Pleural tuberculosis: A concise clinical review.

Tuberculosis (TB) is the leading infectious cause of death worldwide, and the commonest cause of death in people living with HIV. Globally, pleural TB remains one of the most frequent causes of pleural exudates, particularly in TB-endemic areas and in the HIV positive population. Most TB pleural effusions are exudates with high adenosine deaminase (ADA), lymphocyte-rich, straw-coloured and free flowing, with a low yield on mycobacterial culture. TB pleurisy can also present as loculated neutrophil-predominant effusions which mimic parapneumonic effusions. Rarely, they can present as frank TB empyema, containing an abundance of mycobacteria. Up to 80% of patients have parenchymal involvement on chest imaging. The diagnosis is simple if M. tuberculosis is detected in sputum, pleural fluid or biopsy specimens, and the recent advent of liquid medium culture techniques has increased the microbiological yield dramatically. Where the prevalence of TB is high the presence of a lymphocyte-predominant exudate with a high ADA has a positive predictive value of 98%. In low prevalence areas, the absence of an elevated ADA and lymphocyte predominance makes TB very unlikely, and pleural biopsy should be performed to confirm the diagnosis. Pleural biopsy for liquid culture and susceptibility testing must also be considered where the prevalence of drug resistant TB is high. Treatment regimens are identical to those administered for pulmonary TB. Initial pleural drainage may have a role in symptom relief and in hastening the resolution of the effusion. Surgical intervention may be required in loculated effusions and empyemas.

Optimising the utility of pleural fluid adenosine deaminase for the diagnosis of adult tuberculous pleural effusion in Hong Kong.

INTRODUCTION: Pleural fluid adenosine deaminase level can be applied to rapidly detect tuberculous pleural effusion. We aimed to establish a local diagnostic cut-off value for pleural fluid adenosine deaminase to identify patients with tuberculous pleural effusion, and optimise its utility. METHODS: We retrospectively reviewed the medical records of consecutive adults with pleural fluid adenosine deaminase level measured by the Diazyme commercial kit (Diazyme Laboratories, San Diego [CA], United States) during 1 January to 31 December 2011 in a cluster of public hospitals in Hong Kong. We considered its level alongside early (within 2 weeks) findings in pleural fluid and pleural biopsy, with and without applying Light's criteria in multiple scenarios. For each scenario, we used the receiver operating characteristic curve to identify a diagnostic cut-off value for pleural fluid adenosine deaminase, and estimated its positive and negative predictive values. RESULTS: A total of 860 medical records were reviewed. Pleural effusion was caused by congestive heart failure, chronic renal failure, or hypoalbuminaemia caused by liver or kidney diseases in 246 (28.6%) patients, malignancy in 198 (23.0%), non-tuberculous infection in 168 (19.5%), tuberculous pleural effusion in 157 (18.3%), and miscellaneous causes in 91 (10.6%). All those with tuberculous pleural effusion had a pleural fluid adenosine deaminase level of ≤100 U/L. When analysis was restricted to 689 patients with pleural fluid adenosine deaminase level of ≤100 U/L and early negative findings for malignancy and non-tuberculous infection in pleural fluid, the positive predictive value was significantly increased and the negative predictive value non-significantly reduced. Using this approach, neither additionally restricting analysis to exudates by Light's criteria nor adding closed pleural biopsy would further enhance predictive values. As such, the diagnostic cut-off value for pleural fluid adenosine deaminase is 26.5 U/L, with a sensitivity of 87.3%, specificity of 93.2%, positive predictive value of 79.2%, negative predictive value of 96.1%, and accuracy of 91.9%. Sex, age, and co-morbidity did not significantly affect prediction of tuberculous pleural effusion using the cut-off value. CONCLUSION: We have established a diagnostic cut-off level for pleural fluid adenosine deaminase in the diagnosis of tuberculous pleural effusion by restricting analysis to a level of ≤100 U/L, and considering early pleural fluid findings for malignancy and non-tuberculous infection, but not Light's criteria.

[Difficulties in classifying body cavity fluids into transudate/ exudate depending on the various diagnostic criteria]. / Trudnosci w klasyfikacji plynów z jam ciala na przesiek/wysiek na podstawie róznych kryteriów diagnostycznych.

Disease processes may impair the production and reabsorption of fluid from in the body cavities, which results in its excessive accumulation. AIM: The aim of the study was the evaluation of difficulties regarding the classification of fluids from the body cavities into transudate/exudate observing the following: Light's criteria, total fluid protein concentration, and total protein ratio (TP ratio) and lactate dehydrogenase ratio (LDH ratio). MATERIALS AND METHODS: Retrospective analysis was conducted on pleural (N=314), peritoneal (N=114) and pericardial (N=10) fluids, which were tested for the total protein concentration and LDH activity both in fluid and serum and calculated on TP ratio and LDH ratio. RESULTS: Based on the total protein concentration, 278 fluids from pleural cavity were classified as an exudate; 36 as a transudate. Applying the Light's criteria 240 fluids were classified as an exudate; the remaining 74 fluids were classified as a transudate. Based on TP and LDH ratios, 229 fluids from pleural cavity were classified as an exudate; 85 as a transudate. Depending on the total protein concentration, 35 fluids from the peritoneal cavity were classified as an exudate; 79 as a transudate. Applying the Light's criteria 54 fluids were classified as an exudate; the remaining 60 fluids were classified as a transudate. Based on TP and LDH ratios, 22 fluids from peritoneal cavity were classified as an exudate; 92 as a transudate. Analysis of pericardial fluids, depending on the total protein concentration classified 9 of them as an exudate and 1 as a transudate. The same results were obtained by applying Light's criteria. Based on TP and LDH ratios, 7 fluids from pericardial cavity were classified as an exudate; 3 - as a transudate. CONCLUSIONS: Applying the Light's criteria or the total protein concentration in differential diagnostics of fluids from the body cavities resulted in qualification more of them as an exudates as compared to the analysis of the same fluids depending on the TP and LDH ratios. It can be assumed that some of the transudative/exudative fluids were incorrectly classified. Performed analysis suggest that more adequate criteria of the classification of fluids from the body cavities into transudate/exudate are of great importance.

Usefulness of Medical Thoracoscopy in the Management of Pleural Effusion Caused by Chronic Renal Failure.

INTRODUCTION: Although pleural effusion (PE) can be caused by several pathologies like congestive heart failure, infections, malignancies, and pulmonary embolism, it is also a common finding in chronic kidney disease (CKD). Diagnostic thoracentesis is of limited value in the differential diagnosis, and the role of more invasive investigations like medical thoracoscopy (MT) is still unclear. AIM: To evaluate the usefulness of MT in unexplained PE in CKD. MATERIALS AND METHODS: In the electronic database of our Institution, we retrospectively searched for patients with CKD who underwent MT for unexplained PE between January 2008 and August 2016. RESULTS: Ten patients were included in the present study. The average age was 72.4 years, the male:female ratio 9:1 and the average blood creatinine value 5.96 mg/dL. The average follow-up was 18 months.A thoracentesis showed an exudate was found in 9 patients and in 1 case pleural fluid characteristics were not recorded for technical reasons; in none of them the cytologic or microbiological analyses were considered diagnostic.The clinical suspicion was a neoplastic (5) or an infectious disease (5). In 4 patients with recurrent PE, MT was performed to obtain talc pleurodesis.No immediate procedure-related complications were recorded; 1 patient developed empyema after 2 months. In 6 cases final diagnosis was chronic uremic pleuritis, hydrothorax in 2, and chronic lymphocytic pleurisy in 2. CONCLUSIONS: MT represents a safe and effective diagnostic and therapeutic procedure in patients with CKD, that itself is a common cause of exudative effusion, and those patients may not require MT.

Decreased levels of matrix metalloproteinase-2 in root-canal exudates during root canal treatment.

OBJECTIVE: To determine the matrix metalloproteinase-2 (MMP-2) levels in root-canal exudates from teeth undergoing root-canal treatment. MATERIAL AND METHODS: The root-canal exudates from six teeth with normal pulp and periradicular tissues that required intentional root canal treatment for prosthodontic reasons and from twelve teeth with pulp necrosis and asymptomatic apical periodontitis (AAP) were sampled with paper points for bacterial culture and aspirated for the detection of proMMP-2 and active MMP-2 by gelatin zymography and the quantification of MMP-2 levels by ELISA. RESULTS: By gelatin zymography, both proMMP-2 and active MMP-2 were detected in the first collection of root-canal exudates from teeth with pulp necrosis and AAP, but not from teeth with normal pulp, and their levels gradually decreased and disappeared at the last collection. Consistently, ELISA demonstrated a significant decrease in MMP-2 levels in the root-canal exudates of teeth with pulp necrosis and AAP following root canal procedures (p<0.05). Furthermore, the MMP-2 levels were significantly lower in the negative bacterial culture than those in the positive bacterial culture (p<0.001). CONCLUSIONS: The levels of MMP-2 in root-canal exudates from teeth with pulp necrosis and AAP were gradually reduced during root canal procedures. Future studies are required to determine if MMP-2 levels may be used as a biomolecule for the healing of apical lesions, similar to the clinical application of MMP-8 as a biomarker.

Exudate collection using wound sponges-An easy, non-invasive and reliable method to explore protease activities in ulcers.

Proteases are important for wound healing, but in excessive amounts or left uncontrolled, they may cause healing impairment or other severe wound complications. Point-of-care testing for protease activities in wounds may be useful for monitoring the effectiveness of treatment, and for early identification of wounds that potentially fail to heal. Here we describe an easy, noninvasive method to collect wound fluid for evaluating the protease milieu of wounds. Wound fluids were collected using sterile sponges applied between wound surface and normal wound dressing. Wound fluid could be easily squeezed or centrifuged out of the sponges and was tested for gelatinase (MMP-2 and MMP-9) activities by gel zymography. In addition, we measured polymorphonuclear granulocyte elastase levels by ELISA. Both gelatinases were remarkably stable in sponge derived fluids, as no significant loss was observed even when samples were stored for 3 days at room temperature. Protease levels were highly diverse amongst patients and, in some cases, showed substantial variations in the course of the treatment. The here described wound sponge approach represents a patient-friendly and reliable method to collect wound fluid for evaluating wound healing relevant biomarkers, such as matrix metalloproteinases.

Intra-Operative Amylase Concentration in Peri-Pancreatic Fluid Predicts Pancreatic Fistula After Distal Pancreatectomy.

Post-operative pancreatic fistula (POPF) is a potentially severe complication following distal pancreatectomy. The aim of this study was to assess the predictive value of intra-operative amylase concentration (IOAC) in peri-pancreatic fluid after distal pancreatectomy for the diagnosis of POPF. Consecutive patients who underwent a distal pancreatectomy between November 2014 and September 2016 were included in the analysis. IOAC was measured, followed by drain fluid analysis for amylase on post-operative days (PODs) 1, 3, and 5. Receiver operator characteristic (ROC) analysis was performed to evaluate the discriminative capacity of IOAC as a predictor of POPF. IOAC was measured after distal pancreatectomy in 26 patients. The IOAC correlated significantly with (i) PODs 1, 3, and 5 drain amylase (p < 0.01); (ii) the development of POPF (p < 0.01); and (iii) the Clavien-Dindo grade of surgical complications (p = 0.02). Eighty-three percent of patients with an IOAC > 1000 experienced a post-operative complication (OR 18.3, 95% CI 2.51-103, p < 0.01). ROC curve analysis confirmed the predictive relationship of IOAC and POPF as an excellent test with an area under the curve of 0.92 (95% CI 0.81-0.99, p < 0.01). Measurement of IOAC allows early and accurate categorization of patients at risk for POPF in distal pancreatectomy.

Transudate or exudate: can lactate dehydrogenase activity in canine and feline effusions help to differentiate between the 2?

BACKGROUND: Lactate dehydrogenase (LDH) activity is often measured in human effusions to help in differentiating between transudates and exudates. Few studies have been performed using effusion samples from animals. OBJECTIVES: The purpose of the study was to determine whether LDH can be used to differentiate between transudative and exudative effusions in dogs and cats (including postmortem samples), and whether there is a difference between different laboratory methods of LDH measurement. METHODS: Lactate dehydrogenase activity was measured in canine and feline effusions that were submitted to the Murdoch University Veterinary Hospital Clinical Pathology Laboratory over approximately 12 months using 2 wet and one dry chemistry methods, including 10 effusions collected postmortem. Results were compared to classification using traditional methods for effusion types. RESULTS: Lactate dehydrogenase activity was significantly higher in exudates than in transudates, significantly different depending on the method of measurement, and significantly higher in all effusions collected postmortem. An LDH effusion:serum ratio of < 0.5 was associated with transudates. There was no significant difference between samples collected into EDTA or plain serum tubes, in frozen and thawed samples, or after storage at 4°C for 3-7 days. CONCLUSIONS: Measurement of LDH activity may be useful in helping to differentiate between transudates and exudates in cats and dogs. The method of measurement must be known and kept consistent if cutoff values are to be used. The LDH activity was increased in all effusions collected from animals after death, potentially invalidating its use postmortem.

Profile of Metalloproteinases and Their Association with Inflammatory Markers in Pleural Effusions.

BACKGROUND: Matrix metalloproteinases (MMPs) are responsible for the breakdown of the extracellular matrix and play an important role in the inflammatory processes of pleural exudates. The imbalance between MMPs and their inhibitors (TIMPs) is present in various pathological processes. OBJECTIVE: To evaluate the profile of MMPs and TIMPs in pleural effusions of different etiologies correlated with inflammatory markers. METHODS: The patients with pleural effusion due to tuberculosis (TB), cancer (CA) or transudate were prospectively evaluated. Pleural fluid was submitted to cytological, biochemical, cytokines, MMP, and TIMP analysis. Statistical analysis was performed using ANOVA and Spearman's correlation, and p < 0.05 was considered significant. RESULTS: One hundred and fourteen patients were enrolled, 80 exudates (41 TB and 39 CA) and 34 transudates. The levels of MMP-8 and MMP-9 were higher in exudates compared to transudates. The level of MMP-8 was significantly higher in TB than in CA. TIMP-1 levels were higher in exudates. IL-6, VEGF, and TGF-ß1 showed differences between exudates and transudates. However, IL-6 level was higher in TB than in CA. We found a significant correlation between MMPs and TIMPs with inflammation markers. MMP-1 was correlated with LDH levels. MMP-8 was correlated with LDH, total cell count, neutrophils, and ADA as well as MMP-1 levels. MMP-9 was correlated with IL-6, TGF-ß1, and VEGF. TIMP-1 was correlated with MMP-9 and IL-6. CONCLUSIONS: MMPs and TIMPs are expressed in pleural fluid of different etiologies and correlate with inflammatory mediators. MMPs may be useful in determining the cause of fluid, but more studies are needed to determine the spectrum of diseases associated with the various isoforms of MMPS and TIMPs.

Enterobacterias productoras de carbapenemasas en un hospital pediátrico / Carbapenem-resistant enterobacteriaceae in a pediatric hospital

Introducción: El aumento en la incidencia de enterobacterias productoras de carbapenemasas (EPC) experimentado en todo el mundo en los últimos años constituye un importante problema de salud pública, dado que las infecciones provocadas por dichas bacterias se asocian a elevadas tasas de mortalidad y tienen gran capacidad de diseminación. Los estudios sobre infecciones por EPC en población pediátrica son muy escasos en la literatura científica. El presente estudio realiza una descripción de una serie de pacientes ingresados en un centro de referencia nacional pediátrico. Material y métodos: Se ha realizado un estudio retrospectivo descriptivo. Se describen las características clínicas y epidemiológicas de los pacientes infectados o colonizados por EPC entre junio de 2013 y noviembre de 2015. Resultados: Durante el periodo de estudio se han detectado 12 pacientes infectados o colonizados por EPC. La mayoría de los pacientes presentaba comorbilidades (el 58,3% eran pacientes oncológicos). Ha habido 3 casos de infección (25%) y 9 de colonización (75%). La evolución de los 3 pacientes con infección ha sido favorable. El principal mecanismo de resistencia detectado en nuestro estudio ha sido la producción de carbapenemasas tipo VIM. No ha habido transmisión cruzada de EPC entre pacientes durante el periodo de estudio. Conclusiones: Las infecciones por EPC en población pediátrica se dan fundamentalmente en niños con comorbilidades, sobre todo con patología oncológica. La detección precoz de los casos mediante vigilancia epidemiológica es un aspecto clave para prevenir la diseminación de estos microorganismos en el medio hospitalario (AU)

Introduction: Infections with carbapenem-resistant enterobacteriaceae (CRE) have become a major threat to public health because they are associated with significant mortality and they can spread rapidly in health-care settings. There are few studies of pediatric infections due to CRE. Here we describe clinical and microbiological features of infections caused by CRE at a national referral pediatric center. Methods: Retrospective descriptive study. We describe the clinical and epidemiological characteristics of patients infected or colonized with CRE between June 2013 and November 2015. Results: Twelve patients were identified with CRE during the study period. Underlying medical conditions were noted in most patients (58.3% had an oncologic process). Three were patients with clinical infection (25%), whereas 9 were colonized by CRE. The evolution of the three patients with infection has been favourable. Production of VIM was the prevalent mechanism conferring carbapenem resistance. There has been no EPC transmission between patients during the period of study. Conclusions: CRE infections are more common among children with underlying conditions, especially malignancy. Early detection is a key aspect to prevent the spread of CRE infection in hospitals (AU)

Pleural fluid tests to diagnose tuberculous pleuritis.

PURPOSE OF REVIEW: This article summarizes current data regarding the accuracy of pleural fluid tests assisting the diagnosis of tuberculous pleuritis (TBP). RECENT FINDINGS: No pleural fluid test reliably rules-in TBP in settings with low TBP prevalence. Interferon-γ) alone or in combination with adenosine deaminase (ADA) is more reliable than ADA for this purpose in nonlow prevalences. ADA can reliably rule-out TBP in prevalences of less than 40% although in higher prevalences the product of interleukin-27 and ADA is the most accurate rule-out test. SUMMARY: The definite diagnosis of TBP requires the isolation of Mycobacterium tuberculosis from pleural fluid or biopsies. Because of the low sensitivity of pleural fluid cultures and the invasiveness of pleural biopsy techniques, the concept of a pleural fluid test that accurately establishes or excludes TBP diagnosis has been proposed. Numerous pleural fluid tests have been evaluated for this purpose with ADA being the most widely accepted one. During the last years, it has been demonstrated that the ability of ADA to rule-in or rule-out TBP is affected by the prevalence of TBP in the setting where the test is used. The complementary use of interferon-γ or interleukin-27 increases the ability of ADA to rule-in or rule-out the disease, respectively.

Role of matrix metalloproteinases in non-healing venous ulcers.

Chronic venous ulceration (CVU) of the lower limbs is a common condition affecting 1% of the adult population in Western countries, which is burdened with a high complication rate and a marked reduction in the quality of life often due to prolonged healing time. Several metalloproteinases (MMPs) such as MMP-9 together with neutrophil gelatinase-associated lipocalin (NGAL) appear to be involved in the onset and healing phases of venous ulcer, but it is still unclear how many biochemical components are responsible for prolonged healing time in those ulcers. In this study, we evaluate the role of MMP-1 and MMP-8 in long lasting and refractory venous ulcers. In a 2-year period we enroled 45 patients (28 female and 17 male, median age 65) with CVU. The enroled population was divided into two groups: group I were patients with non-healing ulcers (ulcers that had failed to heal for more than 2 months despite appropriate treatments) and group II were patients with healing ulcers (ulcers in healing phases). MMP-1 and MMP-8 were measured in fluids and tissues of healing and non-healing ulcers by means of enzyme-linked immunosorbent assay (ELISA) and Western blot analysis, respectively. In particular the patterns of the collagenases MMP-1 and MMP-8 in healing wounds were distinct, with MMP-8 appearing in significantly greater amounts especially in the non-healing group. Our findings suggest that MMP-1, and MMP-8 are overexpressed in long lasting CVU. Therefore, this dysregulation may represent the main cause of the pathogenesis of non-healing CVU.

[Usefulness of lactate dehydrogenase concentration in thoracic and abdominal fluid of dogs]. / Interpretation des Laktatdehydrogenasespiegels in Thoraxerguss und Aszites beim Hund.

The aims of this study were to investigate the usefulness of LDH measurement in effusions in dogs to classify the fluid as exudate or transudate and to classify the fluid based on the pathophysiological mechanism. In thoracic (n = 107) and abdominal (n = 199) fluid of dogs cell count, protein and LDH concentrations were measured. The fluid was retrospectively categorized into exudate (group A), protein-poor (B) or protein-rich transudate (C) as well as based on pathophysiology into the following five groups (group 1 - 5): hemorrhagic, chylous, inflammatory, oncotic and congestive. In thoracic and abdominal fluid LDH concentrations were significantly higher in group A compared to group B and C. There was a significant difference of LDH concentration between the groups 1 to 5 in both thoracic and abdominal fluid, however there was a large overlap between the five groups. While fluid LDH measurement in dogs is helpful to distinguish exudate from transudate it is only of little help to elucidate the pathophysiological cause.

Dans ce travail, on étudie la signification de la lactatedéshydrogénase (LDH) dans des épanchements pour les classifier en exsudat ou en transsudat ainsi que pour en différencier la pathophysiologie. On a relevé, dans 306 épanchements thoraciques (n = 107) et abdominaux (n = 199), la numération cellulaire, les protéines totales et la LDH et on les a classé rétrospectivement en exsudats (groupe A), transsudats pauvres en protéines (groupe B) ou transsudats riches en protéines (groupe C) ; on les a également différenciés selon leur origine en hémorragiques, chyleux, inflammatoires, tumoraux ou de stase (groupes 1 à 5). Les valeurs de LDH du groupe A étaient significativement plus élevées que celles des groupes B et C, aussi bien dans les épanchements thoraciques qu'abdominaux. Ces valeurs étaient aussi significativement différentes entre les groupes 1 à 5, mais avec une forte superposition des valeurs entre les divers groupes. Alors que la détermination de la LDH dans un épanchement permet de bien différencier entre exsudat et transsudat, elle n'aide que de façon limitée pour différencier la cause de l'épanchement.

The direct inhibition of MMP-2 and MMP-9 by an enzyme alginogel: a possible mechanism of healing support for venous leg ulcers.

Flaminal Forte is an enzyme alginogel,whose activity depends on the absorption and binding of matrix metalloproteinases (MMPs), which are known to play a crucial role in delayed wound healing. The aim of the study was to evaluate the influence of Flaminal on MMP-2/-9 activity in ulcer exudate, ex vivo. Eight patients with bilateral venous leg ulcers were treated for 4 weeks with Flaminal Forte covered by hydrocolloid ('F' wounds), or with hydrocolloid alone ('H' wounds) as a reference control. Clinical assessment did not reveal any differences between F and H wounds regarding surface reduction and general wound condition. Nevertheless, although non-significant, there was a visible difference in peri-wound skin appearance in F wounds, as compared to H wounds. The wound exudate contained high MMP-2/-9 levels, which gradually decreased as wounds healed. The attenuation of MMPs was stronger in F than in H exudate, however, in standard zymography this difference appeared non-significant. Real-time zymography revealed that Flaminal mediated a powerful direct inhibition of gelatinolytic activity of wound exudate and of recombinant MMP-2/-9 in vitro.

Adenosine deaminase activity in pleural effusions of lymphoma patients.

BACKGROUND AND AIM: The purpose of this study was to assess the relationship of pleural adenosine deaminase (P-ADA) and non-Hodgkin's lymphoma (NHL). DESIGN AND METHODS: We retrospectively analysed 63 NHL patients with pleural effusions who accepted a diagnostic thoracentesis and who had P-ADA available at the China Medical University Hospital (Taichung, Taiwan) between January 2003 and April 2012. RESULTS: There were 46 exudates [40 malignant pleural effusions (MPE), 5 complicated para-pneumonic effusions and 1 undiagnosed effusion] and 17 transudates. The P-ADA activity was significantly different between the two groups (P < 0.005). Among 40 MPE cases, 29 were due to B-cell and 11 due to T-cell NHL. There was no pleural transudative effusion with P-ADA value higher than 26 U/l in our study, but simultaneously 48% (22/46) of exudative pleural effusions showed a P-ADA value under that cut-off point. The P-ADA level reached the diagnostic cut-off for tuberculosis (40 IU/l) in 11 cases of MPE (11/40 = 27.5%): 9 B-cell NHL (9/29 = 31%) and 2 T-cell NHL (2/11 = 18%). The median levels (25th, 75th percentiles) of P-ADA were 28 IU/l (14-50) in the MPE of B-cell NHL and 26 IU/l (14-28) in the T-cell NHL (P = 0.693). CONCLUSIONS: The use of P-ADA in NHL effusion could aid the separation of transudates from exudates. Around one-quarter MPE of NHL had abnormal P-ADA ( > 40 IU/l). There was no difference in the P-ADA activity in T-cell and B-cell NHL.

Factors affecting pleural fluid adenosine deaminase level and the implication on the diagnosis of tuberculous pleural effusion: a retrospective cohort study.

BACKGROUND: Adenosine deaminase (ADA) is useful in the diagnosis of tuberculous pleural effusion (TPE). This study aims to determine the factors affecting pleural fluid ADA levels and to establish the optimal ADA levels for diagnosis of TPE for different age groups. METHODS: This was a retrospective study from January 2007 to October 2011. One hundred and sixty patients who had pleural fluid ADA performed for investigation of pleural effusion were analyzed. Variables examined included demographics, pleural fluid characteristics and peripheral blood counts. The ADA cut-offs according to age were selected using the receiver operating characteristic (ROC) curve. RESULTS: The mean pleural fluid ADA was significantly higher in the TPE group (100 ± 35 IU/L) compared to non TPE patients (30 ± 37 IU/L). There was significant correlation between pleural fluid ADA and age, pleural fluid protein, LDH, and fluid absolute lymphocyte count. The strongest correlation was seen with age (r = -0.621). For patients ≤ 55 years old the ROC for ADA had area under curve (AUC) of 0.887. A pleural fluid ADA of 72 IU/L had sensitivity of 95.1%, specificity of 87.5%, positive predictive value (PPV) of 95.1% and negative predictive value (NPV) of 87.5% for the diagnosis of TPE. For patients > 55 years old the AUC is 0.959. ADA of 26 IU/L had a sensitivity of 94.7%, specificity of 80.4%, PPV of 62% and NPV of 97.8%. CONCLUSIONS: There is a significant negative correlation between pleural fluid ADA and age. For older patients, a lower ADA cut-off should be used to exclude TPE.

In vitro studies on the beneficial effect of a hydrokinetic fiber dressing on wound healing by reduction of protease activity.

OBJECTIVE: To test the binding capacity of a hydrokinetic fiber dressing for PMN elastase, MMP-2 and MMP-9 in vitro, and to determine whether testing of dressing material samples in vitro is sufficient to predict the performance of the whole dressing. METHOD: In vitro protease binding assays for PMN elastase, MMP-2 and MMP-9 were used to evaluate the protease modulating capacity of sorbion sachet EXTRA, a superabsorbant dressing that consists of special hydrokinetic fibers, which are formed from cellulose and sodium polyacrylate in a mechanical process without any bonding agents or adhesives. The ability of the hydrokinetic fiber dressing to inhibit elastase and collagenase activity was also tested at 0%, 50% and 100% saturation volume. RESULTS: The hydrokinetic fiber wound dressing was able to bind considerable amounts of elastase, reducing elastase activity by approximately 84%. Moreover, it significantly decreased MMP-2 and MMP-9 concentrations in vitro and was able to completely inhibit collagenase activity. CONCLUSION: In summary, the hydrokinetic fiber dressing sorbion sachet EXTRA was able to significantly reduce the concentration and activity of proteolytic enzymes in vitro. These results suggest that sorbion sachet EXTRA should have a beneficial action by reducing the detrimental effects of proteolytic enzymes in vivo. DECLARATION OF INTEREST: This work was supported by Sorbion GmbH & Co. KG, Senden, Germany.

Binding and inhibition of protease enzymes, including MMPs, by a superabsorbent dressing in vitro.

OBJECTIVE: To demonstrate the binding and inactivation action of a superabsorbent dressing on proteolytic enzymes MMP-2, MMP-9 and collagenase using an established methodology. METHOD: An in vitro assay of MMP binding and collagenase inactivation has been conducted using the superabsorbent wound dressing (Eclypse; Advancis Medical UK). Dressings in this category, and other absorbents, have been claimed to possess MMP-binding characteristics; however, for most there is no published evidence as yet. In this series of experiments, we have used validated experimental techniques to evaluate such activity. RESULTS: Results show that the superabsorbent dressing does have a statistically-significant effect in binding two of the most important MMPs, MMP-2 and MMP-9, as well as inhibiting collagenase. CONCLUSION: These results support this activity for the superabsorbent dressing and indicate a probable beneficial clinical action in reducing the influence of these enzymes in delayed wound healing.