International consensus on lung function testing during the COVID-19 pandemic and beyond.

Coronavirus disease 2019 (COVID-19) has negatively affected the delivery of respiratory diagnostic services across the world due to the potential risk of disease transmission during lung function testing. Community prevalence, reoccurrence of COVID-19 surges and the emergence of different variants of SARS-CoV-2 have impeded attempts to restore services. Finding consensus on how to deliver safe lung function services for both patients attending and for staff performing the tests are of paramount importance. This international statement presents the consensus opinion of 23 experts in the field of lung function and respiratory physiology balanced with evidence from the reviewed literature. It describes a robust roadmap for restoration and continuity of lung function testing services during the COVID-19 pandemic and beyond. Important strategies presented in this consensus statement relate to the patient journey when attending for lung function tests. We discuss appointment preparation, operational and environmental issues, testing room requirements including mitigation strategies for transmission risk, requirement for improved ventilation, maintaining physical distance and use of personal protection equipment. We also provide consensus opinion on precautions relating to specific tests, filters, management of special patient groups and alternative options to testing in hospitals. The pandemic has highlighted how vulnerable lung function services are and forces us to re-think how long-term mitigation strategies can protect our services during this and any possible future pandemic. This statement aspires to address the safety concerns that exist and provide strategies to make lung function tests and the testing environment safer when tests are required.

Pulmonary Function Abnormalities in Regard to Age at the Time of Diagnosis of Hypersensitivity Pneumonitis.

Hypersensitivity pneumonitis (HP) is a complex syndrome caused by exaggerated immune response to inhalation of a variety of organic particles in susceptible individuals. In this study we assessed the relationship between age at the time of diagnosis and the degree of functional and radiological changes in HP. The diagnosis of HP was made on the basis of a combination of clinical symptoms, medical history, serological tests, radiologic evidence of diffuse lung disease, and absence of other identifiable causes of lung disease. We reviewed the records of 111 patients (68 women) diagnosed with HP over a period of 18 years (1995-2013). The patients were stratified into 3 age-groups: <30, 30-49, and ≥50 years old. The commonest cause of HP was avian antigens (56.8 %). Dyspnea was present in 97.3 % of patients, weight loss in 54.7 % of patients, and respiratory insufficiency in 24.3 % of patients. Lung fibrosis in chest computed tomography was found in 35.1 % of patients. Lung function was impaired more seriously in the youngest age-group, with lung diffusing capacity for carbon monoxide (DLCO) <40 % in 69.2 % of these patients. Restrictive pattern was present in 92.3 % of patients in this group, as compared with the 41.0 % in the whole cohort. In this group, desaturation in the six minute walk test also was most notable, amounting to a median of 11 %. In conclusion, diagnosis of HP at young age is predictive of a more severe clinical course of disease, with lung fibrosis and higher disturbances in pulmonary function.

Anti-inflammatory effects of atorvastatin treatment in chronic obstructive pulmonary disease. A controlled pilot study.

UNLABELLED: Observational studies have suggested that statins may have beneficial effects on outcomes in chronic obstructive pulmonary disease (COPD) patients. These effects may be mediated through an anti-inflammatory effect of statins. The purpose of this pilot-study was to determine whether statins have an anti-inflammatory effect on the lungs of COPD patients. We conducted randomized, controlled, parallel group pilot-study to compare the effects of atorvastatin (n=12) or placebo (n=6) on lung inflammation in patients with mild to moderate COPD. The primary endpoint was change in CD45+ cells expression measured by immunohistochemistry and changes in expression of genes measured using microarrays in lung biopsy (TBB) samples before and after 12 weeks of treatment with atorvastatin 40 mg/day. All subjects had spirometry, lung volumes, diffusing capacity of the lungs for carbon monoxide (DLCO), St George's Respiratory Questionnaire (SGRQ), 6 minute walk distance (6 MWD), serum lipids, hs-CRP, induced sputum (IS), bronchoscopy and TBB carried out at baseline and after treatment. TBB specimens were processed for histology, immunohistochemistry and genome-wide association studies (GWAS) profiling. Seventeen subjects completed the study. There was a significant improvement in SGRQ with mean SGRQ decreased by 12 points after treatment with atorvastatin (P=0.012). Atorvastatin treatment produced a significant 34% reduction in sputum neutrophil count, and a 57% reduction in CD45+ cells in lung biopsies (expressed as integrated optical density -IOD; median IOD 62.51% before, 27.01% after atorvastatin treatment, P=0.008). In patients' lung tissue atorvastatin treatment produced downregulation of key genes involved in inflammatory processes, immune response, and leukocyte activation. These data demonstrate the pulmonary anti-inflammatory effects of atorvastatin in COPD patients with the potential for beneficial clinical effects. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01748279.

Impaired lung compliance and DL,CO but no restrictive ventilatory defect in sarcoidosis.

Sarcoidosis is a systemic granulomatous disease with predominant manifestation in the lungs, often presenting as interstitial lung disease. Pulmonary function abnormalities in sarcoidosis include restriction of lung volumes, reduction in diffusing capacity of the lung for carbon monoxide (D(L,CO)), reduced static lung compliance (C(L,s)) and airway obstruction. The aim of the present study was to assess various lung function indices, including C(L,s) and D(L,CO), as markers of functional abnormality in sarcoidosis patients. Results from 830 consecutive patients referred for lung function tests with a diagnosis of sarcoidosis (223 in stage I, 486 in stage II and 121 in stage III) were retreospectively analysed. The mean ± sd age of the patients was 40 ± 11 yrs; 18% were active smokers and 24% were former smokers. Normal total lung capacity was found in 772 (93%) patients. Of these cases, 24.5% had a low C(L,s) and 21.5% had a low D(L,CO). At least one abnormality was observed in 39.3% of these patients, whereas, in restrictive patients, this figure was 88%. Airway obstruction was present in 11.7% of cases. Lung volumes usually remain within the normal range and measurement of either C(L,s) or D(L,CO) often reveal impaired lung function in sarcoidosis patients, even when their lung volumes are still in the normal range; these two measurements provide complementary information.

Human FOXP3+ regulatory T cells in transplantation.

CD4+CD25+FOXP3+ suppressive regulatory T cells (Treg) represent a subset of immune regulatory cells. Based on experimental results, Treg have recently been considered as a potential treatment option in several diseases. Compared with murine Treg, human CD4+CD25+FOXP3+ cells are less well characterized and understood, so a thorough understanding of their biology is vital before clinical applications can be initiated. This review summarizes knowledge on generation, phenotypic characteristics and function of human Treg. The possible role of these cells in organ transplantation, as well as interactions between immunosuppression and Treg are also discussed.

The inspiratory muscle training in elite rowers.

AIM: The aim of the investigation was to assess the effects of the resistive inspiratory muscle training (IMT) in elite male rowers. METHODS: Fifteen senior rowers were assayed for the maximal inspiratory mouth pressure (PImax) and maximal oxygen uptake (VO2max), and then randomized into two groups: the control and the experimental group. The latter athletes, in addition to basic training, were subjected to the 11-week IMT consisting of a series of 30 inspiratory efforts performed twice a day. Athletes from the control group did only the basic training. RESULTS: No significant relations were detected between the initial values of PImax and the VO2max value. After 6 weeks of IMT the PImax values increased by 20+/-10% (P < 0.05), whereas the final improvement (after 11 weeks of IMT) equaled to 34+/-19% (P < 0.05). In the control group, the final increase equaled to 4+/-9% and was statistically insignificant. Compared to the values obtained at the end of IMT, 14 weeks after cessation of the training PImax insignificantly decreased in the experimental group by 10+/-9%, but the measured values were still significantly higher than before the commencement of IMT. CONCLUSION: The data obtained corroborate the observations that in well-trained athletes the introduction of the principle of incremental inspiratory resistance allows to improve methodically the inspiratory muscles' strength. Once the essential period of IMT has been completed, the training volume should be reduced in order to secure the attained level of the inspiratory muscles' strength.

New cellular and molecular immune pathways in ischemia/reperfusion injury.

Ischemia/reperfusion injury (IRI) is a multi-factorial antigen-independent inflammatory condition that profoundly affects both early and long-term function of the allograft as suggested by both clinical and experimental data. In recent years, the acute phase of IRI has been increasingly viewed as part of the innate immune response. Identification of novel molecular pathways and new insights into the mechanisms of known mediators of IRI have established links among innate immunity, adaptive immune responses and organ regeneration, and thus long-term graft function. This review approaches these novel aspects of IRI in the context of solid organ transplantation, presenting data on new observations with kidney, liver and heart allografts.

Intrahepatic expression and release of vascular endothelial growth factor following orthotopic liver transplantation in the rat.

BACKGROUND: Morphological and functional changes to sinusoidal endothelial cells mediated by soluble factors released from activated Kupffer cells, including cytokines, are considered pivotal events in ischemia/reperfusion injury (IRI) to liver grafts. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific cytokine with potent pro-inflammatory and mitogenic effects. We investigated the possible role of VEGF in IRI to liver grafts using a syngeneic rat orthotopic liver transplantation model. METHODS: Transplantation was performed in Lewis rats using livers preserved for various periods of time (24-48 hr) in University of Wisconsin solution at 4 degrees C. Systemic VEGF levels were measured by enzyme-linked immunosorbent assay (ELISA). Intrahepatic VEGF expression was analyzed by Northern blotting and in situ hybridization. The effects of anti-VEGF neutralizing antibody treatment on the extent of IRI were assessed by measuring liver function tests, lipid peroxidation, and metalloproteinase activity. RESULTS/CONCLUSION: VEGF is expressed and released in a biphasic pattern during the early postoperative period after liver transplantation. Anti-VEGF antibody treatment, administered during reperfusion, decreased the degree of damage, suggesting that VEGF may have a role in IRI to liver grafts.

Recurrence of hepatitis C after liver transplantation is associated with increased systemic IL-10 levels.

BACKGROUND: Recurrence of hepatitis C after liver transplantation is an almost universal occurrence. T-cell derived cytokines have an important role in the development of liver damage associated with chronic hepatitis C, their post-transplant levels, however, have not been correlated with histologic recurrence of the disease. AIMS: We sought to analyze levels of TNF-alpha, soluble IL-2 receptor, IL-4 and IL-10 at 1 month, 6 months and 1 year after transplantation in 27 patients undergoing transplantation for hepatitis C related end-stage liver disease. METHODS: HCV RNA levels were monitored by a branched-chain DNA signal amplification assay. Diagnosis of recurrent hepatitis was based on 1-year protocol biopsies and on biopsies performed for liver enzyme elevations. RESULTS: Recurrent hepatitis C was detected in 52% (n=14) of the 27 patients. HCV RNA levels rose over time in all patients regardless of histologic recurrence. TNF-alpha, and IL-4 levels, although elevated, did not show specific patterns over time or in correlation with recurrence. Similarly, the early elevation followed by a gradual decrease over the first year in the amount of soluble IL-2 receptor was not related to histologic recurrence. We observed a significant increase in circulating IL-10 levels over the first year in patients with biopsy-proven recurrence, while patients with no signs of histologic recurrence displayed increased, but steady levels. CONCLUSIONS: These results suggest that while these cytokines are associated with post-transplant recurrence of hepatitis C, their production may be altered by additional factors.

Graft function and survival depend primarily on host factors in compromised recipient models of orthotopic liver transplantation in the rat.

BACKGROUND: Experimental models of liver transplantation use normal recipients, although most patients undergoing liver transplantation suffer from acute or chronic liver failure. This study was designed to analyze the outcome of orthotopic liver transplantation in compromised rat hosts. METHODS: Recipient animals were either rats with D-galactosamine-induced acute or rats with chronic liver failure secondary to common bile duct ligation. Liver damage was evaluated by monitoring enzymes, bilirubin, ammonia levels, prothrombin, thrombin time, and cytokines. In vivo function of hepatocytes and sinusoidal endothelial cells were evaluated by indocyanine green and hyaluronic acid uptake. Transplantation was performed in normal, acute, and chronic liver failure rats at different time points using either freshly harvested or cold-preserved syngeneic livers. RESULTS: Survival with fresh grafts decreased significantly when transplants were performed 48 hr after the induction of acute liver failure. No rats with acute liver failure survived transplantation with grafts stored for 12 or 24 hr although in chronic failure survival was more 80%. Survival of acute liver failure rats receiving 6 hr preserved grafts was 16.6% compared with 83.3% observed with fresh grafts transplanted at the same time point after D-galactosamine injection. Elevated tumor necrosis factor-alpha and interleukin-1beta levels as well as impaired sinusoidal endothelial cell function were detected in acute liver failure rats with 6 h preserved grafts. CONCLUSION: These results suggest that preoperative status and different host factors have a significant effect on outcome and graft function after liver transplantation in rats.

Combination of electroporation and DNA/dendrimer complexes enhances gene transfer into murine cardiac transplants.

Electroporation is a new gene delivery method to increase gene transfer and expression in vivo. Starburst polyamidoamine dendrimers have been demonstrated to augment gene expression in vitro and in vivo. We hypothesized that the combination of electroporation and dendrimer could enhance the gene transfer and gene expression in cardiac transplants. After immersion in DNA/dendrimer complexes or intracoronary transfer of DNA/dendrimer complexes, both nonvascularized and vascularized syngeneic cardiac grafts, respectively, were subjected to serial electrical pulses before transplantation. beta-Galactosidase reporter gene expression in the graft was determined by X-Gal staining. Gene expression was enhanced 10- to 45-fold in grafts immersed in DNA/dendrimer complexes, or after intracoronary transfer of DNA/dendrimer complexes, and subjected to 20 square wave 25-ms pulses with a strength of 200 V/cm. The combination of electroporation and DNA/dendrimer complexes may provide a novel approach to enhance gene transfer and gene expression ex vivo.

DNA/dendrimer complexes mediate gene transfer into murine cardiac transplants ex vivo.

Starburst polyamidoamine dendrimers are synthetic polymers with unique structural and physical characteristics suitable for DNA gene transfer. Our previous studies demonstrated that Starburst dendrimers augment plasmid-mediated gene transfer efficiency in a nonvascularized, cardiac transplantation model. In this study, the fifth generation of ethylenediamine core dendrimer was investigated for its ability to enhance gene transfer and expression in a clinically relevant murine vascularized heart transplantation model. The plasmid pMP6A-beta-gal, encoding beta-galactosidase (beta-Gal), was incubated with dendrimers to form complexes. The complexes were perfused via the coronary arteries during donor graft harvesting, and reporter gene expression was determined by quantitative evaluation of X-Gal staining. The grafts infused with pMP6A-beta-gal/dendrimer complexes showed beta-Gal expression in myocytes from 7 to 14 days. A number of variables for transfer of the DNA/dendrimer complexes were tested, including DNA:dendrimer charge ratios, concentrations of DNA and dendrimer, preservation solutions, ischemic time, and enhancement of vascular permeability by serotonin, papaverine, and VEGF administration. The results showed that DNA/dendrimer complexes containing 20 microg of DNA and 260 microg of dendrimer (1:20 charge ratio) in a total volume of 200 microl resulted in highest gene expression in the grafts. The results also showed that prolonged incubation (cold ischemic time) to 2 h and pretreatment with serotonin further enhanced gene expression.

Serum hepatitis C virus RNA levels and histologic findings in liver allografts with early recurrent hepatitis C.

BACKGROUND: Histopathologic features of early recurrent hepatitis C after orthotopic liver transplantation (OLTx) may be modified by immunosuppressive therapy or complicated by other conditions. Hepatitis C virus (HCV) RNA level usually increases after OLTx, but its correlation to histologic findings is not clear. OBJECTIVE: To evaluate the histologic findings of early recurrent hepatitis C in liver allografts and its correlation to serum HCV RNA level. METHODS: We studied 14 patients who underwent OLTx for chronic HCV infection. Thirty liver biopsy specimens and HCV RNA levels of 22 corresponding plasma samples obtained during the first 6 months following OLTx were analyzed. The control group (9 patients, 25 biopsy specimens) was chosen at random from patients with chronic liver disease other than HCV who were undergoing OLTx, and all tested negative for HCV RNA by polymerase chain reaction after OLTx. RESULTS: Statistically significant pathological features of early recurrent HCV infection were the number of acidophilic bodies, piecemeal necrosis, lymphocyte predominance in the portal tracts, and fibrous septum. These findings and histologic activity index scores increased with time after OLTx. The HCV RNA levels determined by branched DNA assay showed no significant correlation with histologic features. However, patients with higher histologic activity index scores tended to have higher RNA levels. CONCLUSIONS: Liver biopsy specimens are helpful for the diagnosis or confirmation of early recurrent hepatitis C in liver allografts, but serial biopsy specimens are sometimes required for definite diagnosis. The HCV RNA levels are usually higher in patients who display signs of more severe liver damage.

[Respiratory response to inspiratory resistive load changes in patients with obstructive sleep apnea syndrome]. / Odpowiedz oddechowa na zmiane oporu wdechowego u chorych na obturacyjny bezdech senny.

Patients with OSA have many episodes of increased airway resistance because of repeated collapses of upper airways during night. The aim of this work was to evaluate respiratory response during chemical stimulation without and with added inspiratory resistive load (10 cmH2O/L/sec). The studies were performed during quiet breathing with air and during hypercapnic and hypoxic rebreathing tests without and with inspiratory resistive loading in 23 obese (BMI = 34.4 +/- 4.3 kg/m2) patients with OSA and in 10 healthy subjects with similar weight (BMI = 32.4 +/- 4.3 kg/m2). The measurements of respiratory responses (ventilation, mouth occlusion pressure) were performed with the use of computerized equipment. During quiet breathing in response to added load an increase of P0.1 in controls and in OSA patients was observed. During hypercapnic stimulation the ventilatory response with additional load decreased in patients as well as in controls. The slope of mouth occlusion pressure response increased significantly in controls (from 4.40 to 6.83 cmH2O/kPa, p < 0.001) and slightly weaker in OSA patients (from 4.21 to 5.43 cmH2O/kPa, p < 0.05). Although the difference between the slopes was not significant, we found that the absolute increase of P0.1 measured at point 8 kPa of PEtCO2 during loaded breathing was significantly smaller in OSA patients in comparison to controls. (2.1 vs. 10.3 cm H2O; p < 0.001). During hypoxic stimulation occlusion pressure responses were similar in both examined groups. In conclusion we postulate that OSA patients have impaired respiratory compensation of additional inspiratory load, what was demonstrated during hypercapnic rebreathing test.

Th1/Th2 cytokines and ICAM-1 levels post-liver transplant do not predict early rejection.

Th1 derived cytokines IFN-gamma and IL-2, Th2 cytokine IL-4, and ICAM-1 have been implicated in liver allograft rejection. In order to determine whether monitoring of cytokine profiles during the first days post-liver transplant can predict early rejection we measured IFN-gg, IL-2, sIL-2 receptor, IL-4 and ICAM-1 in 22 patients, in plasma samples obtained within 4 h after liver perfusion (baseline) and between postoperative days (POD) 3-6. ICAM-1 and sIL-2R levels at POD 3-6 were significantly higher than at baseline but did not differ in presence or absence of rejection. Mean percentage increase of ICAM-1 levels was significantly lower in patients with Muromonab-C3 Orthoclone OKT3 (J.C. Health Care) (OKT3) whereas percentage increase of sIL-2R levels was higher in OKT3-treated patients. IFN-gamma levels at POD 3-6 increased from baseline while IL-4 levels were unchanged. Levels of IFN-gamma, IL-4 and their ratios did not correlate with rejection or immunosuppressive therapy. Thus, Th1/Th2 cytokine monitoring during the first week post-transplant does not predict early rejection and immunosuppressive therapy is the predominant factor affecting ICAM and sIL-2R levels after liver transplantation.

Expression of GMP-140 (P-selectin) correlates with graft viability in cold-preserved rat livers.

BACKGROUND: Ischemia/reperfusion injury is an inflammatory process involving cytokine release, Kupffer cell activation, and sinusoidal endothelial cell activation. GMP-140 is synthesized by endothelial cells. METHODS: We analyzed by Western blotting the expression of GMP-140 in a syngeneic rat liver transplantation model using grafts preserved for different periods of time. RESULTS: Compared with prereperfusion samples, expression did not change significantly in freshly harvested and 4-hr preserved livers. In grafts preserved for 24 hr (100% survival), GMP-140 levels increased dramatically at 1 hr, then returned to baseline at 24 hr after transplantation. Forty-eight hour preserved grafts (0% survival) showed a decreasing expression. To identify possible mediators, the effects of tumor necrosis factor-alpha and interleukin-1beta on GMP-140 expression in primary sinusoidal endothelial cells were analyzed. These cytokines increased both the percentage of stained cells as well as their mean staining fluorescence. CONCLUSIONS: The absence of increase in 48-hr grafts suggests that GMP-140 may distinguish viable from nonviable livers.

Cytokine profiles in early rejection following OKT3 treatment in liver transplant patients.

OKT3 , a murine monoclonal antibody specific to the human CD3 complex, induces immunosuppression by depletion of T cells. Administration of OKT3 results in significant release of proinflammatory cytokines, such as TNFalpha and IL1beta. Liver recipients who experience rejection within 3 weeks after transplantation with OKT3 prophylaxis recover their T cells by postoperative day 10 despite complete initial clearance. We sought to analyze the role of proinflammatory and Th-1 cytokines in T cell recovery and rejection after liver transplantation with OKT3 prophylaxis. In plasma samples from 32 patients, we measured TNFalpha, IL1beta and IL6 (before transplant and on postoperative days 1, 2 and 3) and IL2, IFNgamma, sIL2R and slCAM (postoperative days 5, 7 and 10) and examined possible correlations with T-cell recovery and occurrence of rejection within 3 weeks. TNFalpha, IL1beta, and IL6 did not correlate with T-cell recovery. In patients who rejected, IL2 and IFNgamma on postoperative days 5 and 7 correlated with degree of T-cell recovery by day 10; a significant rise in sIL2R over time also correlated with T-cell recovery in this group. Our results emphasize the role of Th-1 cytokines in rejection following OKT3 induction and suggest that markers of T cell activation may predict risk.