A very late onset AChR and MuSK double positive myasthenia gravis: a case description and literature review.

AChR and MuSK double positive myasthenia gravis has been rarely reported. Generally, it occurs in children and adults after thymectomy or immunotherapy. Furthermore, in a few patients with bulbar or respiratory involvement, MuSK antibodies might be detected after clinical deterioration. We report a man with a very late onset myasthenia gravis (86-year-old) and the coexistence of both antibodies at the time of the diagnosis. Despite the presence of MuSK antibodies, he manifested no bulbar symptoms and had a favorable clinical outcome. However, side effects related to low dose pyridostigmine were evident. Hence, double positivity can also occur in elderly and in more benign forms of myasthenia gravis. Other cases of AChR and MuSK double positive myasthenia gravis could allow a better definition of this condition.

SUIHTER: a new mathematical model for COVID-19. Application to the analysis of the second epidemic outbreak in Italy.

The COVID-19 epidemic is the latest in a long list of pandemics that have affected humankind in the last century. In this paper, we propose a novel mathematical epidemiological model named SUIHTER from the names of the seven compartments that it comprises: susceptible uninfected individuals (S), undetected (both asymptomatic and symptomatic) infected (U), isolated infected (I), hospitalized (H), threatened (T), extinct (E) and recovered (R). A suitable parameter calibration that is based on the combined use of the least-squares method and the Markov chain Monte Carlo method is proposed with the aim of reproducing the past history of the epidemic in Italy, which surfaced in late February and is still ongoing to date, and of validating SUIHTER in terms of its predicting capabilities. A distinctive feature of the new model is that it allows a one-to-one calibration strategy between the model compartments and the data that are made available daily by the Italian Civil Protection Department. The new model is then applied to the analysis of the Italian epidemic with emphasis on the second outbreak, which emerged in autumn 2020. In particular, we show that the epidemiological model SUIHTER can be suitably used in a predictive manner to perform scenario analysis at a national level.

POSEIDON study: a pilot, safety and feasibility trial of high-dose omega3 fatty acids and high-dose cholecalciferol supplementation in type 1 diabetes.

The anti-inflammatory and immunomodulatory properties of high-dose omega-3 fatty acids and Vitamin D, and the initial encouraging results from case reports on the use of this supplementation in new-onset Type 1 Diabetes (T1D), support further testing of this combination strategy. This intervention appears to be well tolerated, affordable, and sufficiently safe to be further tested in randomized prospective trials to determine whether this combination therapy may be of assistance to halt progression of autoimmunity and/or preserve residual beta-cell function in subjects with new onset and established T1D of up to 10 years duration. In addition, the 1st PreDiRe T1D conference (Preventing Disease and its Recurrence in Type 1 Diabetes - see Editorial in this issue) was organized to discuss initial results and possible alternative/complementary strategies, for collaborative international expansion of these trials, to include strategies for disease prevention. Our POSEIDON clinical trial will test the use of high dose vitamin D3 and highly purified Omega-3 fatty acids in new onset and established T1D. The draft of the study protocol, in addition to the informed consent and assent, is now shared open access to facilitate its international implementation by interested physicians and centers that would like to further test this approach through clinical trials.

Prevalence, molecular characterization, and clinical relevance of sensitization to Anisakis simplex in children with sensitization and/or allergy to Dermatophagoides pteronyssinus.

SUMMARY: Prevalence of the Anisakis Simplex's (AS) sensitization in children sensitized to Dermatophagoides pteronissynus (DP) is not known, neither it is to which percentage it might be due to cross-reactivity. The primary objective of the present retrospective cross-sectional study is to evaluate the prevalence of sensitization to AS in children sensitized or allergic to DP. Secondary outcomes were the prevalence of cross-reactivity and clinical relevance of the condition. The prevalence of sensitization to AS differs significantly among patients sensitized and not to DP (13.43% vs. 3.80%; p=0.019). The higher prevalence is mainly due to cross-reactivity with Der p10 (OR=8.86; 95% CI=4.33-40.74; p=0.0001). Currently, the sensitization to AS seems to have no clinical relevance in the pediatric population.

Correlation between collective and molecular dynamics in pH-responsive cyclodextrin-based hydrogels.

UV Raman and Brillouin light scattering (BLS) experiments have been used in this study to explore the complex phase change behavior occurring in pH-responsive polysaccharide hydrogels as a function of temperature. Due to the different physical quantities measured by the two techniques, the joint analysis of Raman and BLS spectra has provided an unprecedented large-scale characterization of the molecular rearrangements and of the different kinds of hydrophilic and hydrophobic interactions that cooperate to determine the phase transformation observed in these hydrogels during the heating of the gel. As the main result, the analysis of the Raman and BLS spectra showed the existence of a correlation between the local (molecular) and collective properties of the gels during the phase transformation undergone by the system, which is markedly triggered by pH. The joint set of experimental results suggests a model according to which the mechanism of pH dependence in the hydrogels under investigation is dominated by the interactions involving the hydrophobic parts of the polymer skeleton, whereas the solvation process observed under heating of the gels is driven by the progressive distancing of the polymer domains among them, as monitored by the Brillouin sound velocity.

Validation of a rapid type 1 diabetes autoantibody screening assay for community-based screening of organ donors to identify subjects at increased risk for the disease.

The Network for Pancreatic Organ donors with Diabetes (nPOD) programme was developed in response to an unmet research need for human pancreatic tissue obtained from individuals with type 1 diabetes mellitus and people at increased risk [i.e. autoantibody (AAb)-positive] for the disease. This necessitated the establishment of a type 1 diabetes-specific AAb screening platform for organ procurement organizations (OPOs). Assay protocols for commercially available enzyme-linked immunosorbent assays (elisas) determining AAb against glutamic acid decarboxylase (GADA), insulinoma-associated protein-2 (IA-2A) and zinc transporter-8 (ZnT8A) were modified to identify AAb-positive donors within strict time requirements associated with organ donation programmes. These rapid elisas were evaluated by the international islet AAb standardization programme (IASP) and used by OPO laboratories as an adjunct to routine serological tests evaluating donors for organ transplantation. The rapid elisas performed well in three IASPs (2011, 2013, 2015) with 98-100% specificity for all three assays, including sensitivities of 64-82% (GADA), 60-64% (IA-2A) and 62-68% (ZnT8A). Since 2009, nPOD has screened 4442 organ donors by rapid elisa; 250 (5·6%) were identified as positive for one AAb and 14 (0.3%) for multiple AAb with 20 of these cases received by nPOD for follow-up studies (14 GADA+, two IA-2A(+) , four multiple AAb-positive). Rapid screening for type 1 diabetes-associated AAb in organ donors is feasible, allowing for identification of non-diabetic, high-risk individuals and procurement of valuable tissues for natural history studies of this disease.

Risk Factors for Type 1 Diabetes Recurrence in Immunosuppressed Recipients of Simultaneous Pancreas-Kidney Transplants.

Patients with type 1 diabetes (T1D) who are recipients of pancreas transplants are believed to rarely develop T1D recurrence in the allograft if effectively immunosuppressed. We evaluated a cohort of 223 recipients of simultaneous pancreas-kidney allografts for T1D recurrence and its risk factors. With long-term follow-up, recurrence was observed in approximately 7% of patients. Comparing the therapeutic regimens employed in this cohort over time, lack of induction therapy was associated with recurrence, but this occurs even with the current regimen, which includes induction; there was no influence of maintenance regimens. Longitudinal testing for T1D-associated autoantibodies identified autoantibody positivity, number of autoantibodies, and autoantibody conversion after transplantation as critical risk factors. Autoantibodies to the zinc transporter 8 had the strongest and closest temporal association with recurrence, which was not explained by genetically encoded amino acid sequence donor-recipient mismatches for this autoantigen. Genetic risk factors included the presence of the T1D-predisposing HLA-DR3/DR4 genotype in the recipient and donor-recipient sharing of HLA-DR alleles, especially HLA-DR3. Thus, T1D recurrence is not uncommon and is developing in patients treated with current immunosuppression. The risk factors identified in this study can be assessed in the transplant clinic to identify recurrent T1D and may lead to therapeutic advances.

The role of heterogeneity on the invasion probability of mosquito-borne diseases in multi-host models.

Heterogeneity in transmission and stochastic events can play a significant role in shaping the epidemic dynamics of vector-borne infections, especially in the initial phase of an outbreak. In this work, by using multi-type branching process methodologies, we assess how heterogeneities in transmission among a large number of host groups can affect the invasion probabilities of a mosquito-borne disease. We show with both analytical and numerical methods that heterogeneities in transmission can shape the invasion probabilities differently from how they affect the basic reproduction number (R0). In particular, we find that, while R0 always increases with the heterogeneity, the invasion probability after the introduction of infected hosts can decrease with the increase of transmission heterogeneity, even approaching zero when the number of host groups is very large. In addition, we show that the invasion probability via infected vectors is always larger than via infected hosts when heterogeneous transmission is sufficiently high. Our findings suggest that, for multi-species infections (e.g. West Nile fever and Rift Valley fever) or for single-species infections with patchy host distribution, the introduction of primary infected vectors may represent a higher risk for major outbreaks occurrence than introductions of infected hosts.

HLA similarities indicate shared genetic risk in 21-hydroxylase autoantibody positive South African and United States Addison's disease.

Genetic similarities between patients from the United States and South African (SA) Addison's Disease (AD) strengthen evidence for genetic association. SA-AD (n = 73), SA healthy controls (N = 78), and US-AD patients (N = 83) were genotyped for DQA1, DQB1, DRB1, and HLA-B alleles. Serum was tested for the quantity of 21OH-AA and IFNα-AA at the Barbara Davis Center. Although not as profound as in US-AD, in SA-AD 21OH-AA + subjects the predominantly associated risk haplotypes were DRB1*0301-DQB1*0201 (DR3), DRB1*04xx-DQB1*0302 (DR4), and the combined DR3/4 genotype. DQB1*0302 associated DRB1*04xx haplotypes conferred higher risk than those DRB1*04xx haplotypes associated with other DQB1 alleles. We found negative association in 21OH-AA + SA-AD for DQA1*0201-DQB1*0202 and DQA1*0101-DQB1*0501 vs SA controls, and positive association for DQA1*0401-DQB1*0402 vs US-AD. Apart from the class II DR3 haplotype, HLA-B8 did not have an independent effect; however together DR3 and HLA-B8 conferred the highest risk vs 21OH-AA negative SA-AD and SA-controls. HLA-B7 (often with DR4) conferred novel risk in 21OH-AA + SA-AD vs controls. This study represents the first comparison between South African and United States AD populations utilizing genotyping and serology performed at the same center. SA-AD and US-AD 21OH-AA + patients share common HLA risk haplotypes including DR4 (with HLA-B7) and DR3 (with HLA-B8), strengthening previously described HLA associations and implicating similar genetic etiology.

Ear acupuncture and fMRI: a pilot study for assessing the specificity of auricular points.

In recent years research explored different acupuncture stimulation techniques but interest has focused primarily on somatic acupuncture and on a limited number of acupoints. As regards ear Acupuncture (EA) there is still some criticism about the clinical specificity of auricular points/areas representing organs or structures of the body. The aim of this study was to verify through (Functional magnetic resonance imaging) fMRI the hypothesis of EA point specificity using two auricular points having different topographical locations and clinical significance. Six healthy volunteers underwent two experimental fMRI sessions: the first was dedicated to the stimulation of Thumb Auricular Acupoint (TAA) and the second to the stimulation of Brain Stem Auricular Acupoint (BSAA). The stimulation of the needle placed in the TAA of the left ear produced an increase in activation bilaterally in the parietal operculum, region of the secondary somatosensory area SII. Stimulation of the needle placed in the BSAA of the left ear showed a pattern that largely overlapped regions belonging to the pain matrix, as shown to be involved in previous somatic acupuncture studies but with local differences in the left amygdala, anterior cingulate cortex, and cerebellum. The differences in activation patterns between TAA and BSAA stimulation support the specificity of the two acupoints. Moreover, the peculiarity of the regions involved in BSAA stimulation compared to those involved in the pain matrix, is in accordance with the therapeutic indications of this acupoint that include head pain, dizziness and vertigo. Our results provide preliminary evidence on the specificity of two auricular acupoints; further research is warranted by means of fMRI both in healthy volunteers and in patients carrying neurological/psychiatric syndromes.

The multiple origins of Type 1 diabetes.

It is widely accepted that Type 1 diabetes is a complex disease. Genetic predisposition and environmental factors favour the triggering of autoimmune responses against pancreatic ß-cells, eventually leading to ß-cell destruction. Over 40 susceptibility loci have been identified, many now mapped to known genes, largely supporting a dominant role for an immune-mediated pathogenesis. This role is also supported by the identification of several islet autoantigens and antigen-specific responses in patients with recent onset diabetes and subjects with pre-diabetes. Increasing evidence suggests certain viruses as a common environmental factor, together with diet and the gut microbiome. Inflammation and insulin resistance are emerging as additional cofactors, which might be interrelated with environmental factors. The heterogeneity of disease progression and clinical manifestations is likely a reflection of this multifactorial pathogenesis. So far, clinical trials have been mostly ineffective in delaying progression to overt diabetes in relatives at increased risk, or in reducing further loss of insulin secretion in patients with new-onset diabetes. This limited success may reflect, in part, our incomplete understanding of key pathogenic mechanisms, the lack of truly robust biomarkers of both disease activity and ß-cell destruction, and the inability to assess the relative contributions of various pathogenic mechanisms at various time points during the course of the natural history of Type 1 diabetes. Emerging data and a re-evaluation of histopathological, immunological and metabolic findings suggest the hypothesis that unknown mechanisms of ß-cell dysfunction may be present at diagnosis, and may contribute to the development of hyperglycaemia and clinical symptoms.

Advantage of rapamycin over mycophenolate mofetil when used with tacrolimus for simultaneous pancreas kidney transplants: randomized, single-center trial at 10 years.

Simultaneous pancreas kidney transplantation (SPKT) is the treatment of choice for patients with type 1 diabetes and end-stage renal disease. Rapamycin and mycophenolate mofetil (MMF) have been used for maintenance immunosuppression with tacrolimus in SPKT; however, long-term outcomes are lacking. From September 2000 through December 2009, 170 SPKT recipients were enrolled in a randomized, prospective trial receiving Rapamycin (n = 84) or MMF (n = 86). All patients received dual induction therapy with thymoglobulin and daclizumab, and low-dose maintenance tacrolimus and corticosteroids. Compared to MMF, rates of freedom from first biopsy-proven acute kidney or pancreas rejection were superior for Rapamycin at year 1 (kidney: 100% vs. 88%; P = 0.001; pancreas: 99% vs. 92%; P = 0.04) and at year 10 (kidney: 88% vs. 71%, P = 0.01; pancreas: 99% vs. 89%, P = 0.01). The higher rates of rejection were associated with withholding MMF (vs. Rapamycin, p = 0.009), generally for gastrointestinal or bone marrow toxicity. There was no significant difference in creatinine, proteinuria, c-peptide, viral infections, lymphoproliferative disorders or posttransplant diabetes. HbA1C and lipid levels were normal in both groups, although higher in the Rapamycin arm. There were no significant differences in patient or allograft survival. In this 10-year SPKT study, Rapamycin in combination with tacrolimus was better tolerated and more effective than MMF. Overall, the patient and allograft survival were equivalent.

On the formulation of epidemic models (an appraisal of Kermack and McKendrick).

The aim of this paper is to show that a large class of epidemic models, with both demography and non-permanent immunity incorporated in a rather general manner, can be mathematically formulated as a scalar renewal equation for the force of infection.

Model predictions and evaluation of possible control strategies for the 2009 A/H1N1v influenza pandemic in Italy.

We describe the real-time modelling analysis conducted in Italy during the early phases of the 2009 A/H1N1v influenza pandemic in order to estimate the impact of the pandemic and of the related mitigation measures implemented. Results are presented along with a comparison with epidemiological surveillance data which subsequently became available. Simulated epidemics were fitted to the estimated number of influenza-like syndromes collected within the Italian sentinel surveillance systems and showed good agreement with the timing of the observed epidemic. On the basis of the model predictions, we estimated the underreporting factor of the influenza surveillance system to be in the range 3·3-3·7 depending on the scenario considered. Model prediction suggested that the epidemic would peak in early November. These predictions have proved to be a valuable support for public health policy-makers in planning interventions for mitigating the spread of the pandemic.

Premio Dr. Abraham Isaías Kohan - XIII Congreso Argentino de Medicina Transfusional. Proceso de colecta de células progenitoras hematopoyéticas de sangre periférica en pediatría / Dr. Abraham Isaías Kohan Award - XIII Argentine Congress of Transfusion Medicine. Stem cell collections and associated processes in a pediatric population

Fundamento: El trasplante de células progenitoras hematopoyéticas, es una terapéutica utilizada para el tratamiento de pacientes con enfermedades hematológicas y oncológicas, entre otras. Las células progenitoras hematopoyéticas de sangre periférica se obtienen mediante leucaféresis, previa movilización del donante con factores de crecimiento hematopoyético. Objetivos: Comunicar la experiencia de colectas de células progenitoras hematopoyéticas y los procesos asociados, en una población pediátrica candidata a trasplante autólogo o alogeneico. Material y Método: Se evaluaron 53 pacientes y/o donantes para realizar colecta de CPH, entre los años 2008 y 2011. Se tomó consentimiento informado para realizar los procedimientos. Todos fueron evaluados clínicamente y mediante estudios de laboratorio. El momento de colecta se determinó por el número de las células CD34+ en sangre periférica (óptimo 10 a 20 CD34+/uL) en los pacientes y/o donantes, la decisión se tomó en equi­po: médico tratante y de hemoterapia. Resultados: Fueron evaluados 53 candidatos, se realizó colecta en 40: Grupo I autólogo 29 (72,5 %) y Grupo II alogeneico 11 (27,5%). Se realizaron 61 colectas, 50 en Grupo I (82%) y 11 en Grupo II (18%). La mediana de la dosis de movilización con G-CSF fue 12,80 ug/ Kg /día (Rango: 10-25) aplicada entre 4 y 6 días. El recuento de CD34+ en los productos obtenidos resultó en una mediana 6,50 CD34+ x10 6/Kg de receptor (Rango: 1,31-38,34). Conclusiones: Los procesos y procedimientos empleados para obtener células progenitoras hematopoyéticas para el trasplante nos permitieron cumplir los objetivos dentro del programa de garantía de la calidad y obtener resultados clínicos deseados comparables a los publicados en la literatura en este campo.

Background: The hematopoietic stem cell transplantation is a therapy used to treat patients with blood diseases and cancer, among others. Hematopoietic progenitor cells from peripheral blood are obtained by leukapheresis after donor mobilization with hematopoietic growth factors. Objectives: Communicating the experience of stem cell collections and associated processes in a pediatric population candidate for autologous or allogeneic transplantation. Methods: 53 patients and / or donors were evaluated for collection between 2008 and 2011. Informed consent was taken. AII were clinically evaluated and we also performed some laboratory testing. The timing of collection was determined by the number of CD34+ peripheral blood (10 - 20 CD34+ cells /uL) and the decision was made as a team integrated by the physician in charge and the Blood Bank physician.Results: Of the 53 candidates, collection was performed in 40. Group I: autologous 29 (72.5%) and Group II allogeneic 11 (27.5%). 61 collections were made, 50 in Group I (82%) and 11 in Group II (18%). The median dosage of G-CSF mobilization was 12.80 ug/kg/day (range: 10-25) was administered for a period of 4 to 6 days. The CD34+ count in the products resulted in a median of 6,50 x 10 6 CD34+ /kg recipient (range: 1.31 to 38.34). Conclusions: The processes employed in obtaining hematopoietic progenitor cells allowed us to meet goals under the Quality Assurance Program and achieve satisfactory clinical results comparable to those reported in the literature of the field.

Dimorphic histopathology of long-standing childhood-onset diabetes.

AIMS/HYPOTHESIS: Childhood diabetes is thought to usually result from autoimmune beta cell destruction (type 1A) with eventual total loss of beta cells. Analysis of C-peptide in children characterised at diabetes onset for autoantibodies shows heterogeneous preservation of insulin secretion in long-standing diabetes. The aim of this study was to characterise the pancreases of childhood-onset diabetes in order to define the pathological basis of this heterogeneity. METHODS: We evaluated 20 cadaveric organ donor pancreases of childhood-onset long-term patients for disease heterogeneity and obtained corresponding C-peptide measurements. RESULTS: Pancreases from the majority of cadaveric donors contained only insulin-deficient islets (14 of 20). The remaining six patients (30%) had numerous insulin-positive cells within at least some islets, with two different histological patterns. Pattern A (which we would associate with type 1A diabetes) had lobular retention of areas with 'abnormal' beta cells producing the apoptosis inhibitor survivin and HLA class I. In pattern B, 100% of all islets contained normal-appearing but quantitatively reduced beta cells without survivin or HLA class I. CONCLUSIONS/INTERPRETATION: Our data demonstrate that C-peptide secretion in long-standing diabetic patients can be explained by two different patterns of beta cell survival,possibly reflecting different subsets of type 1 diabetes.

Modelling the spatial spread of H7N1 avian influenza virus among poultry farms in Italy.

We analysed the between-farm transmission of the H7N1 highly pathogenic avian influenza virus that disrupted the Italian poultry production in the 1999-2000 epidemic with a SEIR model with a spatial transmission kernel, accounting for the containment measures actually undertaken. We found significant differences in susceptibility between species and a reduction in transmissibility after the first phase. We performed simulations to assess the effectiveness of the implemented and new control measures. The most effective measure was the ban on restocking. An earlier start of pre-emptive culling promotes eradication; restricted pre-emptive culling delays eradication but causes lower losses.

Recambio plasmático terapéutico en enfermedades neurológicas pediátricas / Therapeutic plasma exchange in pediatric neurological diseases

El recambio plasmático terapéutico (RPT) es un procedimiento utilizado en el tratamiento de distintas patologías, especialmente las de etiología autoinmune. La base fisiopatológica del RPT consiste en la eliminación de mediadores inflamatorios a través de la extracción de un volumen variable de plasma del paciente y su sustitución por una solución de reposición, usualmente albúmina al 5%; utilizando separadores celulares. Objetivo: analizar la experiencia de nuestra institución en el tratamiento con RPT de pacientes con enfermedades neurológicas. Material y métodos: estudio retrospectivo, descriptivo sobre una población de 43 pacientes con enfermedad neurológica (Miastenia Gravis, Guillain Barré, Enfermedad de Devic, Encefalomielitis diseminada aguda, Polineuropatía desmielinizante inflamatoria crónica y Encefalitis de Rasmussen), tratados con una serie de RPT entre junio 1994 y junio 2009. Resultados: se pudieron evaluar 38 pacientes, por falta de información sobre los 5 restantes, observándose alguna mejoría del cuadro clínico en el 79% de los mismos. En 68% de los RPT se observó una o más complicaciones (hipocalcemia, hipotensión, parestesias). Conclusiones: en nuestra experiencia el recambio plasmático terapéutico constituye un tratamiento efectivo para las enfermedades neurológicas en las que fenómenos autoinmunes juegan un rol importante en la patogénesis, incluso en aquellas con un bajo nivel de evidencia clínica según la categorización de indicaciones de la ASFA.

Therapuetica plasma exchange (TPE) is a procedure used for the treatment of different diseases, especially those of autoimmune etiology. The pathophysiological basis of the TPE is the removal of inflammatory mediators through the extraction of a variable volume of patient plasma and its replacement by a solution, usually albumin 5%, using cell separators. objective: to analyze our institution's experience in the TPE treatment of patients with neurological diseases. Material and methods: a retrospective, descriptive study of a population of 43 patients with neurological disease ( Myasthenia Gravis, Guillain Barre syndrome, Devic's disease, Acute demyelinating polyneuropathy, Rasmussen's encephalitis) treated with a series of TPE between june 1994 and june 2009. Results: 38 patients were able to assess, for lack of information on the remaining 5. We observed some clinical improvement in 79% of them. In 68% of the TPE one or more complications (hypocalcemia, hypotension, paresthesias) were observed. Conclusions: in our experience the therapeutic plasma exchange is an effective treatment for neurological diseases in which autoimmune phenomena play an important role in pathogenesis, even in those with low levels of clinical evidence according to the categorization of indications of the ASFA.