Pleural fluid adenosine deaminase to serum C-reactive protein ratio for diagnosing tuberculous pleural effusion

BACKGROUND

Tuberculous pleural effusion (TPE) and malignant pleural effusion (MPE) may occasionally show similar cytological and biochemical picture including ADA. In such cases, differentiating TPE and MPE is challenging and needs histopathology of pleural tissue which may involve invasive procedures. The present study aims to evaluate the diagnostic accuracy of pleural fluid ADA to serum CRP (ADA/CRP) ratio to discriminate between tuberculous and malignant pleural effusion. In addition, we investigated whether the ratio ADA/CRP adds diagnostic value to ADA.

METHODS

This cross-sectional study was conducted in the National Institute of Diseases of the Chest and Hospital (NIDCH), Mohakhali, Dhaka, from July 2021 to February 2022 on diagnosed patients of TPE and malignant pleural effusion MPE. A receiver operating characteristic curve (ROC) was constructed for identifying TPE. The added value of the ADA/CRP ratio to ADA was evaluated using the net reclassification improvement (NRI) and integrated discrimination improvement (IDI). A value of p < 0.05 was considered statistically significant for all tests.

RESULTS

Fifty-nine patients were enrolled in this study, of which 31 had TPE, and 28 had MPE. Pleural fluid ADA to serum CRP ratio and pleural fluid ADA level was significantly higher in patients with TPE, but there was no significant difference in serum CRP levels between patients with TPE and MPE. At cut off value of > 1.25, pleural fluid ADA to serum CRP ratio had a sensitivity of 93.8%, specificity of 85.2%, and positive and negative predictive values were 88.2% and 92% respectively, in the diagnosis of TPE and area under ROC curve (AUC) was 0.94. The NRI and IDI analyses revealed added diagnostic value of ADA/CRP to ADA.

CONCLUSION

This study shows that the ADA/CRP ratio improves the diagnostic usefulness of ADA for TPE.

Independent role of Alzheimer's disease genetics and C-reactive protein on cognitive ability in aging

Apolipoprotein E (APOE) ε4, the strongest genetic risk factor for late onset Alzheimer's disease (LOAD), has been associated with cognitive decline independent from AD pathology, but the role for other LOAD risk genes in normal cognitive aging is less studied. We examined the effect of APOE ε4 and several different polygenic risk scores (PRS) for LOAD on cognitive level and decline in aging, using longitudinal data from the UK Biobank. While PRS-LOAD including all variants (except APOE) predicted cognitive level, APOE ε4 and PRS-LOAD based on 17 non-APOE gene variants with strong association to AD (p < 5e-8) predicted age-related decline in verbal numeric reasoning. The effect on decline were partly driven by 4 variants involved in the immune system. Those variants also predicted serum levels of the inflammatory marker C-reactive protein (CRP), but CRP did not mediate the effect on decline. Those findings suggest genetic variations in immune functions play a role in aspects of cognitive aging that may be independent of LOAD pathology as well as systemic inflammation measured by CRP.

Value of the synovial C-reactive protein test in the diagnosis of total hip and knee periprosthetic joint infections: A case-control study

INTRODUCTION

The diagnosis of periprosthetic joint infection (PJI) can be challenging and rests on several principles. The use of diagnostic biomarkers, such as the synovial C-Reactive Protein (CRP), seems promising. The purpose of this study was to determine whether synovial CRP was a more discriminating test than serum CRP for the diagnosis of hip and knee PJI.

MATERIALS AND METHODS

In total, 194 patients were included in this single center prospective study: 42 primary arthroplasties (control group [CG]), 111 revisions for aseptic prosthesis (aseptic revision group [ARG]), and 41 revisions for septic prosthesis (septic revision group [SRG]) based on the Musculoskeletal Infection Society (MSIS) criteria.

RESULTS

The serum and synovial CRP levels were significantly higher in the SRG than the other two groups (SRG serum CRP=75.6mg/L vs. ARG serum CRP=6mg/L and CG serum CRP=2.7mg/L, p<0.001; SRG synovial CRP=31.5mg/L vs. CG synovial CRP=2.6mg/L and ARG synovial CRP=1.7mg/L, p<0.001). The positive likelihood ratios (LR+) were very similar for both the synovial CRP cut-off value of 4.4mg/L (LR+=7.04; sensitivity [Se] 82.5%, specificity [Sp] 88.3%) and the serum CRP cut-off value of 9mg/L (LR+=6.3; Se 87.5%, Sp 86.1%).

CONCLUSION

This study showed that synovial CRP testing was not more discriminating than serum CRP in the diagnosis of hip and knee PJI. A serum CRP level greater than 9mg/L was a sign of PJI.

LEVEL OF EVIDENCE

III; case-control study.

The prognostic value of serum procalcitonin in acute obstructive pyelonephritis

PURPOSE

To evaluate the prognostic value of procalcitonin (PCT) in the occurrence of infectious complications in the management of acute obstructive pyelonephritis (AOP) compared with other biological parameters (leucocyte count, C-reactive protein [CRP]).

METHODS

We conducted a retrospective study including patients who were treated for AOP and performed serum PCT tests in our center between January 1, 2017 and December 31, 2017. Upper urinary tract obstruction was confirmed by either ultrasound or CT urography. Clinical examinations and laboratory tests including leukocyte count, CRP, urine and blood cultures, and serum PCT measurements were performed in the emergency unit. Treatment included early renal decompression using indwelling ureteral stents or nephrostomy and empiric antibiotic therapy. The primary endpoint was occurrence of severe sepsis (SS), a composite criterion including urosepsis and/or septic shock and/or admission to the intensive care unit (ICU) and/or death.

RESULTS

A total of 110 patients (median age: 61 years) were included, of whom 56.3% were female. SS occurred in 39 cases (35.4%). Multivariate regression analysis showed that serum PCT (OR 1.08; 95% CI 1.03-1.17; p = 0.01), CRP (OR 1.007; 95% CI 1.001-1.015; p = 0.03), and diabetes mellitus (OR 5.1; 95% CI 1.27-27.24; p = 0.04) were independent predictors for SS. Serum PCT was the biological marker associated with the highest accuracy to predict SS (ROC 0.912 (95% CI 0.861-0.962) and was superior to CRP (p < 0.001): the sensitivity and specificity of PCT to predict SS were 95% and 77%, respectively, with a serum PCT cutoff value of 1.12 µg/L.

CONCLUSIONS

PCT levels > 1.12 µg/L could help physicians to identify high-risk patients who could benefit from early and aggressive management in collaboration with intensive care specialists.

The proper timing of second-stage revision in treating periprosthetic knee infection: reliable indicators and risk factors

Background

Two-stage revision is the standard procedure for periprosthetic knee infection. But when to perform the second-stage is still under debate. We attempt to search the reliable indicators, risk factors, and proper timing for the second-stage revision.

Methods

We reviewed and followed 81 infected total knee arthroplasty patients who underwent two-stage revision from January 2010 to January 2014. Our cohort included 56 males and 25 females, all patients were confirmed as PJI with the same phenotypic cultures. The average age was 64.8 ± 8.21 (range 36–78) months. The mean follow-up time was 46.5 ± 17.6 (range 12–72) months after the second-stage surgeries. The diagnostic parameters including serum C-reaction protein, erythrocyte sedimentation rate, and intraoperative frozen section at the time of re-implantation were analyzed. The spacer detention time and antibiotic treatment time were compared.

Results

Ten of them went through failed first- or second-stage surgeries. The overall success rate was 87.7%. The intraoperative frozen section is a good indicator at the time of re-implantation; the sensitivity and specificity is 90 and 83.1%. Serum CRP and ESR showed poor diagnostic value at time of re-implantation. Atypical pathogen infection, positive FS, and previous sinus were high-risk factors for failure of two-stage revision. Spacer detention time between 12 and 16 weeks had higher success rate than over 16 weeks.

Conclusion

The proper timing of re-implantation should be combined with disappearance of clinical symptoms and negative intraoperative FS with spacer detention time at 12 to 16 weeks.