Indeterminate serotonin release assays are associated with a high mortality rate

Background

The serotonin release assay (SRA) is considered the gold standard for diagnosis of heparin-induced thrombocytopenia (HIT). Although the SRA holds high sensitivity and specificity when results are definitive, up to 10% of samples from patients with suspected HIT yield "indeterminate" results.

Objectives

We aimed to study the clinical course of patients with indeterminate results.

Methods

We conducted a cohort analysis of 2056 patients that underwent SRA testing.

Results

Of 2056 total patients, 152 (7.4%) had indeterminate assays. The prevalence of thrombocytopenia <50,000 × 10⁶ was higher in patients with an indeterminate or positive SRA, compared with a negative SRA (39.5% and 40.0% vs. 27.5%, p < 4.0 × 10^-4). Patients with an indeterminate SRA were more likely to have been treated in the intensive care unit than patients with a positive SRA (93.3% vs. 73.7%, p = 0.03). The mean thrombocytopenia, timing of platelet count fall, thrombosis or other sequelae, and other causes for thrombocytopenia score in patients with indeterminate SRA was 2.9, corresponding to a HIT probability of <5%. Of 152 patients, 128 (78.9%) had heparin-PF4 optical densities (ODs) below 0.60 OD, whereas four patients (2.6%) had ODs above 2.00 OD. Inpatient mortality was significant in patients with indeterminate SRAs compared with positive or negative SRA (49.3% vs. 21.1% and 27.2%, p < 2.4 × 10^-10).

Conclusions

Our data suggest that an indeterminate SRA may signal an in vivo platelet activation process that is not related to heparin but is associated with increased mortality.

A History of Heart Failure Is an Independent Risk Factor for Death in Patients Admitted with Coronavirus 19 Disease

Aims: The association between cardiovascular diseases, such as coronary artery disease and hypertension, and worse outcomes in COVID-19 patients has been previously demonstrated. However, the effect of a prior diagnosis of heart failure (HF) with reduced or preserved left ventricular ejection fraction on COVID-19 outcomes has not yet been established. Methods and Results: We retrospectively studied all adult patients with COVID-19 admitted to our institution from March 1st to 2nd May 2020. Patients were grouped based on the presence or absence of HF. We used competing events survival models to examine the association between HF and death, need for intubation, or need for dialysis during hospitalization. Of 4043 patients admitted with COVID-19, 335 patients (8.3%) had a prior diagnosis of HF. Patients with HF were older, had lower body mass index, and a significantly higher burden of co-morbidities compared to patients without HF, yet the two groups presented to the hospital with similar clinical severity and similar markers of systemic inflammation. Patients with HF had a higher cumulative in-hospital mortality compared to patients without HF (49.0% vs. 27.2%, p < 0.001) that remained statistically significant (HR = 1.383, p = 0.001) after adjustment for age, body mass index, and comorbidities, as well as after propensity score matching (HR = 1.528, p = 0.001). Notably, no differences in mortality, need for mechanical ventilation, or renal replacement therapy were observed among HF patients with preserved or reduced ejection fraction. Conclusions: The presence of HF is a risk factor of death, substantially increasing in-hospital mortality in patients admitted with COVID-19.

Evaluation of the Effects of the COVID-19 Pandemic on Electronic Consultation Use in Primary Care

Background: Little is known about electronic consultation (e-consult) utilization during the COVID-19 pandemic when health systems rapidly implemented and scaled telehealth alternatives to in-person care. It is also unknown if e-consult utilization during the pandemic replaced or merely deferred the need for a specialty appointment. We evaluated if primary care providers' (PCPs) e-consult utilization and specialists' recommendations for specialty appointments changed after the transition to telemedicine during the COVID-19 pandemic. Methods: This cohort study used an interrupted time series analysis of e-consult utilization in a large, urban academic health care system between December 1, 2019, and June 27, 2020; the post-telemedicine time period began March 15, 2020. The primary outcome measure was the odds of an e-consult ordered during a PCP appointment; the secondary outcome measure was the odds of a specialist recommending a specialty appointment in an e-consult. Results: During 193,263 PCP appointments, 1,318 e-consults were placed to internal medicine subspecialties. Compared to the pre-telemedicine time period, the odds of a PCP ordering an e-consult increased (OR 1.04, 95% CI [1.02-1.07]) and the odds of specialists recommending specialty appointments increased (OR 1.11, 95% CI [1.06-1.15]). Conclusions: E-consult use increased following the transition to telemedicine in the context of the COVID-19 pandemic, suggesting that PCPs consider the e-consult a valuable tool for patient care when there is limited availability of specialty appointments. However, recommendations for specialty appointments following an e-consult also increased, suggesting that the e-consult may not replace the need for a specialty appointment.

Systematic Review of Evidence-Based Guidelines for Prehospital Care

Introduction: Multiple national organizations have identified a need to incorporate more evidence-based medicine in emergency medical services (EMS) through the creation of evidence-based guidelines (EBGs). Tools like the Appraisal of Guidelines for Research and Evaluation (AGREE) II and criteria outlined by the National Academy of Medicine (NAM) have established concrete recommendations for the development of high-quality guidelines. While many guidelines have been created that address topics within EMS medicine, neither the quantity nor quality of prehospital EBGs have been previously reported. Objectives: To perform a systematic review to identify existing EBGs related to prehospital care and evaluate the quality of these guidelines using the AGREE II tool and criteria for clinical guidelines described by the NAM. Methods: We performed a systematic search of the literature in MEDLINE, EMBASE, PubMED, Trip, and guidelines.gov, through September 2018. Guideline topics were categorized based on the 2019 Core Content of EMS Medicine. Two independent reviewers screened titles for relevance and then abstracts for essential guideline features. Included guidelines were appraised with the AGREE II tool across 6 domains by 3 independent reviewers and scores averaged. Two additional reviewers determined if each guideline reported the key elements of clinical practice guidelines recommended by the NAM via consensus. Results: We identified 71 guidelines, of which 89% addressed clinical aspects of EMS medicine. Only 9 guidelines scored >75% across AGREE II domains and most (63%) scored between 50 and 75%. Domain 4 (Clarity of Presentation) had the highest (79.7%) and domain 5 (Applicability) had the lowest average score across EMS guidelines. Only 38% of EMS guidelines included a reporting of all criteria identified by the NAM for clinical practice guidelines, with elements of a systematic review of the literature most commonly missing. Conclusions: EBGs exist addressing a variety of topics in EMS medicine. This systematic review and appraisal of EMS guidelines identified a wide range in the quality of these guidelines and variable reporting of key elements of clinical guidelines. Future guideline developers should consider established methodological and reporting recommendations to improve the quality of EMS guidelines.

MUC1/SEC and MUC1/Y overexpression is associated with inflammation in Sjögren's syndrome

OBJECTIVES

To evaluate the expression and localization of MUC1/SEC and MUC1/Y isoforms in labial salivary glands (LSG) from Sjögren's syndrome patients (SS patients), as well as their in vitro expression induced by cytokines.

SUBJECTS AND METHODS

Labial salivary gland from 27 primary SS patients and 22 non-SS sicca subjects were studied. Relative MUC1/SEC and MUC1/Y mRNA levels were determined by qPCR and protein levels by Western blotting. Induction of mucin mRNAs was assayed in vitro. Immunohistochemistry was used for localization.

RESULTS

Relative MUC1/SEC and MUC1/Y mRNA and protein levels were significantly higher in LSG from SS patients. These mRNAs were induced by cytokines. MUC1/SEC and MUC1/Y were detected in acini apical region of control LSGs, and significant cytoplasmic accumulation was observed in acini of SS patients. MUC1/Y localized in acinar nuclei and cytoplasm of inflammatory cells of LSG from SS patients. A strong positive correlation was observed between cellular MUC1/SEC levels and glandular function determined by scintigraphy.

CONCLUSIONS

We show for the first time that MUC1/SEC and MUC1/Y are expressed in LSG of both SS patients and non-SS sicca subjects. The observed overexpression and aberrant localization of MUC1/SEC and MUC1/Y and their induction by pro-inflammatory cytokines may favor the perpetuation of the inflammatory environment that disrupts the salivary glandular homeostasis in SS patients.

Severe alterations in expression and localisation of {alpha}6{beta}4 integrin in salivary gland acini from patients with Sjogren syndrome

OBJECTIVES

In salivary glands from patients with Sjögren syndrome, overexpression of laminins 1 and 5 and disorganisation of the acinar basal lamina have been reported. Laminin 5 mediates association of the basal lamina with epithelial cells by forming adhesion complexes upon interaction with alpha6beta4 integrin. In the present work, mRNA and protein levels of alpha6beta4 integrin were determined and its localisation in salivary glands evaluated in patients with Sjögren syndrome.

METHODS

Salivary glands of 12 patients with Sjögren syndrome and 8 controls were studied. The mRNA and protein levels of alpha6beta4 were determined by semiquantitative reverse transcriptase (RT)-PCR and western blot analysis, respectively. The subcellular localisation of alpha6beta4 and laminin were evaluated by confocal microscopy.

RESULTS

In patients, no significant differences in alpha6 and beta4 mRNA levels were detected. However, beta4 integrin protein levels were significantly lower, whereas, changes in alpha6, were highly variable. In controls, alpha6beta4 was detected in the basolateral and basal surface of serous and mucous acini, respectively. In patients, alterations in alpha6beta4 distribution were particularly dramatic for acini with strong basal lamina disorganisation. alpha6beta4 was also detected in the cytoplasm and lateral plasma membrane in serous and mucous acini.

CONCLUSION

Mild alterations in the basal lamina correlated with lateral redistribution of alpha6beta4 integrin and the formation of new cell-cell adhesions that help maintain acinar organisation and promote cell survival. Conversely, in cases with severe basal lamina alterations, lateral alpha6beta4 redistribution was no longer sufficient to maintain acinar cell survival. Thus, maintenance of equilibrium between cell-cell and cell-basal lamina attachment is required to sustain gland cell survival.

Default cycle phases determined after modifying discrete DNA sequences in plant cells

After bromosubstituting DNA sequences replicated in the first, second, or third part of the S phase, in Allium cepa L. meristematic cells, radiation at 313 nm wavelength under anoxia allowed ascription of different sequences to both the positive and negative regulation of some cycle phase transitions. The present report shows that the radiation forced cells in late G1 phase to advance into S, while those in G2 remained in G2 and cells in prophase returned to G2 when both sets of sequences involved in the positive and negative controls were bromosubstituted and later irradiated. In this way, not only G2 but also the S phase behaved as cycle phases where cells accumulated by default when signals of different sign functionally cancelled out. The treatment did not halt the rates of replication or transcription of plant bromosubstituted DNA. The irradiation under hypoxia apparently prevents the binding of regulatory proteins to Br-DNA.

Basal lamina disorganisation of the acini and ducts of labial salivary glands from patients with Sjogren's syndrome: association with mononuclear cell infiltration

OBJECTIVE

To study the expression of laminin and type IV collagen as biomarkers of the organisation of the basal lamina of acini and ducts in labial salivary glands from patients with Sjögren's syndrome, and to relate this organisation to inflammatory cell invasion of acini and ducts.

METHODS

Immunohistochemistry for laminin and type IV collagen was undertaken on sections of labial salivary glands from 30 patients with Sjögren's syndrome, 10 control subjects, and 24 controls with chronic sialoadenitis. Immunohistochemistry reaction, alterations to cell morphology, and the presence of inflammatory cells in acini and ducts were evaluated and scored using a semiquantitative method.

RESULTS

Changes in the expression of laminin and type IV collagen in the basal lamina of acini and ducts of labial salivary glands from patients with Sjögren's syndrome were more pronounced than in labial salivary glands from control groups. A remarkable characteristic was the disorganisation of the basal lamina in the labial salivary glands in Sjögren's syndrome. The pattern of immunoreactivity of the basal lamina of other structures (for example, blood vessels) did not change. In Sjögren's syndrome, invasion of cytotoxic T lymphocytes was only observed in acini and ducts which had a disorganised basal lamina.

CONCLUSIONS

The high state of disorganisation of the basal lamina of acini and ducts could allow invasion of cytotoxic T lymphocytes in Sjögren's syndrome, contributing to cell death and ductal hyperplasia.

Differential expression of matrix metalloproteinases in labial salivary glands of patients with primary Sjögren's syndrome

OBJECTIVE

To determine the enzymatic activity and cellular localization of matrix metalloproteinases (MMPs) 2, 3, and 9 in labial salivary glands from patients with different degrees of severity of primary Sjogren's syndrome (primary SS).

METHODS

Gelatinase activity was determined by zymography and quantified by densitometry. The specificity of MMPs was determined using protease inhibitors and chelators, as well as activators of the latent forms of these enzymes. The cellular localization of MMPs was carried out using monoclonal antibodies that recognize their latent and active forms.

RESULTS

Labial glands from control subjects and patients showed gelatinase activity for MMP-2 and MMP-9. Activation studies revealed that both enzymes were predominantly present in their latent forms. The highest levels of MMP-9 activity were detected in patients with severe, active, primary SS (except for patients with severe clinical symptoms for extended periods) and correlated with structural and functional glandular changes. MMP-2 activity was almost the same in patients and controls. MMPs were detected by immunolocalization only in acinar and ductal cells and were homogeneously distributed throughout patients' glands. MMP-2 and MMP-9 expression paralleled their gelatinase activity. MMP-3, detectable only with immunologic methods, was absent in control subjects but abundantly expressed in patients. Importantly, MMP protein levels in acinar and ductal cells were independent of either the presence or the proximity of mononuclear infiltrate cells.

CONCLUSION

MMP-3 and MMP-9 expression, as well as MMP-9 catalytic activity, were increased in tissue samples from SS patients in a manner that correlated with the severity of the disease. Most important, increased MMP activity stemmed from exocrine epithelial cells and was not due to infiltrating lymphocytes. Thus, changes in salivary glands as a consequence of proteolysis may lead to severe glandular destruction.

Impaired chromosome segregation in plant anaphase after moderate hypomethylation of DNA

10(-6) M and 10(-5) M 5-azacytidine, demethylated around 9% and 17% of the 5-methylcytosine residues found in Allium cepa L. native DNA, respectively. Both treatments stimulated RNA synthesis in the cells of root meristems. On the other hand, the 10(-5) M treatment gave rise to multiple chromosomal anomalies in mitosis before any fall in the mitotic index was detectable, but no chromosomal breaks were ever seen. Serious lesions involved in chromatids and segregation in anaphase were preferentially found after hypomethylation of DNA sequences replicated in the second half of the previous S period: (i) sister telomeres remained unresolved at the cell equator while kinetochores had reached the poles, (ii) whole unsegregated chromosomes were pulled to one of the poles by obviously disfunctional kinetochores, resulting in an unbalanced distribution of chromatids, (iii) unsegregated chromosomes in other cells remained at the spindle equator as if kinetochores were nonfunctional, while cytoplasmic division took place before their migration to the poles. Frequently, a growing cytokinetic plate randomly cut the unsegregated chromosomes, giving rise to aneuploid nuclei. These anaphase failures are a firm basis to explain why the 10(-5) M treatment selectively depressed the rate of cell proliferation in these cells in the long run. On the other hand, if hypomethylation occurred at the first half of the previous S period, enlarged chromosomal segments were evident in most metaphases, while chromosome laggards and bridges were recorded in anaphase at rather similar frequencies after the different 5-azacytidine treatments. These data were consistently obtained both in the native mononucleate cells of meristems and in one subpopulation of synchronous cells labelled as binucleate by 5 mM caffeine.

Mucopolysaccharides in peripheral leucocytes of cancer patients

The presence of mucopolysaccharides (MPS) in leucocytes of peripheral blood of 19 cancer patients, 13 patients with pulmonary tuberculosis and 14 normal controls, was studied histochemically. MPS was revealed in different proportions in polynuclears and mononuclears. According to the staining technics, the MPS appear to be mainly carboxylated and contain hyaluronic acid and chondroitinsulphate groups.The quantitative analysis revealed that MPS appeared only in around 3% of leucocytes of normal controls, while in the cancer patients 56% of polynuclear and 90% of mononuclears contained it. In the tuberculous patients, 90% of polynuclears and 86% of the mononuclears revealed MPS. The differences between the prevalence of leucocytes containing MPS in controls and in cancer or tuberculous patients are highly significant.The possibility that the difference in MPS content of leucocytes is related with low inmunological activity is postulated.