Hospital Outcomes in Patients Hospitalized for COVID-19 Pneumonia: The Effect of SARS-CoV-2 Vaccination and Vitamin D Status

SARS-CoV-2 vaccination promises to improve outcomes for patients with COVID-19 pneumonia (most notably those with advanced age and at high risk for severe disease). Here, we examine serum 25-Hydroxyvitamin D (25(OH)D) status and outcomes in both old (>70 years) and young vaccinated (n = 80) and unvaccinated (n = 91) subjects, who were hospitalized due to COVID-19 pneumonia in a single center (Connolly Hospital Dublin). Outcomes included ICU admission and mortality. Serum 25(OH)D levels were categorized as D30 (<30 nmol/L), D40 (30-49.99 nmol/L) and D50 (≥50 nmol/L). In multivariate analyses, D30 was independently associated with ICU admission (OR: 6.87 (95% CI: 1.13-41.85) (p = 0.036)) and mortality (OR: 24.81 (95% CI: 1.57-392.1) (p = 0.023)) in unvaccinated patients, even after adjustment for major confounders including age, sex, obesity and pre-existing diabetes mellitus. While mortality was consistently higher in all categories of patients over 70 years of age, the highest observed mortality rate of 50%, seen in patients over 70 years with a low vitamin D state (D30), appeared to be almost completely corrected by either vaccination, or having a higher vitamin D state, i.e., mortality was 14% for vaccinated patients over 70 years with D30 and 16% for unvaccinated patients over 70 years with a 25(OH)D level greater than 30 nmol/L. We observe that high mortality from COVID-19 pneumonia occurs in older patients, especially those who are unvaccinated or have a low vitamin D state. Recent vaccination or having a high vitamin D status are both associated with reduced mortality, although these effects do not fully mitigate the mortality risk associated with advanced age.

Vitamin D Status and Mortality from SARS CoV-2: A Prospective Study of Unvaccinated Caucasian Adults

COVID-19 and a low vitamin D state share common risk factors, which might explain why vitamin D deficiency has been linked with higher COVID-19 mortality. Moreover, measures of serum vitamin D may become lower during systemic inflammatory responses, further confounding the association via reverse causality. In this prospective study (recruited over 12 months), we examined whether the association between a low vitamin D state and in-hospital mortality due to SARS-CoV-2 pneumonia in unvaccinated subjects is explained by (i) the presence of shared risk factors (e.g., obesity, advanced age) or (ii) a reduction in serum 25(OH)D due to COVID-19 (i.e., reverse causality). In this cohort of 232 (mean age = 56 years) patients (all had SARS-CoV-2 diagnosed via PCR AND required supplemental oxygen therapy), we failed to find an association between serum vitamin D and levels of CRP, or other inflammatory markers. However, the hazard ratio for mortality for subjects over 70 years of age (13.2) and for subjects with a serum 25(OH)D level less than 30 nmol·L−1 (4.6) remained significantly elevated even after adjustment for gender, obesity and the presence of diabetes mellitus. Subjects <70 years and >70 years had significantly higher mortality with a serum 25(OH)D less than 30 nmol·L−1 (11.8% and 55%), than with a serum 25(OH)D greater than 30 nmol·L−1 (2.2% and 25%). Unvaccinated Caucasian adults with a low vitamin D state have higher mortality due to SARS CoV-2 pneumonia, which is not explained by confounders and is not closely linked with elevated serum CRP.

Title: Understanding a Low Vitamin D State in the Context of COVID-19

While a low vitamin D state has been associated with an increased risk of infection by SARS-CoV-2 in addition to an increased severity of COVID-19 disease, a causal role is not yet established. Here, we review the evidence relating to i) vitamin D and its role in SARS-CoV-2 infection and COVID-19 disease ii) the vitamin D status in the Irish adult population iii) the use of supplemental vitamin D to treat a deficient status and iv) the application of the Bradford-Hill causation criteria. We conclude that reverse causality probably makes a minimal contribution to the presence of low vitamin D states in the setting of COVID-19. Applying the Bradford-Hill criteria, however, the collective literature supports a causal association between low vitamin D status, SARS-CoV-2 infection, and severe COVID-19 (respiratory failure, requirement for ventilation and mortality). A biologically plausible rationale exists for these findings, given vitamin D's role in immune regulation. The thresholds which define low, deficient, and replete vitamin D states vary according to the disease studied, underscoring the complexities for determining the goals for supplementation. All are currently unknown in the setting of COVID-19. The design of vitamin D randomised controlled trials is notoriously problematic and these trials commonly fail for a number of behavioural and methodological reasons. In Ireland, as in most other countries, low vitamin D status is common in older adults, adults in institutions, and with obesity, dark skin, low UVB exposure, diabetes and low socio-economic status. Physiological vitamin D levels for optimal immune function are considerably higher than those that can be achieved from food and sunlight exposure alone in Ireland. A window exists in which a significant number of adults could benefit from vitamin D supplementation, not least because of recent data demonstrating an association between vitamin D status and COVID-19. During the COVID pandemic, we believe that supplementation with 20-25ug (800-1000 IU)/day or more may be required for adults with apparently normal immune systems to improve immunity against SARS-CoV-2. We expect that higher monitored doses of 37.5-50 ug (1,500-2,000)/day may be needed for vulnerable groups (e.g., those with obesity, darker skin, diabetes mellitus and older adults). Such doses are within the safe daily intakes cited by international advisory agencies.

An arteriovenous fistula increases exercise capacity in patients with COPD

BACKGROUND

Supplemental oxygen usually increases exercise capacity in hypoxemic COPD, but some patients are refractory because of venous admixture. An arteriovenous fistula (AVF) with left-to-right shunt increases mixed venous oxygen content and cardiac output; therefore, this might improve arterial oxygen delivery. We hypothesized that creation of an AVF would therefore increase exercise capacity in severe COPD.

METHODS

We created an AVF in 12 patients with severe hypoxemic COPD: mean (SD) age, 66 (6) years; Pao(2), 57.5 (3.0) mm Hg, and FEV(1), 19% (8%) predicted. We measured 6-min walk distance (6MWD) while the subjects were breathing room air and again while they were breathing portable supplemental oxygen at baseline, 6 weeks, and 12 weeks after creation of an AVF in the iliofemoral region.

RESULTS

After surgery, the mean (SEM) 6MWD increased from 217 (63) m at baseline to 272 (18) m and 276 (25) m, 6 weeks and 12 weeks after surgery, respectively. Patients who walked > 54 m further while breathing supplemental oxygen at baseline (n = 5) increased 6MWD while breathing room air by 129 (34) m after 6 weeks (P = .02) and by 124 (29) m after 12 weeks (P = .004). Walking distance did not change in patients who did not have a clinically meaningful response to oxygen at baseline.

CONCLUSIONS

An iliofemoral AVF increased 6MWD patients with severe COPD, matching the improvement seen with supplemental oxygen. An initial response to supplemental oxygen predicted a therapeutic response to the AVF.

The effect of an inhaled corticosteroid on glucose control in type 2 diabetes

OBJECTIVE

To determine the effect of inhaled corticosteroid (ICS) therapy on glucose control in adults with type 2 diabetes mellitus and coexisting asthma or chronic obstructive pulmonary disease (COPD).

DESIGN

A prospective randomized, double-blind, double-dummy placebo-controlled, crossover investigation of inhaled steroids and oral leukotriene blockers.

SETTING

A United States Department of Veterans Affairs Health Care System outpatient setting.

PARTICIPANTS

Adults with type 2 diabetes and asthma or COPD.

METHODS

Subjects (n=12) were randomized to receive either inhaled fluticasone propionate (440 microg twice daily) and oral placebo, or inhaled placebo and oral montelukast (10 mg/day). After 6 weeks, subjects were switched to the opposite therapy for 6 weeks. The primary outcome measure was the change in the percentage of glycosylated hemoglobin (%HbA1c) at 6 weeks relative to the baseline value.

RESULTS

Ten patients completed the study. The difference between the mean within-subject changes in %HbA1c associated with 6-week periods of fluticasone and the mean changes associated with montelukast therapy was small but statistically significant (mean difference=0.25; P<0.025). Neither fluticasone nor oral montelukast therapy for 6 weeks led to a significantly different mean % HbA1c compared with the relevant baseline (mean differences=0.11 and -0.14, respectively).

CONCLUSION

The absence of a clinically significant within-subject difference in the changes in %HbA1c associated with fluticasone versus oral montelukast therapy, or between either therapy or baseline does not warrant recommending changes in therapy for asthma or diabetes in patients with these co-morbid conditions. However, we suggest that clinicians carefully monitor blood glucose control when diabetic patients initiate ICS, especially with higher dosages.

Current therapies for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease of the pulmonary vasculature, characterized by relentless deterioration and death. Patients with PAH are known to be at increased risk for anesthetic complications and surgical morbidity and mortality. However, outcomes in patients have improved with the recent development of new drug therapies. The 3 major drug classes for treatment of PAH are prostanoids, endothelin-receptor antagonists, and phosphodiesterase-5 inhibitors. In this review, the authors provide an overview of each drug class, its mechanism of action, indications, and current supportive literature. Surgical and interventional treatments of PAH, including atrial septostomy, pulmonary thromboendarterectomy, and transplantation, are briefly reviewed, and the rationale, indications, and selection criteria for each are discussed. Although available medical and surgical therapies for PAH have improved patient outcomes, acute decompensated right heart failure (RHF) remains a common and challenging complication of PAH. The authors review this topic and provide an outline of the general pathophysiology of RHF and an approach to its management.

CD4+ invariant T-cell-receptor+ natural killer T cells in bronchial asthma

BACKGROUND

Bronchial asthma is associated with an inflammatory process that is characterized by the presence in the airways of large numbers of CD4+ T cells producing interleukin-4 and interleukin-13. However, the CD4 antigen is expressed not only by class II major histocompatibility complex (MHC)-restricted CD4+ T cells, but also by a newly identified subgroup of T cells, CD1d-restricted natural killer T cells. These cells express a conserved (invariant) T-cell receptor and have a potent immunoregulatory function. Because mouse models of allergic asthma indicate that natural killer T cells are required for the development of allergen-induced airway hyperreactivity, we hypothesized that natural killer T cells play an important role in human asthma.

METHODS

We used CD1d-tetramers, antibodies specific for natural killer T cells, as well as reverse-transcriptase-polymerase-chain-reaction analysis of the invariant T-cell receptor of natural killer T cells to assess the frequency and distribution of natural killer T cells in the lungs and in the circulating blood of 14 patients with asthma.

RESULTS

About 60 percent of the pulmonary CD4+CD3+ cells in patients with moderate-to-severe persistent asthma were not class II MHC-restricted CD4+ T cells but, rather, natural killer T cells. The natural killer T cells expressed an invariant T-cell receptor and produced type 2 helper cytokines. In contrast, the CD4+ T cells found in the lungs of patients with sarcoidosis were conventional CD4+CD3+ T cells, not natural killer T cells.

CONCLUSIONS

Together with studies in mice indicating a requirement for natural killer T cells in the development of allergen-induced airway hyperreactivity, our results strongly suggest that CD4+ natural killer T cells play a prominent pathogenic role in human asthma.

Transcutaneous Electrical Nerve Stimulation for Severe Gastroparesis After Lung Transplantation

Gastroparesis is a serious complication of lung transplantation that can lead to weight loss, gastroesophageal reflux disease, and recurrent aspiration pneumonia. We present 2 lung allograft recipients in whom gastroparesis resolved with the use of transcutaneous electrical nerve stimulation (TENS). In both patients, severe symptoms of gastroparesis refractory to medical therapy were completely ablated after 20 and 30 days of therapy. Both patients are currently asymptomatic with a normal diet, without the use of promotility agents. Lung transplant recipients with severe gastroparesis can derive significant benefit from TENS.

Lymphocytic Myocarditis After Lung Transplantation

This study reports the development of lymphocytic myocarditis in a bilateral lung allograft recipient. A 23-year-old woman developed congestive heart failure and severe left ventricular dysfunction 32 months after a bilateral lung allograft for cystic fibrosis. She had taken oral acyclovir for infectious mononucleosis that was diagnosed 11 months previously. Her viral load for Epstein-Barr virus (EBV) increased, and an echocardiogram revealed a left ventricular ejection fraction of 25% and endomyocardial biopsy revealed lymphocytic myocarditis. She received valacyclovir (1 g x 3 times daily) and made a full recovery 6 months later.

Thoracic lymphatic disorders

Thoracic complications of lymphatic disorders can culminate in respiratory failure and death and should be considered in any patient with a lymphatic disease and clinical or radiographic evidence of chest disease. Congenital lymphatic disorders are being increasingly recognized in the adult population. The spectrum of thoracic manifestations of lymphatic disorders ranges from incidental radiographic findings to diffuse lymphatic disease with respiratory failure. This article serves to review some recent advances that allow improved diagnosis and management of thoracic lymphatic disorders. Herein, we describe their anatomical and physiologic effects, the time course of their progression, and the therapies that are currently available. The management of malignant (cancerous) lymphatic disorders of the thorax is beyond the scope of this paper.

Chylothorax after heart/lung transplantation

Chylothorax is a potentially serious complication of lung and heart-lung transplantation. This article describes the clinical course of chylothorax in 3 heart-lung allograft recipients. We discuss management options, including dietary modifications, octreotide infusion, thoracic duct ligation and embolization, and surgical pleurodesis. In addition, we describe the novel use of aminocaproic acid to reduce lymph flow. We propose a multidisciplinary approach for the management of chylothorax that includes both medical and surgical options.

Gastric pacing for severe gastroparesis in a heart-lung transplant recipient

Gastroparesis is a serious complication of lung and heart-lung transplantation that can lead to malnutrition, gastroesophageal reflux, aspiration pneumonia and deteriorating lung function. Some patients with severe gastroparesis have symptoms that are refractory to dietary modifications and gastric promotility agents and require surgery. We describe the successful use of gastric pacing for the management of intractable gastroparesis, malnutrition and recurrent aspiration in a heart-lung allograft recipient. Lung transplant recipients with severe gastroparesis may benefit from gastric pacing.

Longitudinal transcriptional analysis of developing neointimal vascular occlusion and pulmonary hypertension in rats

Pneumonectomized rats injected with the alkaloid toxin, monocrotaline, develop progressive neointimal pulmonary vascular obliteration and pulmonary hypertension resulting in right ventricular failure and death. The antiproliferative immunosuppressant, triptolide, attenuates neointimal formation and pulmonary hypertension in this disease model (Faul JL, Nishimura T, Berry GJ, Benson GV, Pearl RG, and Kao PN. Am J Respir Crit Care Med 162: 2252–2258, 2000). Pneumonectomized rats, injected with monocrotaline on day 7, were killed at days 14, 21, 28, and 35 for measurements of physiology and gene expression patterns. These data were compared with pneumonectomized, monocrotaline-injected animals that received triptolide from day 5 to day 35. The hypothesis was tested that a group of functionally related genes would be significantly coexpressed during the development of disease and downregulated in response to treatment. Transcriptional analysis using total lung RNA was performed on replicate animals for each experimental time point with exploratory data analysis followed by statistical significance analysis. Marked, statistically significant increases in proteases (particularly derived from mast cells) were noted that parallel the development of vascular obliteration and pulmonary hypertension. Mast-cell-derived proteases may play a role in regulating the development of neointimal pulmonary vascular occlusion and pulmonary hypertension in response to injury.

Simvastatin rescues rats from fatal pulmonary hypertension by inducing apoptosis of neointimal smooth muscle cells

BACKGROUND

Pulmonary vascular injury by toxins can induce neointimal formation, pulmonary arterial hypertension (PAH), right ventricular failure, and death. We showed previously that simvastatin attenuates smooth muscle neointimal proliferation and pulmonary hypertension in pneumonectomized rats injected with the alkaloid toxin monocrotaline. The present study was undertaken to investigate the efficacy of simvastatin and its mechanism of reversing established neointimal vascular occlusion and pulmonary hypertension.

METHODS AND RESULTS

Pneumonectomized rats injected with monocrotaline at 4 weeks demonstrated severe PAH at 11 weeks (mean pulmonary artery pressure [mPAP]=42 versus 17 mm Hg in normal rats) and death by 15 weeks. When rats with severe PAH received simvastatin (2 mg x kg(-1) x d(-1) by gavage) from week 11, there was 100% survival and reversal of PAH after 2 weeks (mPAP=36 mm Hg) and 6 weeks (mPAP=24 mm Hg) of therapy. Simvastatin treatment reduced right ventricular hypertrophy and reduced proliferation and increased apoptosis of pathological smooth muscle cells in the neointima and medial walls of pulmonary arteries. Longitudinal transcriptional profiling revealed that simvastatin downregulated the inflammatory genes fos, jun, and tumor necrosis factor-alpha and upregulated the cell cycle inhibitor p27Kip1, endothelial nitric oxide synthase, and bone morphogenetic protein receptor type 1a.

CONCLUSIONS

Simvastatin reverses pulmonary arterial neointimal formation and PAH after toxic injury.

Effect of a surgical aortocaval fistula on monocrotaline-induced pulmonary hypertension

OBJECTIVE

Increased pulmonary blood flow is believed to contribute to the development of pulmonary hypertension. We investigated the effect of overcirculation via an aortocaval fistula, on the development of monocrotaline-induced pulmonary hypertension in rats. Monocrotaline was administered 1 wk after the creation of an aortocaval fistula.

DESIGN

Randomized, controlled study.

SETTING

Research laboratory of an academic institution.

SUBJECTS

Male Sprague-Dawley rats.

INTERVENTIONS

Overcirculation was induced by pneumonectomy and by surgical creation of aortocaval fistula. Pulmonary artery hypertension was induced by administration of monocrotaline.

MEASUREMENTS AND MAIN RESULTS

Aortic blood flow, Pao(2), and pulmonary arterial pressure were measured 4 wks later. A blinded investigator quantified pulmonary arterial neointimal formation in small pulmonary arteries. Compared with animals that received monocrotaline and/or underwent pneumonectomy but did not undergo aortocaval fistula, the presence of a surgical aortocaval fistula was associated with increased aortic blood flow (p <.001), increased Pao(2) (p <.001), and lower mean pulmonary arterial pressure (p <.001). In addition, rats with aortocaval fistula had less pulmonary arterial neointimal formation than matched animals without an aortocaval fistula (p =.034).

CONCLUSIONS

The presence of a surgical aortocaval fistula attenuates, rather than worsens, the development of monocrotaline-induced pulmonary hypertension in rats.

Simvastatin attenuates smooth muscle neointimal proliferation and pulmonary hypertension in rats

Hypertensive pulmonary vascular disease is characterized by abnormal proliferation of vascular endothelial and smooth muscle cells, leading to occlusion of pulmonary arterioles, pulmonary hypertension, right ventricular failure, and death. Compounds with antiproliferative effects on vascular endothelial and smooth muscle cells, such as 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, may prevent the development of experimental hypertensive pulmonary vascular disease. Pneumonectomized rats injected with monocrotaline at 7 days develop severe hypertensive pulmonary vascular disease with neointimal formation. Rats were randomized to receive either vehicle or treatment with the HMG-CoA reductase inhibitor simvastatin (2 mg/kg per day). By Day 35, rats that received vehicle had higher mean pulmonary arterial pressures (53 +/- 2 mm Hg) and right ventricular hypertrophy (right ventricle/[left ventricle plus septum] [RV/LV+S] = 0.78 +/- 0.09) than rats in Group PMS5-35 that received simvastatin from Day 5 to 35 (mean pulmonary arterial pressure = 27 +/- 3 mm Hg, RV/LV+S = 0.34 +/- 0.08; p < or = 0.001). Pulmonary vascular remodeling with neointimal formation consisting of vascular smooth muscle cells was more severe in vehicle-treated rats (vascular occlusion score, 1.98 +/- 0.02) than in Group PMS5-35 (vascular occlusion score, 0.59 +/- 0.46; p < 0.001). In addition, lung endothelial nitric oxide synthase gene expression was decreased in vehicle-treated animals but was restored toward normal levels in simvastatin-treated animals. Simvastatin attenuates monocrotaline-induced pulmonary vascular remodeling with neointimal formation, pulmonary arterial hypertension, and right ventricular hypertrophy in rats.

High prevalence of autoimmune thyroid disease in pulmonary arterial hypertension

STUDY OBJECTIVES

An association between thyroid disease and pulmonary arterial hypertension (PAH) has been reported, yet the pathogenetic relationship between these conditions remains unclear. Because immune system dysfunction may underlie this association, we sought to determine the prevalence of autoimmune thyroid disease (AITD) in patients with PAH.

DESIGN AND SETTING

Prospective observational study at a single academic institution.

PATIENTS

Sixty-three consecutive adults with PAH (ie, sustained pulmonary artery systolic pressure, > 25 mm Hg) were evaluated for clinical, biochemical, and serologic features of AITD.

MEASUREMENTS

Thyroid gland dysfunction was determined by clinical examination for goiter, and by biochemical measurements of thyrotropin and free thyroxine. Immune system dysfunction was determined by serologic measurements of antibodies to thyroglobulin and thyroid peroxidase. First-degree family history of AITD also was ascertained in order to investigate for genetic clustering of autoimmunity.

RESULTS

Thirty-one patients (49%; 95% confidence interval [CI], 37 to 62%) received diagnoses of AITD. Eighteen patients were newly diagnosed, and 9 patients required the initiation of pharmacologic treatment. There was no chronologic relationship between the diagnosis or treatment of PAH and that of AITD. Sixteen patients (25%; 95% CI, 15 to 36%) had 24 first-degree family members with AITD.

CONCLUSIONS

Approximately half of the patients with PAH have concomitant AITD. These two conditions may be linked by a common immunogenetic susceptibility, and the elucidation of this association may advance the understanding of the pathophysiology and treatment of PAH. Systematic surveillance for occult thyroid dysfunction in patients with PAH may prevent the hemodynamic exacerbation of right heart failure.

Alterations in airway inflammation and lung function during corticosteroid therapy for atopic asthma

INTRODUCTION

Although corticosteroid therapy for asthma improves lung function and reduces airway inflammation, the relation between these two events is unclear. This article investigates associations between changes in bronchial inflammation and lung function during high-dose inhaled corticosteroid therapy for asthma.

METHODS

Nine subjects with atopic asthma received high-dose inhaled fluticasone propionate (FP), 2,000 microg/d for 8 weeks. Fiberoptic bronchoscopy with endobronchial biopsies, spirometry, and histamine provocation challenge were performed on each subject at baseline, after 2 weeks, and again after 8 weeks of therapy. Spearman rank correlation coefficients between changes in parameters of bronchial inflammation and lung function were computed.

RESULTS

As expected, significant down-regulation of airway inflammation and improvements in lung function were observed after both short-term and long-term therapy with high-dose inhaled FP. During corticosteroid therapy, changes in lymphocyte and macrophage numbers in bronchial biopsy specimens were closely correlated. Changes in EG1+ eosinophils were associated with changes in EG2+ eosinophils after 8 weeks of therapy. Although changes in airway inflammation and changes in lung function were not closely associated after 2 weeks of therapy, changes in eosinophils (EG1) in bronchial biopsy specimens correlated with changes in bronchodilator response (r = 0.77, p = 0.016) after 8 weeks of therapy.

CONCLUSION

In patients with atopic asthma, changes in bronchial eosinophils and lung function during steroid therapy are closely related but do not occur simultaneously.

Sleep-disordered breathing and hypotension

We investigated the presence of low blood pressure (BP) in 4,409 subjects referred for overnight polysomnography. A low resting arterial BP (systolic BP < 105 mm Hg, diastolic BP < 65 mm Hg) was present in 101 subjects (2.3%). Low BP was more prevalent in subjects with upper airway resistance syndrome (UARS) (23%) than in subjects with obstructive sleep apnea syndrome (OSAS) (0.06%), parasomnia (0.7%), restless leg syndrome (0.9%), or psychological insomnia (0.9%). In order to investigate BP homeostasis, we conducted polysomnography followed by tilt-table testing on 15 subjects with orthostatic intolerance (OI) and UARS, five normotensive subjects with UARS, five subjects with insomnia and low BP, 15 subjects with OSAS, and 15 healthy control subjects. Fifteen subjects with UARS and OI and 15 healthy controls also underwent 24-h ambulatory BP monitoring. Subjects with OI and UARS had lower mean daytime systolic (119 +/- 28 mm Hg) and diastolic (75 +/- 18 mm Hg) BP than did control subjects (131 +/- 35 mm Hg and 86 +/- 19 mm Hg, respectively) (p < 0.05). During tilt-table testing, subjects with UARS and a history of OI had a greater decrease in systolic BP (27 +/- 3 mm Hg) than did control subjects (7.5 +/- 1.6 mm Hg), subjects with OSAS (6.8 +/- 1.2 mm Hg), normotensive subjects with UARS (7.2 +/- 0.84 mm Hg), or hypotensive insomniacs (7.4 +/- 1.1 mm Hg) (p < 0.01). We conclude that approximately one fifth of subjects with UARS have low BP and complain of OI. Tilt-table testing may be indicated to confirm orthostatic intolerance in subjects with UARS.

Activated, cytotoxic CD8(+) T lymphocytes contribute to the pathology of asthma death

This study investigates the presence of CD8(+) T lymphocytes and their possible association with viral infection in bronchi of victims of fatal asthma. Postmortem samples from the peribronchial region of the lung were obtained from seven patients who died an asthma death (AD), seven asthmatic patients who died of unrelated causes (AUC), and seven postmortem cases with no history of lung disease (control subjects). Using immunohistochemical techniques, the CD8(+) cytotoxic T-cell population in peribronchial tissue was characterized in three patient groups. The percentage of CD8(+) cells expressing the activation marker CD25 was higher in the AD group than in both the AUC and control groups (11.91 +/- 1.92% versus 3.93 +/- 1.63% and 1.09 +/- 0.56%, respectively (p < 0.001). Perforin expression, a marker of cytotoxicity, was highest in the AD group (9.16 +/- 1.5%) compared with 1.39 +/- 0.9; 1.8 +/- 0.6% in the AUC and control groups respectively (p < 0.001). Expression of interleukin-4 (IL-4) and interferon gamma (IFN-gamma) by CD8(+) T cells was higher in the AD group than the control group (p < 0.05). Furthermore, the IFN-gamma/IL-4 ratio in the AD group was less than half that of the control group (1.46 +/- 0.2 versus 3.2 +/- 0.1; p = 0.02). Using polymerase chain reaction (PCR), viral genome for rhinovirus (RV) was detected in lung tissue from three of the seven cases in the AD group. Two of these cases also had detectable respiratory syncytial virus (RSV). Viral genome for RSV was detected in five of the AUC group and in one of these cases, RV was also detected. No viral genome was detected in the lungs of the control group. In conclusion, this study provides novel evidence of an aberrant CD8(+) T-cell population, possibly in response to viral infection in subjects who die of acute asthma.

Biomedical ethics and the withdrawal of advanced life support

It is common for health care providers to deal with the complex and difficult issue of withdrawing advanced life support. The patient is always the key source of authority in these decisions. The most important ingredient in end-of-life decision making is effective communication. It is important to try to ascertain what the patient thought about quality-of-life values before surrogate decisions can be made on the patient's behalf. The concepts of beneficence, nonmaleficence, autonomy, and justice are the foundation of ethical decision making. Numerous legal precedents have laid the groundwork for end-of-life decision making. Most state courts have supported withholding and withdrawing life support from patients who will not regain a reasonable quality of life. The recent Patient Self-Determination Act encourages patients to fill out advance directives that state their desires. When continued intensive care is futile, advanced life support should be withdrawn. However, a narrow definition of futility in this situation is the key, since the concept of futility could lead to inappropriate decisions. It is best to consider a situation futile when the patient is terminally ill, the condition is irreversible, and death is imminent. During the withdrawal of advanced life support, terminal or rapid weaning is preferable to extubation. Combinations of opiates, benzodiazepines, and other agents help provide comfort to patients who are suffering.

40-O-(2-hydroxyethyl)-rapamycin attenuates pulmonary arterial hypertension and neointimal formation in rats

Pneumonectomized rats develop pulmonary hypertension (PH) and pulmonary vascular neointimal formation 4 wk after monocrotaline (MCT) administration. Male Sprague-Dawley rats were injected with MCT (60 mg/kg) on Day 7 after left pneumonectomy. Three groups (n = 5) received 40-O-(2-hydroxyethyl)-rapamycin (RAD, 2.5 mg/kg/d, by gavage): Group PMR(5-35) from Day 5 to Day 35, Group PMR5-14 from Day 5 to Day 14, and Group PMR15-35 from Day 15 to Day 35. By Day 35, rats that received vehicle had higher mean pulmonary arterial pressures (Ppa = 41 +/- 3 mm Hg) (p < 0.001), right ventricular systolic pressures (Prv,s = 45 +/- 2 mm Hg) (p < 0.01), and right ventricle/(left ventricle plus septum) (0.55 +/- 0.05) (p = 0.028) than rats in Groups PMR5-35 (Ppa = 25 +/- 3 mm Hg, Prv,s = 32 +/- 7 mm Hg, RV/LV&S = 0.42 +/- 0.06) and PMR5-14 (Ppa = 29 +/- 4 mm Hg, Prv,s = 30 +/- 5 mm Hg, RV/LV&S = 0.43 +/- 0.07). Pulmonary arterial neointimal formation (quantified by a vascular occlusion score) was more severe in vehicle-treated rats (1.93 +/- 0.03) than in Groups PMR5-14 (1.56 +/- 0.27) and PMR(5-35) (1.57 +/- 0.1) (p < 0.01). RAD attenuates the development of MCT-induced pulmonary arterial hypertension in the pneumonectomized rat.

Triptolide attenuates pulmonary arterial hypertension and neointimal formation in rats

This paper reports the effect of triptolide (a diterpenoid triepoxide) on the development of monocrotaline (MCT)-induced pulmonary hypertension in pneumonectomized rats. Male Sprague- Dawley rats were injected with MCT (60 mg/kg) on Day 7 after left pneumonectomy. Rats received therapy from Day 5 to 35 with triptolide (0.25 mg/kg intraperitoneally, every other day, n = 10), or vehicle (0.1 ml of ethanol/cremophor intraperitoneally, every other day, n = 10). By Day 35, triptolide-treated rats demonstrated lower mean pulmonary arterial pressure (mPAP) than vehicle-treated rats (mPAP 21 +/- 3 versus 42 +/- 5 mm Hg, p < 0.001). Triptolide-treated rats also had significantly less right ventricular hypertrophy (RVH) and pulmonary arterial neointimal formation. In a rescue experiment, rats initiated therapy on Day 21. At Day 35, vehicle-treated rats (n = 4) had higher mPAP (40 +/- 9 mm Hg), greater RVH, and more severe pulmonary arterial neointimal formation than rats that received triptolide (0.25 mg/kg every other day, n = 7, mPAP 30 +/- 4 mm Hg) and rats that received triptolide (0.2 mg/kg daily, n = 7, mPAP 25 +/- 5 mm Hg, p < 0.01). In pneumonectomized rats that receive MCT, triptolide attenuates the development of pulmonary hypertension and RVH, and promotes regression of pulmonary arterial neointimal formation.

Influenza pneumonia in a paediatric lung transplant recipient

Although a common cause of morbidity and mortality in the general population, influenza infections are uncommon in lung transplant recipients and, to date, have only been associated with transient declines in pulmonary function and a relatively benign clinical course. This paper describes severe influenza pneumonia in a 13-year-old paediatric lung transplant recipient (5 months after double lung transplantation). Influenza pneumonia was diagnosed by direct fluorescent antibody testing and viral culture of bronchoalveolar lavage fluid. The patient required mechanical ventilation for 2 days due to respiratory failure and fatigue. Since his recovery from this pneumonia, he has developed obliterative bronchiolitis and currently awaits re-transplantation.

The surgical management of severe gastroparesis in heart/lung transplant recipients

This article describes the use of gastric bypass surgery for severe gastroparesis in two lung transplant recipients. In addition to feeding intolerance, both our patients suffered from severe erosive esophagitis, transfusion-dependent upper GI hemorrhage, and recurrent aspiration pneumonia. They responded poorly to promotility agents and were eventually treated with Roux-en-Y esophagojejunostomy-one patient with subtotal gastrectomy, and one with gastric bypass without distal gastric resection. Both cases were improved by surgery. Early surgical referral may be indicated in the management of lung transplant recipients with severe symptomatic gastroparesis in whom medical management has failed. On the basis of our experience, gastric bypass with esophagojejunostomy is a worthwhile option in lung transplant recipients with severe gastroparesis.

Vascular reactivity in obstructive sleep apnea syndrome

The obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular disease and systemic hypertension. Because systemic arterial blood pressure is proportional to venodilation and venous return to the heart, we hypothesized that altered vascular responsiveness might exist in the veins of subjects with OSAS. We therefore investigated venodilator responses in awake, normotensive subjects with and without OSAS, using the dorsal hand vein compliance technique. Dose-response curves to bradykinin and nitroglycerin were obtained from 12 subjects with OSAS and 12 matched control subjects. Maximal dilation (E(max)) to bradykinin was significantly lower in the OSAS group (62.1% +/- 26.1%) than in the control group (94.3% +/- 10.7%) (p < 0.005). Vasodilation to nitroglycerin tended to be lower in the OSAS group (78.6% +/- 31.8%) than the control group (100.3% +/- 12.9%), but this effect did not reach statistical significance. When six of the OSAS subjects were retested after 60 d of treatment with nasal continuous positive airway pressure (CPAP), E(max) to bradykinin rose from 60.3% +/- 20. 3% to 121.4% +/- 26.9% (p < 0.01). Vasodilation to nitroglycerin also increased, but this effect did not reach statistical significance. These results demonstrate that a blunted venodilatory responsiveness to bradykinin exists in OSAS. This effect appears to be reversible with nasal CPAP therapy.

Rapid detection of glycoprotein G gene for the diagnosis and typing of herpes simplex virus infection in genital herpes

OBJECTIVE

To develop a new, rapid, and convenient technique for the diagnosis and typing of herpes simplex virus (HSV) in genital herpes (GH).

METHODS

Using samples from skin vesicle fluid and urogenital mucosal swabs of subjects with GH, conventional polymerase chain reaction (PCR) (directed to polymerase gene: PCRpG) were compared with a newly developed PCR (directed to HSV glycoprotein gene: PCRgG). Both PCR methods were compared with virus isolation culture (VI) with indirect immunofluorescent staining (IIF).

RESULTS

80 samples from 40 GH patients (25 males) were tested. Positive results were seen in 52.5% (42/80) using PCRgG compared with 40% (32/80) by VI. Most of PCRgG positive samples (95.1%) were caused by HSV-2 infection. In samples from healing lesions, HSV was detected more often by PCRgG, than by VI. The results of typing by PCRgG and IIF were highly consistent.

CONCLUSION

PCRgG is more sensitive than VI and PCRgG in detecting HSV in urogenital samples from subjects with GH. PCRgG is a convenient technique for the rapid detection and typing of GH.

The reproducibility of repeat measures of airway inflammation in stable atopic asthma

Measures of airway inflammation are increasingly being used as outcome measures in asthma intervention studies. Meaningful interpretation of observed changes in bronchial mucosal cell numbers should depend, in part, on the reproducibility of repeat measures over time. We wanted to investigate the reproducibility of immunopathologic and physiologic parameters after short and long measurement intervals. We therefore performed spirometry, bronchial provocation challenge, and fiberoptic bronchoscopy with endobronchial biopsy (always right upper lobe second-generation bronchus) at baseline, after 2 wk, and again after 8 wk on nine subjects with stable atopic asthma (receiving inhaled placebo and beta-agonist therapy only). Numbers of T cells, memory T cells (CD45Ro(+)), macrophages (CD68(+)), and eosinophils (EG1(+) and EG2(+)) on immunohistochemical stains of bronchial biopsies were quantified by computerized image analysis. Intraclass correlation coefficients (ICCs) of reproducibility were calculated for repeat measures of each parameter and a high ICC (greater than 0.6) was interpreted as "highly reproducible." Repeat measures of FEV(1), FEF(25-75%), and PC(20) were highly reproducible after short (2-wk) and long (8-wk) intervals. Only repeat measures of EG2(+) had an ICC greater than 0.6 after 8 wk. Repeat measures of CD45Ro(+), EG2(+), and T cell numbers (but not CD68(+) and EG1(+) cells) are highly reproducible and reliable parameters of asthmatic airway inflammation after a 2 wk interval.

Constrictive pericarditis due to coccidiomycosis

Coccidiomycosis is a fungal infection that rarely causes cardiac disease. Constrictive pericarditis in the setting of disseminated coccidiomycosis can be fatal, despite antifungal therapy and pericardiectomy. We report on a patient with constrictive pericarditis due to localized infection by Coccidioides immitis. The patient underwent successful surgical pericardiectomy and antifungal chemotherapy, and remains well 1 year later.

Endobronchial stenting for severe airway obstruction in relapsing polychondritis

Airway complications of relapsing polychondritis (RP), including tracheobronchial stenosis, can be fatal. This paper describes a life-saving technique (placement of multiple metallic endobronchial stents under conscious sedation) to prevent life-threatening airway closure in a 50-year-old woman with RP. Using fluoroscopic and bronchoscopic guidance, a tracheal stent and three endobronchial metallic stents were deployed in the central airways, with good functional outcome. There were no complications. In critical airway compromise caused by RP, the insertion of endobronchial stents can result in improved symptoms, pulmonary function, and a return to daily activities, without the use of tracheotomy and mechanical ventilation.

Tick-borne pulmonary disease: update on diagnosis and management

Ticks are capable of transmitting viruses, bacteria, protozoa, and rickettsiae to man. Several of these tick-borne pathogens can lead to pulmonary disease. Characteristic clinical features, such as erythema migrans in Lyme disease, or spotted rash in a spotted fever group disease, may serve as important diagnostic clues. Successful management of tick-borne diseases depends on a high index of suspicion and recognition of their clinical features. Patients at risk for tick bites may be coinfected with two or more tick-borne pathogens. A Lyme vaccine has recently become available for use in the United States. Disease prevention depends on the avoidance of tick bites. When patients present with respiratory symptoms and a history of a recent tick bite or a characteristic skin rash, a differential diagnosis of a tick-borne pulmonary disease should be considered. Early diagnosis and appropriate antibiotic therapy for these disorders lead to greatly improved outcomes.

Recurrent Pneumocystis carinii colonization in a heart-lung transplant recipient on long-term trimethoprim-sulfamethoxazole prophylaxis

INTRODUCTION

In the setting of organ transplantation, prior to prophylaxis, Pneumocystis carinii pneumonia (PCP) had been a common clinical problem, particularly in heart-lung and lung recipients who receive long-term immunosuppressive therapy to prevent allograft rejection. Continuous oral trimethoprim-sulfamethoxazole (TMP-SMX) has been highly effective in preventing PCP in these patients.

REPORT

In this paper we report a case of recurrent Pneumocystis carinii infection in a chronic (> 15 years) heart-lung allograft recipient on long-term TMP-SMX prophylaxis. Twice, in 1995 and again in 1998, Pneumocystis carinii infection was diagnosed by bronchoalveolar lavage (BAL), in the same patient, despite continued oral TMP-SMX (960 mg TMP/4800 mg SMX per week) prophylaxis. The subject was not lymphopenic (his CD4 count was 569/mm3) and there was no associated deterioration in pulmonary function, nor evidence of hypoxemia.

CONCLUSION

This case demonstrates that asymptomatic Pneumocystis carinii lung infections may recur in chronic heart-lung transplant recipients who take standard oral PCP prophylaxis.