Cytokine-driven inflammatory response is associated with the hypermetabolism of AIDS patients with opportunistic infections

Identification of predictive markers of Pneumocystis jirovecii pneumonia in kidney transplant recipients

BACKGROUND

Kidney transplantation has emerged as the most effective treatment for patients with uremia. Advances in immunosuppressant medications have significantly reduced the risk of rejection. However, a notable increase in opportunistic infections, such as Pneumocystis jirovecii pneumonia (PJP), demands special attention in clinical practice. Our study aims to evaluate risk factors and identify predictive markers associated with PJP in kidney transplantation recipients.

METHODS

We conducted a case-control study (1:2 ratio) involving kidney transplant recipients with and without PJP, matched based on the same surgical date. The study was carried out at Zhongnan Hospital of Wuhan University, China.

RESULTS

Ninety-three participants were enrolled at Zhongnan Hospital of Wuhan University, comprising 31 with PJP and 62 without PJP. All patients tested negative for HIV. Our findings indicate that PJP patients exhibited lower levels of serum albumin (P = 0.001), reduced counts of total and CD3+ (P < 0.001), CD4+ (P = 0.001), and CD8+ T lymphocytes (P < 0.001), and a lower rate of prophylactic trimethoprim-sulfamethoxazole (TMP-SMZ) usage compared to non-PJP patients (P = 0.02). Conversely, urea levels in PJP patients were significantly higher than in non-PJP controls (P < 0.001). We developed a model combining CD8+ T cell count (< 241.11/μL, P < 0.001) and ALB levels (< 35.2 g/L, P = 0.003), which demonstrated excellent discriminatory power in distinguishing PJP from non-PJP cases, with an area under the curve (AUC) of 0. 920 (95% CI, 0.856-0.989).

CONCLUSIONS

Our study suggests that a baseline CD8+ T cell count (< 241.11/μL) and serum ALB levels (< 35.2 g/L) offer robust predictive value for the occurrence of PJP infections in kidney transplant recipients.

Clinical significance of mutations in dihydropteroate synthase in Pneumocystis jirovecii pneumonia among non-HIV-infected patients

BACKGROUND

Dihydropteroate synthase (DHPS) mutations may be associated with trimethoprim-sulfamethoxazole resistance in Pneumocystis jirovecii pneumonia (PCP) and worse clinical outcomes. However, the clinical significance of DHPS mutations in PCP among non-human immunodeficiency virus (HIV)-infected patients remains unclear.

METHODS

Patients with PCP in three tertiary referral hospitals in Taiwan between 2016 and 2020 were retrospectively enrolled. Two point mutations, Thr55Ala and Pro57Ser, in the DHPS protein were analysed. Patients with invalid DHPS mutations in the respiratory specimen, chronic respiratory failure, receiving endotracheal intubation for surgical intervention, HIV infection, Pneumocystis jirovecii colonisation, and no lactate dehydrogenase (LDH) data were excluded. The primary outcome was 30-day survival.

RESULTS

A total of 215 patients were analysed. Mutants inside DHPS were found in 78 patients (36.3%) and 68 patients (31.6%) died within 30 days. A total of 214 patients (99.5%) received trimethoprim-sulfamethoxazole as the first-line treatment. The rates of mechanical ventilation, 30-day, and in-hospital mortality were similar between wild-type and mutant DHPS PCP. After adjusting for important confounders, LDH > 500 µ/L (adjusted hazard ratio [aHR] = 2.448, P = 0.001), pneumonia severity index > 135 mg/dL (aHR = 1.689, P = 0.049), and having solid tumours (aHR = 1.832, P = 0.034) were independently associated with higher mortality. In subgroup analysis, mutant DHPS PCP patients had less 30-day mortality among patients aged > 65 years (P = 0.049), with lymphopenia (P = 0.040), and those without solid tumour (P = 0.045).

CONCLUSIONS

In non-HIV-infected PCP, point mutants inside DHPS may not be associated with trimethoprim-sulfamethoxazole treatment outcomes. Further prospective large-scale studies are warranted.

Clinical Performance of BAL Metagenomic Next-Generation Sequence and Serum (1,3)-β-D-Glucan for Differential Diagnosis of Pneumocystis jirovecii Pneumonia and Pneumocystis jirovecii Colonisation

Background

Differentiating Pneumocystis jirovecii infection from colonisation is crucial for appropriate therapy administration. In this study, we evaluated the performance of bronchoalveolar lavage fluid (BAL) metagenomic next-generation sequencing (mNGS) and serum 1,3-β-D-glucan (BDG) tests in differentiating colonisation and infection with P. jirovecii.

Methods

From January 2018 to March 2021, 47 patients were enrolled in this study at the Hunan Provincial People’s Hospital. The final diagnosis was used as a reference, and cases were classified into the P. jirovecii pneumonia (PJP) group or the P. jirovecii colonisation (PJC) group. Clinical data were recorded. The performances of mNGS and BDG were compared.

Result

The fungal load significantly differed between patients with PJP and PJC, with median reads of 3,215.79 ± 1,797 vs. 5.61 ± 0.88 in the PJP and PJC groups, respectively (P < 0.0001). BDG also significantly differed between the two groups, with a median titre of 233.60 ± 39.65 pg/ml in the PJP group and 68.48 ± 19.21 pg/ml in the PJC group (P = 0.0006). The area under the curve was 0.973 (95%CI: 0.868–1.007) for mNGS of the BAL and 0.879 (95%CI: 0.769–0.989) for the serum BDG. The optimal threshold value for discriminating P. jirovecii infection from colonisation appeared to be 14 reads (sensitivity, 83.3%; specificity, 95.7%; positive likelihood ratio, 19.2) and BDG = 88.6 pg/ml (sensitivity, 79.2%; specificity, 92.9%; positive likelihood ratio, 18.2). No correlation between mNGS reads and the BDG titre was found in mNGS-positive patients (r² = 0.0076, P = 0.583). The levels of lactate dehydrogenase and C-reactive protein were significantly higher in the PJP group than in the PJC group.

Conclusion

BAL mNGS and serum BDG are useful adjunct tests that can assist with differentiating between colonisation and infection of P. jirovecii.

Using Routine Laboratory Markers and Immunological Indicators for Predicting Pneumocystis jiroveci Pneumonia in Immunocompromised Patients

Background

Pneumocystis jiroveci pneumonia (PJP) is the most common opportunistic infection in immunocompromised patients. The accurate prediction of PJP development in patients undergoing immunosuppressive therapy remains challenge.

Methods

Patients undergoing immunosuppressive treatment and with confirmed pneumocystis jiroveci infection were enrolled. Another group of matched patients with immunosuppressant treatment but without signs of infectious diseases were enrolled to control group.

Results

A total of 80 (40 PJP, 40 non-PJP) participants were enrolled from Tongji Hospital. None of the patients were HIV positive. The routine laboratory indicators, such as LYM, MON, RBC, TP, and ALB, were significantly lower in PJP patients than in non-PJP patients. Conversely, LDH in PJP patients was significantly higher than in non-PJP controls. For immunological indicators, the numbers of T, B, and NK cells were all remarkably lower in PJP patients than in non-PJP controls, whereas the functional markers such as HLA-DR, CD45RO and CD28 expressed on CD4⁺ or CD8⁺ T cells had no statistical difference between these two groups. Cluster analysis showing that decrease of host immunity markers including CD3⁺, CD4⁺ and CD8⁺ T cells, and increase of tissue damage marker LDH were the most typical characteristics of PJP patients. A further established model based on combination of CD8⁺ T cells and LDH showed prominent value in distinguishing PJP from non-PJP, with AUC of 0.941 (95% CI, 0.892-0.990).

Conclusions

A model based on combination of routine laboratory and immunological indicators shows prominent value for predicting the development of PJP in HIV-negative patients undergoing immunosuppressive therapy.

Resting energy expenditure in HIV/AIDS patients: Development and validation of a predictive equation

BACKGROUND

Accurate measurements of resting energy expenditure (REE) are important for determining nutritional needs in HIV patients. Indirect calorimetry (IC) is a noninvasive method that reflects REE but can be costly and is frequently calculated with predictive equations. Research suggests that REE obtained by predictive equations in people living with HIV/AIDS (PLWH) is inaccurate. The aim of the study is to develop and validate a new predictive equation of REE based on a population of PLWH.

METHODS

Cross-sectional study including 164 PLWH (82 to develop and 82 to validate the equation). Multiple linear regression was used to determine the relationship between variables and to develop the new predictive equation. Intraclass correlation coefficient (ICC) and Bland-Altman methods were used to evaluate agreement between the new predictive equation and indirect calorimetry.

RESULTS

A new predictive equation with an accuracy of 67% when compared with IC was developed. This equation included as covariates: fat free mass, antiretroviral therapy status and age.

CONCLUSION

A new equation to predict energy expenditure in PLWH was developed and validated. This formula can be used to estimate REE if IC is not available.

Energy Expenditure in Older Adults Who Are Frail: A Doubly Labeled Water Study

BACKGROUND AND PURPOSE

Frailty is a common and important geriatric syndrome, distinct from any single chronic disease, and an independent predictor of mortality. It is characterized by age-associated decline in physiological reserve and function across multiple systems, culminating in a vicious cycle of altered energy expenditure. The total energy expenditure (TEE) of an individual includes the resting metabolic rate (RMR), the thermic effect of feeding, and the energy expenditure in physical activity (PAEE). The investigation of the energy expenditure of older adults who are frail is essential for better understanding the syndrome. Therefore, we compared the RMR, the PAEE, the physical activity level (PAL), and the TEE of older adults who were frail with those who were not frail.

METHODS

A cross-sectional study was conducted with 26 community-dwelling older adults (66-86 years of age). Older adults in the frail and nonfrail groups were matched for age and gender, and the matched pairs were randomly selected to continue the study. The RMR was measured by indirect calorimetry. The TEE was obtained by the multipoint, doubly labeled water method. After collecting a baseline urine sample, each participant received an oral dose of doubly labeled water composed of deuterium oxide and oxygen-18 (H2O). Subsequently, urine samples were collected on the 1st, 2nd, 3rd, 7th, 12th, 13th, and 14th days after the baseline collection and analyzed by mass spectrometry.

RESULTS AND DISCUSSION

The older adults who were frail presented significantly lower PAEE (1453.7 [1561.9] vs 3336.1 [1829.3] kj/d, P < .01), PAL (1.4 [0.3] vs 1.9 [0.6], P = .04), and TEE (7919.0 [2151.9] vs 10442.4 [2148.0] kj/d, P < .01) than the older adults who were nonfrail. There was no difference in their RMRs (5673.3 [1569.2] vs 6062.0 [1891.7] kj/d, P = .57). Frailty has been associated with a smaller lean body mass and with a disease-related hypermetabolic state, which might explain the lack of difference in the RMR. The PAL of the older adults who were frail was below the recommended level for older adults and determined a lower PAEE and TEE when compared with older adults who were not frail.

CONCLUSION

This study showed that low energy expenditure in physical activity is a main component of frailty. The PAL of the older adults who were frail was far below the recommended level for older adults.

Energy metabolism in cachexia

Cachexia is a wasting disorder that accompanies many chronic diseases including cancer and results from an imbalance of energy requirements and energy uptake. In cancer cachexia, tumor-secreted factors and/or tumor-host interactions cause this imbalance, leading to loss of adipose tissue and skeletal and cardiac muscle, which weakens the body. In this review, we discuss how energy enters the body and is utilized by the different organs, including the gut, liver, adipose tissue, and muscle, and how these organs contribute to the energy wasting observed in cachexia. We also discuss futile cycles both between the organs and within the cells, which are often used to fine-tune energy supply under physiologic conditions. Ultimately, understanding the complex interplay of pathologic energy-wasting circuits in cachexia can bring us closer to identifying effective treatment strategies for this devastating wasting disease.

Plasma Metabolomics Biosignature According to HIV Stage of Infection, Pace of Disease Progression, Viremia Level and Immunological Response to Treatment

BACKGROUND

We evaluated plasma samples HIV-infected individuals with different phenotypic profile among five HIV-infected elite controllers and five rapid progressors after recent HIV infection and one year later and from 10 individuals subjected to antiretroviral therapy, five of whom were immunological non-responders (INR), before and after one year of antiretroviral treatment compared to 175 samples from HIV-negative patients. A targeted quantitative tandem mass spectrometry metabolomics approach was used in order to determine plasma metabolomics biosignature that may relate to HIV infection, pace of HIV disease progression, and immunological response to treatment.

RESULTS

Twenty-five unique metabolites were identified, including five metabolites that could distinguish rapid progressors and INRs at baseline. Severe deregulation in acylcarnitine and sphingomyelin metabolism compatible with mitochondrial deficiencies was observed. β-oxidation and sphingosine-1-phosphate-phosphatase-1 activity were down-regulated, whereas acyl-alkyl-containing phosphatidylcholines and alkylglyceronephosphate synthase levels were elevated in INRs. Evidence that elite controllers harbor an inborn error of metabolism (late-onset multiple acyl-coenzyme A dehydrogenase deficiency [MADD]) was detected.

CONCLUSIONS

Blood-based markers from metabolomics show a very high accuracy of discriminating HIV infection between varieties of controls and have the ability to predict rapid disease progression or poor antiretroviral immunological response. These metabolites can be used as biomarkers of HIV natural evolution or treatment response and provide insight into the mechanisms of the disease.

Nuclear magnetic resonance based profiling of biofluids reveals metabolic dysregulation in HIV-infected persons and those on anti-retroviral therapy

BACKGROUND

Although HIV causes immune deficiency by infection and depletion of immunocytes, metabolic alterations with clinical manifestations are also reported in HIV/AIDS patients. Here we aimed to profile metabolite changes in the plasma, urine, and saliva of HIV/AIDS patients, including those on anti-retroviral therapy (ART).

METHODS

Metabolic profiling of biofluids collected from treatment naïve HIV/AIDS patients and those receiving ART was done with solution-state nuclear magnetic resonance (NMR) spectroscopy followed by statistical analysis and annotation.

RESULTS

In Principal Component Analysis (PCA) of the NMR spectra, Principal Component 1 (PC1) alone accounted for 99.3%, 87.2% and 78.8% variations in plasma, urine, and saliva, respectively. Partial least squares discriminant analysis (PLS-DA) was applied to generate three-component models, which showed plasma and urine to be better than saliva in discriminating between patients and healthy controls, and between ART-naïve patients and those receiving therapy. Twenty-six metabolites were differentially altered in any or two types of samples. Our results suggest that urinary Neopterin, and plasma Choline and Sarcosine could be used as metabolic biomarkers of HIV/AIDS infection. Pathway analysis revealed significant alternations in 12 metabolic pathways.

CONCLUSIONS

This study catalogs differentially regulated metabolites in biofluids, which helped classify subjects as healthy controls, HIV/AIDS patients, and those on ART. It also underscores the importance of further studying the consequences of HIV infection on host metabolism and its implications for pathogenesis.

Increase in muscle mitochondrial biogenesis does not prevent muscle loss but increased tumor size in a mouse model of acute cancer-induced cachexia

Cancer-associated cachexia is a complex metabolic condition characterized by the progressive loss of body fat and deterioration of muscle mass. Although the cellular and molecular mechanisms of cachexia are incompletely understood, previous studies have suggested mitochondrial dysfunction in murine models of cancer cachexia. To better understand the metabolic shift in cancer-induced cachexia, we studied the effects of enhanced oxidative capacity on muscle wasting using transgenic mice over-expressing Peroxisome Proliferator-Activated Receptor gamma Co-activator-1α (PGC-1α) in skeletal muscle in a Lewis lung carcinoma-implanted model. Increased mitochondrial biogenesis was observed in the skeletal muscle of tumor-implanted mice. However, these increases did not prevent or reverse muscle wasting in mice harboring tumors. Moreover, tumor size was increased in muscle PGC-1α over-expressing mice. We found similar levels of circulating inflammatory cytokines in tumor-implanted animals, which was not affected by increased muscle expression of PGC-1α. Our data indicated that increased mitochondrial biogenesis in skeletal muscle is not sufficient to rescue tumor-associated, acute muscle loss, and could promote tumor growth, possibly through the release of myokines.

Influence of inflammation on total energy expenditure in hemodialysis patients

BACKGROUND AND OBJECTIVES

Studies show that inflammation can contribute to an increase in resting energy expenditure in patients with chronic kidney disease; however, findings about total energy expenditure (TEE) have not been reported. The aim of this study was to evaluate the effects of inflammation on TEE and physical activity energy expenditure in hemodialysis (HD) patients.

DESIGN

This was a cross-sectional study.

SETTING

This study was conducted from Hôpital Edouard Herriot, Lyon, France.

PATIENTS

This study included 24 HD patients and 18 healthy subjects.

MAIN OUTCOME MEASURE

TEE and step counts were measured over a 7-day period by the SenseWear Pro2 Armband in 24 HD patients (15 patients with C-reactive protein <5 mg/L, aged 67.0 ± 14.7 years, and 9 with C-reactive protein >5 mg/L, aged 69.0 ± 18.0 years) and compared with 18 healthy subjects (62.3 ± 15.3 years).

RESULTS

Mean estimated TEE measured with SenseWear Pro2 Armband was significantly lower (25.5 ± 4.1 kcal/kg/day) in patients with inflammation when compared with those without inflammation (32.0 ± 6.7 kcal/kg/day) and with healthy subjects (31.8 ± 7.0 kcal/kg/day) (P = .012). There was a difference in the physical activity (step counts) between patient groups (P < .05). Healthy subjects and patients without inflammation walked more (8,107 ± 5,419 and 6,016 ± 3,752 steps/day, respectively) as compared with patients with inflammation (2,801 ± 2,754 steps/day, P = .001).

CONCLUSION

Our findings suggest that patients with inflammation have a lower TEE when compared with healthy subjects and patients without inflammation. TEE is influenced by physical activity because patients with inflammation appear to be less active.

Dysregulated Energy Expenditure in HIV-Infected Patients: A Mechanistic Review

Metabolic abnormalities are common in patients with human immunodeficiency virus (HIV) infection and range from protein catabolism to lipodystrophy and dyslipidemia associated with the use of highly active antiretroviral therapy. One abnormality is increased resting energy expenditure, which even occurs in clinically stable HIV-infected patients. Increased resting energy expenditure may aggravate the tendency towards weight loss and wasting, which are independent predictors of mortality. Despite much investigation, the factors associated with altered resting energy expenditure remain unclear; viral load, CD4 cell count, use of antiretroviral drugs, body composition, hormones, and proinflammatory cytokines have been imputed. Mechanisms that could explain increased resting energy expenditure include the HIV accessory protein viral protein R, antiretroviral drugs that affect mitochondrial function, and futile cycling within adipocytes. Other components of energy expenditure are also important to overall energy balance and may also be affected. Identifying unifying mechanisms will be an important step to finding effective treatments for HIV-related alterations in energy expenditure and to reversing metabolic risks in patients with HIV infection.

Resting energy expenditure and its determinants in hemodialysis patients

OBJECTIVE

Chronic kidney disease is associated with several metabolic disturbances that can affect energy metabolism. As resting energy expenditure (REE) is scarcely investigated in patients on hemodialysis (HD) therapy, we aimed to evaluate the REE and its determinants in HD patients.

DESIGN

Cross-sectional study.

SETTING

Dialysis Unit of the Nephrology Division, Federal University of São Paulo, Brazil.

SUBJECTS

The study included 55 patients (28 male, 41.4+/-12.6 years old) undergoing HD therapy thrice weekly for at least 2 months, and 55 healthy individuals pair matched for age and gender. Subjects underwent fasting blood tests, as well as nutritional assessment, and the REE was assessed by indirect calorimetry.

RESULTS

REE of HD patients was similar to that of pair-matched controls (1379+/-272 and 1440+/-259 kcal/day, respectively), even when adjusted for fat-free mass (P=0.24). REE of HD patients correlated positively with fat-free mass (r=0.74; P<0.001) and body mass index (r=0.37; P<0.01), and negatively with dialysis adequacy (r=-0.46; P<0.001). No significant univariate correlation was found between REE and age, dialysis vintage, serum creatinine, urea, albumin, bicarbonate, parathyroid hormone (PTH) or high-sensitivity C-reactive protein (CRP). In the multiple linear regression analysis, using REE as dependent variable, the final model showed that besides the well-recognized determinants of REE such as fat-free mass and age, PTH and CRP were the independent determinants of REE in HD patients (R (2)=0.64).

CONCLUSIONS

In this study, the REE of HD patients was similar to that of healthy individuals, even with the positive effect of secondary hyperparathyroidism and inflammation on REE of these patients.

Inflammation is associated with increased energy expenditure in patients with chronic kidney disease

BACKGROUND

Inflammation, a clinical condition observed in patients with chronic kidney disease (CKD), may be related to increased resting energy expenditure (REE).

OBJECTIVES

The main objective was to investigate the relation between inflammation and REE in patients with CKD who are not undergoing dialysis. We also aimed to analyze whether a decrease in C-reactive protein (CRP) would result in a reduction in REE.

DESIGN

This study enrolled 132 patients with CKD who were not undergoing dialysis, who had creatinine clearance from 5 to 65 mL.min(-1).1.73 m(-2), and who were 53.6 +/- 16 y old; 82 (62.1%) were men. Twenty-nine patients had clinical signs of infection. REE was measured by using indirect calorimetry, and inflammation was evaluated by using high-sensitivity CRP measurement. Patients were divided according to tertiles of CRP with the following intertertile ranges: first tertile, CRP < or = 0.14 mg/dL (n = 43); second tertile, CRP 0.15-0.59 mg/dL (n = 46); and third tertile, CRP > or = 0.60 mg/dL (n = 43). REE was measured before and after treatment in 10 patients who had inflammation or infection.

RESULTS

After adjustment for age, sex, and lean body mass, the REE of the third (1395 kcal/d; P = 0.02) and second (1355 kcal/d; P = 0.04) tertiles was significantly higher than that of the first tertile (1286 kcal/d). In the multiple linear regression analysis (n = 132), the independent determinants of REE were lean body mass, CRP, and age (R2 = 0.55). After treatment of infection in a subgroup of 10 patients, it was observed that a significant reduction in CRP concentration was accompanied by a significant reduction of 174 +/- 165 kcal that accounted for 13% of the initial REE.

CONCLUSION

This study showed that inflammation is associated with increased REE in patients with CKD.

Resting energy expenditure of chronic kidney disease patients: influence of renal function and subclinical inflammation

BACKGROUND

The resting energy expenditure (REE) of patients with chronic kidney disease (CKD) might be influenced by the degree of renal function and by a subclinical inflammatory condition. The aim of this study is to evaluate the impact of these 2 variables on the REE of patients with CKD.

METHODS

A cross-sectional study was performed on 91 nondialyzed and nondiabetic patients with CKD with no clinical signs of inflammation. Patients were divided into quartiles of creatinine clearance (CrCl) and tertiles of C-reactive protein (CRP) level. REE was measured by means of indirect calorimetry, and the presence of a subclinical inflammatory condition was assessed by means of serum CRP concentration.

RESULTS

CrCl interquartile ranges calculated were: quartile 1 (CrCl < or = 18 mL/min [< or =0.30 mL/s]; n = 24); quartile 2 (CrCl, 19 to 29 mL/min [0.31 to 0.48 mL/s]; n = 22); quartile 3 (CrCl, 30 to 42 mL/min [0.49 to 0.70 mL/s]; n = 23), and quartile 4 (CrCl > or = 43 mL/min [> or =0.71 mL/s]; n = 22). Nonadjusted REE and REE adjusted for sex, age, and lean body mass did not differ among the 4 CrCl quartiles. The following ranges were calculated for CRP tertiles: tertile 1 (CRP < or = 0.14 mg/dL; n = 30), tertile 2 (CRP, 0.15 to 0.49 mg/dL; n = 31), and tertile 3 (CRP > or = 0.50 mg/dL; n = 30). The nonadjusted REE in CRP tertile 3 was significantly greater than those in tertiles 1 and 2. REE adjusted for sex, age, and lean body mass was greater in CRP tertile 3 than tertile 1, a difference equivalent to 123.7 kcal/d (P = 0.003; 95% confidence interval, 42.9 to 204.5). A borderline difference was observed between CRP tertiles 3 and 2. When analyzing the entire group, REE did not correlate with either serum creatinine level or CrCl, and a borderline correlation between REE and log of CRP was observed (r = 0.19; P = 0.07).

CONCLUSION

This study suggests that REE is not influenced by degree of renal function, but it may be elevated during a condition of subclinical inflammation.

The spectrum of infection-related morbidity in hospitalized haemodialysis patients

BACKGROUND

Infection is a common cause of mortality and morbidity in haemodialysis patients. Few prospective studies have examined the clinical consequences of infection-related hospitalizations in haemodialysis patients or the risk factors predictive of clinical outcomes.

METHODS

The outcomes of all first infection-related hospitalizations of patients enrolled in the HEMO Study were categorized in terms of mortality, requirement for intensive care unit (ICU) stay and length of hospitalization. In addition, the association of hospitalization outcomes with clinical and laboratory parameters was evaluated.

RESULTS

Among the 783 first infection-related hospitalizations, 57.7% had a severe outcome (death, ICU stay or hospitalization >/=7 days). The likelihood of a severe outcome increased with patient age (P<0.0001) and with decreased serum albumin (P<0.001). The frequency of a severe outcome varied greatly by infectious disease category (P<0.001), being highest for cardiac infections (95.6%) and infection of unknown source (68.4%), and lowest for urinary tract infections (35.5%) and access-related infections (43.8%). On multivariate analysis, hospitalization outcome was independently associated with patient age, serum albumin and disease category, but not with the randomized Kt/V or flux, gender, race or diabetic status.

CONCLUSION

In summary, infection-related hospitalizations are associated with substantial morbidity. Patient age, serum albumin and infectious disease category are independently correlated with the hospitalization outcome, and can be used to estimate the likelihood of serious outcomes at the time of hospital admission.

Investigating heterogeneity in studies of resting energy expenditure in persons with HIV/AIDS: a meta-analysis

BACKGROUND

There is conflict in the literature about the extent of alterations of resting energy expenditure (REE) in persons with HIV.

OBJECTIVE

The study was conducted to ascertain the mean difference in REE (in kJ) per kilogram of fat-free mass (FFM; REE/FFM) between HIV-positive subjects and control subjects and to investigate heterogeneity in the literature.

DESIGN

A meta-analysis comparing classical and Bayesian methods was conducted. Heterogeneity was investigated by using subgroup analysis, metaregression, and a mixed indirect comparison.

RESULTS

Of 58 studies meeting the inclusion criteria, 32 included both HIV-positive and control groups; 24 of these 32 were included. Thirty-seven studies were used in the mixed indirect comparison, and 30 were used in the subgroup comparisons of the HIV-symptomatic, lipodystrophy, weight-losing, and weight-stable subgroups and the healthy (HIV-negative) control group. Mean REE/FFM was significantly higher in 732 HIV-positive subjects than in 340 control subjects [11.93 kJ/kg (95% CI: 8.44,15.43 kJ/kg) and 12.47 kJ/kg (95% CI: 8.19,16.57 kJ/kg), classical and Bayesian random effects, respectively]; the test for heterogeneity was significant (P < 0.001). Both the mixed indirect comparison and the subgroup analysis indicated that REE/FFM was highest in the symptomatic subgroup; however, the small number of studies investigating symptomatic subjects limited statistical comparisons. The presence of lipodystrophy, use of highly active antiretroviral therapy, subject age, and method of body-composition measurement could not explain the heterogeneity in the data with the use of metaregression.

CONCLUSIONS

REE/FFM (kJ/kg) is significantly higher in HIV-positive subjects than in healthy control subjects. Symptomatic HIV infection may contribute to the variations reported in the literature.

Proinflammatory cytokines and the hypermetabolism of children with sickle cell disease

Sickle cell anemia (HbSS) includes chronic inflammation, but the origin is unclear. We hypothesized that in stable HbSS patients the inflammation was associated with hypermetabolism. We compared selected hypermetabolic and key immunomodulator indicators in HbSS versus control children and examined associations between measures of hypermetabolism and inflammation. Twelve fasting asymptomatic HbSS children 6-12 years and 9 controls matched for age, gender and fat mass (FM) were studied. Proportional reticulocyte count (retic%) and resting energy expenditure (REE) represented hypermetabolism, and C-reactive protein (CRP) indicated inflammation. Proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), chemokine monocyte chemoattractant protein-1 (MCP-1), and energy balance cytokine leptin were measured. Methods were indirect calorimetry, enzyme-linked immunosorbent assay, and radioimmunoassay. Statistical analysis included simple correlation and regression analysis. REE (51 +/- 6 vs. 43 +/- 12 kcal/kg per fat-free mass (FFM), mean +/- SD), retic% (12 +/- 4 vs. 0.7 +/- 0.3%), CRP (5 +/- 3 vs. 0.3 +/- 0.4 mg/liter), and IL-6 (71 +/- 40 vs. 20 +/- 7 pg/ml) were significantly higher for HbSS than controls (P < 0.05). Conversely, leptin (0.1 +/- 0.1 vs. 2 +/- 1 microg/liter per kgFM) and MCP-1 (34 +/- 5 vs. 41 +/- 4 pg/ml) were significantly lower for the HbSS subjects (P < 0.01). TNF-alpha was not significantly different. There were no significant associations between REE or retic% and any cytokine measured. However, CRP was significantly associated with REE in HbSS (r = 0.8, P = 0.003) and an important predictor of REE/FFM. We provide new evidence for low circulating levels of inflammatory chemokine MCP-1 in stable HbSS children, confirm mostly low cytokine levels, inflammation, and hypermetabolism and demonstrate association of hypermetabolism with inflammation via CRP but not via cytokines.

Predictors of HIV serostatus among HIV discordant couples in Lusaka, Zambia and female antenatal clinic attendants in Kigali, Rwanda

Clinical manifestations of HIV disease in Africa are nonspecific and easily confused with other endemic diseases. Several studies have compared the prevalence of HIV-related signs and symptoms in infected versus uninfected populations, but little is known about differences in HIV disease manifestations between African men and women across geographic areas. We conducted a cross-sectional study to define predictors of HIV status and assess their differences by gender and country in two African cohorts: 1351 heterosexual couples recruited from a voluntary HIV counseling and testing center in Lusaka, Zambia, and 1458 women recruited from antenatal and pediatric clinics in Kigali, Rwanda. HIV-positive Zambian men and women differed most with respect to prevalence of wasting syndrome (48.1% vs. 35.5%, p < 0.01). Zambian women were more likely to have a disseminated adenopathy than Rwandan women (33.2% vs. 7.8%, p < 0.01) and had a much higher median erythrocyte sedimentation rate (ESR) than either of the two other groups (78 mm/hr vs. 47 mm/hr, p < 0.01). Multivariable logistic regression modeling showed a history of tuberculosis [odds ratio (OR): 2.8-20.7], adenopathy on examination (OR: 4.0-6.3), and an ESR of >65 mm/hr (OR: 3.1-5.9) to be strongly predictive of HIV status in all groups. These screening tools, though highly predictive of HIV infection, were insensitive, as most infected persons were asymptomatic. Given these differences in HIV disease manifestation, screening tools based on signs and symptoms should be adapted accordingly. Additional studies are required to evaluate clinical markers as predictors of HIV disease progression and adjust them according to regional and gender differences.

Energy requirements in patients with chronic kidney disease

Knowledge concerning energy requirements of patients with chronic kidney disease (CKD) is important to providing a sufficient amount of energy to maintain adequate nutritional status for these patients. Data regarding energy expenditures of CKD patients are still scarce, and the results obtained are conflicting, with studies showing energy expenditures to be similar, higher, or lower than those of healthy individuals. More recently, studies focusing the role of the comorbidities and of the dialysis procedure on energy expenditure have been carried out, opening a new field of discussion that may help to clarify the profile of the energy expenditure of CKD patients. Another point of interest is related to the evaluation of energy intake. It has been shown that energy intake of CKD patients is lower than the 30 to 35 kcal/kg/day usually recommended. Although anorexia and consequently reduction of food intake is often present in these patients, a degree of underreporting in energy intake cannot be excluded. This review provides an overview of the studies that evaluated energy expenditures as well as those that studied the energy intakes and energy requirements of patients with CKD.

Micronutrientes en la infección por el virus de la inmunodeficiencia humana y su relación con la respuesta inflamatoria

BACKGROUND

Our aim was to measure the plasma concentrations of various vitamins and micronutrients involved in the immune response and antioxidant systems of an HIV+ population and to determine how they are related to the inflammatory response.

PATIENTS AND METHOD

We studied 86 subjects with known HIV-infection who were divided into three groups (asymptomatic HIV+; AIDS without opportunistic infection; and AIDS with active opportunistic infection) which were compared with a control group. Serum concentrations of vitamin A, vitamin E, copper and zinc were measured, as well as several inflammatory parameters. Absorption tests for fat and sugar were performed in all patients.

RESULTS

Serum vitamin A and E levels were below the reference range in 36.4% and 14.3% patients, respectively, but not in controls subjects. The prevalence of vitamin A deficiency increased with the severity of the disease. Fewer patients than controls had values below the reference range regarding serum copper. AIDS patients with active opportunistic infection showed significantly lower serum concentrations of vitamin A (p < 0.001) and significantly higher serum concentrations of copper (p < 0.0001). Both serum concentrations of vitamin A and copper were correlated with various inflammatory parameters.

CONCLUSIONS

Micronutrient deficiencies are prevalent in HIV-infected patients including asymptomatic patients. Vitamin A and copper were significantly correlated with inflammatory parameters, suggesting that their serum concentrations have more to do with the inflammatory response than with the nutritional status.

The metabolic puzzle during the evolution of HIV infection

Abnormalities in energy, protein, lipid and glucose metabolism have been described in HIV patients since the beginning of the epidemic. With the new antiretroviral agents, nutritional status and survival have improved dramatically. However, since these therapies were introduced, there have been more descriptions of metabolic abnormalities, some of which were similar to and others of which were in conflict with those reported in previous years. This paper reviews the complexity of the metabolic abnormalities in HIV infections before and after the introduction of highly active antiretroviral therapy, and discusses such etiopathogenic mechanisms as secondary infections, antiretroviral drugs and persistent immune activation, which may be involved in these derangements.