Role of C-reactive protein and procalcitonin in differentiation of tuberculosis from bacterial community acquired pneumonia

Persistently high plasma procalcitonin levels despite successful treatment of tuberculous pleuritis and tuberculous lymphadenitis patients

In a prospective cohort study, we evaluated plasma PCT levels in 48 TB lymphadenitis (TBLN) and 41 TB pleuritis (TBPE) patients. Measurements of PCT were done in unstimulated plasma of microbiologically and clinically confirmed TBLN and TBPE patients registered for anti-TB treatment at a tertiary care hospital in Lahore, Pakistan. Plasma levels of PCT were found to be raised in 89% of the patients at baseline with a median of 1.5 ng/ml. Levels were higher (p = 0.001) in TBLN as compared to TBPE (2.69, 0.96 ng/ml). PCT levels were not related to the bacterial burden depicted by culture positivity in these patients. PCT showed a negative correlation with the severity of constitutional symptoms (rho = - 0.238, p = 0.034), and inflammatory biomarkers; ferritin (rho = - 0.43, p < 0.001), INF-γ (rho = - 0.314, p = 0.003), TNF-α (rho = - 0.220, p = 0.039), IL-6 (rho = - 0.224, p = 0.035), and several chemokines of CCL and CCXL group. Raised plasma levels of PCT did not decrease with anti-TB treatment, indicating it is not a good biomarker to monitor treatment response in TBLN and TBPE patients. More studies with a larger number of confirmed EPTB cases are needed to define the role of PCT and its interaction with other biomarkers in EPTB.

Can Complete Blood Count Parameters and Serum Electrolyte Levels Have a Predictive Role in Differential Diagnosis of Tuberculosis from Community-acquired Pneumonia in Children?

The complete blood count (CBC) parameters and the ratios regarding these parameters have been demonstrated to be useful diagnostic biomarkers for many infectious diseases. Herein, we aimed to evaluate and compare the usefulness of the predictive role of the CBC in the differential diagnosis of pulmonary tuberculosis (TB) from community-acquired pneumonia (CAP) in children. We also compared serum electrolyte levels between the 2 diseases. In this retrospective study, we analyzed the efficacy of CBC parameters and neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), plateletto-lymphocyte ratio (PLR), neutrophil-to-monocyte-plus-lymphocyte ratio (NMLR), and serum electrolyte levels in the differential diagnosis of pulmonary TB from CAP in children. We also classified patients with TB into 2 groups according to the microbiologic confirmation. We investigated whether there is any difference regarding these parameters in patients with positive microbiologic results. A total of 163 patients diagnosed with TB and CAP were included in this study. The WBC, neutrophil and monocyte counts, NLR, MLR, NMLR, mean platelet volume (MPV), and C-reactive protein (CRP) values were higher in CAP. There was statistical significance among serum sodium and phosphorus (P) levels between the 2 groups. Microbiologic confirmation was determined in 37 (35.5%) patients with the diagnosis of TB. The NLR, MLR, NMLR, CRP, and P values were significantly higher in patients with microbiologic confirmation. The results of the present study suggest that complete blood count parameters, NLR, MLR, NMLR, and CRP can be useful and cost-effective markers in differentiating pulmonary TB from CAP in the early stages of diagnosis.

Sensitivity and specificity of CRP and symptom screening as tuberculosis screening tools among HIV-positive and negative outpatients at a primary healthcare facility in Lusaka, Zambia: a prospective cross-sectional study

OBJECTIVES

To evaluate the performance of point-of-care C-reactive protein (CRP) as a screening tool for tuberculosis (TB) using a threshold of 10 mg/L in both people living with HIV (PLHIV) and HIV-negative individuals and compare it to symptom screening using a composite reference for bacteriological confirmation of TB.

METHODS

Prospective cross-sectional study.

SETTING

A primary healthcare facility in Lusaka, Zambia.

PARTICIPANTS

Consecutive adults (≥18 years) presenting for routine outpatient healthcare were enrolled. Of the 816 individuals approached to participate in the study, 804 eligible consenting adults were enrolled into the study, of which 783 were included in the analysis.

PRIMARY OUTCOME MEASURES

Sensitivity, specificity, positive predictive value and negative predictive value (NPV) of CRP and symptom screening.

RESULTS

Overall, sensitivity of WHO-recommended four-symptom screen (W4SS) and CRP were 87.2% (80.0-92.5) and 86.6% (79.6-91.8) while specificity was 30.3% (26.7-34.1) and 34.8% (31.2-38.6), respectively. Among PLHIV, sensitivity of W4SS and CRP was 92.2% (81.1-97.8) and 94.8% (85.6-98.9) while specificity was 37.0% (31.3-43.0) and 27.5% (22.4-33.1), respectively. Among those with CD4≥350, the NPV for CRP was 100% (92.9-100). In the HIV negative, sensitivity of W4SS and CRP was 83.8% (73.4-91.3) and 80.3% (69.5-88.5) while specificity was 25.4% (20.9-30.2) and 40.5% (35.3-45.6), respectively. Parallel use of CRP and W4SS yielded a sensitivity and NPV of 100% (93.8-100) and 100% (91.6-100) among PLHIV and 93.3% (85.1-97.8) and 90.0% (78.2-96.7) among the HIV negatives, respectively.

CONCLUSION

Sensitivity and specificity of CRP were similar to symptom screening in HIV-positive outpatients. Independent use of CRP offered limited additional benefit in the HIV negative. CRP can independently accurately rule out TB in PLHIV with CD4≥350. Parallel use of CRP and W4SS improves sensitivity irrespective of HIV status and can accurately rule out TB in PLHIV, irrespective of CD4 count.

Assessment of Urinary Biomarkers for Infectious Diseases Using Lateral Flow Assays: A Comprehensive Overview

Screening of biomarkers is a powerful approach for providing a holistic view of the disease spectrum and facilitating the diagnosis and prognosis of the state of infectious diseases. Unaffected by the homeostasis mechanism in the human body, urine accommodates systemic changes and reflects the pathophysiological condition of an individual. Easy availability in large volumes and non-invasive sample collection have rendered urine an ideal source of biomarkers for various diseases. Infectious diseases may be communicable, and therefore early diagnosis and treatment are of immense importance. Current diagnostic approaches preclude the timely identification of clinical conditions and also lack portability. Point-of-care (POC) testing solutions have gained attention as alternative diagnostic measures due to their ability to provide rapid and on-site results. Lateral flow assays (LFAs) are the mainstay in POC device development and have attracted interest owing to their potential to provide instantaneous results in resource-limited settings. The discovery and optimization of a definitive biomarker can render POC testing an excellent platform, thus impacting unwarranted antibiotic administration and preventing the spread of infectious diseases. This Review summarizes the importance of urine as an emerging biological fluid in infectious disease research and diagnosis in clinical settings. We review the academic research related to LFAs. Further, we also describe commercial POC devices based on the identification of urinary biomarkers as diagnostic targets for infectious diseases. We also discuss the future use of LFAs in developing more effective POC tests for urinary biomarkers of various infections.

Clinical features of atypical tuberculosis mimicking bacterial pneumonia

OBJECTIVES

The aim of this study is to investigate clinical features of atypical pulmonary tuberculosis (aPTB) mimicking bacterial pneumonia, determine imaging features with the highest degree of correlation, and identify predictors for acid-fast bacilli (AFB) positivity.

METHODS

The clinical data of 259 patients considered as aPTB were retrospectively analyzed. The correlation of CT patterns was evaluated with Spearman analysis, and the predictors for AFB positivity were assessed with the multivariate analysis.

RESULTS

The most common symptom of aPTB was cough (84.6%), followed by fever and anorexia (47.1 and 41.7%, respectively). Infiltrated patchy was the most common radiological pattern (84.9%), followed by nodules (3-10 mm), micronodules (<3 mm), and consolidation (79.2, 78.8, and 66.0%, respectively). Nodules (3-10 mm) and micronodules (r = 0.988, p < 0.001), consolidation and air bronchogram (r = 0.590, p < 0.001), and pulmonary atelectasis and consolidation (r = 0.323, p < 0.001) showed high correlation. In the multivariate analysis, hyperpyrexia (OR, 2.29; 95% CI, 1.22-4.29) and bronchiectasis (OR, 2.06; 95% CI, 1.04-4.06) were the predictors of AFB-smear positivity, while bulla (OR, 0.22; 95% CI, 0.05-0.97) was the predictor of AFB-smear negativity.

CONCLUSION

This study demonstrated the clinical and radiological features of aPTB mimicking pneumonia. Several paired radiological findings may guide us to the diagnosis of aPTB. Hyperpyrexia and bronchiectasis may be helpful for predicting AFB positivity, and bulla may be a predictive sign of AFB negativity.

Socio-clinico-radiological profile of smear-positive pulmonary tuberculosis patients in association with sputum conversion and baseline hsCRP levels

Our was an observational follow-up study where the aim was to assess the baseline high-sensitivity C-reactive protein levels in 50 smear-positive pulmonary tuberculosis patients in association with socio-clinico-radiological profile and microbiological conversion. Smear and culture conversion of sputum samples at the end of intensive phase of anti-tubercular treatment were recorded. Baseline serum high-sensitivity C-reactive protein estimation was done by ELISA. Mean high-sensitivity C-reactive protein levels at baseline, smear/culture converted and delayed converters were 68.1 ± 22.2 mg/l, 66.7 ± 22.0 mg/l and 91.6 ± 6.7 mg/l, respectively; high-sensitivity C-reactive protein levels were significantly higher in delayed converters as compared to sputum converters. Significantly higher baseline high-sensitivity C-reactive protein levels were seen in patients with bilateral chest X-ray lesions, cavitations, evening rise of temperature, haemoptysis and dyspnoea as compared to those without these features. high-sensitivity C-reactive protein, being a non-specific inflammatory marker could be an adjunct tool for TB prognosis.

Comparison of chest computed tomography features between pulmonary tuberculosis patients with culture-positive and culture-negative sputum for non-mycobacteria: A retrospective observational study

Although complication with non-mycobacterial pneumonia among patients with pulmonary tuberculosis (TB) may lead to poor prognosis, discrimination between TB complicated with and without non-mycobacterial pneumonia using radiological imaging has not been fully elucidated. We aimed to clarify the differences in chest computed tomography (CT) features between pulmonary TB patients with culture-positive and culture-negative sputum for non-mycobacteria.We retrospectively included consecutive patients admitted to our hospital from January 2013 to December 2015 for bacteriologically-confirmed pulmonary TB, who were tested by sputum culture for non-mycobacteria, and who underwent chest CT within 2 weeks before or after admission. Chest CT features were compared between pulmonary TB patients who had positive non-mycobacterial cultures and in those who had not.Of 202 patients with pulmonary TB, 186 (92%) were tested by sputum culture for non-mycobacteria and underwent chest CT. Among these, non-mycobacteria were isolated in 118 patients (63%), while 68 patients (37%) had negative cultures. Patients with a positive culture for non-mycobacteria were significantly older and had lower levels of physical activity and albumin, higher levels of C-reactive protein, and a greater number of respiratory failures. By CT, emphysematous lesions, ground-glass opacities, airspace consolidation, air-bronchogram, interlobular septal thickening, bronchiectasis, pleural effusion, pleural thickening, and lymph node enlargement were more frequently in patients with a positive culture for non-mycobacteria. These chest CT features could be helpful for detecting complication with non-mycobacterial pneumonia in patients with pulmonary TB.

Old biomarkers in tuberculosis management: are they still useful? a systematic review

Introduction: The diagnosis of childhood tuberculosis (TB) can be challenging, given the lack of a gold standard test. Several new biomarkers have been studied for research purposes, but despite encouraging results, they are not used in clinical practice yet. Old biomarkers can be valuable tools in TB management. We conducted a systematic review to provide an update on their possible usefulness in TB patients.Areas covered: C-reactive protein could be useful to rule out TB, due to its high negative predictive value. Moreover, ferritin and erythrocyte sedimentation rates were found to be higher in TB patients with positive sputum smears. The lack of biomarkers decreases during an appropriate treatment course, indicating a poor response to treatment, seems to be correlated with a higher risk of death. Finally, procalcitonin and C-reactive protein seems to be useful in the differential diagnosis with pneumonia.Expert opinion: Old biomarkers are point-of-care tests, cheap and easily interpretable. These characteristics make them particularly useful, especially in TB endemic areas, to better manage patients with TB. Further studies performed in children are essential to implement the use of old biomarkers as diagnostic and prognostic tests.

C-Reactive Protein Testing for Active Tuberculosis among Inpatients without HIV in Uganda: a Diagnostic Accuracy Study

The objective of this prospective cross-sectional study, conducted at a national referral hospital in Kampala, Uganda, was to determine diagnostic performance of serum C-reactive protein (CRP) as a triage test for tuberculosis (TB) among HIV-seronegative inpatients. We calculated the sensitivity, specificity, positive and negative likelihood ratios, and positive and negative predictive values to determine the diagnostic performance of a CRP enzyme-linked immunosorbent assay (ELISA) (Eurolyser) in comparison to that of a reference standard of Mycobacterium tuberculosis culture on two sputum samples. We constructed receiver operating curves and reported performance in reference to the manufacturer's cutoff and also to a threshold chosen to achieve sensitivity of >90%, in accordance with the WHO's target-product profile for a triage test. Among 119 HIV-seronegative inpatients, 46 (39%) had culture-positive pulmonary TB. In reference to M. tuberculosis culture, CRP had a sensitivity of 78% (95% confidence interval [CI], 64 to 89%) and a specificity of 52% (95% CI, 40 to 64%) at the manufacturer's threshold of 10 mg/liter. At a threshold of 1.5 mg/liter, the sensitivity was 91% (95% CI, 79 to 98%) but the specificity was only 21% (95% CI, 12 to 32%). Performance did not differ when stratified by illness severity at either threshold. In conclusion, among HIV-seronegative inpatients, CRP testing performed substantially below targets for a TB triage test. Additional studies among HIV-seronegative individuals in clinics and community settings are needed to assess the utility of CRP for TB screening.

A three-marker protein biosignature distinguishes tuberculosis from other respiratory diseases in Gambian children

Background

Our study aimed to identify a host cytokine biosignature that could distinguish childhood tuberculosis (TB) from other respiratory diseases (OD).

Methods

Cytokine responses in prospectively recruited children with symptoms suggestive of TB were measured in whole blood assay supernatants, harvested after overnight incubation, using a Luminex platform. We used logistic regression models with Least Absolute Shrinkage and Selection Operator (LASSO) penalty to identify the optimal biosignature associated with confirmed TB disease in the training set. We subsequently assessed its performance in the test set.

Findings

Of the 431 children included in the study, 44 had bacteriologically confirmed TB, 60 had clinically diagnosed TB while 327 had OD. All children were HIV-negative. Application of LASSO regression models to the training set (n = 260) resulted in the combination of IL-1ra, IL-7 and IP-10 from unstimulated samples as the optimally discriminant cytokine biosignature associated with bacteriologically confirmed TB. In the test set (n = 171), this biosignature distinguished children diagnosed with TB disease, irrespective of microbiological confirmation, from OD with area under the receiver operator characteristic curve (AUC) of 0•74 (95% CI: 0•67, 0•81), and demonstrated sensitivity and specificity of 72•2% (95% CI: 60•4, 82•1%) and 75•0% (95% CI: 64•9, 83•4%) respectively, with its performance independent of their age group and their age- and sex-adjusted nutritional status.

Interpretation

This novel biosignature of childhood TB derived from unstimulated supernatants is promising. Independent validation with further optimisation will improve its performance and translational potential.

Funding

Steinberg Fellowship (McGill University); Grand Challenges Canada; MRC Program Grant.

C-reactive protein evaluation in communityacquired pneumonia with comorbid chronic heart failure as criterion of antibiotic prescription

AIM

To prove that diagnostic algorithm based on additional measurement of serum C-reactive protein (CRP) for administration of systemic antibacterial therapy (ABT) to patients with suspected community-acquired pneumonia (CAP) and concomitant chronic heart failure (CHF) does not influence outcomes of disease.

MATERIALS AND METHODS

This open, single-center, randomized, prospective, noninferiority study included 160 adult patients with documented functional class II-IV CHF who had been admitted with a preliminary diagnosis of non-severe CAP. Patients were randomized at 1:1 to two groups; group 1 - with additional measurement of CRP (n=80) and group 2 - with the use of routine diagnostic methods (n=80). In group 1, systemic ABT was administered only when serum CRP was &gt;28.5 mg / l (threshold level of the biomarker calculated at the previous stage of the study); group 2 received a standard treatment. Noninferiority test result for both algorithms was evaluated by the number of patients with clinical success on days 12-14 (primary endpoint). Non-inferiority margin was δ=-13.5 %. In addition secondary endpoints (early clinical response on days 3-5; early in-hospital adverse events (development of complications; admission to intensive care unit (ICU); death), death, recurrent CAP or CHF worsening with readmission at 28 day; mortality at 90 and 180 days) were estimated. Standard statistical tools were used for all intergroup comparisons.

RESULTS

76 patients of each group reached the primary endpoint. Systemic ABT was administered to 51 (67.1 %) patients in group 1 and 76 (100 %) patients in group 2 (p&lt;0.05). Both groups were comparable (p&gt;0.05) regarding all endpoints: clinical success, 70 (92.1 %) vs. 69 (90.8 %), Δ=1.3 % (one-sided 97.5 % CI: - 8.25 % for non-inferiority margin δ=-13.5 %); early clinical response, 66 (86.8 %) vs. 68 (89.5 %); admission to ICU, 1 (1.3 %) vs. 1 (1.3 %); development of complications, 20 (26.3 %) vs. 22 (28.9 %); readmission, 5 (6.6 %) vs. 6 (7.9 %); in-hospital mortality, 2 (2.6 %) vs. 1 (1.3 %), mortality at 28 day, 3 (3.9 %) vs. 2 (2.6 %), at 90 day, 5 (6.6 %) vs. 4 (5.3 %), at 180 day, 8 (10.5 %) vs. 9 (11.8 %) cases, respectively.

CONCLUSION

additional measurement of serum CRP in patients with CHF and suspected non-severe CAP was able to reduce rate of systemic ABT administration without outcomes and prognosis worsening.

The predictive role of haematological parameters in the diagnosis of osteoarticular brucellosis

BACKGROUND

Brucellosis is a zoonosis that affects several systems, especially with the osteoarticular involvement.

OBJECTIVES

This study aims to compare the neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), monocyte/lymphocyte ratio (MLR), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), mean platelet volume (MPV) and red blood cell distribution (RDW) in patients with the osteoarticular involvement and those with non-localised brucellosis and evaluate their predictive value for the diagnosis of osteoarticular brucellosis.

METHODS

We enrolled 140 patients with brucellosis, 70 with the osteoarticular involvement and 70 without any localised involvement. We collected patients' data retrospectively and compared haematological parameters between both groups. In patients with osteoarticular brucellosis, a correlation of the NLR with the ESR and CRP and correlation of the MLR with the ESR and CRP were assessed. Furthermore, the predictive performance of the ESR, CRP, NLR and MLR on the osteoarticular involvement was evaluated.

RESULTS

The NLR, MLR, ESR, CRP, neutrophil and monocyte levels were higher in the patient group than the control group.

CONCLUSION

The NLR, MLR, ESR and CRP are useful parameters to estimate the clinical course of patients with brucellosis, and the NLR and MLR are alternative to inflammatory markers in the osteoarticular involvement.

Dynamic changes and diagnostic and prognostic significance of serum PCT, hs-CRP and s-100 protein in central nervous system infection

The aim of the study was to analyze the dynamic changes and diagnostic and prognostic significance of serum procalcitonin (PCT), high-sensitivity C-reactive protein (hs-CRP) and s-100 protein in central nervous system infection. A total of 110 patients diagnosed with central nervous system infection in Department of Neurology in the People's Hospital of Rizhao from January 2014 to January 2016 were selected and retrospectively analyzed; they were divided into the bacterium (n=70) and virus (n=40) groups. Another 45 normal subjects were selected as the control group. PCT, hs-CRP and s-100 protein values in serum and cerebrospinal fluid were measured. The serum PCT, hs-CRP and s-100 protein levels in the bacterium group were significantly higher than those in the virus and control groups (p<0.05). The serum PCT, hs-CRP and s-100 protein levels in the bacterium and virus groups after treatment were obviously decreased compared with those before treatment (p<0.05). PCT, hs-CRP and s-100 protein levels in serum and cerebrospinal fluid in the bacterium and virus groups had no statistically significant differences after treatment (p>0.05). PCT, hs-CRP and s-100 protein levels in deaths in bacterium group were significantly higher than those in survivors (p<0.05). The serum PCT, hs-CRP and s-100 protein levels, can serve as important indexes for the diagnosis of central nervous system infection and their dynamic changes can be used to monitor the changes in disease condition, severity of bacterial infection and prognosis, providing help for the clinical treatment thereof.

The utility of delta neutrophil index in differentiation of pulmonary tuberculosis from community acquired pneumonia

No data exist on the usefulness of the delta neutrophil index (DNI) to discriminate pulmonary tuberculosis (PTB) from community-acquired pneumonia (CAP). We performed a retrospective cohort study involving patients with PTB (n = 62) and CAP (n = 215), and compared their initial DNI levels. The median DNI values were 0% (interquartile ranges [IQR] 0–0.2%) and 1.6% (IQR 0.7–2.9%) in PTB and CAP, respectively, which was significantly lower in PTB patients (P < 0.001). Sixty-nine percent of patients with PTB had DNI value of 0%; however, only 15% of patients with CAP had 0% DNI. The discriminatory power of the DNI for diagnosing PTB was high with 89% sensitivity and 67% specificity at a DNI cut-off ≤ 1.0% (area under the curve, 0.852). The diagnostic sensitivity and negative predictive value (NPV) for PTB were 89% (55/62) and 95% (145/152) at the DNI cut-off ≤ 1.0%, respectively, and in multivariate analyses after adjusting for other factors (smoking, no fever, upper lobe involvement), DNI ≤ 1.0% remained significant (odds ratio, 15.265; P < 0.001). We demonstrated that the DNI was lower in PTB compared with CAP, and an initially elevated DNI (>1.0%) may be useful to rule out the possibility of PTB due to its high NPV.

Acute phase proteins and IP-10 as triage tests for the diagnosis of tuberculosis: systematic review and meta-analysis

OBJECTIVES

We examined the data reported in studies for diagnostic purposes and to discuss whether their intended use could be extended to triage, as rule-in or rule-out tests to select individuals who should undergo further confirmatory tests.

METHODS

We searched Scopus, PubMed and Web of Science with the terms 'acute phase proteins,' 'IP-10,' 'tuberculosis,' 'screening' and 'diagnosis,' extracted the sensitivity and specificity of the biomarkers and explored methodologic differences to explain performance variations. Summary estimates were calculated using random-effects models for overall pooled accuracy. The hierarchical summary receiver operating characteristic model was used for meta-analysis.

RESULTS

We identified 14, four and one studies for C-reactive protein (CRP), interferon γ-induced protein 10 (IP-10) and alpha-1-acid glycoprotein (AGP). The pooled CRP sensitivity/specificity (95% confidence interval) was 89% (80-96) and 57% (36-65). Sensitivity/specificity were higher in high-tuberculosis-burden countries (90%/64%), HIV-infected individuals (91%/61%) and community-based studies (90%/62%). IP-10 sensitivity/specificity in TB vs. non-TB studies was 85%/63% and in TB and HIV coinfected vs. other lung conditions 94%/21%. However, IP-10 studies included diverse populations and a high risk of bias, resulting in very low-quality evidence. AGP had 86%/93% sensitivity/specificity.

CONCLUSIONS

Few studies have evaluated CRP, IP-10 and AGP for the triage of symptomatic patients. Their high sensitivity and moderate specificity warrant further prospective studies exploring whether their combined use could optimize performance.

Procalcitonin as Biomarker of Infection: Implications for Evaluation and Treatment

Procalcitonin (PCT) is a quickly measurable marker, assumed to have high sensitivity and specificity for sepsis and infection. A literature search was conducted to evaluate PCT ability as a diagnostic and prognostic tool in infectious processes and its ability to monitor the antibiotic therapy. PCT level is increased in bacterial and fungal infections, but not in viral infections, with a significantly higher level in patients with bacteremia compared with uninfected patients (2.5 vs. 0.3 ng/mL; P < 0.0001). A PCT value of ≤0.1 ng/mL discards bacteremia and microbiological tests (negative predictive value of 96.3%), >0.1 ng/mL needs microbiological tests, and >1.0 ng/mL is indicative of bacteremia. Antibiotic treatment algorithms guided by PCT decreased the need for antibiotic treatment in approximately 50%. PCT is a promising test in clinical practice to decide the introduction of antibiotic therapy in addition to the existing tools, without neglecting the clinical assessment, with a significant decrease in costs.

Diagnostic accuracy of C-reactive protein for active pulmonary tuberculosis: a meta-analysis

SETTING

Systematic screening for active pulmonary tuberculosis (PTB) is recommended for high-risk populations, including people living with the human immunodeficiency virus (PLHIV); however, currently recommended TB screening tools are inadequate for most high-burden settings.

OBJECTIVE

To determine whether C-reactive protein (CRP) possesses the necessary test characteristics to screen individuals for active PTB.

DESIGN

We performed a systematic review and meta-analysis of studies evaluating the diagnostic accuracy of CRP (10 mg/l cut-off point) for culture-positive PTB. Pooled diagnostic accuracy estimates were generated using random-effects meta-analysis for out-patients and in-patients, and for pre-specified subgroups based on HIV status and test indication.

RESULTS

We identified nine unique studies enrolling 1793 adults from out-patient (five studies, 1121 patients) and in-patient settings (five studies, 672 patients), 72% of whom had confirmed HIV infection. Among out-patients, CRP had high sensitivity (93%, 95%CI 88-98) and moderate specificity (60%, 95%CI 40-75) for active PTB. Specificity was lowest among in-patients (21%, 95%CI 6-52) and highest among out-patients undergoing TB screening (range 58-81%). There was no difference in summary estimates by HIV status.

CONCLUSION

CRP, which is available as a simple, inexpensive and point-of-care test, can be used to screen PLHIV presenting for routine HIV/AIDS (acquired immune-deficiency syndrome) care for active TB.

Point-of-care C-reactive protein-based tuberculosis screening for people living with HIV: a diagnostic accuracy study

Background

Symptom-based screening for tuberculosis (TB) is recommended for all people living with HIV (PLHIV) resulting in unnecessary Xpert MTB/RIF testing for the vast majority of individuals living in TB endemic areas and thus, poor implementation of intensified case finding (ICF) and TB preventive therapy. Novel approaches to TB screening are therefore critical in achieving global targets for TB elimination.

Methods

In a prospective study of PLHIV with CD4+ T-cell count ≤350 cells/uL initiating antiretroviral therapy (ART) from two HIV/AIDS clinics in Uganda, we evaluated the performance of C-reactive protein (CRP) measured using a rapid and inexpensive point-of-care (POC) assay as a screening tool for active pulmonary TB.

Findings

Of 1177 HIV-infected adults (median CD4+ T-cell count 168 cells/µL) enrolled, 163 (14%) had culture-confirmed TB. POC CRP had 89% (145/163) sensitivity and 72% (731/1014) specificity for culture-confirmed TB. Compared to the WHO symptom screen, POC CRP had lower sensitivity (difference −7% [95% CI: −12 to −2], p=0.002) but substantially higher specificity (difference +58% [95% CI: +61 to +55], p<0.0001). When Xpert MTB/RIF results were used as the reference standard, sensitivity of POC CRP and the WHO symptom screen were similar (94% [79/84] vs. 99% [83/84]; difference −5% [95% CI: −12 to +2], p=0.10).

Interpretation

The performance characteristics of CRP support its use as a TB screening test for PLHIV with CD4+ T-cell count ≤350 cells/µL initiating ART. HIV/AIDS programs should consider POC CRP-based TB screening to improve the efficiency of ICF and increase uptake of TB preventive therapy.

FUNDING

National Institutes of Health; Presidential Emergency Plan for AIDS Relief; University of California, San Francisco, Nina Ireland Program for Lung Health

Procalcitonin-guided antibiotic therapy in critically ill adults: a meta-analysis

Background

As a novel biomarker of inflammation, procalcitonin (PCT) has proven useful to guide antibiotic therapy in intensive care unit (ICU). However, there are controversial on mortality. The aim of this study was to evaluate the utility of PCT-guided antibiotic therapy in critically ill adults and determine whether studies are sufficient.

Methods

A systematic search in PubMed, Embase and Cochrane was performed. We included only randomized controlled trials which compared the safety and efficacy between PCT-guided or standard antibiotic therapy groups in ICU adults. Trial sequential analysis and GARDE approach were performed.

Results

Fifteen studies met our criteria for inclusion finally, with a cumulative number of 5486 ICU patients. There was no difference in 28-day mortality between two compared groups (P = 0.626), but significant decreases were observed in the duration of antibiotic therapy for the first episode of infection (P < 0.001) and length of hospitalization (P = 0.049). No significant deference was found in secondary endpoints except total duration of antibiotic therapy (P < 0.001). TSA revealed that the pooled sample sizes of 28-day mortality and the duration of antibiotic therapy for the first episode of infection exceeded the estimated required information size, but not the length of hospitalization.

Conclusions

PCT-guided therapy is a better and safer algorithm to be applied into ICU patients, which appears no effect on 28-day mortality while performing preferable utility in reducing the duration of antibiotic therapy for the first episode of infection. More studies on these endpoints were not recommended.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2622-3) contains supplementary material, which is available to authorized users.

Serum enolase-2, high-sensitivity C-reactive protein, and serum cholesterol in smear-positive drug-naïve pulmonary tuberculosis

Background:

Pulmonary tuberculosis (PTB) is a chronic granulomatous disease caused by Mycobacterium tuberculosis. The present study determined the serum human enolase-2 (ENO-2), high-sensitive C-reactive protein (hs-CRP), and serum cholesterol levels as biological marker of disease activity and treatment response in smear-positive drug-naïve PTB.

Materials and Methods:

This case–control study was done in the Department of Medicine, Liaquat University of Medical and Health Sciences (LUMHS), Jamshoro/Hyderabad, Sindh, from January 2015 to April 2016. Thirty-five sputum smear-positive drug-naïve PTB patients and thirty controls were studied. MTB culture and drug sensitivity were performed at the Diagnostic and Research Laboratory of LUMHS. Serum ENO-2, hs-CRP, and serum cholesterol were estimated at baseline, 3^rd and 6^th month of antituberculosis (TB) therapy.

Results:

Serum ENO-2 and hs-CRP were found raised in PTB compared to controls and showed decrease of 13% and 21.55%, 19.6% and 31.5% at 3^rd and 6^th month, respectively (P = 0.0001). Serum ENO-2 revealed positive correlation with hs-CRP (r = 0.734, P = 0.0001), and serum cholesterol revealed negative correlation with ENO-2 and hs-CRP (r = −0.509, P = 0.0001) and (r = −0.566, P = 0.0001), respectively.

Conclusion:

The present study reports the baseline ENO-2 and hs-CRP were raised, and serum cholesterol was low in smear-positive PTB patients and the ENO-2 and hs-CRP were reduced by anti-TB drug therapy.

The mask of acute bacterial pneumonia may disguise the face of tuberculosis

Introduction

Pulmonary tuberculosis (TB) can present as acute pneumonia. Differentiation of tuberculous from non-tuberculous community-acquired pneumonia (CAP) is an important challenge in endemic areas. The purpose of this study was the comparison between characteristics of tuberculous and non-tuberculous CAP patients.

Methods

In this prospective and observational study, all adult patients (aged ≥16 years) who were admitted to Imam Reza Hospital in Mashhad (Iran) with the diagnosis of CAP, between February 2013 and January 2014, were enrolled. Clinical, radiological, and microbiological data of the patients were collected and reviewed. Statistical analyses were performed using SPSS 14 software and R programming language.

Results

We studied 120 patients with diagnosis of acute CAP including 21 (17.5%) tuberculous and 99 (82.5%) non-tuberculous CAP. The etiologies of CAP in the latter group were as follow: S. pneumoniae 29 (29.3%), followed by S. aureus, polymicrobial including anaerobes, and other agents. The diagnosis of pneumonia remained unknown in 49 (40%) patients. We found approximately equal gender distribution among two study groups (14/21 vs. 61/99, 63.6% vs. 62.9%, p=0.948). Fifty percent of patients with tuberculous CAP had opioid addiction that was more frequent compared with non-tuberculous group (p=0.240). 52.4%, 63.2%, 30%, and 90% of patients with tuberculous CAP had severe presentation based on PSI, IDSA/ATS, CURB-65, and SMART-COP, respectively.

Conclusions

The diagnosis of TB should be considered in all patients who presented with CAP in endemic regions. It could not be differentiated from other causes of pneumonia on clinical and radiological grounds.

Neuron-specific enolase as a novel biomarker reflecting tuberculosis activity and treatment response

BACKGROUND/AIMS

It is not clear which tests are indicative of the activity and severity of tuberculosis (TB). This study aimed to investigate the predictive value of neuron-specific enolase (NSE) and to determine the origin of NSE in TB patients.

METHODS

A single-center retrospective analysis was conducted on newly diagnosed TB patients between January and December 2010. Patients were categorized into one of two disease groups (focal segmental or extensive) based on chest X-ray. Pre- and post-treatment NSE concentrations were evaluated. To determine the origin of serum NSE concentration, NSE staining was compared with macrophage-specific CD68 staining in lung tissues and with a tissue microarray using immunohistochemistry and immunofluorescence.

RESULTS

A total of 60 newly diagnosed TB patients were analyzed. In TB patients, NSE serum concentration was significantly increased and NSE level decreased after treatment (p < 0.001). In proportion to serum high-sensitivity C-reactive protein concentration, the mean serum concentration of NSE in the extensive group (25.12 ng/mL) was significantly higher than that in the focal segmental group (20.23 ng/mL, p = 0.04). Immunohistochemical staining revealed a large number of macrophages that stained positively for both NSE and CD68 in TB tissues. In addition, NSE signals mostly co-localized with CD68 signals in the tissue microarray of TB patients.

CONCLUSIONS

Our results suggest that NSE may be a practical parameter that can be used to monitor TB activity and treatment response. Elevated serum NSE level originates, at least in part, from macrophages in granulomatous lesions.

Diagnostic yield of computed tomography-guided bone biopsy and clinical outcomes of tuberculous and pyogenic spondylitis

BACKGROUND/AIMS

This study aimed to evaluate the efficacy of computed tomography (CT)-guided bone biopsy for the diagnosis of spinal infection and compared the clinical outcomes between tuberculous and pyogenic spinal infections.

METHODS

The retrospective cohort study included patients who received CT-guided bone biopsy at a tertiary hospital over the 13 years.

RESULTS

Among 100 patients, 67 had pyogenic spondylitis and 33 had tuberculous spondylitis. Pathogens were isolated from bone specimens obtained by CT-guided biopsy in 42 cases, with diagnostic yields of 61% (20/33) for tuberculous spondylitis and 33% (22/67) for pyogenic spondylitis. For 36 culture-proven pyogenic cases, Staphylococcus aureus was the most commonly isolated organism. Patients with pyogenic spondylitis more frequently presented with fever accompanied by an increase in inflammatory markers than did those with tuberculosis. Among all patients who underwent surgery, the incidence of late surgery performed one month after diagnosis was higher in patients with tuberculous infection (56.3%) than in those with pyogenic disease (23.3%, p = 0.026).

CONCLUSIONS

Results obtained by CT-guided bone biopsy contributed to prompt diagnoses of spinal infections, especially those caused by tuberculosis. Despite administration of anti-tuberculous agents, patients with tuberculous spondylitis showed an increased tendency to undergo late surgery.

Variation in C - reactive protein response according to host and mycobacterial characteristics in active tuberculosis

Background

The C - reactive protein (CRP) response is often measured in patients with active tuberculosis (TB) yet little is known about its relationship to clinical features in TB, or whether responses differ between ethnic groups or with different Mycobacterium tuberculosis (M.tb) strain types. We report the relationship between baseline serum CRP prior to treatment and disease characteristics in a metropolitan population with TB resident in a low TB incidence region.

Methods

People treated for TB at four London, UK sites between 2003 and 2014 were assessed and data collected on the following characteristics: baseline CRP level; demographics (ethnicity, gender and age); HIV status; site of TB disease; sputum smear (in pulmonary cases) and culture results. The effect of TB strain-type was also assessed in culture-positive pulmonary cases using VNTR typing data.

Results

Three thousands two hundred twenty-two patients were included in the analysis of which 72 % had a baseline CRP at or within 4 weeks prior to starting TB treatment. CRP results were significantly higher in culture positive cases compared to culture negative cases: median 49 mg/L (16–103 mg/L) vs 19 mg/L (IQR 5–72 mg/L), p = <0.001. In those with pulmonary disease, smear positive cases had a higher CRP than smear negative cases: 67 mg/L (31–122 mg/L) vs 24 mg/L (7–72 mg/L), p < 0.001. HIV positive cases had higher baseline CRPs than HIV negative cases: 75 mg/L (26–136 mg/L) vs 37 mg/L (10–88 mg/L), p <0.001. Differing sites of disease were associated with differences in baseline CRP: locations that might be expected to have a high mycobacterial load (e.g. pulmonary disease and disseminated disease) had a significantly higher CRP than those such as skin, lymph node or CNS disease, where the mycobacterial load is typically low in HIV negative subjects. In a multivariable log-scale linear regression model adjusting for host characteristics and M.tb strain type, infection with the East African Indian strain was associated with significantly lower baseline-CRP (fold-change in CRP 0.51 (0.34–0.77), p < 0.01).

Conclusions

Host and mycobacterial factors are strongly associated with baseline CRP response in tuberculosis. This analysis suggests that there are important differences in innate immune response according to ethnicity, Mtb strain type and site of disease. This may reflect differing mycobacterial loads or host immune responses.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1612-1) contains supplementary material, which is available to authorized users.

Procalcitonin as a Diagnostic and Prognostic Factor for Tuberculosis Meningitis

Background and Purpose

We investigated the potential role of serum procalcitonin in differentiating tuberculosis meningitis from bacterial and viral meningitis, and in predicting the prognosis of tuberculosis meningitis.

Methods

This was a retrospective study of 26 patients with tuberculosis meningitis. In addition, 70 patients with bacterial meningitis and 49 patients with viral meningitis were included as the disease control groups for comparison. The serum procalcitonin level was measured in all patients at admission. Differences in demographic and laboratory data, including the procalcitonin level, were analyzed among the three groups. In addition, we analyzed the predictive factors for a prognosis of tuberculosis meningitis using the Glasgow Coma Scale (GCS) at discharge, and the correlation between the level of procalcitonin and the GCS score at discharge.

Results

Multiple logistic regression analysis showed that a low level of procalcitonin (≤1.27 ng/mL) independently distinguished tuberculosis meningitis from bacterial meningitis. The sensitivity and specificity for distinguishing tuberculosis meningitis from bacterial meningitis were 96.2% and 62.9%, respectively. However, the level of procalcitonin in patients with tuberculosis meningitis did not differ significantly from that in patients with viral meningitis. In patients with tuberculosis meningitis, a high level of procalcitonin (>0.4 ng/mL) was a predictor of a poor prognosis, and the level of procalcitonin was negatively correlated with the GCS score at discharge (r=-0.437, p=0.026).

Conclusions

We found that serum procalcitonin is a useful marker for differentiating tuberculosis meningitis from bacterial meningitis and is also valuable for predicting the prognosis of tuberculosis meningitis.

Serum Procalcitonin for Differential Diagnosis of Acute Exacerbation and Bacterial Pneumonia in Patients With Interstitial Lung Disease

BACKGROUND

Acute exacerbation and bacterial pneumonia are major life-threatening conditions in patients with interstitial lung disease (ILD). The rapid recognition of these 2 different conditions is important for their proper treatment. An elevated procalcitonin (PCT) level is commonly detected in patients with bacterial infections. This study assessed the usefulness of the serum PCT level as a biomarker for the differential diagnosis of acute exacerbation and bacterial pneumonia in patients with ILD.

MATERIALS AND METHODS

In this prospective observational study, we enrolled patients with ILD who had experienced recently progressive dyspnea and exhibited new infiltrations on chest radiographs. We classified these patients into an acute exacerbation group and a bacterial pneumonia group and compared their baseline characteristics and laboratory parameters, including the PCT level.

RESULTS

Of 21 patients with ILD, 9 patients had bacterial pneumonia. Both the groups showed similar baseline characteristics. The bacterial pneumonia group demonstrated a high PCT level. The PCT level in the acute exacerbation group was significantly lower than that in the bacterial pneumonia group (0.05 versus 0.91ng/mL, respectively; P < 0.001). Other parameters, such as the C-reactive protein level, leukocyte count and body temperature, were also lower in the acute exacerbation group. At a cutoff value of 0.1ng/mL, the sensitivity, specificity and negative predictive values of the serum PCT level were 88.9%, 100.0% and 92.3%, respectively.

CONCLUSIONS

These findings suggest that the serum PCT level is useful in the differential diagnosis of acute exacerbation and bacterial pneumonia in patients with ILD.

Utility of blood procalcitonin concentration in the management of cancer patients with infections

Diagnosis of infections in cancer patients is usually problematic since differentiating between infection and fever of unknown origin is often a considerable clinical challenge. In general, increase concentration of blood procalcitonin (PCT) is associated with severe bacterial infection. PCT with an optimal cutoff level of 0.5 ng/mL seems to be the most helpful biochemical parameter in detecting severe infections, mainly bloodstream infection, in patients with hematological cancers. In all clinical situations, the elevated level of PCT should be carefully analyzed, always with a thorough physical examination and an appropriate microbiological assessment.

Comparison of serum procalcitonin in respiratory infections and bloodstream infections

PURPOSE

This study observed the relationship between procalcitonin (PCT) and results of sputum culture, the relationship between PCT and results of blood culture to evaluate and compare the value of PCT in respiratory and bloodstream infections.

METHODS

We analyzed 1616 patients in which PCT and sputum culture were concurrently ordered and analyzed, and 1096 patients in which PCT and blood culture were concurrently ordered and analyzed from January 2014 to May 2015. PCT concentrations were measured by on a Roche Cobas E601 ECL analyzer.

RESULTS

The average values of PCT from patients with sputum culture positive and negative were 0.42 (0.17-2.16) and 0.12 (0.06-0.57) ng/ml respectively, and the average values of PCT from patients with blood culture positive and negative were 9.54 (2.10-48.47) and 0.28 (0.10-1.23) ng/ml respectively. In sputum culture, positive rate of PCT in cases with growth of pathogens was 47.1%. In blood culture, positive rate of PCT in cases with growth of pathogens was 89.2%.

CONCLUSIONS

PCT is useful in early diagnosis of respiratory infections and bloodstream infections, but the specificity of PCT in diagnosing respiratory infections is not as high as it is in bloodstream infections.

Utility of immune response-derived biomarkers in the differential diagnosis of inflammatory disorders

Differentiating between inflammatory disorders is difficult, but important for a rational use of antimicrobial agents. Biomarkers reflecting the host immune response may offer an attractive strategy to predict the etiology of an inflammatory process and can thus be of help in decision making. We performed a review of the literature to evaluate the diagnostic value of inflammatory biomarkers in adult patients admitted to the hospital with suspected systemic acute infections. Elevated procalcitonin (PCT) concentrations indicate a bacterial infection in febrile patients with an auto-immune disease, rather than a disease flare. CD64 expression on neutrophils can discriminate between non-infectious systemic inflammation and sepsis, and limited evidence suggests the same for decoy receptor 3. PCT is useful for both diagnosing bacterial infection complicating influenza and guiding antibiotic treatment in lower respiratory tract infections in general. In undifferentiated illnesses, increased CD35 expression on neutrophils distinguishes bacterial from viral infections. Compared to bacterial infections, invasive fungal infections are characterized by low concentrations of PCT. No biomarker predicting a specific infecting agent could be identified.

Cutoff value of serum procalcitonin as a diagnostic biomarker of infection in end-stage renal disease patients

BACKGROUND/AIMS

Serum procalcitonin (PCT) levels are low in healthy individuals but are elevated in patients with a serious bacterial infection or sepsis. In this study, we examined the ability of serum PCT concentration to diagnose infections in end-stage renal disease (ESRD) patients, and sought to determine an appropriate threshold level.

METHODS

Serum PCT levels were measured in ESRD patients on antibiotic therapy for a suspected bacterial infection (ESRD infection [iESRD] group, n = 21), and compared with those of ESRD patients on hemodialysis with no sign of infection (ESRD control [cESRD] group, n = 20).

RESULTS

The mean serum PCT concentration of the iESRD group was significantly higher than in the cESRD group (2.95 ± 3.67 ng/mL vs. 0.50 ± 0.49 ng/mL, p = 0.006), but serum PCT concentrations did not correlate with severity of infection. The optimized threshold level derived for serum PCT was 0.75 ng/mL, rather than the currently used 0.5 ng/mL; this threshold demonstrated a sensitivity and specificity of 76.2% and 80.0% for infection and 100% and 60.6% for systemic inflammatory response syndrome, respectively, compared with the cutoff of 0.5 ng/mL.

CONCLUSIONS

This study suggests that serum PCT at a cutoff value of 0.75 ng/mL is an appropriate indicator of infection in ESRD patients.

Point-of-care C-reactive protein testing to facilitate implementation of isoniazid preventive therapy for people living with HIV

BACKGROUND

Symptom-based tuberculosis screening identifies less than one-third of eligible HIV-infected patients as candidates for isoniazid preventive therapy (IPT). We evaluated whether testing for C-reactive protein (CRP) improves patient selection for IPT.

METHODS

We measured CRP levels (normal <10 mg/L) using a point-of-care (POC) assay on stored serum samples from HIV-infected Ugandan adults initiating antiretroviral therapy. We assessed diagnostic accuracy in reference to baseline tuberculosis status adjudicated by an expert committee and calculated net reclassification improvement to quantify the incremental discriminatory benefit of POC-CRP in determining IPT eligibility compared to the World Health Organization (WHO) symptom screen.

RESULTS

Of 201 patients (median CD4 cell count, 137 cells/μL; interquartile range, 83-206), 5 (2.5%) had tuberculosis. Compared to the WHO symptom screen, POC-CRP had similar sensitivity (100% vs. 80%, P = 0.30) but greater specificity (21% vs. 87%, P < 0.0001) for tuberculosis. If based on the WHO symptom screen, no patients with tuberculosis but only 42 of 196 patients without tuberculosis would have been considered IPT eligible. If POC-CRP were used instead, 1 patient with tuberculosis (reclassification of cases, -20%; P = 0.32) and 129 patients without tuberculosis (reclassification of noncases, +66%; P < 0.001) would have been reclassified as IPT eligible, a net reclassification improvement of 46% (P = 0.03). In addition, POC-CRP testing would have reduced the proportion of patients without active tuberculosis requiring confirmatory tuberculosis testing (87% vs. 21%, P < 0.0001).

CONCLUSIONS

POC-CRP testing increased more than 4-fold the proportion of HIV-infected adults immediately identified as IPT eligible and decreased the proportion of patients requiring referral for further tuberculosis diagnostic testing. POC-CRP testing could substantially improve implementation of tuberculosis screening guidelines.

Community-acquired pneumonia and tuberculosis: differential diagnosis and the use of fluoroquinolones

The respiratory fluoroquinolones moxifloxacin, gemifloxacin, and high-dose levofloxacin are recommended in guidelines for effective empirical antimicrobial therapy of community-acquired pneumonia (CAP). The use of these antibiotics for this indication in areas with a high prevalence of tuberculosis (TB) has been questioned due to the perception that they contribute both to delays in the diagnosis of pulmonary TB and to the emergence of fluoroquinolone-resistant strains of Mycobacterium tuberculosis. In this review, we consider some of the important questions regarding the potential use of fluoroquinolones for the treatment of CAP where the burden of TB is high. The evidence suggests that the use of fluoroquinolones as recommended for 5-10 days as empirical treatment for CAP, according to current clinical management guidelines, is appropriate even in TB-endemic regions. It is critical to quickly exclude M. tuberculosis as a cause of CAP using the most rapid relevant diagnostic investigations in the management of all patients with CAP.

Distinctive biochemical changes in pulmonary tuberculosis and pneumonia

INTRODUCTION

We aimed to investigate the relationship between radiological extent and serum biochemical changes and body mass index (BMI) in patients with pulmonary tuberculosis (PTB) and pneumonia and to determine the usefulness of C-reactive protein (CRP) in clinical discriminative diagnosis.

MATERIAL AND METHODS

One hundred fifteen patients with tuberculosis (group 1), 70 patients with pneumonia (group 2) and 30 healthy controls (group 3) were included in this case-control study.

RESULTS

Total cholesterol (TC, p < 0.001 in group 1; p = 0.011 in group 2), high-density lipoprotein (HDL, p < 0.001), albumin (ALB, p < 0.001) and BMI (p < 0.001) values were significantly lower group 1 and group 2 than group 3. Erythrocyte sedimentation rate (ESR), leucocyte (LEU) and CRP were higher in group 2 than group 1 and group 3 (p < 0.001). As important point; triglyceride (TG) and BMI were significantly lower in group 1 than group 2 (p < 0.001). In group 1; BMI, HDL, TG, total protein (TP) and albumin were found to decrease, while CRP and ESR increased as the radiological stage increased (p < 0.05). But no significant difference was found in levels of TC and LDL (p > 0.05). In group 2; BMI, TC, HDL, LDL, TP and ALB were observed to decrease, while LEU, CRP and ESR increased as the radiological stage increased (p < 0.05). But no significant difference was found in levels of TG (p > 0.05). The best serum CRP cut-off value in differential diagnosis of tuberculosis and pneumonia was defined as 9.4.

CONCLUSIONS

The acute phase response occurring in tuberculosis and pneumonia determines the severity of the disease, leads to a decrease of serum levels of lipoproteins and BMI, and is correlated with the radiological extent. The CRP and ESR were found to be useful in differential diagnosis of tuberculosis and pneumonia.

Role of the neutrophil-lymphocyte count ratio in the differential diagnosis between pulmonary tuberculosis and bacterial community-acquired pneumonia

Background

Differential diagnosis between pulmonary tuberculosis (TB) and bacterial community-acquired pneumonia (CAP) is often challenging. The neutrophil-lymphocyte count ratio (NLR), a convenient marker of inflammation, has been demonstrated to be a useful biomarker for predicting bacteremia. We investigated the usefulness of the NLR for discriminating pulmonary TB from bacterial CAP in an intermediate TB-burden country.

Methods

We retrospectively analyzed the clinical and laboratory characteristics of 206 patients suspected of having pulmonary TB or bacterial CAP from January 2009 to February 2011. The diagnostic ability of the NLR for differential diagnosis was evaluated and compared with that of C-reactive protein.

Results

Serum NLR levels were significantly lower in patients with pulmonary TB than in patients with bacterial CAP (3.67±2.12 vs. 14.64±9.72, P<0.001). A NLR <7 was an optimal cut-off value to discriminate patients with pulmonary TB from patients with bacterial CAP (sensitivity 91.1%, specificity 81.9%, positive predictive value 85.7%, negative predictive value 88.5%). The area under the curve for the NLR (0.95, 95% confidence interval [CI], 0.91-0.98) was significantly greater than that of C-reactive protein (0.83, 95% CI, 0.76-0.88; P=0.0015).

Conclusions

The NLR obtained at the initial diagnostic stage is a useful laboratory marker to discriminate patients with pulmonary TB from patients with bacterial CAP in an intermediate TB-burden country.

Role of ascites adenosine deaminase in differentiating between tuberculous peritonitis and peritoneal carcinomatosis

AIM: To investigate the usefulness of tumor markers and adenosine deaminase in differentiating between tuberculous peritonitis (TBP) and peritoneal carcinomatosis (PC).

METHODS: A retrospective analysis of data was performed on consecutive patients who underwent peritoneoscopic and abdominal computed tomography (CT) evaluations. Among 75 patients at the Seoul National University Hospital from January 2000 to June 2010 who underwent both tests, 27 patients (36.0%) and 25 patients (33.3%) were diagnosed with TBP and PC, respectively. Diagnosis was confirmed by peritoneoscopic biopsy.

RESULTS: Serum c-reactive protein (7.88 ± 6.62 mg/dL vs 3.12 ± 2.69 mg/dL, P = 0.01), ascites adenosine deaminase (66.76 ± 32.09 IU/L vs 13.89 ± 8.95 IU/L, P < 0.01), ascites lymphocyte proportion (67.77 ± 23.41% vs 48.36 ± 18.78%, P < 0.01), and serum-ascites albumin gradient (0.72 ± 0.49 g/dL vs 1.05 ± 0.50 g/dL, P = 0.03) were significantly different between the two groups. Among tumor markers, serum and ascites carcinoembryonic antigen, serum carbohydrate antigen 19-9 showed significant difference between two groups. Abdominal CT examinations showed that smooth involvement of the parietal peritoneum was more common in the TBP group (77.8% vs 40.7%) whereas nodular involvement was more common in the PC group (14.8% vs 40.7%, P = 0.04). From receiver operating characteristic (ROC) curves ascites adenosines deaminase (ADA) showed better discriminative capability than tumor markers. An ADA cut-off level of 21 IU/L was found to yield the best results of differential diagnosis; sensitivity, specificity, positive predictive value, and negative predictive value were 92.0%, 85.0%, 88.5% and 89.5%, respectively.

CONCLUSION: Besides clinical and radiologic findings, ascitic fluid ADA measurement is helpful in the differential diagnosis of TBP and PC.

Performance of serum C-reactive protein as a screening test for smear-negative tuberculosis in an ambulatory high HIV prevalence population

Background

Delayed diagnosis has contributed to the high mortality of sputum smear-negative tuberculosis (SNTB) in high HIV prevalence countries. New diagnostic strategies for SNTB are urgently needed. C-reactive protein (CRP) is a non-specific inflammatory protein that is usually elevated in patients with tuberculosis, but its role in the diagnosis of tuberculosis is uncertain.

Methodology/Principal Findings

To determine the diagnostic utility of CRP we prospectively evaluated the performance of CRP as a screening test for SNTB in symptomatic ambulatory tuberculosis suspects followed up for 8 weeks in KwaZulu-Natal, South Africa. Confirmed tuberculosis was defined as positive culture or acid-fast bacilli with granulomata on histology, and possible tuberculosis as documented response to antitubercular therapy. The CRP quotient was defined as a multiple of the upper limit of normal of the serum CRP result. Three hundred and sixty four participants fulfilled entry criteria: 135 (37%) with confirmed tuberculosis, 114 (39%) with possible tuberculosis, and 115 (24%) without tuberculosis. The median CRP quotient was 15.4 (IQR 7.2; 23.3) in the confirmed tuberculosis group, 5.8 (IQR 1.4; 16.0) in the group with possible tuberculosis, and 0.7 (IQR 0.2; 2.2) in the group without tuberculosis (p<0.0001). The CRP quotient above the upper limit of normal had sensitivity 0.98 (95% CI 0.94; 0.99), specificity 0.59 (95% CI 0.50; 0.68), positive predictive value 0.74 (95% CI 0.67; 0.80), negative predictive value 0.96 (95% CI 0.88; 0.99), and diagnostic odds ratio 63.7 (95% CI 19.1; 212.0) in the confirmed tuberculosis group compared with the group without tuberculosis. Higher CRP quotients improved specificity at the expense of sensitivity.

Significance

In high HIV prevalence settings a normal CRP could be a useful test in combination with clinical evaluation to rule out tuberculosis in ambulatory patients. Point-of-care CRP should be further evaluated in primary care clinics.