant (HSCT) patients are high, ranging between 20% and 40%. We prospectively evaluated the mortality outcomes of COVID-19 in Western Australian HSCT patients. A total of 32/492 (6.5%) HSCT recipients contracted COVID-19 during the study, of whom 30/32 (94%) developed mild or asymptomatic disease. Two allogeneic HSCT patients were hospitalised for severe COVID-19; one patient died. Stringent healthcare, social isolation practices, aggressive vaccination programmes and rapid access to COVID-19 antivirals may have promoted mild COVID-19 illness in Western Australian HSCT patients, resulting in one of the lowest COVID-19 mortality rates in HSCT recipients worldwide.

Transcription factor 3 is dysregulated in megakaryocytes in myelofibrosis.

Transcription factor 3 (TCF3) is a DNA transcription factor that modulates megakaryocyte development. Although abnormal TCF3 expression has been identified in a range of hematological malignancies, to date, it has not been investigated in myelofibrosis (MF). MF is a Philadelphia-negative myeloproliferative neoplasm (MPN) that can arise de novo or progress from essential thrombocythemia [ET] and polycythemia vera [PV] and where dysfunctional megakaryocytes have a role in driving the fibrotic progression. We aimed to examine whether TCF3 is dysregulated in megakaryocytes in MPN, and specifically in MF. We first assessed TCF3 protein expression in megakaryocytes using an immunohistochemical approach analyses and showed that TCF3 was reduced in MF compared with ET and PV. Further, the TCF3-negative megakaryocytes were primarily located near trabecular bone and had the typical "MF-like" morphology as described by the WHO. Genomic analysis of isolated megakaryocytes showed three mutations, all predicted to result in a loss of function, in patients with MF; none were seen in megakaryocytes isolated from ET or PV marrow samples. We then progressed to transcriptomic sequencing of platelets which showed loss of TCF3 in MF. These proteomic, genomic and transcriptomic analyses appear to indicate that TCF3 is downregulated in megakaryocytes in MF. This infers aberrations in megakaryopoiesis occur in this progressive phase of MPN. Further exploration of this pathway could provide insights into TCF3 and the evolution of fibrosis and potentially lead to new preventative therapeutic targets.

What is the context? We investigated TCF3 (transcription factor 3), a gene that regulates megakaryocyte development, for genomic and proteomic changes in myelofibrosis.Myelofibrosis is the aggressive phase of a group of blood cancers called myeloproliferative neoplasms, and abnormalities in development and maturation of megakaryocytes is thought to drive the development of myelofibrosis.What is new? We report detection of three novel TCF3 mutations in megakaryocytes and decreases in TCF3 protein and gene expression in primary megakaryocytes and platelets from patients with myelofibrosis.This is the first association between loss of TCF3 in megakaryocytes from patients and myelofibrosis.What is the impact? TCF3 dysregulation may be a novel mechanism that is responsible for the development of myelofibrosis and better understanding of this pathway could identify new drug targets.

Imaging flow cytometric detection of del(17p) in bone marrow and circulating plasma cells in multiple myeloma.

BACKGROUND: Detection of del(17p) in myeloma is generally performed by fluorescence in situ hybridization (FISH) on a slide with analysis of up to 200 nuclei. The small cell sample analyzed makes this a low precision test. We report the utility of an automated FISH method, called "immuno-flowFISH", to detect plasma cells with adverse prognostic risk del(17p) in bone marrow and blood samples of patients with myeloma. METHODS: Bone marrow (n = 31) and blood (n = 19) samples from 35 patients with myeloma were analyzed using immuno-flowFISH. Plasma cells were identified by CD38/CD138-immunophenotypic gating and assessed for the 17p locus and centromere of chromosome 17. Cells were acquired on an AMNIS ImageStreamX MkII imaging flow cytometer using INSPIRE software. RESULTS: Chromosome 17 abnormalities were identified in CD38/CD138-positive cells in bone marrow (6/31) and blood (4/19) samples when the percent plasma cell burden ranged from 0.03% to 100% of cells. Abnormalities could be identified in 14.5%-100% of plasma cells. CONCLUSIONS: The "immuno-flowFISH" imaging flow cytometric method could detect del(17p) in plasma cells in both bone marrow and blood samples of myeloma patients. This method was also able to detect gains and losses of chromosome 17, which are also of prognostic significance. The lowest levels of 0.009% (bone marrow) and 0.001% (blood) for chromosome 17 abnormalities was below the detection limit of current FISH method. This method offers potential as a new means of identifying these prognostically important chromosomal defects, even when only rare cells are present and for serial disease monitoring.

A complex case of necrobiotic xanthogranuloma with IgG-kappa paraproteinemia: Disease regression achieved with melphalan and prednisone combination therapy.

Necrobiotic xanthogranuloma (NXG) is a rare dermatosis that is often associated with monoclonal paraproteinemia and hematological malignancies. We report the rare case of an 84-year-old gentleman with extensive truncal NXG and IgG-kappa paraproteinemia who achieved significant disease regression following six cycles of combination melphalan/prednisone therapy.

Double trouble: A case of fraternal twins with iron-refractory iron-deficiency anemia.

Iron-refractory iron-deficiency anemia (IRIDA) is a rare autosomal recessive disease that presents in childhood. We report the case of fraternal twins presenting with severe hypochromic microcytic anemia and hypoferritinemia. Two missense mutations affecting the TRMPSS6 gene were identified, consistent with IRIDA. Subsequent parenteral iron therapy improved clinical and blood parameters.

Isolated Anemia in a 69-Year-Old Man with HIV-1: Features of Pure Red Cell Aplasia Mediated by Chronic Parvovirus-B19 Infection.

BACKGROUND Pure red cell aplasia (PRCA) is an uncommon syndrome characterized by ineffective erythropoiesis and severe anemia. Among immunodeficient patients, including those with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), persistent parvovirus-B19 can cause PRCA. We report a rare case of an Australian man with parvovirus-B19 mediated PRCA secondary to a new diagnosis of HIV-1/AIDS. The case highlights the importance of early treatment initiation with anti-retroviral drugs and pooled immunoglobulins to enable marrow recovery and long-term disease remission. CASE REPORT A 64-year-old man residing in rural Indonesia presented with severe anemia. Apart from 8 kg of unintentional weight loss, he denied any occult bleeding, diatheses, or constitutional symptoms. His bloodwork revealed a normocytic, normochromic anemia (Hb 81 g/L) with profound reticulocytopenia (9.5×109/L). Parvovirus-B19 serology and polymerase chain reaction testing confirmed active viremia. Lymphopenia and an undetectable CD4 T-lymphocyte count (<1%) were also noted; HIV-1 was subsequently diagnosed. Bone marrow sampling later confirmed features consistent with parvovirus-B19-driven PRCA secondary to HIV-1/AIDS. The patient received 1 g/kg intravenous immunoglobulin for two days and initiated anti-retroviral HIV therapy. Rapid reticulocytosis with slow incrementation of his hemoglobin were observed over one month. At three years following his diagnosis, he remains in remission. CONCLUSIONS Severe, isolated anemia in immunodeficient patients, particularly those with HIV-1/AIDS, should prompt consideration of parvovirus-B19-mediated PRCA. Depletion of CD4-T-lymphocyte populations enables the establishment of parvovirus-B19 reservoirs within erythroid progenitors, thereby hampering physiological erythropoiesis. Long-term remission can be achieved with the rapid institution of intravenous immunoglobulin and anti-retroviral HIV therapies.

Automated digital enumeration of plasma cells in bone marrow trephine biopsies of multiple myeloma.

AIMS: Determination of the number of plasma cells in bone marrow biopsies is required for the diagnosis and ongoing evaluation of plasma cell neoplasms. We developed an automated digital enumeration platform to assess plasma cells identified by antigen expression in whole bone marrow sections in multiple myeloma, and compared it with manual assessments. METHODS: Bone marrow trephine biopsy specimens from 91 patients with multiple myeloma at diagnosis, remission and relapse were stained for CD138 and multiple myeloma oncogene 1 (MUM1). Manual assessment and digital quantification were performed for plasma cells in the entire trephine section. Concordance rates between manual and digital methods were evaluated for each antigen by intraclass correlation analyses (ICC) with associated Spearman's correlations. RESULTS: The digital platform counted 16 484-1 118 868 cells and the per cent CD138 and MUM1-positive plasma cells ranged from 0.05% to 93.5%. Overall concordance between digital and manual methods was 0.63 for CD138 and 0.89 for MUM1. Concordance was highest with diffuse plasma cell infiltrates (MUM1: ICC=0.90) and lowest when in microaggregates (CD138: ICC=0.13). Manual counts exceeded digital quantifications for both antigens (CD138: mean=26.4%; MUM1: mean=9.7%). Diagnostic or relapse threshold counts, as determined by CD138 manual assessments, were not reached with digital counting for 16 cases (18%). CONCLUSIONS: Automated digital enumeration of the entire, immunohistochemically stained bone marrow biopsy section can accurately determine plasma cell burden, irrespective of pattern and extent of disease (as low as 0.05%). This increases precision over manual visual assessments which tend to overestimate plasma burden, especially for CD138, and when plasma cells are in clusters.

Mutation profile of acute myeloid leukaemia in a Chinese cohort by targeted next-generation sequencing.

BACKGROUND: Acute myeloid leukaemia (AML) results from the clonal expansion of blast cells of myeloid origin driven by genomic defects. The advances in next-generation sequencing (NGS) have allowed the identification of many mutated genes important in the pathogenesis of AML. AIMS: In this study, we aimed to assess the mutation types and frequency in a Chinese cohort presenting with de novo AML cohort using a targeted NGS strategy. METHODS: In total, we studied samples from 87 adult patients with de novo AML who had no prior history of cytotoxic chemotherapy. Samples were evaluated using a 120-gene targeted NGS panel to assess the mutation profile. RESULTS: Of the 87 AML patients, there were 60 (69%) with a normal karyotype. 89.7% of patients had variants, with an average of 1.9 mutations per patient (range: 0-5 mutations per patient). DNMT3A variants were the most common, being detected in 33 patients (37.9%). NPM1 (34.5%), IDH1/2 (24.1%) and FLT3-ITD (20.7%) mutations was the next most common. Of the patients with DNMT3A mutations, 24.2% also had mutations NPM1 and FLT3-ITD and 6.1% NPM1, FLT3-ITD and IDH mutations. CONCLUSION: Both DNMT3A and NPM1 mutations were more common than in other Chinese and Western AML cohorts that have been studied. DNMT3A mutations tended to co-occur with NPM1 and FLT3-ITD mutations and were most commonly seen with a normal karyotype.

Delayed Fulminant Hepatic Failure from Dydrogesterone-Related In Vitro Fertilization Therapy Requiring Liver Transplantation During Pregnancy.

BACKGROUND Drug-induced liver failure is a rare complication of pregnancy and occasionally requires liver transplantation. However, fulminant liver failure arising from in vitro fertilization (IVF) therapy involving progestogens (e.g. dydrogesterone) is extremely rare and has not been reported in pregnancy. Furthermore, dydrogesterone-mediated hepatic dysfunction has not previously necessitated liver transplantation and is usually conservatively managed. We report the first Australian case of a pregnant woman with delayed fulminant liver failure and in utero fetal death requiring a liver transplant from dydrogesterone use. CASE REPORT A 35-year-old multiparous (G5P2) woman presented with painless jaundice and transaminitis (alanine aminotransferase and aspartate aminotransferase of 2800 U/L and 2990 U/L respectively). She was pregnant at 14 weeks' gestation after successful IVF in Thailand four months before involving dydrogesterone therapy. She was diagnosed with delayed, subfulminant liver failure arising from previous dydrogesterone use. Initially, she was not encephalopathic and conservative management strategies were instituted. Her hepatic dysfunction progressed and she deteriorated clinically with encephalopathy, necessitating an emergent liver transplantation. Fetal death was confirmed in utero four days before transplantation. A combined orthotopic liver transplant and hysterotomy with fetal evacuation were performed without complication. CONCLUSIONS Fulminant liver failure in pregnancy due to idiosyncratic drug reactions are rare. Dydrogesterone may cause significant, albeit delayed, liver dysfunction in pregnancy necessitating the need for liver transplantation. Early recognition of progressive liver failure despite best supportive care efforts should prompt early considerations for liver transplantation. Delays in liver transplantation with prolonged hyperbilirubinemia and coagulopathy may exacerbate fetal death in utero.

A novel translocation t(10;17)(p13;q11.2) harboring two cryptic deletions identified by array-CGH and characterized by SUZ12 overexpression in a patient with chronic thrombocytosis.

No specific translocation is associated with myeloproliferative neoplasms (MPNs). However, an interstitial deletion involving subband 17q11.2 which includes the NF1 gene, although rare, is a recurrent aberration in several myeloid disorders including MPNs. For the first time, we report an acquired novel translocation involving 10p13 and 17q11.2 in a 62-year-old Caucasian female which was referred for investigation of chronic and persistent unexplained thrombocytosis. The patient had no history of hematological sequelae and genomic testing for JAK2, CALR, and MPL mutations were negative. She was subsequently diagnosed with a triple negative essential thrombocythemia. Array-CGH analysis noted that the translocation harbored two cryptic deletions, one of which involved 17q11.2 encompassing the NF1 gene. One of the junction breakpoints involved the SUZ12 gene. Immunohistochemical assessment of the marrow trephine showed increased megakaryocytic expression of the SUZ12 protein, as well as EZH2 and Ki67; biochemical abnormalities suggestive of excess megakaryocytic hyperplasia. This novel translocation may affect the expression of SUZ12 and its downstream targets, and may represent a unique pathogenomic etiology which drives chronic thrombocytosis in essential thrombocythemia.

An Atraumatic Sacral Fracture with Lumbosacral Radiculopathy Complicating the Early Postpartum Period: A Case Report.

BACKGROUND Sacral stress fractures are rare complications of pregnancy and the early postpartum. Of these, few present with lumbosacral radiculopathy. We report the first Australian case of a young multiparous woman who sustained an atraumatic, fatigue sacral fracture with associated radiculopathy. We highlight the diagnostic process and chronic management of this case, particularly in relation to a future pregnancy. CASE REPORT A 26-year-old multiparous Caucasian female presented with worsening lumbosacral back pain and radicular symptoms following the rapid and spontaneous vaginal delivery of her second infant. Her pregnancy was unremarkable and she had no personal risk factors for osteoporosis. A magnetic resonance imaging (MRI) scan confirmed the diagnosis of a right S1 vertebral fracture. Bone densitometry and fasting bone metabolic testing excluded pregnancy-associated osteoporosis. She was managed conservatively with intermittent bed rest, regular physiotherapy and multimodal analgesia. During a future pregnancy, she experienced a severe exacerbation of her lumbosacral radiculopathy requiring hospital admission, up-titration of her analgesia and a right S1 epidural injection. She subsequently underwent an elective caesarean section and has since benefitted from regular hydrotherapy. CONCLUSIONS Lumbosacral radiculopathy in the absence of trauma during pregnancy or the early postpartum should prompt consideration of an underlying atraumatic, fatigue sacral fracture. Such fractures may result from the abnormal biomechanical loading of the sacrum during rapid vaginal deliveries and are most effectively diagnosed by MRI. Conservative management strategies involving physiotherapy and multimodal analgesia are recommended. Future pregnancies may exacerbate radicular symptoms. Such patients may subsequently benefit from elective caesarean section deliveries and hydrotherapy.

X-Linked Dilated Cardiomyopathy Presenting as Acute Rhabdomyolysis and Presumed Epstein-Barr Virus-Induced Viral Myocarditis: A Case Report.

BACKGROUND Rhabdomyolysis and primary dilated cardiomyopathies without skeletal muscle weakness are rare features of X-linked dystrophinopathies. We report a rare case of an X-linked dilated cardiomyopathy (XLDCM) presenting with acute rhabdomyolysis and myocarditis. We illustrate the confounding diagnostic influence of a reactivated, persistent EBV myocarditis as the presumed cause for this patient's XLDCM. CASE REPORT A 23-year-old Australian man presented with acute rhabdomyolysis and elevated creatine kinase (CK) levels. He was managed conservatively with intravenous hydration and developed acute pulmonary edema. Cardiac MRI and transthoracic echocardiogram revealed a dilated cardiomyopathy and viral myocarditis. Extensive sero-logical investigations identified reactivation of EBV, which was presumed to account for his viral myocarditis. The patient recovered and was discharged with down-trending CK levels. Follow-up transthoracic echocardiograms and cardiac MRI showed a persisting dilated cardiomyopathy. His CK continued to remain elevated and his EBV IgM serology remained positive. An inflammatory polymyositis with either a primary autoimmune pathophysiology or secondary to a chronic EBV infection was considered. Oral corticosteroids were trialed and reduced his CK significantly until therapy was ceased. Massively parallel sequencing eventually identified a two-exon deletion targeting Xp21 consistent with the diagnosis of a rare XLDCM. CONCLUSIONS Rhabdomyolysis and co-existing primary dilated cardiomyopathies are rare diagnostic manifestations in a minority of X-linked dystrophinopathies. Chronic viral infections and their reactivation may complicate the diagnostic process and incorrectly attribute an inherited cardiomyopathy to an acquired infective etiology. EBV reactivation rarely induces myocarditis. Therefore, primary and unresolving dilated cardiomyopathy with persistently elevated CK must prompt consideration of an underlying dystrophinopathy.

Automated enumeration of lymphoid and plasma cells in bone marrow to establish normal reference ranges.

AIMS: The number of precursor and mature lymphoid cells and plasma cells in normal bone marrow trephine (BMT) biopsies throughout the human lifespan is unknown. Reference ranges have been established from aspirated marrow, but due to haemodilution errors, these do not accurately reflect the native marrow milieu. We aimed to define age-specific, normal reference ranges for lymphoid and plasma cells in BMT biopsy specimens using a combined immunophenotyping and digital enumeration approach. METHODS: Morphologically normal BMT biopsy specimens (n=483) were obtained from patients aged 1 month to 90 years of age. Immunohistochemistry was performed to identify lymphoid progenitors , T-lymphocytes (CD3), B-lymphocytes (CD20) and plasma cells (CD138 and MUM1). Positive cells were counted using digital enumeration software, and the percent positivity for each antigen was determined per case. Mean values were generated for specific age groups, and age-defined reference ranges were determined for each antigen using normalised data. RESULTS: A mean of 16 609 cells (range: 7210-34 097) were counted per biopsy. Infant marrows showed a predominance of immature lymphoid progenitors and B cells. With increasing age, an increase in mean T cell and plasma cell numbers were observed. The results showed the same trends to flow cytometry references for aspirate material although the absolute values differed. CONCLUSIONS: Combined immunohistochemistry and automated enumeration gives an accurate, reproducible number of antigen-positive cells and has generated normal reference ranges for these cell types in BMT biopsies. The method and ranges we have established have the potential to be applied in routine clinical practice.

Dysregulation of the intrinsic apoptotic pathway mediates megakaryocytic hyperplasia in myeloproliferative neoplasms.

AIMS: Megakaryocyte expansion in myeloproliferative neoplasms (MPNs) is due to uncontrolled proliferation accompanied by dysregulation of proapoptotic and antiapoptotic mechanisms. Here we have investigated the intrinsic and extrinsic apoptotic pathways of megakaryocytes in human MPNs to further define the mechanisms involved. METHODS: The megakaryocytic expression of proapoptotic caspase-8, caspase-9, Diablo, p53 and antiapoptotic survivin proteins was investigated in bone marrow specimens of the MPNs (n=145) and controls (n=15) using immunohistochemistry. The megakaryocyte percentage positivity was assessed by light microscopy and correlated with the MPN entity, JAK2V617F/CALR mutation status and platelet count. RESULTS: The proportion of megakaryocytes in the MPNs expressing caspase-8, caspase-9, Diablo, survivin and p53 was significantly greater than controls. A greater proportion of myeloproliferative megakaryocytes expressed survivin relative to its reciprocal inhibitor, Diablo. Differences were seen between myelofibrosis, polycythaemia vera and essential thrombocythaemia for caspase-9 and p53. CALR-mutated cases had greater megakaryocyte p53 positivity compared to those with the JAK2V617F mutation. Proapoptotic caspase-9 expression showed a positive correlation with platelet count, which was most marked in myelofibrosis and CALR-mutated cases. CONCLUSIONS: Disruptions targeting the intrinsic apoptotic cascade promote megakaryocyte hyperplasia and thrombocytosis in the MPNs. There is progressive dysfunction of apoptosis as evidenced by the marked reduction in proapoptotic caspase-9 and accumulation of p53 in myelofibrosis. The dysfunction of caspase-9, which is necessary for proplatelet formation, may be the mechanism for the excess thrombocytosis associated with CALR mutations. Survivin seems to be the key protein mediating the megakaryocyte survival signature in the MPNs and is a potential therapeutic target.

Megakaryocytic hyperplasia in myeloproliferative neoplasms is driven by disordered proliferative, apoptotic and epigenetic mechanisms.

AIMS: Myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal proliferative bone marrow diseases characterised by extensive megakaryocytic hyperplasia and morphological atypia. Despite knowledge of genomic defects, the pathobiological processes driving these megakaryocytic abnormalities in MPN remain poorly explained. We have explored the proliferative, apoptotic and epigenetic profiles of megakaryocytes in human MPN. METHODS: Immunohistochemical staining was performed on bone marrow trephine biopsies of 81 MPN (with and without JAK2(V617F) and CALR mutations) and 15 normal controls to assess the megakaryocytic expression of biomarkers associated with proliferation (Ki67), apoptosis (Bcl-XL, BNIP-3) and epigenetic regulation (EZH2, SUZ12). RESULTS: Myeloproliferative megakaryocytes showed significantly greater expression of proliferative Ki67 and anti-apoptotic Bcl-XL, reduced pro-apoptotic BNIP-3 and increased SUZ12 compared with controls. In essential thrombocythaemia, large-giant megakaryocytes with hyperlobated nuclei showed a trend towards a proliferative signature. In contrast, myelofibrotic megakaryocytes with condensed nuclear chromatin, and cases with CALR mutations, had significant reductions in pro-apoptotic BNIP-3. CONCLUSIONS: Uncontrolled megakaryocytic expansion in MPN results from a combination of increased proliferation, attenuated apoptosis and defective epigenetic regulation with CALR mutations favouring apoptotic failure. The higher platelet counts reported to be seen in MPN with CALR mutations may be due to greater dysregulation of megakaryocyte apoptosis.