Adult presentation of ornithine transcarbamylase deficiency: a possible cause of hyperammonemia after high-dose chemotherapy and stem cell transplantation

Hyperammonemia is a rare and often fatal complication following the conditioning therapy in autologous and allogeneic stem cell transplant recipients. It is characterized by anorexia, vomiting, lethargy and coma without any other apparent cause. The diagnosis is often delayed because symptoms can be subtle and ammonia is usually not included among the routine analyzes. Previous reports have not identified the molecular mechanisms behind hyperammonemia in stem cell transplant recipients. Urea cycle disorders (UCDs) are inborn errors of metabolism leading to hyperammonemia that usually presents in early childhood, whereas first presentation in adults is less common. Here we describe an adult woman with hyperammonemia following autologous stem cell transplantation for multiple myeloma. No apparent cause of hyperammonemia was identified, including portosystemic shunting, liver dysfunction or recent hyperammonemia-inducing chemotherapy. Hyperammonemia, normal blood glucose as well as anion gap and a previous history of two male newborns that died early after birth, prompted biochemical and genetic investigations for a UCD. A heterozygous variant in the X-linked gene encoding ornithine transcarbamylase (OTC) was identified and was regarded as a cause of UCD. The patient improved after treatment with nitrogen scavengers and high caloric intake according to a UCD protocol. This case report suggests that UCD should be considered as a possible cause of hyperammonemia following stem cell transplantation.

A partial form of AIRE deficiency underlies a mild form of autoimmune polyendocrine syndrome type 1

Autoimmune polyendocrine syndrome type 1 (APS-1) is caused by mutations in the autoimmune regulator (AIRE) gene. Most patients present with severe chronic mucocutaneous candidiasis and organ-specific autoimmunity from early childhood, but the clinical picture is highly variable. AIRE is crucial for negative selection of T cells, and scrutiny of different patient mutations has previously highlighted many of its molecular mechanisms. In patients with a milder adult-onset phenotype sharing a mutation in the canonical donor splice site of intron 7 (c.879+1G>A), both the predicted altered splicing pattern with loss of exon 7 (AireEx7-/-) and normal full-length AIRE mRNA were found, indicating leaky rather than abolished mRNA splicing. Analysis of a corresponding mouse model demonstrated that the AireEx7-/- mutant had dramatically impaired transcriptional capacity of tissue-specific antigens in medullary thymic epithelial cells but still retained some ability to induce gene expression compared with the complete loss-of-function AireC313X-/- mutant. Our data illustrate an association between AIRE activity and the severity of autoimmune disease, with implications for more common autoimmune diseases associated with AIRE variants, such as primary adrenal insufficiency, pernicious anemia, type 1 diabetes, and rheumatoid arthritis.

A first-level customization study of SAPS II with Norwegian Intensive Care and Pandemic Registry (NIPaR) data

BACKGROUND

Severity scores and mortality prediction models (MPMs) are important tools for benchmarking and stratification in the intensive care unit (ICU) and need to be regularly updated using data from a local and contextual cohort. Simplified acute physiology score II (SAPS II) is widely used in European ICUs.

METHODS

A first-level customization was performed on the SAPS II model using data from the Norwegian Intensive Care and Pandemic Registry (NIPaR). Two previous SAPS II models (Model A: the original SAPS II model and Model B: a SAPS II model based on NIPaR data from 2008 to 2010) were compared to the new Model C. Model C was based on patients from 2018 to 2020 (corona virus disease 2019 patients omitted; n = 43,891), and its performances (calibration, discrimination, and uniformity of fit) compared to the previous models (Model A and Model B).

RESULTS

Model C was better calibrated than Model A with a Brier score 0.132 (95% confidence interval 0.130-0.135) versus 0.143 (95% confidence interval 0.141-0.146). The Brier score for Model B was 0.133 (95% confidence interval 0.130-0.135). In the Cox's calibration regression α ≈ 0 and β ≈ 1 for both Model C and Model B but not for Model A. Uniformity of fit was similar for Model B and for Model C, both better than for Model A, across age groups, sex, length of stay, type of admission, hospital category, and days on respirator. The area under the receiver operating characteristic curve was 0.79 (95% confidence interval 0.79-0.80), showing acceptable discrimination.

CONCLUSIONS

The observed mortality and corresponding SAPS II scores have significantly changed during the last decades and an updated MPM is superior to the original SAPS II. However, proper external validation is required to confirm our findings. Prediction models need to be regularly customized using local datasets in order to optimize their performances.

Patients over 75 years admitted to the National Burn Centre, Haukeland University Hospital, 2000-19

BACKGROUND

The number of burn patients over the age of 75 receiving advanced treatment, including extensive surgery and intensive care, is increasing. We aimed to describe the treatment and outcomes for burn patients over the age of 75 admitted to the National Burn Centre at Haukeland University Hospital. We also wanted to investigate whether frailty scores can be a predictor of the treatment outcome.

MATERIAL AND METHOD

All patients ≥ 75 years admitted to the National Burn Centre at Haukeland University Hospital in the period 2000-19 were included in the study. Frailty scores were calculated retrospectively based on patients' medical records.

RESULTS

Our study included 101 patients (50 women and 51 men). The number of admissions of older burn patients increased from an average of 3.3 per year in 2000-14 to 10.2 in the period 2015-19. The median total body surface area with burns was 11 % (range 0.9-80 %). Seventeen patients received palliative care, and 12 patients receiving active treatment died in hospital. In 68 of 84 (81 %) actively treated patients, tangential excision and split-thickness skin grafting were performed. The remainder received conservative treatment (non-surgical) with wound care and application of a silver dressing. Patients who died in hospital had a significantly higher total body surface area with burns (p < 0.0001) and higher frailty scores (p = 0.003) than patients who survived.

INTERPRETATION

The yearly number of patients over the age of 75 treated at the National Burn Centre tripled during the period. More than two-thirds of the patients were discharged alive. Extent of burn injury and frailty score are associated with mortality and may be useful for adjusting therapy.

The Regulation of Neutrophil Migration in Patients with Sepsis: The Complexity of the Molecular Mechanisms and Their Modulation in Sepsis and the Heterogeneity of Sepsis Patients

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Common causes include gram-negative and gram-positive bacteria as well as fungi. Neutrophils are among the first cells to arrive at an infection site where they function as important effector cells of the innate immune system and as regulators of the host immune response. The regulation of neutrophil migration is therefore important both for the infection-directed host response and for the development of organ dysfunctions in sepsis. Downregulation of CXCR4/CXCL12 stimulates neutrophil migration from the bone marrow. This is followed by transmigration/extravasation across the endothelial cell barrier at the infection site; this process is directed by adhesion molecules and various chemotactic gradients created by chemotactic cytokines, lipid mediators, bacterial peptides, and peptides from damaged cells. These mechanisms of neutrophil migration are modulated by sepsis, leading to reduced neutrophil migration and even reversed migration that contributes to distant organ failure. The sepsis-induced modulation seems to differ between neutrophil subsets. Furthermore, sepsis patients should be regarded as heterogeneous because neutrophil migration will possibly be further modulated by the infecting microorganisms, antimicrobial treatment, patient age/frailty/sex, other diseases (e.g., hematological malignancies and stem cell transplantation), and the metabolic status. The present review describes molecular mechanisms involved in the regulation of neutrophil migration; how these mechanisms are altered during sepsis; and how bacteria/fungi, antimicrobial treatment, and aging/frailty/comorbidity influence the regulation of neutrophil migration.

Systemic Metabolomic Profiles in Adult Patients with Bacterial Sepsis: Characterization of Patient Heterogeneity at the Time of Diagnosis

Sepsis is a dysregulated host response to infection that causes potentially life-threatening organ dysfunction. We investigated the serum metabolomic profile at hospital admission for patients with bacterial sepsis. The study included 60 patients; 35 patients fulfilled the most recent 2016 Sepsis-3 criteria whereas the remaining 25 patients only fulfilled the previous Sepsis-2 criteria and could therefore be classified as having systemic inflammatory response syndrome (SIRS). A total of 1011 identified metabolites were detected in our serum samples. Ninety-seven metabolites differed significantly when comparing Sepsis-3 and Sepsis-2/SIRS patients; 40 of these metabolites constituted a heterogeneous group of amino acid metabolites/peptides. When comparing patients with and without bacteremia, we identified 51 metabolites that differed significantly, including 16 lipid metabolites and 11 amino acid metabolites. Furthermore, 42 metabolites showed a highly significant association with the maximal total Sequential Organ Failure Assessment (SOFA )score during the course of the disease (i.e., Pearson's correlation test, p-value < 0.005, and correlation factor > 0.6); these top-ranked metabolites included 23 amino acid metabolites and a subset of pregnenolone/progestin metabolites. Unsupervised hierarchical clustering analyses based on all 42 top-ranked SOFA correlated metabolites or the subset of 23 top-ranked amino acid metabolites showed that most Sepsis-3 patients differed from Sepsis-2/SIRS patients in their systemic metabolic profile at the time of hospital admission. However, a minority of Sepsis-3 patients showed similarities with the Sepsis-2/SIRS metabolic profile even though several of them showed a high total SOFA score. To conclude, Sepsis-3 patients are heterogeneous with regard to their metabolic profile at the time of hospitalization.

Implementation of a low-titre whole blood transfusion program in a civilian helicopter emergency medical service

BACKGROUND

Early balanced transfusion is associated with improved outcome in haemorrhagic shock patients. This study describes the implementation and evaluates the safety of a whole blood transfusion program in a civilian helicopter emergency medical service (HEMS).

METHODS

This prospective observational study was performed over a 5-year period at HEMS-Bergen, Norway. Patients in haemorrhagic shock receiving out of hospital transfusion of low-titre Group O whole blood (LTOWB) or other blood components were included. Two LTOWB units were produced weekly and rotated to the HEMS for forward storage. The primary endpoints were the number of patients transfused, mechanisms of injury/illness, adverse events and survival rates. Informed consent covered patient pathway from time of emergency interventions to last endpoint and subsequent data handling/storage.

RESULTS

The HEMS responded to 5124 patients. Seventy-two (1.4%) patients received transfusions. Twenty patients (28%) were excluded due to lack of consent (16) or not meeting the inclusion criteria (4). Of the 52 (100%) patients, 48 (92%) received LTOWB, nine (17%) received packed red blood cells (PRBC), and nine (17%) received freeze-dried plasma. Of the forty-six (88%) patients admitted alive to hospital, 35 (76%) received additional blood transfusions during the first 24 h. Categories were blunt trauma 30 (58%), penetrating trauma 7 (13%), and nontrauma 15 (29%). The majority (79%) were male, with a median age of 49 (IQR 27-70) years. No transfusion reactions, serious complications or logistical challenges were reported. Overall, 36 (69%) patients survived 24 h, and 28 (54%) survived 30 days.

CONCLUSIONS

Implementing a whole blood transfusion program in civilian HEMS is feasible and safe and the logistics around out of hospital whole blood transfusions are manageable. Trial registration The study is registered in the ClinicalTrials.gov registry (NCT02784951).

21-Hydroxylase-Specific CD8+ T Cells in Autoimmune Addison's Disease Are Restricted by HLA-A2 and HLA-C7 Molecules

Objectives

CD8+ T cells targeting 21-hydroxylase (21OH) are presumed to play a central role in the destruction of adrenocortical cells in autoimmune Addison’s disease (AAD). Earlier reports have suggested two immunodominant CD8+ T cell epitopes within 21OH: LLNATIAEV (21OH_342-350), restricted by HLA-A2, and EPLARLEL (21OH_431-438), restricted by HLA-B8. We aimed to characterize polyclonal CD8+ T cell responses to the proposed epitopes in a larger patient cohort with AAD.

Methods

Recombinant fluorescent HLA-peptide multimer reagents were used to quantify antigen-specific CD8+ T cells by flow cytometry. Interferon-gamma (IFNγ) Elispot and biochemical assays were used to functionally investigate the 21OH-specific T cells, and to map the exactly defined epitopes of 21OH.

Results

We found a significantly higher frequency of HLA-A2 restricted LLNATIAEV-specific cells in patients with AAD than in controls. These cells could also be expanded in vitro in an antigen specific manner and displayed a robust antigen-specific IFNγ production. In contrast, only negligible frequencies of EPLARLEL-specific T cells were detected in both patients and controls with limited IFNγ response. However, significant IFNγ production was observed in response to a longer peptide encompassing EPLARLEL, 21OH_430-447, suggesting alternative dominant epitopes. Accordingly, we discovered that the slightly offset ARLELFVVL (21OH_434-442) peptide is a novel dominant epitope restricted by HLA-C7 and not by HLA-B8 as initially postulated.

Conclusion

We have identified two dominant 21OH epitopes targeted by CD8+ T cells in AAD, restricted by HLA-A2 and HLA-C7, respectively. To our knowledge, this is the first HLA-C7 restricted epitope described for an autoimmune disease.

Transcriptional Changes in Regulatory T Cells From Patients With Autoimmune Polyendocrine Syndrome Type 1 Suggest Functional Impairment of Lipid Metabolism and Gut Homing

Autoimmune polyendocrine syndrome type I (APS-1) is a monogenic model disorder of organ-specific autoimmunity caused by mutations in the Autoimmune regulator (AIRE) gene. AIRE facilitates the expression of organ-specific transcripts in the thymus, which is essential for efficient removal of dangerous self-reacting T cells and for inducing regulatory T cells (Tregs). Although reduced numbers and function of Tregs have been reported in APS-I patients, the impact of AIRE deficiency on gene expression in these cells is unknown. Here, we report for the first time on global transcriptional patterns of isolated Tregs from APS-1 patients compared to healthy subjects. Overall, we found few differences between the groups, although deviant expression was observed for the genes TMEM39B, SKIDA1, TLN2, GPR15, FASN, BCAR1, HLA-DQA1, HLA-DQB1, HLA-DRA, GPSM3 and AKR1C3. Of significant interest, the consistent downregulation of GPR15 may indicate failure of Treg gut homing which could be of relevance for the gastrointestinal manifestations commonly seen in APS-1. Upregulated FASN expression in APS-1 Tregs points to increased metabolic activity suggesting a putative link to faulty Treg function. Functional studies are needed to determine the significance of these findings for the immunopathogenesis of APS-1 and for Treg immunobiology in general.

Critical upper airway obstruction as the first symptom of acute myeloid leukemia - an anesthesiologic reminder

Acute upper airway obstruction can be fatal. Early recognition of airway distress followed by diagnostic laryngoscopy and prompt intervention to secure airway control is crucial. We here present a 62-year old male patient who presented with cough and increasing respiratory distress for three weeks. Within the next 24 h, he developed symptoms of critical upper airway obstruction, endotracheal intubation was not possible, and an acute surgical tracheotomy was performed to retain patent airways. A computer tomography scan revealed severe laryngopharyngeal soft tissue thickening and upper airway obstruction caused by leukemic infiltration. He was diagnosed with acute leukemia and responded to induction chemotherapy. This case report points out the importance of establishing the diagnosis of critical upper airway obstruction in patients presenting with respiratory symptoms, and highlights the emergency management of airway obstruction due to malignant infiltration of leukemic blasts. laryngotracheal trauma, bleeding, tonsillar hypertrophy, paralysis of the vocal cords or folds, allergic reactions, and acute infections affecting the upper respiratory tract.¹ We present a 62-year old male patient with cough and increasing respiratory distress for the last three weeks. Within 24 h in hospital, he developed symptoms of critical upper airway obstruction. Endotracheal intubation with the patient awakes and selfbreathing using a fiber optic scope was not possible, thus an acute surgical tracheotomy was performed to retain patent airways. Acute myeloid leukemia (AML) with leukemic infiltrations of the upper airways was found to be the underlying cause.

Francisella tularensis bacteraemia causing multi-organ failure

Tularemia is a zoonosis caused by the gram-negative coccobacillus Francisella tularensis. The bacterium can be transmitted in several ways including direct contact with animal reservoirs, ingestion, inhalation and bites, and typical clinical symptoms are headache, fever, diarrhea and dyspnea. Francisella tularensis has two predominant subspecies (ssp), namely ssp. tularensis and ssp. holarctica. Ssp. holarctica is less virulent and does usually not cause fatal disease. We here present a 51-year-old male with sepsis and multi-organ failure caused by F. tularensis ssp. holarctica infection suggesting that atypical agents including F. tularensis should be considered in patients presenting symptoms of infections without response to standard treatments.

Successful eradication of leptomeningeal plasma cell disease

Plasma cell leukaemia (PCL) is a rare and aggressive form of malignant monoclonal gammopathy characterized by the presence of high levels of plasma cells in peripheral blood. Central nervous system involvement of PCL has no established treatment and an extremely poor prognosis. We here present a 59-year-old male patient diagnosed with PCL, initially treated with induction chemotherapy followed by autologous peripheral blood hematopoietic stem cell transplantation. After achieving a partial response, he relapsed and presented with leptomeningeal disease. He was then successfully treated with dexamethasone, pomalidomide, and an intrathecal combination of methotrexate, methylprednisolone and cytarabine. This cleared his cerebrospinal fluid from plasma cells achieving a durable partial response.

Autonomous dysfunction in Lyme neuroborreliosis. A case report

The diagnosis of Lyme neuroborreliosis should be considered whenever a patient presents with neurological symptoms and comes from an endemic area. However, atypical clinical presentation occurs including gastrointestinal manifestations because of autonomous dysfunction.

A pilot study of single nucleotide polymorphisms in the interleukin-6 receptor and their effects on pre- and post-transplant serum mediator level and outcome after allogeneic stem cell transplantation

Interleukin (IL)-6 is an important regulator of immunity and inflammation in many diseases. Single nucleotide polymorphisms (SNPs) in the IL-6 gene influence outcome after allogeneic stem cell transplantation (ASCT), but the possible importance of SNPs in the IL-6 receptor has not been examined. We therefore investigated whether SNPs in the IL-6R gene influenced biochemical characteristics and clinical outcomes after ASCT. We examined the IL-6 promoter variant rs1800975 and the IL-6R SNPs rs4453032, rs2228145, rs4129267, rs4845374, rs4329505, rs4845617, rs12083537, rs4845618, rs6698040 and rs4379670 in a 101 population-based cohort of allotransplant recipients and their family donors. Patients being homozygous for the major alleles of the IL-6R SNPs rs2228145 and rs4845618 showed high pretransplant CRP serum levels together with decreased sIL-6R levels; the decreased IL-6R levels persisted 6 months post-transplant. In contrast, patients being homozygous for the minor allele of the IL-6R SNP rs4379670 showed decreased pretransplant CRP levels. Furthermore, the IL-6R rs4845618 donor genotype showed an association with severe acute graft-versus-host disease (GVHD), whereas the donor genotype of the IL-6 SNP rs1800795 was associated with decreased survival 100 days post-transplant. Finally, the recipient genotype of the IL-6R SNP rs4329505 showed a strong association with 2-years non-relapse mortality, and this effect was also highly significant in multivariate analysis. IL-6 and IL-6R SNPs influence the clinical outcome after allogeneic stem cell transplantation.

Hypomagnesemia in critically ill patients

BACKGROUND

Magnesium (Mg) is essential for life and plays a crucial role in several biochemical and physiological processes in the human body. Hypomagnesemia is common in all hospitalized patients, especially in critically ill patients with coexisting electrolyte abnormalities. Hypomagnesemia may cause severe and potential fatal complications if not timely diagnosed and properly treated, and associate with increased mortality.

MAIN BODY

Mg deficiency in critically ill patients is mainly caused by gastrointestinal and/or renal disorders and may lead to secondary hypokalemia and hypocalcemia, and severe neuromuscular and cardiovascular clinical manifestations. Because of the physical distribution of Mg, there are no readily or easy methods to assess Mg status. However, serum Mg and the Mg tolerance test are most widely used. There are limited studies to guide intermittent therapy of Mg deficiency in critically ill patients, but some empirical guidelines exist. Further clinical trials and critical evaluation of empiric Mg replacement strategies is needed.

CONCLUSION

Patients at risk of Mg deficiency, with typical biochemical findings or clinical symptoms of hypomagnesemia, should be considered for treatment even with serum Mg within the normal range.

Oral microbiota in autoimmune polyendocrine syndrome type 1

Background: Autoimmune polyendocrine syndrome type-1 (APS-1) is a rare, childhood onset disease caused by mutations in the Autoimmune Regulator gene. The phenotypic expression is highly variable and includes disease manifestations in the oral cavity, including mucocutaneous candidiasis. Increasing evidence suggests a potential role of the skin, oral and gut microbiotas in the pathogenesis of autoimmunity. To date, no information exists regarding the oral microbiota in APS-1. Objective: To assess the bacterial microbiota of whole saliva in APS-1 patients by using high throughput sequencing. Design: Whole unstimulated saliva was collected from 10 APS-1 patients and 17 healthy controls and examined by high throughput sequencing of the hypervariable region V1-V2 of 16S rRNA using the 454 GS Junior system. Metastats (http://cbcb.umd.edu/software/metastats) was used to analyse the pyrosequencing reads. Results: A reduction in the total number of bacterial genera and species was detected in APS-1 compared to healthy controls. The proportion of the major phyla Firmicutes was higher (60% vs 41%, p = 0.002) and Bacteroidetes lower (15% vs 28%, p = 0.007) in APS-1 compared to healthy controls. On the genus level, Streptococcus and Gemella were prevalent in APS-1. Conclusion: Our findings indicate a significantly altered oral microbiota in APS-1.

Oral Tongue Malignancies in Autoimmune Polyendocrine Syndrome Type 1

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) or Autoimmune polyendocrine syndrome type-1 (APS-1) (APECED, OMIM 240300) is a rare, childhood onset, monogenic disease caused by mutations in the Autoimmune Regulator (AIRE) gene. The overall mortality is increased compared to the general population and a major cause of death includes malignant diseases, especially oral and esophageal cancers. We here present a case series of four APS-1 patients with oral tongue cancers, an entity not described in detail previously. Scrutiny of history and clinical phenotypes indicate that chronic mucocutaneous candidiasis and smoking are significant risk factors. Preventive measures and early diagnosis are important to successfully manage this potentially fatal disease.

Altered Immune Activation and IL-23 Signaling in Response to Candida albicans in Autoimmune Polyendocrine Syndrome Type 1

Objective

Autoimmune polyendocrine syndrome type 1 (APS-1) is a rare, childhood onset disease caused by mutations in the autoimmune regulator (AIRE) gene. Chronic mucocutaneous candidiasis (CMC) is one of the three major disease components and is, to date, mainly explained by the presence of neutralizing auto-antibodies against cytokines [interleukin (IL)-17A, IL-17F, and IL-22] from T helper 17 cells, which are critical for the protection against fungal infections. However, patients without current auto-antibodies also present CMC and we, therefore, hypothesized that other immune mechanisms contribute to CMC in APS-1.

Methods

Whole blood was stimulated with Candida albicans (C. albicans) in a standardized assay, and immune activation was investigated by analyzing 46 secreted immune mediators. Then, peripheral blood mononuclear cells were stimulated with curdlan, a Dectin-1 agonist and IL-23 inducer, and the IL-23p19 response in monocytes was analyzed by flow cytometry.

Results

We found an altered immune response in APS-1 patients compared with healthy controls. Patients fail to increase the essential ILs, such as IL-2, IL-17A, IL-22, and IL-23, when stimulating whole blood with C. albicans. A significantly altered IL-23p19 response was detected in patients’ monocytes upon stimulation with curdlan.

Conclusion

APS-1 patients have an altered immune response to C. albicans including a dysregulation of IL-23p19 production in monocytes. This probably contributes to the selective susceptibility to CMC found in the majority of patients.

Autoantibody Repertoire in APECED Patients Targets Two Distinct Subgroups of Proteins

High titer autoantibodies produced by B lymphocytes are clinically important features of many common autoimmune diseases. APECED patients with deficient autoimmune regulator (AIRE) gene collectively display a broad repertoire of high titer autoantibodies, including some which are pathognomonic for major autoimmune diseases. AIRE deficiency severely reduces thymic expression of gene-products ordinarily restricted to discrete peripheral tissues, and developing T cells reactive to those gene-products are not inactivated during their development. However, the extent of the autoantibody repertoire in APECED and its relation to thymic expression of self-antigens are unclear. We here undertook a broad protein array approach to assess autoantibody repertoire in APECED patients. Our results show that in addition to shared autoantigen reactivities, APECED patients display high inter-individual variation in their autoantigen profiles, which collectively are enriched in evolutionarily conserved, cytosolic and nuclear phosphoproteins. The APECED autoantigens have two major origins; proteins expressed in thymic medullary epithelial cells and proteins expressed in lymphoid cells. These findings support the hypothesis that specific protein properties strongly contribute to the etiology of B cell autoimmunity.

AIRE-mutations and autoimmune disease

The gene causing the severe organ-specific autoimmune disease autoimmune polyendocrine syndrome type-1 (APS-1) was identified in 1997 and named autoimmune regulator (AIRE). AIRE plays a key role in shaping central immunological tolerance by facilitating negative selection of T cells in the thymus, building the thymic microarchitecture, and inducing a specific subset of regulatory T cells. So far, about 100 mutations have been identified. Recent advances suggest that certain mutations located in the SAND and PHD1 domains exert a dominant negative effect on wild type AIRE resulting in milder seemingly common forms of autoimmune diseases, including pernicious anemia, vitiligo and autoimmune thyroid disease. These findings indicate that AIRE also contribute to autoimmunity in more common organ-specific autoimmune disorders.

A Longitudinal Follow-up of Autoimmune Polyendocrine Syndrome Type 1

CONTEXT

Autoimmune polyendocrine syndrome type 1 (APS1) is a childhood-onset monogenic disease defined by the presence of two of the three major components: hypoparathyroidism, primary adrenocortical insufficiency, and chronic mucocutaneous candidiasis (CMC). Information on longitudinal follow-up of APS1 is sparse.

OBJECTIVE

To describe the phenotypes of APS1 and correlate the clinical features with autoantibody profiles and autoimmune regulator (AIRE) mutations during extended follow-up (1996-2016).

PATIENTS

All known Norwegian patients with APS1.

RESULTS

Fifty-two patients from 34 families were identified. The majority presented with one of the major disease components during childhood. Enamel hypoplasia, hypoparathyroidism, and CMC were the most frequent components. With age, most patients presented three to five disease manifestations, although some had milder phenotypes diagnosed in adulthood. Fifteen of the patients died during follow-up (median age at death, 34 years) or were deceased siblings with a high probability of undisclosed APS1. All except three had interferon-ω) autoantibodies, and all had organ-specific autoantibodies. The most common AIRE mutation was c.967_979del13, found in homozygosity in 15 patients. A mild phenotype was associated with the splice mutation c.879+1G>A. Primary adrenocortical insufficiency and type 1 diabetes were associated with protective human leucocyte antigen genotypes.

CONCLUSIONS

Multiple presumable autoimmune manifestations, in particular hypoparathyroidism, CMC, and enamel hypoplasia, should prompt further diagnostic workup using autoantibody analyses (eg, interferon-ω) and AIRE sequencing to reveal APS1, even in adults. Treatment is complicated, and mortality is high. Structured follow-up should be performed in a specialized center.

Hypomagnesemia as a potentially life-threatening adverse effect of omeprazole

Hypomagnesemia can be caused by a wide range of diseases (e.g. gastrointestinal disorders, kidney diseases or endocrine disorders), but it can also be a side effect of several drugs. It can be asymptomatic or cause many different clinical symptoms, and the clinical manifestations mainly depend on the rate of development rather than the actual serum magnesium concentration. We here present a 40-year-old female patient with Torsade de pointes ventricular tachycardia and cardiac arrest caused by severe hypomagnesemia as an adverse effect of the proton pump inhibitor omeprazole.

Differences in proliferative capacity of primary human acute myelogenous leukaemia cells are associated with altered gene expression profiles and can be used for subclassification of patients

OBJECTIVES

Proliferative capacity of acute myelogenous leukaemia (AML) blasts is important for leukaemogenesis, and we have investigated whether proliferative capacity of primary human AML cells could be used for subclassification of patients.

MATERIALS AND METHODS

In vitro proliferative capacity of AML cells derived from two independent groups was investigated. Cells were cultured under highly standardized conditions and proliferation assayed by (3) H-thymidine incorporation after seven days culture. Patients were subclassified by clustering models, and gene expression profile was examined by microarray analyses.

RESULTS

Based on proliferative capacity of the AML cells, three different patient clusters were identified: (i) autocrine proliferation that was increased by exogenous cytokines; (ii) detectable proliferation only in presence of exogenous cytokines; and (iii) low or undetectable proliferation even in presence of exogenous cytokines. Patients with highest proliferative capacity cells had no favourable prognostic impact by NPM-1 mutation. Analysis of gene expression profiles showed that the most proliferative cells generally had altered expression of genes involved in regulation of transcription/RNA functions, whereas patients with high proliferative capacity and internal tandem duplications (ITDs) in the FLT3 cytokine receptor gene had altered expression of several molecules involved in cytoplasmic signal transduction.

CONCLUSIONS

In vitro proliferative capacity of primary human AML cells was considerably variable between patients and could be used to identify biologically distinct patient subsets.

Hyperleukocytosis and leukocytapheresis in acute leukaemias: experience from a single centre and review of the literature of leukocytapheresis in acute myeloid leukaemia

BACKGROUND

Hyperleukocytosis is usually defined as leukocyte count >100 × 10(9)  L(-1) and can be seen in newly diagnosed leukaemias. Hyperleukocytic leukaemia is associated with a risk of organ failure and early death secondary to leukostasis. Mechanical removal of leukocytes by the apheresis technique, leukocytapheresis, is a therapeutic option in these patients.

METHODS

During a 16-year period, 16 patients were treated with leukocytapheresis (35 apheresis procedures) for hyperleukocytosis/leukostasis. We present our experience, and in addition we review previous studies of hyperleukocytosis/leukocytapheresis in patients with acute myeloid leukaemia (AML).

RESULTS

We used a highly standardised approach for leukocytapheresis in leukaemia patients with hyperleukocytosis. The average leukocytapheresis number for each patient was 2·2 (range 1-6). Median leukocyte count before apheresis was 309 × 10(9)  L(-1) (range 104-935); the mean leukocyte count reduction was 71%, corresponding to a mean absolute reduction of 219 × 10(9)  L(-1). No serious side effects were seen during or immediately after apheresis.

CONCLUSIONS

The data suggest that our standardised technique for leukocytapheresis effectively reduced the peripheral blood leukaemia cell counts. Previous studies in AML also support the conclusion that this is a safe and effective procedure for the treatment of a potentially life-threatening complication, but apheresis should always be combined with early chemotherapy.

Bidirectional crosstalk between platelets and monocytes initiated by Toll-like receptor: an important step in the early defense against fungal infections?

Monocytes are important in the defense against fungal infections due to their phagocytic and immunoregulatory functions. Platelets also contribute in such immune responses through their release of soluble mediators, including chemokines as well as several other soluble mediators. Both monocytes and platelets express several Toll-like receptors (TLRs) that can recognize fungal molecules and thus initiate intracellular signaling events. TLR ligation on monocytes and platelets may thereby be an early immunological event and function as an initiator of a local proinflammatory crosstalk between platelets and monocytes resulting in (i) monocyte-induced increase of platelet activation and (ii) platelet-associated enhancement of the monocyte activation/function. These effects may have clinical implications both for the efficiency of antifungal treatment and for the predisposition to fungal infections, for example, increased predisposition in patients with thrombocytopenia/monocytopenia due to chemotherapy- or disease-induced bone marrow failure.

The chemokine system and its contribution to leukemogenesis and treatment responsiveness in patients with acute myeloid leukemia

The chemokine family consists of approximately 50 small (8-14 kDa), basic proteins that are expressed and released by a wide range of normal and malignant cells. Most chemokines act through heptahelical transmembrane G protein- coupled receptors. Based on their molecular structure these cytokines are divided into the two major subgroups CCL and CXCL chemokines that bind to CCR or CXCR receptors respectively. Primary human acute myelogenous leukemia (AML) cells show constitutive release of a wide range of chemokines, but the chemokine release profile differs between patients. Among the commonly expressed chemokines are proangiogenic CXCL8, antiangiogenic CXCL4/9-11 and several leukocyte-chemotactic chemokines. Systemic serum levels of leukocyte-chemotactic chemokines depend both on patient age, disease status, the chemotherapy regimen and development of complicating infections. The local chemokine network in human AML is probably further modulated by the hypoxic bone marrow microenvironment and the local release of chemokines by nonleukemic bone marrow stromal cells. Usually primary AML cells also express several chemokine receptors. Specific chemokine inhibitors are now being developed, including chemokine-neutralizing or receptor-blocking antibodies, antisense strategies, receptor-blocking small molecules or inhibitors of downstream signaling. The use of CXCR4-antagonists for mobilization of peripheral blood stem cells has been documented in several clinical studies. Although animal studies suggest that chemokine inhibition also may become useful in the treatment of graft versus host disease, the possible use of chemokine-targeting therapy for other indications than stem cell mobilization requires further studies.

[Changes in smoking habits among medical students in Bergen 2004-2006]

BACKGROUND

Smoking and snuff habits among medical students are of interest because they may reflect the attitude to smoking and snuff among future doctors, but few longitudinal studies have been performed.

MATERIAL AND METHOD

A standard questionnaire, developed by Statistics Norway, was handed out to all medical students at the University of Bergen during plenum lectures in the spring 2004 and 2006. The questionnaires were marked by personal codes to enable follow-up of smoking and snuff habits for each individual student during the study period. New questionnaires were sent by post to all students who did not respond after the initial handout.

RESULTS

799 medical students (89 %) responded in the spring 2004 and 789 students (84 %) in the spring 2006. The study revealed that 3 % of the students smoked regularly in 2004 and 1 % in 2006 and that 20 % were occasional smokers in 2004 and 18 in 2006. 15 % of the students were snuff users in 2004 and this had increased to 24 % in 2006.

INTERPRETATION

A decrease was observed in both daily and occasional smokers among medical students in Bergen during the two-year study period. However, the frequency of snuff users increased. The frequency of regular smokers is low, but the number of occasional smokers is higher than in the general population of the same age.

Histone deacetylase inhibitors in cancer treatment: a review of the clinical toxicity and the modulation of gene expression in cancer cell

Characterization of epigenetic events in carcinogenesis has led to the discovery of a new class of oncogenes and thereby a new class of therapeutic targets. Among the new therapeutic approaches are modulation of protein lysine acetylation through inhibition of histone deacetylases (HDACs). HDACs deacetylate histones as well as transcription factors and can modulate gene expression through both these mechanisms in normal and malignant cells. Furthermore, acetylation is an important posttranslational modulation of several proteins involved in the regulation of cell proliferation, differentiation and apoptosis in normal as well as cancer cells. Even though several HDAC inhibitors have been characterized in vitro, only a limited number of these agents are in clinical trials. Various HDAC inhibitors differ in their toxicity profile when comparing the side effects described in the available clinical studies of HDAC inhibition in the treatment of cancer. These drugs may also affect normal hematopoiesis; hematologic toxicity is common to many drugs but stimulation of hematopoiesis seems to occur for others. HDAC inhibitors usually affect <10% of the genes in cancer cells. Divergent effects of HDAC inhibition on the global gene expression profiles have been described when testing various cancer cells, and this is further complicated by altered HDAC expression induced by HDAC inhibitors. However, increased p21 expression seems to be a common characteristic for most studies, suggesting an important role of this molecule during HDAC inhibitory treatment. Even though the initial studies are encouraging, additional in vitro and in vivo pharmacological characterization is definitely needed.

The viability of cryopreserved PBPC depends on the DMSO concentration and the concentration of nucleated cells in the graft

BACKGROUND

DMSO is widely used as a cryoprotectant for PBPC. It is desirable to reduce the amount of DMSO without jeopardizing the quality of the stem cell product. The present study was undertaken to investigate whether recovery and survival of CD34+ cells would be significantly altered when PBPC used for autologous transplantations were cryopreserved with four different DMSO concentrations.

METHODS

Apheresis samples of PBPC from 20 consecutive patients were mixed in parallel with 2%, 4%, 5% and 10% DMSO, frozen with identical cell concentrations at a controlled rate, and stored in liquid nitrogen for 6-8 weeks. PBPC samples from 11 consecutive patients were also cryopreserved with two different cell concentrations (150 and 300 x 10(6) nucleated cells/mL) to investigate the effect of increasing the cell concentrations while decreasing the DMSO concentration. The flow cytometric absolute count method, based on ISHAGE guidelines, was used to measure the absolute count of total and viable CD34+ cells in the post-thaw samples.

RESULTS

PBPC cryopreserved at 150 x 10(6) cells/mL with 2% DMSO yielded significantly inferior CD34+ cell recovery (P < 0.001) and survival (P < 0.001) compared with cryopreservation with 4% and 5% DMSO. This was also observed when comparing higher cell concentrations. However, a reduced cell survival (P = 0.02) was observed when the nucleated cell concentration was increased from 150 to 300 x 10(6) cells/mL in samples cryopreserved with 5% DMSO.

DISCUSSION

We conclude that 5% DMSO may be the optimal dose for cryopreserving PBPC as long as the cells have not been concentrated at much more than 200 x 10(6) nucleated cells/mL.

Effects of normal platelets on proliferation and constitutive cytokine secretion by human acute myelogenous leukaemia blasts

The effects of soluble E-selectin, P-selectin and normal platelets on acute myelogenous leukaemia (AM L) blasts were investigated in vitro. We investigated effects on spontaneous and cytokine-dependent blast proliferation, and constitutive blast secretion of different cytokines. The presence of normal platelets during in vitro culture caused a dose-dependent increase in both spontaneous and cytokine-dependent AML blast proliferation. Addition of platelets also increased constitutive blast secretion of Interleukin 1beta (IL1beta ), IL6, GM-CSF and TNFalpha, whereas platelets had no effect on the release of IL1 receptor antagonist. The effects of platelets on constitutive cytokine secretion were also detected when platelets and AML blasts were cultured in different chambers separated by a permeable membrane, and a further enhancement was achieved when blasts and platelets were cultured together. Soluble P-selectin had no effect on constitutive AML blast cytokine secretion or the platelet-induced enhancement of the secretion. However, both soluble E- and P-selectin altered AML blast proliferation for a minority of patients. We conclude that normal platelets can modulate the function of human AML blasts in vitro.

Effects of acute myelogenous leukemia blasts on platelet release of soluble P-selectin and platelet-derived growth factor

Complex interactions occur between platelets and normal as well as leukemic myeloid cells. In vitro co-culture of platelets and acute myelogenous leukemia (AML) blasts with allogeneic platelets enhances blast proliferation and constitutive cytokine secretion. In the present study the effects of AML blasts on the platelet release of soluble mediators are characterized. Normal platelets released soluble (s) P-selectin and platelet-derived growth factor (PDGF), both when cultured alone and in the presence of AML blasts, and for certain patients the presence of AML blasts increased the platelet release of these mediators. Addition of exogenous interleukin (IL) 10 to platelet-AML blast cultures further increased platelet release of PDGF and sP-selectin. For certain patients decreased AML blast cytokine secretion was observed when PDGF-specific antibodies were added to cultures with blasts plus platelets, these results indicate that platelet release of PDGF is a molecular mechanism for the enhancement of AML blast cytokine secretion. We conclude that complex functional alterations are induced both in AML blasts and normal allogeneic platelets during in vitro co-culture of leukemia cells and platelets.

Serum levels of thrombopoietin and stem cell factor in acute leukemia patients with chemotherapy-induced cytopenia and complicating infections

Thrombopoietin (Tpo) and stem cell factor (SCF) are growth factors for megakaryocyte progenitor cells and can also modulate platelet function. We have characterized variations in serum levels of these two cytokines in acute leukemia patients undergoing intensive chemotherapy. Compared with healthy controls, serum Tpo levels were significantly increased prior to consolidation chemotherapy, and serum levels were correlated to peripheral blood platelet counts. Serum Tpo levels increased when the patients developed chemotherapy-induced cytopenia, and a further increase was observed during complicating bacterial infections. In contrast to Tpo, SCF serum levels in leukemia patients did not differ from healthy controls neither before chemotherapy nor during the period of chemotherapy-induced cytopenia. Serum levels of Tpo (and possibly SCF) may influence thrombopoiesis and/or platelet functions in patients undergoing intensive chemotherapy for acute leukemia.

Characterization of Ribosomal P Autoantibodies in Relation to Cell Destruction and Autoimmune Disease

Autoantibodies against the ribosomal P proteins are related to cell death and tissue destruction and are frequently exhibited in patients with systemic lupus erythematosus (SLE). In an attempt to explore the effect of tissue destruction on the induction of anti-P autoantibodies, we searched for anti-P autoantibodies by enzyme-linked immunosorbent assay in 201 antinuclear antibody (ANA)-positive individuals, in 10 patients with treated kidney SLE and in 45 acute leukaemia patients undergoing intensive chemotherapy. The autoantibody reactivity was further characterized using one- and two-dimensional immunoblot analysis and immunofluorescence. Anti-P were detected in 5.5% (11/201) of ANA-positive individuals, but not in kidney-affected SLE patients or in patients with leukaemia. Seven of 11 anti-P-positive patients had SLE (3/11), primary Sjögrens's syndrome (1/11) and other autoimmune diseases (3/11). A relation between disease activity and anti-P was suggested by follow-up examinations in one SLE patient, supported by the absence of anti-P autoantibodies in the 10 treated kidney SLE patients. Anti-P autoantibodies were detected by immunoblot in one patient with SLE indicating anti-P2 predominance and in the patient with Sjögrens's syndrome indicating anti-P1 predominance. Diverging humoral responses in these ANA- and anti-P-positive patients were further illustrated by immunofluorescence, elucidating varying nuclear reactivity and anti-P pattern. The observation of anti-P in individuals with active autoimmune disease, but not in patients with chemotherapy-induced cell damage, suggests that anti-P antibodies are part of a specific disease process, and not elicited as a response to cell destruction per se.

Antiproliferative effects of a non-beta-oxidizable fatty acid, tetradecylthioacetic acid, in native human acute myelogenous leukemia blast cultures

The lipid metabolism is important in the regulation of cell proliferation. We have examined effects of a fatty acid analogue, tetradecylthioacetic acid (TTA), on the functional phenotype of native, human AML cells. TTA inhibited AML blast proliferation in the presence of single cytokines (GM-CSF and SCF: P > 0.05, 35 patients with detectable proliferation) and a combination of cytokines (P < 0.005, n = 21). This antiproliferative effect was generally stronger than for the normal fatty acid palmitic acid (PA). Both TTA and PA increased the secretion of tumor necrosis factor alpha (TNFalpha) (P < 0.05, 27 patients with detectable cytokine release), but only PA increased interleukein 1beta (IL-1beta) release (P < 0.005, n = 34). AML blast populations varied significantly in their levels and activities of metabolites and enzymes characterizing oxidative status and fatty acid metabolism, and there was no significant correlation between the intrinsic oxidative status and the effects of PA and TTA on blast proliferation. Although TTA reduced the proliferation of mitogen-stimulated normal T cells derived from healthy individuals (P < 0.05, n = 8), no adverse effects were seen on peripheral blood cell counts (reticulocytes, platelets, total white blood cells, differential leukocyte counts) for healthy volunteers receiving TTA (oral administration of 1000 mg/day for 7 consecutive days). Our results suggest that TTA can inhibit AML blast proliferation through pathways that are unrelated to autocrine cytokine secretion and intrinsic oxidative status.