Tissue-Specific Immunopathology in Fatal COVID-19.

Rationale: In life-threatening coronavirus disease (COVID-19), corticosteroids reduce mortality, suggesting that immune responses have a causal role in death. Whether this deleterious inflammation is primarily a direct reaction to the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or an independent immunopathologic process is unknown.Objectives: To determine SARS-CoV-2 organotropism and organ-specific inflammatory responses and the relationships among viral presence, inflammation, and organ injury.Methods: Tissue was acquired from 11 detailed postmortem examinations. SARS-CoV-2 organotropism was mapped by using multiplex PCR and sequencing, with cellular resolution achieved by in situ viral S (spike) protein detection. Histologic evidence of inflammation was quantified from 37 anatomic sites, and the pulmonary immune response was characterized by using multiplex immunofluorescence.Measurements and Main Results: Multiple aberrant immune responses in fatal COVID-19 were found, principally involving the lung and reticuloendothelial system, and these were not clearly topologically associated with the virus. Inflammation and organ dysfunction did not map to the tissue and cellular distribution of SARS-CoV-2 RNA and protein between or within tissues. An arteritis was identified in the lung, which was further characterized as a monocyte/myeloid-rich vasculitis, and occurred together with an influx of macrophage/monocyte-lineage cells into the pulmonary parenchyma. In addition, stereotyped abnormal reticuloendothelial responses, including excessive reactive plasmacytosis and iron-laden macrophages, were present and dissociated from viral presence in lymphoid tissues.Conclusions: Tissue-specific immunopathology occurs in COVID-19, implicating a significant component of the immune-mediated, virus-independent immunopathologic process as a primary mechanism in severe disease. Our data highlight novel immunopathologic mechanisms and validate ongoing and future efforts to therapeutically target aberrant macrophage and plasma-cell responses as well as promote pathogen tolerance in COVID-19.

The metastasis suppressor RARRES3 as an endogenous inhibitor of the immunoproteasome expression in breast cancer cells.

In breast cancer metastasis, the dynamic continuum involving pro- and anti-inflammatory regulators can become compromised. Over 600 genes have been implicated in metastasis to bone, lung or brain but how these genes might contribute to perturbation of immune function is poorly understood. To gain insight, we adopted a gene co-expression network approach that draws on the functional parallels between naturally occurring bone marrow-derived mesenchymal stem cells (BM-MSCs) and cancer stem cells (CSCs). Our network analyses indicate a key role for metastasis suppressor RARRES3, including potential to regulate the immunoproteasome (IP), a specialized proteasome induced under inflammatory conditions. Knockdown of RARRES3 in near-normal mammary epithelial and breast cancer cell lines increases overall transcript and protein levels of the IP subunits, but not of their constitutively expressed counterparts. RARRES3 mRNA expression is controlled by interferon regulatory factor IRF1, an inducer of the IP, and is sensitive to depletion of the retinoid-related receptor RORA that regulates various physiological processes including immunity through modulation of gene expression. Collectively, these findings identify a novel regulatory role for RARRES3 as an endogenous inhibitor of IP expression, and contribute to our evolving understanding of potential pathways underlying breast cancer driven immune modulation.

Palmitoylation: a protein S-acylation with implications for breast cancer.

Protein S-acylation is a reversible post-translational lipid modification that involves linkage of a fatty acid chain predominantly to a cysteine amino acid via a thioester bond. The fatty acid molecule is primarily palmitate, thus the term 'palmitoylation' is more commonly used. Palmitoylation has been found to modulate all stages of protein function including maturational processing, trafficking, membrane anchoring, signaling range and efficacy, and degradation. In breast cancer, palmitoylation has been shown to control the function of commonly dysregulated genes including estrogen receptors, the epidermal growth factor (EGF) family of receptors, and cancer stem cell markers. Importantly, palmitoylation is a critical factor controlling the formation of complexes at the plasma membrane involving tetraspanins, integrins, and gene products that are key to cell-cell communication. During metastasis, cancer cells enhance their metastatic capacity by interacting with stroma and immune cells. Although aberrant palmitoylation could contribute to tumor initiation and growth, its potential role in these cell-cell interactions is of particular interest, as it may provide mechanistic insight into metastasis, including cancer cell-driven immune modulation. Compelling evidence for a role for aberrant palmitoylation in breast cancer remains to be established. To this end, in this review we summarize emerging evidence and highlight pertinent knowledge gaps, suggesting directions for future research.

Coexpression of nuclear receptors and histone methylation modifying genes in the testis: implications for endocrine disruptor modes of action.

BACKGROUND: Endocrine disruptor chemicals elicit adverse health effects by perturbing nuclear receptor signalling systems. It has been speculated that these compounds may also perturb epigenetic mechanisms and thus contribute to the early origin of adult onset disease. We hypothesised that histone methylation may be a component of the epigenome that is susceptible to perturbation. We used coexpression analysis of publicly available data to investigate the combinatorial actions of nuclear receptors and genes involved in histone methylation in normal testis and when faced with endocrine disruptor compounds. METHODOLOGY/PRINCIPAL FINDINGS: The expression patterns of a set of genes were profiled across testis tissue in human, rat and mouse, plus control and exposed samples from four toxicity experiments in the rat. Our results indicate that histone methylation events are a more general component of nuclear receptor mediated transcriptional regulation in the testis than previously appreciated. Coexpression patterns support the role of a gatekeeper mechanism involving the histone methylation modifiers Kdm1, Prdm2, and Ehmt1 and indicate that this mechanism is a common determinant of transcriptional integrity for genes critical to diverse physiological endpoints relevant to endocrine disruption. Coexpression patterns following exposure to vinclozolin and dibutyl phthalate suggest that coactivity of the demethylase Kdm1 in particular warrants further investigation in relation to endocrine disruptor mode of action. CONCLUSIONS/SIGNIFICANCE: This study provides proof of concept that a bioinformatics approach that profiles genes related to a specific hypothesis across multiple biological settings can provide powerful insight into coregulatory activity that would be difficult to discern at an individual experiment level or by traditional differential expression analysis methods.

Feeding experiences and growth status in a Rett syndrome population.

OBJECTIVES: Feeding difficulties in Rett syndrome are complex and multifactorial. In this study, we describe the feeding experiences in Rett syndrome and examine the factors affecting growth. MATERIALS AND METHODS: Using questionnaire data related to a population-based cohort, ages 2 to 29 years (n = 201), we measured the feeding experiences, growth, and factors affecting growth (enteral nutritional support, mutations, mobility, breath-holding, hyperventilation) in subjects with Rett syndrome. RESULTS: The mean weight, height, and body mass index z scores in subjects with Rett syndrome were below that of their age group and decreased steadily with age. Twenty percent of subjects had enteral nutrition support, and it was more common in the older age group. Those with truncating mutations had significantly less enteral nutrition support than the other mutation groups. Furthermore, those with low mobility had lower mean body mass index z scores than those with higher mobility, and increased frequency of breath-holding and hyperventilation also was associated with lower body mass index z scores. CONCLUSIONS: Routine monitoring of growth should continue to determine the severity of nutritional problems in Rett syndrome. Active nutritional management is recommended to ensure females affected with Rett syndrome have the best opportunity to reach their growth potential.

The Participation Scale: measuring a key concept in public health.

PURPOSE: To develop a scale to measure (social) participation for use in rehabilitation, stigma reduction and social integration programmes. METHOD: A scale development study was carried out in Nepal, India and Brazil using standard methods. The instrument was to be based on the Participation domains of the International Classification of Functioning, Disability and Health (ICF), be cross-cultural in nature and assess client-perceived participation. Respondents rated their participation in comparison with a "peer", defined as "someone similar to the respondent in all respects except for the disease or disability". RESULTS: An 18-item instrument was developed in seven languages. Crohnbach's alpha was 0.92, intra-tester stability 0.83 and inter-tester reliability 0.80. Discrimination between controls and clients was good at a Participation Score threshold of 12. Responsiveness after a "life change" was according to expectation. CONCLUSIONS: The Participation Scale is reliable and valid to measure client-perceived participation in people affected by leprosy or disability. It is expected to be valid in other (stigmatised) conditions also, but this needs confirmation. The scale allows collection of participation data and impact assessment of interventions to improve social participation. Such data may be compared between clients, interventions and programmes. The scale is suitable for use in institutions, but also at the peripheral level.

Steroid prophylaxis for prevention of nerve function impairment in leprosy: randomised placebo controlled trial (TRIPOD 1).

OBJECTIVE: To determine whether addition of low dose prednisolone to multidrug treatment can prevent reaction and nerve function impairment in leprosy. DESIGN: Multicentre, double blind, randomised, placebo controlled, parallel group trial. SETTING: Six centres in Bangladesh and Nepal. PARTICIPANTS: 636 people with newly diagnosed multibacillary leprosy. INTERVENTION: Prednisolone 20 mg/day for three months, with tapering dose in month 4, plus multidrug treatment, compared with multidrug treatment alone. MAIN OUTCOME MEASURES: Signs of reaction, impairment of sensory and motor nerve function, and nerve tenderness needing full dose prednisolone at four months and one year. RESULTS: Prednisolone had a significant effect in the prevention of reaction and nerve function impairment at four months (relative risk 3.9, 95% confidence interval 2.1 to 7.3), but this was not maintained at one year (relative risk 1.3, 0.9 to 1.8). Fewer events occurred in the prednisolone group at all time points up to 12 months, but the difference at 12 months was small. Subgroup analysis showed a difference in response between people with and without impairment of nerve function at diagnosis. CONCLUSIONS: The use of low dose prophylactic prednisolone during the first four months of multidrug treatment for leprosy reduces the incidence of new reactions and nerve function impairment in the short term, but the effect is not sustained at one year. The presence of nerve function impairment at diagnosis may influence the response to low dose prednisolone.

The prognostic importance of detecting mild sensory impairment in leprosy: a randomized controlled trial (TRIPOD 2).

This study was designed to investigate whether leprosy patients diagnosed with mild sensory impairment have a better prognosis when treated with steroids than similarly impaired patients treated with placebo. A multi-centre, randomized, double-blind, placebo-controlled trial was conducted in Nepal and Bangladesh. Patients were eligible if they had a confirmed leprosy diagnosis, were between 15 and 50 years old, had mild sensory impairment of the ulnar or posterior tibial nerve of less than 6 months duration and did not require steroids for other reasons. 'Mild impairment' was defined as 'impaired on the Semmes-Weinstein monofilament test, but testing normal on the ballpen sensory test'. Subjects were randomized to either prednisolone treatment starting at 40 mg per day, tapering over 4 months, or placebo. Nerve function was monitored monthly. Any patient who deteriorated was taken out of the trial and was put on full-dose steroid treatment. Outcome assessment was done at 4, 6, 9 and 12 months from the start of the treatment. Outcome measures were the proportion of patients needing full-dose prednisolone and the Semmes-Weinstein sum scores. Each patient contributed only one nerve to the analysis. Seventy-five patients had nerves eligible for analysis, of whom 41 (55%) and 34 (45%) were allocated to the prednisolone and placebo arms, respectively. At 4 months, three patients in the prednisolone arm (7%) and six in the placebo arm (18%) had an outcome event requiring full dose steroids. At 12 months, these proportions had almost reversed, 11 (27%) and 6 (18%) in the treatment and placebo arms, respectively. In the latter group, 75% had recovered spontaneously after 12 months. Prednisolone treatment of sensory impairment of the ulnar and posterior tibial nerves detectable with the monofilament test, but not with the ballpen test, did not improve the long-term outcome in terms of recovery of touch sensibility, not did it reduce the risk of leprosy reactions or nerve function impairment beyond the initial 4-month treatment phase. Two unexpected main findings were the strong tendency of mild sensory impairment to recover spontaneously and the fact that patients with mild sensory impairment without any other signs or symptoms of reaction or nerve function impairment are relatively rare.

Treatment with corticosteroids of long-standing nerve function impairment in leprosy: a randomized controlled trial (TRIPOD 3).

Some leprosy patients with long-standing nerve function impairment (NFI) appear to have responded favourably to treatment with corticosteroids. This study investigated whether patients with untreated NFI between 6 and 24 months duration and who are given standard regimen corticosteroid therapy, will have a better treatment outcome than a placebo group. A multicentre, randomized, double-blind placebo-controlled trial was conducted in Nepal and Bangladesh. Subjects were randomised to either prednisolone treatment starting at 40 mg/day, tapered by 5 mg every 2 weeks, and completed after 16 weeks, or placebo. Outcome assessments were at 4, 6, 9, and 12 months from the start of treatment. 92 MB patients on MDT were recruited, of whom 40 (45%) received prednisolone and 52 (55%) placebo treatment. No demonstrable additional improvement in nerve function, or in preventing further leprosy reaction events was seen in the prednisolone group. Overall, improvement of nerve function at 12 months was seen in about 50% of patients in both groups. Analysis of subgroups according to nerve (ulnar and posterior tibial), duration of NFI, and sensory and motor function, also did not reveal any differences between the treatment and placebo groups. There was however, indication of less deterioration of nerve function in the prednisolone group. Finally, there was no difference in the occurrence of adverse events between both groups. The trial confirms current practice not to treat long-standing NFI with prednisolone. Spontaneous recovery of nerve function appears to be a common phenomenon in leprosy. Leprosy reactions and new NFI occurred in a third of the study group, emphasizing the need to keep patients under regular surveillance during MDT, and, where possible, after completion of MDT.

Adverse events of standardized regimens of corticosteroids for prophylaxis and treatment of nerve function impairment in leprosy: results from the 'TRIPOD' trials.

Reactions in leprosy causing nerve function impairment (NFI) are increasingly treated with standardized regimens of corticosteroids, often under field conditions. Safety concerns led to an assessment of adverse events of corticosteroids, based on data of three trials studying prevention of NFI (the TRIPOD study). A multicentre, randomized, double-blind placebo-controlled trial was conducted in leprosy control programmes in Nepal and Bangladesh. Treatment was with prednisolone according to fixed schedules for 16 weeks, starting in one trial with 20 mg/day (prophylactic regimen: total dosage 1.96 g) and in the other two trials with 40 mg/day (therapeutic regimen: total dosage 2.52 g). Minor adverse events were defined as moon face, fungal infections, acne, and gastric pain requiring antacid. Major adverse events were defined as psychosis, peptic ulcer, glaucoma, cataract, diabetes and hypertension. Also, the occurrence of infected plantar, palmar, and corneal ulceration was monitored, together with occurrence of TB. Considering all three trials together, minor adverse events were observed in 130/815 patients (16%). Of these, 51/414 (12%) were in the placebo group and 79/401 (20%) in the prednisolone group. The relative risk for minor adverse events in the prednisolone group was 1.6 (P = 0.004). Adverse events with a significantly increased risk were acne, fungal infections and gastric pain. Major adverse events were observed in 15/815 patients (2%); 7/414 (2%) in the placebo group and 8/401 (2%) in the prednisolone group. No major adverse events had a significantly increased risk in the prednisolone arm of the trials. No cases of TB were observed in 300 patients who could be followed-up for 24 months. Standardized regimens of corticosteroids for both prophylaxis and treatment of reactions and NFI in leprosy under field conditions in developing countries are safe when a standard pre-treatment examination is performed, treatment for minor conditions can be carried out by field staff, referral for specialized medical care is possible, and sufficient follow-up is done during and after treatment.