Pneumococcal pneumonia infection is associated with end-stage renal disease in adult hospitalized patients

Unplanned hemodialysis initiation: A retrospective analysis of patient characteristics and prognosis in an emergency hospital

INTRODUCTION

Functional decline occurs during dialysis initiation, particularly in unplanned cases. To prevent unplanned hemodialysis, we aimed to identify associated factors from the first referral to the nephrology department to hemodialysis initiation and assess patient prognosis post-unplanned hemodialysis initiation.

METHODS

This retrospective study involved 257 Japanese patients initiating hemodialysis and compared patient characteristics based on whether hemodialysis was planned or unplanned at a single center. Patient outcomes were evaluated in collaboration with maintenance hemodialysis centers.

RESULTS

Unplanned hemodialysis initiation correlated with heart failure history (p < 0.05) and infections like pneumonia (p < 0.001). Patients with unplanned hemodialysis initiation had a worse prognosis than those with planned initiation (p < 0.001), and multivariable Cox regression showed it as an independent risk factor for death (p < 0.05).

CONCLUSIONS

Hygiene and careful attention to heart failure may reduce unplanned hemodialysis and improve patient well-being and healthcare efficiency. This retrospective analysis highlights crucial considerations for optimizing the initiation of hemodialysis.

The role of pneumococcal extracellular vesicles on the pathophysiology of the kidney disease hemolytic uremic syndrome

Streptococcus pneumoniae-induced hemolytic uremic syndrome (Sp-HUS) is a kidney disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. This disease is frequently underdiagnosed and its pathophysiology is poorly understood. In this work, we compared clinical strains, isolated from infant Sp-HUS patients, with a reference pathogenic strain D39, for host cytotoxicity and further explored the role of Sp-derived extracellular vesicles (EVs) in the pathogenesis of an HUS infection. In comparison with the wild-type strain, pneumococcal HUS strains caused significant lysis of human erythrocytes and increased the release of hydrogen peroxide. Isolated Sp-HUS EVs were characterized by performing dynamic light-scattering microscopy and proteomic analysis. Sp-HUS strain released EVs at a constant concentration during growth, yet the size of the EVs varied and several subpopulations emerged at later time points. The cargo of the Sp-HUS EVs included several virulence factors at high abundance, i.e., the ribosomal subunit assembly factor BipA, the pneumococcal surface protein A, the lytic enzyme LytC, several sugar utilization, and fatty acid synthesis proteins. Sp-HUS EVs strongly downregulated the expression of the endothelial surface marker platelet endothelial cell adhesion molecule-1 and were internalized by human endothelial cells. Sp-HUS EVs elicited the release of pro-inflammatory cytokines (interleukin [IL]-1β, IL-6) and chemokines (CCL2, CCL3, CXCL1) by human monocytes. These findings shed new light on the overall function of Sp-EVs, in the scope of infection-mediated HUS, and suggest new avenues of research for exploring the usefulness of Sp-EVs as therapeutic and diagnostic targets. IMPORTANCE Streptococcus pneumoniae-associated hemolytic uremic syndrome (Sp-HUS) is a serious and underdiagnosed deadly complication of invasive pneumococcal disease. Despite the introduction of the pneumococcal vaccine, cases of Sp-HUS continue to emerge, especially in children under the age of 2. While a lot has been studied regarding pneumococcal proteins and their role on Sp-HUS pathophysiology, little is known about the role of extracellular vesicles (EVs). In our work, we isolate and initially characterize EVs from a reference pathogenic strain (D39) and a strain isolated from a 2-year-old patient suffering from Sp-HUS. We demonstrate that despite lacking cytotoxicity toward human cells, Sp-HUS EVs are highly internalized by endothelial cells and can trigger cytokine and chemokine production in monocytes. In addition, this work specifically highlights the distinct morphological characteristics of Sp-HUS EVs and their unique cargo. Overall, this work sheds new light into potentially relevant players contained in EVs that might elucidate about pneumococcal EVs biogenesis or pose as interesting candidates for vaccine design.

The incidence of acute renal failure and high mortality rate in elderly patients hospitalized with community acquired pneumonia

Community acquired pneumonia is associated with high mortality and health care costs, especially in old age. The clinical presentation of pneumonia in the elderly may be asymptomatic or atypical. One of the known complication is an acute kidney injury. The purpose of our study was to estimate the incidence of this complication in elderly patients hospitalized with pneumonia in our geriatric hospital. From a group of 180 elderly patients hospitalized with community-acquired pneumonia 34.4 % developed acute kidney injury. In this group, 51.6 % of patients died compared to 14.4 % in the group of patients without acute kidney injury (p < 0.001). The lower level of e-GFR was significantly associated with mortality (p < 0.001): out of seven patients with e-GFR level of 15-29 mg/mmol, five patients died (71.4 %). Elderly patients with community-acquired pneumonia suffering acute kidney injury experienced worse in-hospital outcomes; mortality rate was significantly higher in our study. We found a relationship between low level of e-GFR and mortality. Clinicians should be alert for early detection and prevention of kidney injury in patients admitted with pneumonia.

Acute organ injury and long-term sequelae of severe pneumococcal infections

Streptococcus pneumoniae (Spn) is a major public health problem, as it is a main cause of otitis media, community-acquired pneumonia, bacteremia, sepsis, and meningitis. Acute episodes of pneumococcal disease have been demonstrated to cause organ damage with lingering negative consequences. Cytotoxic products released by the bacterium, biomechanical and physiological stress resulting from infection, and the corresponding inflammatory response together contribute to organ damage accrued during infection. The collective result of this damage can be acutely life-threatening, but among survivors, it also contributes to the long-lasting sequelae of pneumococcal disease. These include the development of new morbidities or exacerbation of pre-existing conditions such as COPD, heart disease, and neurological impairments. Currently, pneumonia is ranked as the 9^th leading cause of death, but this estimate only considers short-term mortality and likely underestimates the true long-term impact of disease. Herein, we review the data that indicates damage incurred during acute pneumococcal infection can result in long-term sequelae which reduces quality of life and life expectancy among pneumococcal disease survivors.

Acute Kidney Injury and Hemolytic Uremic Syndrome in Severe Pneumococcal Pneumonia—A Retrospective Analysis in Pediatric Intensive Care Unit

Objectives: This study aimed to evaluate the prevalence of acute kidney injury (AKI) and hemolytic uremic syndrome (HUS) in severe pediatric pneumonia due to Streptococcus pneumoniae and to identify factors associated with AKI and HUS in these patients.

Methods: We retrospectively analyzed pediatric patients who were admitted to our pediatric intensive care unit due to severe pneumococcal pneumonia between 2013 and 2019.

Results: Forty-two patients with a median age of 4.3 years were included. Among these patients, 14 (33.3%) developed AKI, including seven (16.7%) stage 1, two (4.8%) stage 2, and five (11.9%) stage 3 AKI. Features of HUS were present in all of the patients with stage 3 AKI, and four required renal replacement therapy (RRT), with a median duration of 10.5 days (range 3 to 16 days). All patients with HUS required mechanical ventilation and inotropic supports. Patients with lower leukocyte and platelet counts, serum sodium and bicarbonate levels, positive urine dipstick (heme or protein ≥ 2 + ), and presence of bacteremia were associated with stage 2 and 3 AKI.

Conclusions: Pediatricians should be aware of the relatively high prevalence of kidney involvement in severe pneumococcal pneumonia, with one-third having AKI and 11.9% developing HUS. Majority (80%) of HUS patients required RRT. Positive urine dipstick, serum sodium, and bicarbonate at presentation, which can be measured in point-of-care tests, may potentially be useful as quick tests to stratify the risks of moderate-to-severe AKI.

Infection in Living Donor Liver Transplantation Leads to Increased Risk of Adverse Renal Outcomes

(1) Background: Little is known about the subsequent renal function change following incident infectious diseases in living-donor liver transplant (LT) recipients. (2) Methods: We studied patients who underwent living-donor LT from January 2003 to January 2019 to evaluate the association of incident hospitalization with major infections or pneumonia with adverse renal outcomes, including a sustained 40% reduction in estimated glomerular filtration rate (eGFR) and renal composite outcome (a 40% decline in eGFR, end-stage renal disease, or death.). Multivariable-adjusted time-dependent Cox models with infection as a time-varying exposure were used to estimate hazard ratio (HR) with 95% confidence interval (CI) for study outcomes. (3) Results: We identified 435 patients (mean age 54.6 ± 8.4 years and 76.3% men), of whom 102 had hospitalization with major infections during follow-up; the most common cause of infection was pneumonia (38.2%). In multiple Cox models, hospitalization with a major infection was associated with an increased risk of eGFR decline > 40% (HR, 3.32; 95% CI 2.13−5.16) and renal composite outcome (HR, 3.41; 95% CI 2.40−5.24). Likewise, pneumonia was also associated with an increased risk of eGFR decline > 40% (HR, 2.47; 95% CI 1.10−5.56) and renal composite outcome (HR, 4.37; 95% CI 2.39−8.02). (4) Conclusions: Our results illustrated the impact of a single infection episode on the future risk of adverse renal events in LT recipients. Whether preventive and prophylactic care bundles against infection and judicious modification of the immunosuppressive regimen benefit renal outcomes may deserve further study.

Causes of Hospitalization among End-Stage Kidney Disease Cohort before and after Hemodialysis

Patients with end-stage kidney disease (ESKD) have a greater risk of comorbidities, including diabetes and anemia, and have higher hospital admission rates than patients with other diseases. The cause of hospital admissions is associated with ESKD prognosis. This retrospective cohort study involved patients with ESKD who received hemodialysis and investigated whether the cause of hospital admission changed before versus after they started hemodialysis. This study recruited 592 patients with ESKD who received hemodialysis at any period between January 2005 and November 2017 and had been assigned the International Classification of Diseases Ninth Revision Clinical Modification (ICD-9-CM) code for ESKD. The patients' demographic data and hospitalization status one year before and two years after they received hemodialysis were analyzed. A McNemar test was conducted to analyze the diagnostic changes from before to after hemodialysis in patients with ESKD. The study's sample of patients with ESKD comprised more women (51.86%) than men and had an average age of 67.15 years. The numbers of patients admitted to the hospital for the following conditions all decreased significantly after they received hemodialysis: type 2 (non-insulin-dependent and adult-onset) diabetes; native atherosclerosis; urinary tract infection; gastric ulcer without mention of hemorrhage, perforation, or obstruction; pneumonia; reflux esophagitis; duodenal ulcer without mention of hemorrhage, perforation, or obstruction; and bacteremia. Most patients exhibited one or more of the following comorbidities: diabetes (n = 407, 68.75%), hypertension (n = 491, 82.94%), congestive heart failure (n = 161, 27.20%), ischemic heart disease (n = 125, 21.11%), cerebrovascular accident (n = 93, 15.71%), and gout (n = 96, 16.22%). An analysis of variance (ANOVA) indicated that changes in the ICD-9-CM codes for native atherosclerosis, urinary tract infection, pneumonia, and hyperkalemia were associated with age. Patients who developed pneumonia before or after they received hemodialysis tended to be older (range: 69-70 years old). This study investigated the causes of hospital admission among patients with ESKD one year before and two years after they received hemodialysis. This study's results revealed hypertension to be the most common comorbidity. Regarding the cause of admission, pneumonia was more prevalent in older than in younger patients. Moreover, changes in the ICD-9-CM codes of native atherosclerosis, urinary tract infection, pneumonia, and hyperkalemia were significantly correlated with age. Therefore, when administering comprehensive nursing care and treatment for ESKD, clinicians should not only focus on comorbidities but also consider factors (e.g., age) that can affect patient prognosis.

An in vivo atlas of host-pathogen transcriptomes during Streptococcus pneumoniae colonization and disease

Streptococcus pneumoniae (Spn) colonizes the nasopharynx and can cause pneumonia. From the lungs it spreads to the bloodstream and causes organ damage. We characterized the in vivo Spn and mouse transcriptomes within the nasopharynx, lungs, blood, heart, and kidneys using three Spn strains. We identified Spn genes highly expressed at all anatomical sites and in an organ-specific manner; highly expressed genes were shown to have vital roles with knockout mutants. The in vivo bacterial transcriptome during colonization/disease was distinct from previously reported in vitro transcriptomes. Distinct Spn and host gene-expression profiles were observed during colonization and disease states, revealing specific genes/operons whereby Spn adapts to and influences host sites in vivo. We identified and experimentally verified host-defense pathways induced by Spn during invasive disease, including proinflammatory responses and the interferon response. These results shed light on the pathogenesis of Spn and identify therapeutic targets.

Short- and long-term outcomes after incident pneumonia in adults with chronic kidney disease: a time-dependent analysis from the Stockholm CREAtinine Measurement project

BACKGROUND

Little is known about the health sequelae of pneumonia in persons with chronic kidney disease (CKD).

METHODS

We studied adults with CKD in Stockholm during 2006-11, who not previously been diagnosed with lower respiratory tract infections. We used multivariable-adjusted Cox regression with pneumonia as a time-varying exposure to estimate hazard ratios (HRs) [95% confidence intervals (CIs)] for the events of death, major adverse cardiovascular events (MACEs), acute kidney injury (AKI), CKD progression or hospitalization for urinary tract infections (UTIs)/sepsis. Cataract and knee/joint replacement served as negative control outcomes.

RESULTS

We identified 71 931 adults (mean age 79 years, 59% women), of whom 8379 (12%) were diagnosed with pneumonia during follow-up; incident pneumonia was associated with 10 times higher adjusted mortality risk during the first 90 days [HR = 10.0, 95% confidence interval (CI) 9.5-10.5] and double the mortality beyond 90 days from pneumonia diagnosis (HR = 2.0; 95% CI 1.9-2.1). Incident pneumonia was similarly associated with higher adjusted risk of MACE (<90 days: HR = 12.6; 95% CI 12.0-13.3; ≥90 days: HR = 1.5; 95% CI 1.4-1.6). The adjusted risk of CKD progression and UTI/sepsis hospitalization was highest within 90 days from pneumonia but remained elevated thereafter. For AKI, the association with incident pneumonia was only seen within 90 days. Neither cataract nor knee/joint replacement was related to pneumonia.

CONCLUSIONS

Incident pneumonia was associated with increased risks of MACE, CKD progression, severe UTI/sepsis and death, with risks highest soon after pneumonia diagnosis but extending beyond 90 days. Our findings highlight the susceptibility for adverse outcomes of CKD patients following pneumonia diagnosis, and may inform clinical decisions regarding vaccination strategies.

Hospitalization With Major Infection and Incidence of End-Stage Renal Disease: The Atherosclerosis Risk in Communities (ARIC) Study

OBJECTIVE

To evaluate whether the incidence of infectious diseases increases the long-term risk for incident end-stage renal disease (ESRD) in the general population.

PATIENTS AND METHODS

In 10,290 participants of the Atherosclerosis Risk in Communities Study who attended visit 4 (1996-1998), we evaluated the association of incident hospitalization with major infections (pneumonia, urinary tract infection, bloodstream infection, and cellulitis and osteomyelitis) with subsequent risk for ESRD through September 30, 2015. Hospitalization with major infection was entered into multivariable Cox models as a time-varying exposure to estimate the hazard ratios.

RESULTS

Mean age was 63 years, and of 10,290 individuals, 56% (n=5781) were women, 22% (n=2252) were black, and 7% (n=666) had an estimated glomerular filtration rate less than 60 mL/min/1.73 m2. During a median follow-up of 17.4 years, there were 2642 incident hospitalizations with major infection and 281 cases of ESRD (132 cases after hospitalization with major infection). The risk for ESRD was higher following major infection compared with while free of major infection (crude incidence rate, 10.9 vs 1.0 per 1000 person-years). In multivariable time-varying Cox analysis, hospitalization with major infection was associated with a 3.3-fold increased risk for ESRD (hazard ratio, 3.34; 95% CI, 2.56-4.37). The association was similar across pneumonia, urinary tract infection, bloodstream infection, and cellulitis and osteomyelitis, and remained significant across subgroups of age, sex, race, diabetes, history of cardiovascular disease, and chronic kidney disease.

CONCLUSION

Hospitalization with major infection was independently and robustly associated with subsequent risk for ESRD. Whether preventive approaches against infection have beneficial effects on kidney outcomes may deserve future investigations.

Stratified risks of infection-related hospitalization in patients with chronic kidney disease - A prospective cohort study

Patients with chronic kidney disease (CKD) are at high risk of infection, but whether the risks are attenuated in different patient groups remains unclear. This study enrolled participants with CKD stages 1-3 in the New Taipei City Health Screening Program between 2005 and 2008. A proportional hazard regression model was employed to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) for infection-related hospitalization and mortality in younger (<50-year-old) and older (≥50-year-old) CKD patients. Of 119,871 adults, there were 14,207 cases of first hospitalization for infection during a median follow-up of 8.14 years; 45.5% of these cases were younger patients. Unlike CKD stage 1 and 2 patients, the risk of infection-related hospitalization in younger CKD stage 3 patients is as high as for older CKD stage 3 patients. Proteinuria increases the risk of infection-related hospitalization independent of estimated glomerular filtration rate (eGFR) levels in older CKD patients but this relationship is weak in their younger counterparts. In conclusion, the risk of infection-related hospitalization is high in subgroups of CKD patients. Prevention and treatment of infections in these patients merit more attention.

Commentary: Why Has Uptake of Pneumococcal Vaccines for Children Been So Slow? The Perils of Undervaluation

Pediatric pneumococcal disease exacts a substantial burden on global health, much of which is vaccine-preventable. Despite this considerable burden and the demonstrably high efficacy of pneumococcal conjugate vaccines (PCVs), the overall level of PCV uptake remains concerningly low, especially compared with that of other childhood-recommended vaccines, such as tuberculosis and polio. A broad set of plausible explanations exists for this low uptake, including logistical challenges, psychosocial factors and affordability. One additional and systematic cause of low uptake, which is the focus of our discussion, is economists' and policymakers' tendency to undervalue vaccination in general by adopting a narrow health sector perspective when performing economic evaluations of vaccines. We present an alternative, societal framework for economic evaluations that encompasses a broader set of socioeconomic benefits in addition to health benefits. Quantifying a more comprehensive taxonomy of PCV's benefits will help to address potential undervaluation and may be sufficient not only to justify recommendation and reimbursement but also to stimulate efforts and investment toward closing coverage gaps.

Mortality and costs of pneumococcal pneumonia in adults: a cross-sectional study

Objective

Pneumococcal pneumonia is a significant cause of morbidity and mortality among adults. The study’s main aim was to evaluate the in-hospital mortality and related costs of community-acquired pneumococcal pneumonia in adults.

Methods

This cross-sectional study used medical records of adult patients with pneumococcal pneumonia hospitalized in a university hospital in Brazil from October 2009 to April 2017. All patients aged ≥ 18 years diagnosed with pneumococcal pneumonia were included. Risk factors, intensive care unit admission, length of hospital stay, in-hospital mortality, and direct and indirect costs were analyzed.

Results

In total, 186 patients were selected. The mean in-hospital mortality rate was 18% for adults aged < 65 years and 23% for the elderly (≥ 65 years). Bacteremic pneumococcal pneumonia affected 20% of patients in both groups, mainly through chronic respiratory disease (adjusted OR: 3.07, 95% CI: 1.23–7.65, p < 0.01). Over 7 years, annual total direct and indirect costs were USD 28,188 for adults < 65 years (USD 1,746 per capita) and USD 16,350 for the elderly (USD 2,119 per capita).

Conclusion

Pneumococcal pneumonia remains an important cause of morbidity and mortality among adults, significantly affecting direct and indirect costs. These results suggest the need for prevention strategies for all adults, especially for patients with chronic respiratory diseases.

Renal complications and subsequent mortality in acute critically ill patients without pre-existing renal disease

BACKGROUND

Most studies of long-term renal outcomes after acute critical illness have enrolled patients with pre-existing renal dysfunction. We assessed renal outcomes in patients who did not have pre-existing renal disease and who were admitted to hospital for acute critical illness.

METHODS

We identified adults who did not have pre-existing renal disease and who were admitted to hospital for acute critical illness between 2000 and 2011, from the Taiwan National Health Insurance Research Database. Each patient was matched 1:2 with controls without acute critical illness, according to age, sex and index date. A subset was further matched 1:1 with controls using propensity scores. Outcomes included acute kidney injury, chronic kidney disease and end-stage renal disease.

RESULTS

We evaluated 33 613 patients with acute critical illness matched to 63 148 controls, of whom 14 218 were propensity matched to 14 218 controls. Patients with acute critical illness had incidence rates per 10 000 person-years of 9.45 for acute kidney injury, 78.3 for chronic kidney disease and 21.0 for end-stage renal disease. In the propensity-matched cohort, patients with acute critical illness had significantly higher risks of acute kidney injury (adjusted hazard ratio [aHR] 2.92, 95% confidence interval [CI] 1.78-4.77), chronic kidney disease (aHR 1.81, 95% CI 1.57-2.08), and end-stage renal disease (aHR 3.60, 95% CI 2.50-5.18). Acute critical illness conferred higher mortality risk among patients who subsequently developed end-stage renal disease (aHR 3.37, 95% CI 2.07-5.49) or chronic kidney disease (aHR 2.16, 95% CI 1.67-2.80).

INTERPRETATION

Patients with acute critical illness and without pre-existing renal disease have a higher risk of adverse renal outcomes and subsequent mortality. A resolved episode of critical illness has implications for future renal function surveillance, even in patients without pre-existing renal disease.

Association of Kidney Function with Infections by Multidrug-Resistant Organisms: An Electronic Medical Record Analysis

Antibiotic resistance is a major global health threat. High prevalences of colonization and infection with multi-drug resistance organisms (MDROs) have been reported in patients undergoing dialysis. It is unknown if this finding extends to patients with mild and moderate/severe kidney disease. An observational study included all adult incident patients hospitalized with a discharge diagnosis of infection in four hospitals from Guangzhou, China. Inclusion criteria: Serum creatinine measurement at admission together with microbial culture confirmed infections. Exclusion criterion: Undergoing renal replacement therapy. Four categories of Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) estimated glomerular filtration rate (eGFR) were compared: eGFR ≥ 105, 60–104 (reference), 30–59, and <30 ml/min/1.73 m². The odds ratio of MDROs, defined as specific pathogens (Staphylococcus aureus, Enterococcus spp., Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter spp.) resistant to three or more antibiotic classes, were calculated using a multivariable logistic regression model across eGFR strata. Of 94,445 total microbial culture records, 7,288 first positive cultures matched to infection diagnosis were selected. Among them, 5,028 (68.9%) were potential MDROs. The odds of infections by MDROs was 19% and 41% higher in those with eGFR between 30–59 ml/min/1.73 m² (Adjusted odds ratio, AOR): 1.19, 95% CI:1.02–1.38, P = 0.022) and eGFR < 30 ml/min/1.73 m² (AOR: 1.41, 95% CI:1.12–1.78, P = 0.004), respectively. Patients with impaired renal function have a higher risk of infections by MDROs. Kidney dysfunction at admission may be an indicator for need of closer attention to microbial culture results requiring subsequent change of antibiotics.

Hospital admission with pneumonia and subsequent persistent risk of chronic kidney disease: national cohort study

Background

Although acute onset kidney complications associated with severe infections including pneumonia are well characterized, little is known about possible subsequent delayed risk of chronic kidney disease (CKD).

Patients and methods

Associations between hospital admission with pneumonia in adulthood and raised risks of subsequent CKD were evaluated in a cohort of all male residents in Sweden born from 1952 to 1956 (n=284,198) who attended mandatory military conscription examinations in late adolescence (n=264,951) and were followed up through 2009. CKD and pneumonia were identified using Swedish national registers, and their associations were evaluated using Cox regression. Excluding the first year, the subsequent period was divided into ≤5, >5–≤15, and >15 years after hospital admission with pneumonia. Follow-up ended on the date of first incident diagnosis of kidney disease, death, emigration, or December 31,2009, whichever occurred first.

Results

During a median follow-up of 36.7 (interquartile range 35.3–37.9) years from late adolescence, 5,822 men had an inpatient pneumonia diagnosis without contemporaneous kidney disease. Among exposed men, 136 (2.3%) were later diagnosed with CKD compared with 2,749 (1.2%) of the unexposed. The adjusted hazard ratio for CKD in the first year after the first episode of pneumonia was 14.55 (95% confidence interval, 10.41–20.32), identifying early onset kidney complications and possibly pre-existing undiagnosed CKD. Starting follow-up 1 year after pneumonia to reduce the potential influence of surveillance bias and the risk of reverse causation, the adjusted hazard ratio for CKD in the first 5 years of follow-up was 5.20 (95% confidence interval, 3.91–6.93) and then attenuated with increasing time.

Conclusion

Pneumonia among inpatients is associated with a persistently increased risk for subsequent CKD, with the highest risk during the years immediately after pneumonia. Health care professionals should be aware of this period of heightened risk to facilitate early diagnosis and secondary preventive interventions.

Streptococcus pneumoniae in the heart subvert the host response through biofilm-mediated resident macrophage killing

For over 130 years, invasive pneumococcal disease has been associated with the presence of extracellular planktonic pneumococci, i.e. diplococci or short chains in affected tissues. Herein, we show that Streptococcus pneumoniae that invade the myocardium instead replicate within cellular vesicles and transition into non-purulent biofilms. Pneumococci within mature cardiac microlesions exhibited salient biofilm features including intrinsic resistance to antibiotic killing and the presence of an extracellular matrix. Dual RNA-seq and subsequent principal component analyses of heart- and blood-isolated pneumococci confirmed the biofilm phenotype in vivo and revealed stark anatomical site-specific differences in virulence gene expression; the latter having major implications on future vaccine antigen selection. Our RNA-seq approach also identified three genomic islands as exclusively expressed in vivo. Deletion of one such island, Region of Diversity 12, resulted in a biofilm-deficient and highly inflammogenic phenotype within the heart; indicating a possible link between the biofilm phenotype and a dampened host-response. We subsequently determined that biofilm pneumococci released greater amounts of the toxin pneumolysin than did planktonic or RD12 deficient pneumococci. This allowed heart-invaded wildtype pneumococci to kill resident cardiac macrophages and subsequently subvert cytokine/chemokine production and neutrophil infiltration into the myocardium. This is the first report for pneumococcal biofilm formation in an invasive disease setting. We show that biofilm pneumococci actively suppress the host response through pneumolysin-mediated immune cell killing. As such, our findings contradict the emerging notion that biofilm pneumococci are passively immunoquiescent.

Risk of empyema in patients with end-stage renal disease: a nationwide propensity-matched cohort study

BACKGROUND

Empyema is a rare but important complication among patients with end-stage renal disease (ESRD). However, a nationwide, propensity-matched cohort study has never been performed.

METHODS

We conducted a retrospective cohort study using data from the National Health Insurance Research Database of Taiwan. The ESRD group consisted of 82 765 patients diagnosed between 2000 and 2008. The comparison group consisted of individuals without kidney disease selected at a 1:1 ratio matched by propensity score estimated with age, gender, year of diagnosis and comorbidities. The occurrence of empyema was monitored until the end of 2011. The hazard ratios (HRs) of empyema were estimated using the Cox proportional hazards model.

RESULTS

The incidence of empyema was 2.76-fold higher in the ESRD group than in the comparison group (23.7 vs. 8.19/10 000 person-years, P  <0.001), with an adjusted HR of 3.01 [95% confidence interval (CI) = 2.67-3.39]. There was no difference of the incidence of empyema between hemodialysis (HD) and peritoneal dialysis (PD) (adjusted HR = 0.96, 95% CI = 0.75-1.23). In addition, 30-day mortality rate since empyema diagnosis was significantly higher in ESRD group than the comparison group (15.9% vs. 10.9%), with an adjusted OR of 1.69 (95% CI = 1.17-2.44).

CONCLUSION

The risk of empyema was significantly higher in patients with ESRD than in those without kidney disease. The occurrence of empyema was without difference in patients undergoing HD compared to those undergoing PD. The 30-day mortality rate since empyema diagnosis was also significantly higher in patients with ESRD.

Dipstick proteinuria level is significantly associated with pre-morbid and in-hospital functional status among hospitalized older adults: a preliminary study

Although chronic kidney disease (CKD) is associated with functional decline, whether proteinuria alone is associated with functional statuses over the course of acute illnesses independent of CKD is unclear. During 2014, we prospectively enrolled non-dialysis patients aged ≥65 years, and all participants underwent spot dipstick urinalysis on admission, divided into 3 groups according to the results (none, trace to 1 + , and 2 + or higher); functional status was evaluated using the pre-morbid and in-hospital Barthel index (BI) scores. Of 136 community-dwelling elderly patients enrolled (age 80.7 ± 8.2 years, with 19% having CKD), 17%, 57%, and 26% had no, trace to 1 + , or 2 + or higher proteinuria. Overall pre-morbid, on-admission, and on-discharge BI scores were 50.4 ± 41.9, 38.6 ± 31.8, and 38.7 ± 35.3, respectively with significant negative correlations with proteinuric severity on admission. Finally, multivariate linear stepwise regression analysis with backward variable selection found that dipstick proteinuric severity was significantly associated with pre-morbid, on-admission, and on-dischrage BI scores (p = 0.048, <0.01, and <0.01, respectively), independent of diabetes and CKD. This relationship between dipstick proteinuric levels and functional status of hospitalized elderly suggests an under-recognized association. Prospective evaluation of long-term outcome is needed.

Non-obvious correlations to disease management unraveled by Bayesian artificial intelligence analyses of CMS data

OBJECTIVE

Given the availability of extensive digitized healthcare data from medical records, claims and prescription information, it is now possible to use hypothesis-free, data-driven approaches to mine medical databases for novel insight. The goal of this analysis was to demonstrate the use of artificial intelligence based methods such as Bayesian networks to open up opportunities for creation of new knowledge in management of chronic conditions.

MATERIALS AND METHODS

Hospital level Medicare claims data containing discharge numbers for most common diagnoses were analyzed in a hypothesis-free manner using Bayesian networks learning methodology.

RESULTS

While many interactions identified between discharge rates of diagnoses using this data set are supported by current medical knowledge, a novel interaction linking asthma and renal failure was discovered. This interaction is non-obvious and had not been looked at by the research and clinical communities in epidemiological or clinical data. A plausible pharmacological explanation of this link is proposed together with a verification of the risk significance by conventional statistical analysis.

CONCLUSION

Potential clinical and molecular pathways defining the relationship between commonly used asthma medications and renal disease are discussed. The study underscores the need for further epidemiological research to validate this novel hypothesis. Validation will lead to advancement in clinical treatment of asthma & bronchitis, thereby, improving patient outcomes and leading to long term cost savings. In summary, this study demonstrates that application of advanced artificial intelligence methods in healthcare has the potential to enhance the quality of care by discovering non-obvious, clinically relevant relationships and enabling timely care intervention.

Infection in advanced chronic kidney disease leads to increased risk of cardiovascular events, end-stage kidney disease and mortality

The risk of infection in advanced chronic kidney disease (CKD) and its subsequent impact on adverse outcomes are not well established. Therefore, we determined the association of an infectious episode with the subsequent risk of cardiovascular ischemia, congestive heart failure, end-stage kidney disease or mortality in a Canadian prospective cohort (CanPREDDICT) of patients with advanced CKD (eGFR: 15-45 ml/min/1.73m(2)) followed by nephrologists for up to 5 years. Infectious episodes were classified by anatomic location and identified by positive culture, hospital admission, or use of antibiotics. Competing risk models were used to examine the time-varying risk of infection and the risk of cardiovascular ischemia, congestive heart failure, or end-stage kidney disease accounting for the competing risk of mortality. All outcomes were independently adjudicated. Of 2370 patients (mean age, 68 years; mean baseline eGFR, 28.2 mL/min/1.73m(2)), 575 patients (24.3%) had recorded infections; 378 had 1 infection episode, whereas 197 had 2 or more episodes, the most common being urinary and respiratory. An infectious episode was independently associated with an increased risk of cardiovascular ischemia (hazard ratio 1.80, 95% confidence interval 1.24-2.60), congestive heart failure (hazard ratio, 3.2; confidence interval, 2.25-4.61), end-stage kidney disease (hazard ratio, 1.58; confidence interval, 1.22-2.05) or mortality (hazard ratio, 3.39; confidence interval, 2.65-4.33). Thus, there is a high risk of infection in advanced CKD being associated with subsequent adverse outcomes.

Increased Risk of Acute Kidney Injury following Pneumococcal Pneumonia: A Nationwide Cohort Study

Purpose

Pneumococcal disease leads to renal complications ranging from persistent proteinuria to end-stage renal disease. Studies on the association between pneumococcal pneumonia (PP) and acute kidney injury (AKI) are scant. This study assessed the relationship between PP and risk of AKI.

Methods

This nationwide population-based cohort study examined data from the Taiwan National Health Insurance Research Database for the period 2000–2011. We identified inpatients with newly diagnosed PP according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. In addition, we selected a comparison cohort from inpatient claims without the diagnosis of PP that was randomly frequency-matched with the PP cohort according to age, sex, index year and comorbidities. We analyzed the risks of AKI by using Cox proportional hazards regression models, adjusted for sex, age, and comorbidities.

Results

A total of 10,069 patients with PP and 10,069 controls were enrolled in this study. After adjustments for age, sex, and comorbidities, patients with PP had a 1.11-fold risk of developing AKI compared with the comparison cohort.

Conclusion

This study indicates that AKI risks are higher in patients with PP compared with the comparison cohort. Careful follow-up observation and aggressive treatment are necessary for patients with PP to reduce the risk of AKI.

Comparative Outcome Analysis of Penicillin-Based Versus Fluoroquinolone-Based Antibiotic Therapy for Community-Acquired Pneumonia: A Nationwide Population-Based Cohort Study

Community-acquired pneumonia (CAP) is a common but potentially life-threatening condition, but limited information exists on the effectiveness of fluoroquinolones compared to β-lactams in outpatient settings. We aimed to compare the effectiveness and outcomes of penicillins versus respiratory fluoroquinolones for CAP at outpatient clinics.This was a claim-based retrospective cohort study. Patients aged 20 years or older with at least 1 new pneumonia treatment episode were included, and the index penicillin or respiratory fluoroquinolone therapies for a pneumonia episode were at least 5 days in duration. The 2 groups were matched by propensity scores. Cox proportional hazard models were used to compare the rates of hospitalizations/emergence service visits and 30-day mortality. A logistic model was used to compare the likelihood of treatment failure between the 2 groups.After propensity score matching, 2622 matched pairs were included in the final model. The likelihood of treatment failure of fluoroquinolone-based therapy was lower than that of penicillin-based therapy (adjusted odds ratio [AOR], 0.88; 95% confidence interval [95%CI], 0.77-0.99), but no differences were found in hospitalization/emergence service (ES) visits (adjusted hazard ratio [HR], 1.27; 95% CI, 0.92-1.74) and 30-day mortality (adjusted HR, 0.69; 95% CI, 0.30-1.62) between the 2 groups.The likelihood of treatment failure of fluoroquinolone-based therapy was lower than that of penicillin-based therapy for CAP on an outpatient clinic basis. However, this effect may be marginal. Further investigation into the comparative effectiveness of these 2 treatment options is warranted.

Association Between Chronic Osteomyelitis and Risk of End-Stage Renal Disease: A Nationwide Population-Based Cohort Study

Inflammation, which initiates endothelial dysfunction, vascular atherosclerosis, and oxidative stress, may negatively influence renal function and accelerate the development of end-stage renal disease (ESRD). The role of chronic osteomyelitis (COM), a chronic inflammatory disease, in the development of ESRD has not been investigated. This study explored whether patients with COM have a higher risk of ESRD than that of patients without COM.Taiwan National Health Insurance claims from 1997 to 2010 were used to identify 24,267 newly diagnosed patients with COM and 97,068 age- and sex-matched non-COM controls for comparison. The risks of ESRD among COM patients, with adjustment for comorbidities, namely, hypertension, diabetes, coronary artery disease, congestive heart failure, and hyperlipidemia, were assessed until the end of 2010.ESRD risk was 2.01-fold higher (95% confidence interval [CI]: 1.81-2.25) in the COM cohort than in the non-COM cohort. Regarding the joint effect of COM with comorbidity, the ESRD risk was 1.57-fold higher (95% CI: 1.23-2.00) for the COM cohort without comorbidities and increased to 2.25 (95% CI: 1.97-2.57) for the COM cohort with at least 1 comorbidity. Age-specific analysis revealed that the adjusted ESRD risk for the COM cohort increased as age decreased, with the highest hazard ratio being 17.8 (95% CI: 5.18-61.4) for patients aged 20-34 years.This was the first study to report that COM is associated with an increased risk of ESRD, particularly among patients with comorbidities and younger patients.

Association between Helicobacter pylori infection and the subsequent risk of end-stage renal disease: a nationwide population-based cohort study

BACKGROUND & AIMS

The association between Helicobacter pylori infection and end-stage renal disease (ESRD) events remains unknown. We assessed the relationship between H. pylori infection requiring hospital admission and the subsequent risks of ESRD.

METHODS

This was a retrospective cohort study in which data from the National Health Insurance system of Taiwan was used. The H. pylori-infected cohort comprised 20,068 patients. Each participant was frequency-matched by age and sex with 4 individuals from the general population without H. pylori-infected. Cox proportional hazards regression analysis was used to estimate the influence of H. pylori infection on the risk of ESRD.

RESULTS

The overall incidence of ESRD was 3.72 times greater in the H. pylori-infected cohort than in the non-infected cohort (11.1 vs. 2.96 per 1000 person-years), with an adjusted HR of 2.58 [95% confidence interval (CI)=2.33-2.86]. The risk of ESRD markedly increased in patients with H. pylori infection combined with at least one of the following concomitant comorbidities: hypertension, diabetes, hyperlipidaemia and coronary artery disease.

CONCLUSIONS

This is currently the largest nation-based study in which the risk of ESRD in H. pylori-infected patients was examined. H. pylori infection was associated with a subsequent risk of ESRD. H. pylori-infected patients with concomitant chronic kidney disease (CKD) or cardiovascular disease (CVD) risk factors were at higher risk of ESRD than were those who had a single CKD or CVD risk factor.