The effect of immunosuppressive therapies on the endothelial host response in critically ill COVID-19 patients.

While several effective therapies for critically ill patients with COVID-19 have been identified in large, well-conducted trials, the mechanisms underlying these therapies have not been investigated in depth. Our aim is to investigate the association between various immunosuppressive therapies (corticosteroids, tocilizumab and anakinra) and the change in endothelial host response over time in critically ill COVID-19 patients. We conducted a pre-specified multicenter post-hoc analysis in a Dutch cohort of COVID-19 patients admitted to the ICU between March 2020 and September 2021 due to hypoxemic respiratory failure. A panel of 18 immune response biomarkers in the complement, coagulation and endothelial function domains were measured using ELISA or Luminex. Biomarkers were measured on day 0-1, day 2-4 and day 6-8 after start of COVID-19 treatment. Patients were categorized into four treatment groups: no immunomodulatory treatment, corticosteroids, anakinra plus corticosteroids, or tocilizumab plus corticosteroids. The association between treatment group and the change in concentrations of biomarkers was estimated with linear mixed-effects models, using no immunomodulatory treatment as reference group. 109 patients with a median age of 62 years [IQR 54-70] of whom 72% (n = 78) was male, were included in this analysis. Both anakinra plus corticosteroids (n = 22) and tocilizumab plus corticosteroids (n = 38) were associated with an increase in angiopoietin-1 compared to no immune modulator (n = 23) (beta of 0.033 [0.002-0.064] and 0.041 [0.013-0.070] per day, respectively). These treatments, as well as corticosteroids alone (n = 26), were further associated with a decrease in the ratio of angiopoietin-2/angiopoietin-1 (beta of 0.071 [0.034-0.107], 0.060 [0.030-0.091] and 0.043 [0.001-0.085] per day, respectively). Anakinra plus corticosteroids and tocilizumab plus corticosteroids were associated with a decrease in concentrations of complement complex 5b-9 compared to no immunomodulatory treatment (0.038 [0.006-0.071] and 0.023 [0.000-0.047], respectively). Currently established treatments for critically ill COVID-19 patients are associated with a change in biomarkers of the angiopoietin and complement pathways, possibly indicating a role for stability of the endothelium. These results increase the understanding of the mechanisms of interventions and are possibly useful for stratification of patients with other inflammatory conditions which may potentially benefit from these treatments.

Seasonal variation of anti-PD-1 outcome in melanoma-Results from a Dutch patient cohort.

Despite the improved survival rates of patients with advanced stage melanoma since the introduction of ICIs, many patients do not have (long-term) benefit from these treatments. There is evidence that the exposome, an accumulation of host-extrinsic factors including environmental influences, could impact ICI response. Recently, a survival benefit was observed in patients with BRAF wild-type melanoma living in Denmark who initiated immunotherapy in summer as compared to winter. As the Netherlands lies in close geographical proximity to Denmark and has comparable seasonal differences, a Dutch validation cohort was established using data from our nationwide melanoma registry. In this study, we did not observe a similar seasonal difference in overall survival and are therefore unable to confirm the Danish findings. Validation of either the Dutch or Danish findings in (combined) patient cohorts from other countries would be necessary to determine whether this host-extrinsic factor influences the response to ICI-treatment.

ONCOR: design of the Dutch cardio-oncology registry.

BACKGROUND: The relative new subspecialty 'cardio-oncology' was established to meet the growing demand for an interdisciplinary approach to the management of cancer therapy-related cardiovascular adverse events. In recent years, specialised cardio-oncology services have been implemented worldwide, which all strive to improve the cardiovascular health of cancer patients. However, limited data are currently available on the outcomes and experiences of these specialised services, and optimal strategies for cardio-oncological care have not been established. AIM: The ONCOR registry has been created for prospective data collection and evaluation of cardio-oncological care in daily practice. METHODS: Dutch hospitals using a standardised cardio-oncology care pathway are included in this national, multicentre, observational cohort study. All patients visiting these cardio-oncology services are eligible for study inclusion. Data collection at baseline consists of the (planned) cancer treatment and the cardiovascular risk profile, which are used to estimate the cardiotoxic risk. Information regarding invasive and noninvasive tests is collected during the time patients receive cardio-oncological care. Outcome data consist of the incidence of cardiovascular complications and major adverse cardiac events, and the impact of these events on the oncological treatment. DISCUSSION: Outcomes of the ONCOR registry may aid in gaining more insight into the incidence of cancer therapy-related cardiovascular complications. The registry facilitates research on mechanisms of cardiovascular complications and on diagnostic, prognostic and therapeutic strategies. In addition, it provides a platform for future (interventional) studies. Centres with cardio-oncology services that are interested in contributing to the ONCOR registry are hereby invited to participate.

Newborn screening for hunter disease: a small-scale feasibility study.

Hunter disease (Mucopolysaccharidosis type II, MPS II) is an X-linked lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase (IDS). Two main therapies have been reported for MPS II patients: enzyme-replacement therapy (ERT) and hematopoietic stem-cell transplantation (HSCT). Both treatment modalities have been shown to improve some symptoms, but the results with regard to cognitive functioning have been poor. Early initiation of therapy, i.e., before neurological symptoms have manifested, may alter cognitive outcome. The need for early identification makes Hunter disease a candidate for newborn screening (NBS). Our objective was to explore the use of a fluorometric assay that could be applicable for high-throughput analysis of IDS activity in dried blood spots (DBS). The median IDS activity in DBS samples from 1,426 newborns was 377 pmol/punch/17 h (range 78-1111). The IDS activity in one sample was repeatedly under the cutoff value (set at 20% of the median value), which would imply a recall rate of 0.07%. A sample from a clinically diagnosed MPS II individual, included in each 96-well test plate, had IDS activities well below the 20% cutoff value. Coefficients of variation in quality control samples with low, medium, and high IDS activities (190, 304, and 430 pmol/punch/17 h, respectively) were 12% to 16%. This small-scale pilot study shows that newborn screening for Hunter disease using a fluorometric assay in DBS is technically feasible with a fairly low recall rate. NBS may allow for identification of infants with Hunter disease before clinical symptoms become evident enabling early intervention.

Hemoglobin precipitation greatly improves 4-methylumbelliferone-based diagnostic assays for lysosomal storage diseases in dried blood spots.

Derivatives of 4-methylumbelliferone (4MU) are favorite substrates for the measurement of lysosomal enzyme activities in a wide variety of cell and tissue specimens. Hydrolysis of these artificial substrates at acidic pH leads to the formation of 4-methylumbelliferone, which is highly fluorescent at a pH above 10. When used for the assay of enzyme activities in dried blood spots the light emission signal can be very low due to the small sample size so that the patient and control ranges are not widely separated. We have investigated the hypothesis that quenching of the fluorescence by hemoglobin leads to appreciable loss of signal and we show that the precipitation of hemoglobin with trichloroacetic acid prior to the measurement of 4-methylumbelliferone increases the height of the output signal up to eight fold. The modified method provides a clear separation of patients' and controls' ranges for ten different lysosomal enzyme assays in dried blood spots, and approaches the conventional leukocyte assays in outcome quality.

[Summary of the practice guideline 'Thyroid disorders' (first revision) from the Dutch College of General Practitioners]. / Samenvatting van de standaard 'Schildklieraandoeningen' (eerste herziening) van het Nederlands Huisartsen Genootschap.

--The practice guideline 'Thyroid disorders' developed by the Dutch College of General Practitioners replaces the practice guideline 'Functional thyroid disorders' from 1996. Recommendations for palpable thyroid disorders have been added. --Hypothyroidism can often be treated by the general practitioner. The guideline offers specific recommendations for substitution therapy based on the 'start low, go slow'-principle. --Pharmacological treatment of hyperthyroidism is described as an optional activity for general practitioners. --A conservative approach is taken to the treatment of subclinical thyroid dysfunction. The development of symptoms may justify treatment initiation. --Cooperation has improved harmonisation of this practice guideline with the Netherlands Association for Internal Medicine's practice guideline 'Functional thyroid disorders' and the Dutch Institute for Healthcare Improvement's practice guideline 'Thyroid carcinomas'.

[Gastroenteritis caused by Salmonella from pet snakes]. / Gastro-enteritis door salmonella aflkomstig van als huisdier gehouden slangen.

A Salmonella subspecies associated with reptiles (Salmonella enterica subspecies diarizonae) was isolated from the stool of a 19-year-old man with gastroenteritis. The same species was isolated from stool and urine samples taken from terraria found in the home of the patient's parents where snakes were kept. A high percentage of reptiles in the wild and in captivity are asymptomatic carriers of Salmonella species that can be transmitted to humans who come in contact with these animals. Unlike in the United States of America, for example, cases of reptile-associated infections have scarcely been published in the Netherlands and targeted information on the risk of infection is lacking. Because the popularity of exotic pets--and thereby the risk of infection--is increasing in The Netherlands, targeted information for veterinarians, traders and owners of exotic pets is warranted to prevent reptile-associated salmonellosis.

Brassica oleracea pollen, a new source of occupational allergens.

BACKGROUND: Vegetable pollen is a rare source of occupational allergens. Occupational allergy has only been described in the case of paprika pollen and tomato pollen. We describe a new source of occupational pollen allergy. AIM: To study the incidence and the impact of broccoli and cauliflower pollen allergy in employees involved in classical plant breeding. METHODS: Fifty-four employees of five companies working with cauliflower (Brassica oleracea botrytis) and broccoli (B. oleracea italica/cymosa) pollen were eligible for complete evaluation. Allergy to cauliflower and broccoli pollen was evaluated by questionnaire and determination of sensitization by radioallergosorbent test (RAST) and skin-prick tests (SPT). SPT and RAST were performed with a panel of commercial and homemade extracts from cauliflower and broccoli pollen. RESULTS: Work-related symptoms such as rhinitis, conjunctivitis, asthma and urticaria caused by B. oleracea pollen were reported by 44% of the participants (24/54), of whom all but one had positive SPT for cauliflower- and/or broccoli-pollen/flower extracts and 58% (14/24) had positive RAST results. Symptoms had developed within the first 2 years in 33% of the patients. Six patients had to stop or change work. CONCLUSIONS: Brassica oleracea pollen is a new source of occupational allergen with strong allergenic potential leading to symptoms in almost half of the exposed employees.

Phosphoglycerate kinase deficiency in two brothers with McArdle-like clinical symptoms.

Phosphoglycerate kinase (PGK) catalyses the transfer of the acylphosphate group of 1,3-diphosphoglycerate to ADP with formation of 3-phosphoglycerate and ATP in the terminal stage of the glycolytic pathway. Two young brothers are presented who both experienced muscle pain, cramps and stiffness shortly after beginning heavy exercise. After these episodes they noticed that the urine was dark brown, indicating rhabdomyolysis and myoglobinuria. The neurological examinations were without remarks. There was no lactate increase in the ischaemic forearm exercise test. Both had very low PGK levels in muscle, erythrocytes, leukocytes and fibroblasts. This is the first family with more than one affected case of PGK deficiency and exercise-induced stiffness, myalgia and rhabdomyolysis. The clinical manifestations may resemble myophosphorylase deficiency (McArdle's disease: glycogenosis Type V) and muscle phosphofructokinase deficiency (Tarui's disease: glycogenosis Type VII). PGK deficiency is inherited as an X-linked trait and may show other features such as mental retardation and/or haemolytic anaemia.

Asymptomatic and late-onset ornithine transcarbamylase (OTC) deficiency in males of a five-generation family, caused by an A208T mutation.

In a large five-generation Polish family, late-onset ornithine transcarbamylase (OTC) deficiency in males segregated with the missense mutation Ala208Thr (A208T), and all heterozygous females were asymptomatic. No other mutations were found in the coding sequences and intron-exon boundaries of the OTC gene. Surprisingly, the mutation originated from the great-grandfather of the index patient who died at age 59 of liver carcinoma. He never had dietary restrictions or hyperammonemic spells throughout life and appears to be the oldest male reported with OTC deficiency. The index patient had a severe OTC deficiency (3% of normal). Eight males died suddenly at ages 4 months to 23 years (average 14 years) after a foudroyant episode triggered by a common infection. The patients remained undiagnosed for 28 years because a metabolic defect was not considered to be the cause of the acute episodes. Recognition of the familial pattern of inheritance was initially unnoticed since the patients were admitted to eight different hospitals. DNA analysis predicted that two 'healthy' boys also had OTC deficiency, which was confirmed by abnormal results of allopurinol challenge tests. Initial suspicion of OTC deficiency in such families is complicated, since symptoms can develop at any age, or even remain absent. This obscures the typical pattern of X-linked inheritance in small families.

Elevated plasma chitotriosidase activity in various lysosomal storage disorders.

Recently a striking elevation of the activity of chitotriosidase, an endo beta-glucosaminidase distinct from lysozyme, was found in plasma from patients with Gaucher type I disease (McKusick 230800). Plasma chitotriosidase originates from activated macrophages and this elevation is secondary to the basic defect in Gaucher disease. To investigate the specificity of this phenomenon, we have investigated 24 different lysosomal storage diseases. In 11 different diseases increased chitotriosidase activity in plasma was found (in 28% of the patients). None of these diseases showed elevations as high as in Gaucher disease. Chitotriosidase was not significantly elevated in plasma from 20 different non-lysosomal enzymopathies or in plasma from patients with infectious diseases associated with hepatomegaly. The results show that marked elevation of chitotriosidase activity in plasma appears to be specific for Gaucher disease. The data further suggest that elevated levels of chitotriosidase activity in plasma from patients with unexplained diseases may be indicative for a lysosomal disorder.

A fluorimetric enzyme assay for the diagnosis of Sanfilippo disease C (MPS III C).

Both the alpha- and beta-anomers of 4-methylumbelliferyl-D-glucosaminide were synthesized and shown to be substrates for the lysosomal acetyl-CoA:glucosaminide N-acetyltransferase. Using the beta-anomer, fibroblasts and leukocytes from 11 different Sanfilippo C patients showed < 1% of mean normal N-acetyltransferase activity. Heterozygotes showed intermediate activities. The enzymatic liberation of the fluorochrome from 4-methylumbelliferyl-beta-D-glucosaminide requires the sequential action of the N-acetyltransferase and beta-hexosaminidase. Normal beta-hexosaminidase activity caused complete hydrolysis of the reaction intermediate 4-methylumbelliferyl-beta-D-N-acetylglucosaminide formed by the N-acetyltransferase. In cell extracts with a beta-hexosaminidase deficiency, however, a second incubation in the presence of excess beta-hexosaminidase is needed to avoid underestimation of the N-acetyltransferase activity.

A fluorimetric enzyme assay for the diagnosis of Sanfilippo disease type D (MPS IIID).

4-Methylumbelliferyl-alpha-N-acetylglucosamine 6-sulphate was synthesized and shown to be a substrate for the lysosomal N-acetylglucosamine-6-sulphate sulphatase (GlcNAc-6S sulphatase). Fibroblasts and leukocytes from 3 different Sanfilippo D patients showed < 1% of mean normal GlcNAc-6S sulphatase activity. The enzymatic liberation of the fluorochrome from 4-methyl-umbelliferyl-alpha-N-acetylglucosamine 6-sulphate requires the sequential action of the GlcNAc-6S sulphatase and alpha-N-acetylglucosaminidase. A normal level of alpha-N-acetylglucosaminidase activity was insufficient to complete the hydrolysis of the reaction intermediate 4-methylumbelliferyl-alpha-N-acetylglucosaminide formed by the GlcNAc-6S sulphatase. A second incubation in the presence of excess alpha-N-acetylglucosaminidase is needed to avoid underestimation of the GlcNAc-6S sulphatase activity.

Factors that inhibit adherence of Treponema pallidum (Nichols strain) to a human fibroblastic cell line: development in serum of patients with syphilis.

Serum samples from 25 patients at five different stages of syphilis were investigated for their ability to inhibit the adherence of pathogenic Nichols treponemes to cultured human fibroblasts. Serum taken from patients at the end of the primary stage showed an appreciable inhibition of treponemal adherence, and maximum inhibition of adherence was produced by serum from patients with secondary syphilis. Some freshly harvested treponemal suspensions were resistant to the adherence inhibition factors in serum from patients with syphilis; after incubation in vitro for 24 hours this resistance was lost. In vitro incubation almost doubled the number of adherent treponemes/fibroblast. These phenomena are discussed in terms of loss and reconstruction of the treponemal outer envelope. This leads to the suggestion that adherence occurs not only at the tips of the treponemes, but that surface components are also implicated, possibly as an initial contact mechanism. The composition of the outer envelope may in this way determine localisation versus dissemination of the treponemes.

Autolymphocytotoxins in syphilis.

Nineteen of 23 serum samples from patients with secondary syphilis, six of 24 from patients with primary syphilis, and four of seven from patients with early latent syphilis had complement-dependent autolymphocytotoxic reactivity at 15 degrees C. After treatment, the reactivity was decreased. It was not directed only against autologous lymphocytes but also against allogeneic lymphocytes. Sephadex G-200 gel filtration showed that the lymphocytotoxins were present in the IgM-containing exclusion peak. Furthermore, serum samples that had high antibody titres in the Reiter protein complement-fixation test or Wassermann-Kolmer reaction also had a high frequency of cold-reacting autolymphocytotoxins. This indicates that the autolymphocytotoxic reactivity is related to the humoral response in syphilis.

On the ecogenetics of Stellaria media (L.) Vill. and Stellaria pallida (Dum.) pire from abandoned arable field.

Isoenzyme analyses were carried out on the hypotetraploid Stellaria media and the diploid Stellaria pallida occurring on abandoned sandy fields in the coastal dunes of the Netherlands. Amylase isoenzymes in germinating seeds of Stellaria media showed a striking intrapopulational variability, which is in accordance with the germination behaviour of the different subpopulations. In contrast to these findings no intrapopulational variation nor developmental change in isoenzyme pattern could be detected on basis of 14 other analysed leaf enzymes. For five enzymes there was a difference in isoenzyme pattern between the species Stellaria media and Stellaria pallida. Of these five enzymes two showed an interpopulational variation in Stellaria media. The fact that there was almost no variability of the isoenzyme pattern in Stellaria pallida could be explained by the permanent autogamous (cleistogamous) state of the species. Effects of polyploidy on the isoenzyme pattern and its activity could not be demonstrated. Consequences of the extreme difference between the monomorphic pattern of the leaf enzymes as opposed to the polymorphism of the amylase are discussed in view of the difference in germination ecology and lifecycle strategy of Stellaria media subpopulations.