Human alveolar macrophage antibacterial activity in the alcoholic lung

Pioglitazone reverses alcohol-induced alterations in alveolar macrophage mitochondrial phenotype

BACKGROUND

People with alcohol use disorder (AUD) have an increased risk of developing pneumonia and pulmonary diseases. Alveolar macrophages (AMs) are immune cells of the lower respiratory tract that are necessary for clearance of pathogens. However, alcohol causes AM oxidative stress, mitochondrial damage and dysfunction, and diminished phagocytic capacity, leading to lung injury and immune suppression.

METHODS

AMs were isolated by bronchoalveolar lavage from people with AUD and male and female C57BL/6J mice given chronic ethanol (20% w/v, 12 weeks) in drinking water. The peroxisome proliferator-activated receptor γ ligand, pioglitazone, was used to treat human AMs ex vivo (10 μM, 24 h) and mice in vivo by oral gavage (10 mg/kg/day). Levels of AM mitochondrial superoxide and hypoxia-inducible factor-1 alpha (HIF-1α) mRNA, a marker of oxidative stress, were measured by fluorescence microscopy and RT-qPCR, respectively. Mouse AM phagocytic ability was determined by internalized Staphylococcus aureus, and mitochondrial capacity, dependency, and flexibility for glucose, long-chain fatty acid, and glutamine oxidation were measured using an extracellular flux analyzer. In vitro studies used a murine AM cell line, MH-S (±0.08% ethanol, 72 h) to investigate mitochondrial fuel oxidation and ATP-linked respiration.

RESULTS

Pioglitazone treatment decreased mitochondrial superoxide in AMs from people with AUD and ethanol-fed mice and HIF-1α mRNA in ethanol-fed mouse lungs. Pioglitazone also reversed mouse AM glutamine oxidation and glucose or long-chain fatty acid flexibility to meet basal oxidation needs. In vitro, ethanol decreased the rate of AM mitochondrial and total ATP production, and pioglitazone improved changes in glucose and glutamine oxidation.

CONCLUSIONS

Pioglitazone reversed chronic alcohol-induced oxidative stress in human AM and mitochondrial substrate oxidation flexibility and superoxide levels in mouse AM. Decreased ethanol-induced AM HIF-1α mRNA with pioglitazone suggests that this pathway may be a focus for metabolic-targeted therapeutics to improve morbidity and mortality in people with AUD.

Acute-on-chronic liver failure in Egypt: an underestimated complication of liver cirrhosis

BACKGROUND

Acute-on-chronic liver failure (ACLF) is a severe liver cirrhosis complication with high mortality rates. Despite that chronic liver diseases are prevalent in Egypt, there is no available data about patients with ACLF. We aimed to evaluate the pattern of ACLF in Egypt.

METHODS

This prospective cohort study included all patients with ACLF, according to the American Association for the Study of Liver Diseases and the European Association for the Study of the Liver, admitted to Al-Rajhi liver Hospital, Egypt, between November 2018 and October 2019. We recorded data at admission, days 3, 7, 14 and 28, and calculated ACLF grades and Chronic Liver Failure Consortium scores until discharge or death. Kaplan-Meier survival analysis was used for survival analysis.

RESULTS

We analyzed 52 patients with ACLF. Liver cirrhosis was secondary to hepatitis C virus in 46 patients (88.9%), and hepatitis B virus in 4 (7.4%). The main ACLF precipitating factors were infection in 38 (73.1%) and variceal bleeding in 9 (17.3%). The most common infections were spontaneous bacterial peritonitis (44.7%) and chest infection (31.6%). The 28 and 90-day mortality rates were 86.5 and 96.2%. None of the patients who survived >28 days had ACLF 3 at admission or day 7. Among those who died <28 days, ACLF 3 was reported in 7 at admission and 19 on day 7. Living donor liver transplantation was not offered in any case.

CONCLUSION

In this study, the 28-day mortality rate was higher than in the literature. Egypt urgently needs to develop specific protocols for the proper management of ACLF.

Peripheral immune system suppression in early abstinent alcohol-dependent individuals: Links to stress and cue-related craving

BACKGROUND

Peripheral immune system cytokines may play an integral role in the underlying sensitized stress response and alcohol craving during early alcohol withdrawal. To date, the nature of these immune changes during early abstinence have not been examined.

METHODS

A total of 39 early abstinent, treatment-seeking, alcohol-dependent individuals and 46 socially drinking controls were exposed to three guided imageries: stress, alcohol cue and neutral. These were presented randomly across consecutive days. Plasma measures of tumor necrosis factor alpha (TNFα), tumor necrosis factor receptor 1 (TNFR1), interleukin-6 (IL-6), and interleukin-10 (IL-10), were collected at baseline, immediately after imagery and at various recovery time-points. Ratings of alcohol craving, negative mood and anxiety were also obtained at the same time-points.

RESULTS

The alcohol group demonstrated decreased basal IL-10 compared with controls particularly following exposure to alcohol cue. They also showed a dampened TNFα and TNFR1 response to stress and cue, respectively, and a generalized suppression of IL-6. In the alcohol group, these immune system adaptations occurred alongside significant elevations in anxiety, negative mood and alcohol craving.

CONCLUSIONS

Findings demonstrate that broad immunosuppression is still observed in alcohol-dependent individuals after 3 weeks of abstinence and may be linked to motivation for alcohol.

Alcohol abuse, the alveolar macrophage and pneumonia

Alcohol use, and misuse, has been a part of human culture for thousands of years. In the modern medical era, a great deal of attention has been justifiably focused on elucidating the mechanisms underlying the psychological and biological addiction to alcohol. However, a significant percentage, if not the majority, of alcohol-related morbidity and mortality occurs in individuals who do not meet the formal diagnostic criteria for alcohol use disorders. For example, many serious medical consequences of chronic alcohol ingestion can occur in individuals who do not have signs or symptoms of alcohol dependence. There is now clear evidence that even in otherwise healthy-appearing individuals who chronically consume excessive amounts of alcohol, alveolar macrophage immune capacity is impaired and, as a consequence, these individuals are at significantly increased risk of pneumonia. This brief review summarizes some of the key mechanisms underlying this phenomenon and proposes a hypothetical scheme by which alcohol interferes with zinc bioavailability within the alveolar space and thereby dampens macrophage function.

Clonality and phenotyping analysis of alveolar lymphocytes is suggestive of pulmonary MALT lymphoma

BACKGROUND

Mucosa-associated lymphoid tissue (MALT) lymphoma, a low-grade B-cell extranodal lymphoma, is the most frequent subset of primary pulmonary lymphoma (PPL). It often associates with connective tissue disease (CTD). We aimed to evaluate the impact of concomitant CTD on diagnostic value of flow cytometry and genetic clonality analyses for the diagnostic of MALT lymphoma.

METHODS

All chest disease and pathology departments of teaching hospitals in Paris were contacted to identify patients with a histological diagnosis of PPL of the MALT subtype with or without associated CTD. We identified 44 patients in the lymphoma group; 11 had a CTD and were matched to 11 patients with CTD but without lymphoma.

RESULTS

Results of BAL analyses of MALT-PPL showed normal cellularity (370 cells/mm(3) [range 21-2300]) but increased proportion of lymphocytes (31.5% [80-2]) of the B-cell subtype (20% [1-88]). A B-cell clone was detected in 82% of cases, and specificity of clonality was 90%. Interestingly, BAL analysis results different by presence or not of a CTD. The frequency of B lymphocyte alveolitis was significantly greater in MALT patients without than with CTD (34% vs 6.5%, p = 0.007). However, BAL results for patients with CTD did not differ between those with and without lymphoma.

CONCLUSION

BAL results may be highly suggestive of pulmonary MALT lymphoma. The proportion of B-cells may vary depending on the presence of an associated CTD, but clonality analyses remained informative for the diagnostic of MALT lymphoma.

Risk factors for mortality in cirrhotic patients with sepsis

BACKGROUND

Patients with cirrhosis and sepsis had increased mortality.

AIM

Determine factors associated with increased in-hospital mortality in cirrhotic patients admitted for sepsis.

METHODS

All cirrhotic patients admitted from 2004 to 2007 for sepsis were identified from hospital electronic database. Patients were included if they had liver cirrhosis and sepsis, defined as identified sources of infection, and at least one of fever, altered total white cell count, or raised C-reactive protein. Baseline characteristics, investigations, infections, and outcomes were collected. Main outcome measure was in-hospital mortality.

RESULTS

A total of 205 admissions in 153 patients were included. In-hospital mortality rate was 24.4%. In predicting in-hospital death, area under the receiver-operating-characteristic curve for Child-Pugh score was 0.934, with optimum cut-off at 10 and above, while for model for end-stage liver disease (MELD) score was 0.751, with optimum cut-off at 17 and above. Four factors were significantly associated with in-hospital mortality on multivariate analysis: presence of >1 site of infection, pneumonia, Child's C status, and MELD score 17 and above. In-hospital mortality rate increased with more factors: 0% with no factor, 7% with one factor, 21% with two factors, 87% with three factors, and 100% with four factors. The mortality of those with <3 risk factors was significantly lower than those with three or more risk factors (7 vs. 91%, p = 0.000).

CONCLUSIONS

Septic cirrhotic patients with pneumonia, >1 site of infection, Child's C cirrhosis, and high MELD score had a high mortality risk.

Alcohol use disorders affect antimicrobial proteins and anti-pneumococcal activity in epithelial lining fluid obtained via bronchoalveolar lavage

AIMS

Our overall objective was to examine whether characteristics of epithelial lining fluid (ELF) from subjects with alcohol use disorders (AUDs) obtained via bronchoalveolar lavage (BAL) contribute to their predisposition to pneumococcal pneumonia. We sought to compare the anti-pneumococcal activity of acellular human BAL from subjects with AUDs to matched controls. Further, differences in BAL lysozyme activity and lactoferrin concentrations between these two groups were examined to determine the effect of AUDs on these antimicrobial proteins.

METHODS

BAL was performed in subjects with AUDs and matched controls. Acellular BAL was used at varying concentrations in an in vitro killing assay of Streptococcus pneumoniae, type 2, and the percent kill of organisms per microgram per milliliter total BAL protein was ascertained. Lysozyme activity and lactoferrin concentrations were measured in BAL from subjects and controls at measured concentrations of BAL protein.

RESULTS

AUD subjects (n = 15) and controls (n = 10) were enrolled in these investigations who were balanced in terms of smoking history. Using a mixed effect model, across the range of BAL protein concentrations, killing of pneumococcus tended to be less potent with BAL fluid from AUD subjects. Additionally, lysozyme activity and lactoferrin concentrations were significantly lower in the AUD group.

CONCLUSIONS

The predisposition for pneumococcal pneumonia among those with AUDs may be in part mediated through effects of alcohol on substances within ELF that include antimicrobial proteins. Clarifying the composition and activity of ELF antimicrobial proteins in the setting of AUDs via investigations with human BAL fluid can help establish their contribution to the susceptibility for pulmonary infections in these individuals.

Severe sepsis in cirrhosis

Sepsis is physiologically viewed as a proinflammatory and procoagulant response to invading pathogens. There are three recognized stages in the inflammatory response with progressively increased risk of end-organ failure and death: sepsis, severe sepsis, and septic shock. Patients with cirrhosis are prone to develop sepsis, sepsis-induced organ failure, and death. There is evidence that in cirrhosis, sepsis is accompanied by a markedly imbalanced cytokine response ("cytokine storm"), which converts responses that are normally beneficial for fighting infections into excessive, damaging inflammation. Molecular mechanisms for this excessive proinflammatory response are poorly understood. In patients with cirrhosis and severe sepsis, high production of proinflammatory cytokines seems to play a role in the worsening of liver function and the development of organ/system failures such as shock, renal failure, acute lung injury or acute respiratory distress syndrome, coagulopathy, or hepatic encephalopathy. In addition, these patients may have sepsis-induced hyperglycemia, defective arginine-vasopressin secretion, adrenal insufficiency, or compartmental syndrome. In patients with cirrhosis and spontaneous bacterial peritonitis (SBP), early use of antibiotics and intravenous albumin administration decreases the risk for developing renal failure and improves survival. There are no randomized studies that have been specifically performed in patients with cirrhosis and severe sepsis to evaluate treatments that have been shown to improve outcome in patients without cirrhosis who have severe sepsis or septic shock. These treatments include recombinant human activated C protein and protective-ventilation strategy for respiratory failure. Other treatments should be evaluated in the cirrhotic population with severe sepsis including the early use of antibiotics in "non-SBP" infections, vasopressor therapy, hydrocortisone, renal-replacement therapy and liver support systems, and selective decontamination of the digestive tract or oropharynx.

Cirrhosis as a risk factor for sepsis and death: analysis of the National Hospital Discharge Survey

STUDY OBJECTIVES

The unfavorable influence of cirrhosis on survival in the critically ill has been supported by several single-center reports. Variations in case mix, the technological capabilities of individual facilities, and differences in organizational staffing and structure could limit the extrapolation and generalization of these data to other institutions. To assess the impact of a diagnosis of cirrhosis on outcomes of sepsis, sepsis-related mortality, and respiratory failure in hospitalized patients, we analyzed data from the National Hospital Discharge Survey (NHDS) from 1995 to 1999 to determine its national consequence.

DESIGN

Secondary analysis of an existing national database.

PATIENTS OR PARTICIPANTS

Based on NHDS estimates, 175 million hospital discharges occurred during the 5-year period of study. One percent (1.7 million) of these hospitalizations involved a diagnosis of cirrhosis.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

After adjustments for age, race, and gender, cirrhotic individuals are significantly more likely to die while hospitalized (adjusted risk ratio [RR], 2.7; 95% confidence interval [CI], 2.3 to 3.1), to have hospitalizations associated with sepsis (adjusted RR, 2.6; 95% CI, 1.9 to 3.3), and to die from sepsis (adjusted RR, 2.0; 95% CI, 1.3 to 2.6). Additionally, cirrhosis is associated with an increased RR for acute respiratory failure (adjusted RR, 1.4; 95% CI, 1.1 to 1.8) and death from acute respiratory failure (adjusted RR, 2.6; 95% CI, 1.5 to 3.6).

CONCLUSIONS

In this national database of hospital discharge information, a diagnosis of cirrhosis is strongly associated with an increased risk of sepsis, acute respiratory failure, sepsis-related mortality, and acute respiratory failure-related mortality.

Alveolar macrophage release of tumor necrosis factor-alpha in chronic alcoholics without liver disease

Alcohol is an immunosuppressive drug, and chronic abuse has been associated with increased susceptibility to a variety of infections, including bacterial pneumonia and tuberculosis. Alveolar macrophages are the resident phagocytes of the lung and play a central role in lung host defenses against infection ranging from direct antibacterial activity to the release of proinflammatory cytokines such as tumor necrosis factor-alpha (TNFalpha). TNFalpha, in particular, plays a key role in the development of the early inflammatory response. In this study, we investigated the effects of chronic alcohol consumption on alveolar macrophage release of TNFalpha in vitro. We prospectively studied lipopolysaccharide (LPS)-stimulated release of TNFalpha from alveolar macrophages obtained from bronchoalveolar lavage fluid (BALF) in 22 alcoholic (18 smokers, 4 nonsmokers) and 7 nondrinking healthy volunteers (3 smokers, 4 nonsmokers). The total number of cells recovered by bronchoalveolar lavage (BAL) and their differential distribution were not significantly different in alcoholics versus controls (43 +/- 8 x 10(6) and 39 +/- 13 x 10(6), respectively). However, the total number of cells recovered from BALF was significantly higher in smokers (51 +/- 8 x 10(6)) than in nonsmokers (19 +/- 5 x 10(6)). Spontaneous (basal) release of TNFalpha by alveolar macrophages was the same in alcoholics and controls. In contrast, LPS-stimulated release of TNFalpha was significantly suppressed in alcoholics compared with that of controls (1343 +/- 271 vs. 3806 +/- 926 U TNF/ml/10(6) cells, respectively, p < 0.015). When controlled for smoking, LPS-stimulated TNFalpha production was suppressed in alcoholic nonsmokers (563 +/- 413 U TNF/ml/10(6)) compared with control nonsmokers (5113 +/- 1264 U TNF/ml/10(6)). LPS-stimulated TNFalpha production was also less in control smokers (2063 +/- 386 U TNF/ml/10(6) cells) than in control nonsmokers (5113 +/- 1264 U TNF/ml/10(6) cells). There was no difference in TNFalpha production between smoking alcoholics and smoking control subjects. We conclude that chronic alcohol consumption significantly suppresses LPS-stimulated alveolar macrophage production of TNFalpha. This effect is obscured if the subject also smokes. Because TNFalpha production is an important element in host defense, this may explain, in part, the susceptibility of chronic alcohol abusers to a variety of infections.

Rapidly fatal outcome of bacteremic Klebsiella pneumoniae pneumonia in alcoholics

Twenty-eight alcoholic patients with community-acquired pneumonia who were admitted to a referral medical center during a 3-year period were reviewed. All were men and with few exceptions were heavy smokers. The overall mortality was 64.3%. The most dramatic group was that of 11 patients (39.3%) with bacteremic Klebsiella pneumoniae pneumonia (BKPP), which had high mortality rate (100%), short onset of illness before hospital admission (42.6 +/- 8.2 h, mean +/- SD), and short survival time after the admission (24.6 +/- 7.9 h). All these 11 patients needed intensive care unit (ICU) management and ventilatory support. ARterial blood gas values showed marked hypoxemia and metabolic acidosis in most of these 11 patients, and presence of shock at arrival in the hospital was noted in 8 patients. Acute renal failure and disseminated intravascular coagulation developed in six patients. Chest radiographs showed pleural effusion and radiographic spread in nearly 50% of patients. Combination chemotherapy consisting of one aminoglycoside and one second- or third-generation cephalosporin was initiated in all patients. The rapidly fatal outcome of these 11 patients with BKPP despite management with adequate antibiotics and intensive care indicated the fulminant nature of this disease. High virulence of the microorganism, altered immune response, and increased susceptibility to infection may all have contributed to the fulminancy in this group of patients. The disease continues to present many difficulties in management.

Expression of tumor necrosis factor-alpha and interleukin-6 cell-surface receptors of the alveolar macrophage in alcohol-treated rats

The hypothesis was tested that alcohol may modulate alveolar macrophage cytokine receptors, thus interfering in lung immune defense mechanisms. Male rats were treated with alcohol either acutely (7 hr continuous intravenous alcohol infusion at a rate of 30 mg/100 g body weight/hr after a priming dose of 175 mg/100 g body weight) or chronically (feeding an alcohol-containing liquid diet for 12-14 weeks). Three hr before killing, the rats received an intravenous injection of Gram-negative bacterial lipopolysaccharide (LPS; Escherichia coli, O26:B6, 100 micrograms/100 g body weight). After anesthesia with sodium pentobarbital, the trachea was cannulated, and the lungs excised and lavaged to obtain alveolar macrophages. The recovered cells were used to measure the binding of recombinant human [125I]tumor necrosis factor-alpha (TNF-alpha) and [125I]interleukin-6 (IL-6). Kd and Bmax were determined at 4 degrees C, thus reflecting only the cell-surface binding sites and their affinity. Two binding sites were detected for both cytokines: high-affinity (Kd1 in the range of 20-110 pM), low-capacity (Bmax1 in the range of 1-13 fmol/10(6) cells), and low-affinity (Kd2 in the range of 0.6-1.3 nM), high-capacity (Bmax2 in the range of 34-100 fmol/10(6) cells). Acute alcohol treatment significantly decreased Bmax1 (39%) and Bmax2 (79%) for TNF-alpha, whereas chronic alcohol feeding abrogated the Bmax1 (Bmax1 = 0), without affecting Bmax2. In the acute group, LPS had an effect similar to that of alcohol. Alcohol administration did not modify the LPS effects. The following changes were monitored for IL-6 binding. Acute alcohol treatment markedly reduced (86%) Bmax2.(ABSTRACT TRUNCATED AT 250 WORDS)

Impaired function of macrophage Fc gamma receptors and bacterial infection in alcoholic cirrhosis

BACKGROUND

Bacterial infection is a frequent and often fatal complication in patients with cirrhosis. Macrophages play an important part in the host defense against infection because their Fc gamma receptors recognize antibody-coated bacteria.

METHODS

We prospectively studied macrophage Fc gamma-receptor function in vivo and in vitro in 49 patients with alcoholic cirrhosis, 10 alcoholics without cirrhosis, and 20 normal volunteers.

RESULTS

The clearance of IgG-sensitized autologous red cells was decreased in 37 of the 49 patients with cirrhosis but in none of the subjects without cirrhosis. In the 49 patients clearance was inhibited by a mean (+/- SE) of 47 +/- 3 percent at 1 hour and 53 +/- 3 percent at 1 1/2 hours, as compared with the clearance in the normal controls (P < 0.001). The impairment of macrophage Fc gamma-receptor-dependent clearance correlated with the degree of liver insufficiency but not with age, sex, nutritional status, HLA haplotype, or the presence of circulating immune complexes. The clearance of unsensitized and heat-altered autologous erythrocytes was normal. In vitro recognition of IgG-sensitized red cells by monocytes from the patients was not significantly decreased. During a two-year follow-up period, 11 patients had severe bacterial infections, and in 4 they were fatal. The mean clearance of IgG-sensitized red cells in these 11 patients (half-time, 126.2 +/- 22 hours) was significantly impaired, as compared with that in the 38 patients without severe infection (half-time, 32.2 +/- 18 hours, P < 0.001).

CONCLUSIONS

The function of macrophage Fc gamma receptors is impaired in patients with alcoholic cirrhosis, and this impairment probably contributes to the high incidence of bacterial infections among such patients.

Host defenses against respiratory infection

The respiratory tract is protected from infection by its formidable mechanical and cellular defenses, supplemented when necessary by inflammatory and immune responses. Impairments in these defenses develop as a result of underlying disease and therapeutic interventions. Specific defects in host defenses often predispose to infection with particular etiologic agents. New opportunities for the therapeutic augmentation of defenses are emerging that may be particularly helpful in the care of immunocompromised patients.

[Pneumonia in alcoholic patients: the clinical and etiological characteristics]

Twenty-four alcoholic patients with community-acquired pneumonia were studied for 2 years in order to define clinical signs and etiology. Blood cultures and serological profiles were done for all patients in addition to standard blood analyses. All had an invasive procedure -transthoracic puncture with an ultrafine 25G needle (20 patients) or telescopic catheter with bacteriologic brush (4 patients). When we were unable to obtain a good sputum sample (5 patients), a culture was grown. The patients' mean age was 48 and 83% had an acute clinical profile (< or = 7 days with symptoms) with "typical" signs. The X-rays showed an alveolar pattern in all patients, with cavitation in 29%. Etiological diagnosis was reached in 17 (71%) cases, with St. Pneumoniae (25%), anaerobic microorganisms (20%) and C. burnetii (12.5%) being the germs found most frequently. The invasive techniques were more useful (54%) than the blood cultures (17%) or sputum cultures (4%), and they were well tolerated and uncomplicated. Empirical antibiotic treatment was modified for 12 patients (50%). Seventeen percent required intensive care treatment and mortality was 12.5%.