Anaplastic Multiple Myeloma With a Novel Proliferation of Pleomorphic Binuclear Plasma Cells.

This study describes an unusual case of multiple myeloma that progressed to anaplastic multiple myeloma in the pleural fluid. The Wright-stained cytospin of the pleural fluid showed a predominant population of mononuclear plasma cells with pleomorphic nuclei, characterized by both small and large nuclei, which is typical of anaplastic multiple myeloma. However, there were also more binuclear plasma cells with pleomorphic nuclei. Morphometric analysis showed that the mean nuclear length was 1.9-fold and 2.3-fold higher in the large nuclei compared to the small nuclei for the mononuclear plasma cells and binuclear plasma cells, respectively (p<0.001). The patient received B cell maturation antigen chimeric antigen receptor T cell (CAR-T) therapy for relapsed disease, with a significant reduction of the serum monoclonal paraprotein level at day 51 post-therapy. Pathologists should be aware that pleomorphic binuclear plasma cells can be part of the morphologic spectrum in anaplastic multiple myeloma.

Eikenella corrodens isolated from pleural effusion: A case report.

BACKGROUND: The bacterium Eikenella, classified as a gram-negative member of the phylum Proteobacteria, is distinguished by its rarity, corrosive nature, facultative anaerobic properties, and conditional pathogenicity. It represents the sole species within its genus-Eikenella corrodens (E. corrodens)-and can be found colonizing both human and animal oral and nasopharyngeal regions. Additionally, it occasionally inhabits the gastrointestinal or urogenital tracts. However, its slow growth rate can be attributed to its high nutritional requirements. However, there is an uneven distribution of construction and diagnostic capacity in China which poses undeniable challenges for the clinical examination and analysis of this case, especially in the basic hospitals. CASE SUMMARY: Here we presented a case of empyema associated with E. corrodens infection in a 67-year-old male patient without any previous history of infectious diseases in our primary hospital in Dongguan district of China. The patient was admitted due to recurrent worsening cough, sputum production, and dyspnea for 3 d, which had persisted for over 20 years. Moreover, the patient experienced a one-hour episode of unconsciousness. Upon admission, immediate comprehensive examinations were conducted on the patient which subsequently led to his admission to the intensive care unit. Meanwhile, the patient presented with drowsiness and profuse sweating along with bilateral conjunctival edema observed during initiation of non-invasive ventilation, suggesting empyema. A significant amount of coffee-colored malodorous pleural fluid was drained during the procedure above and sent to the laboratory department for inspection. Finally, laboratory culture results confirmed the presence of E. corrodens infection in the pleural fluid sample. The patient received antimicrobial therapy until died on day 22 in the hospital. CONCLUSION: In this report, we presented a case of empyema associated with E. corrodens infection. Multiple courses of morphological examination, viable culture analysis, and biochemical identification revealed its difficulties in detecting distinctive characteristics, as well as a detection model worth promoting. It's just that there were still certain deficiencies in terms of morphological assessment, biochemical identification, and drug susceptibility testing.

Iatrogenically Acquired Mycobacterium abscessus Infection in an Indwelling Intercostal Drainage In Situ in a Patient With Alcoholic Liver Disease and Bilateral Hepatic Hydrothorax: A Report of a Rare Case.

A 47-year-old male, a known case of alcoholic chronic liver disease with portal hypertension, presented with complaints of abdominal distension and shortness of breath. A provisional diagnosis of ethanol-related compensated chronic liver disease (CLD) with portal hypertension and splenomegaly, gross ascites with bilateral hepatic hydrothorax was made. The left-sided pleural effusion subsided after three pleural taps, but the right-sided effusion kept refilling even after four to five days of repeated therapeutic taps, so a pigtail catheter was left in situ. The pleural fluid was sent for culture which did not grow any pathogenic organisms. Cartridge-based nucleic acid amplification tests where Mycobacterium tuberculosis complex (MTBC) was not detected, Ziehl-Neelsen staining was done in which acid-fast bacilli were not seen, and cytology was done where no malignant cells were seen. The patient was discharged with the pigtail in situ on the right side and, after 20 days, the patient again presented with shortness of breath, and imaging revealed moderate right-side pleural effusion. Draining of pleural fluid was done and sent for investigation which again revealed no infective etiology. The patient was admitted to the hospital for one month as the right-sided effusion did not resolve. Suddenly, the patient developed shortness of breath, and a chest X-ray was done, which showed pigtail blockage; pigtail flushing was done, and the bag was drained. The patient was empirically started on IV meropenem 500 mg TID, IV teicoplanin 400 mg BD, and inj polymyxin B 500,000 IU IV BD. The pleural fluid was sent continuously for investigation for the first two months which again did not reveal any infective etiology. After two months of pigtail in situ, the pleural fluid was sent for CBNAAT where MTBC was not detected, and ZN stain showed smooth acid-fast bacilli. The sample was cultured, and it grew acid-fast bacilli in 72 hours on blood agar, MacConkey agar, and Lowenstein-Jensen media. A line probe assay done from the isolate revealed it to be Mycobacterium abscessus subsp. abscessus which was resistant to macrolides and sensitive to aminoglycosides. Mycobacterium abscessus subsp. abscessus was isolated from repeated cultures of pleural fluid, and the patient was advised on a combination treatment of amikacin, tigecycline, and imipenem. The patient was discharged with the indwelling pigtail with the advised treatment; unfortunately, we lost patient follow-up as the patient never returned to us.

Prognostic significance of Pleural Fluid triglyceride levels based on a low-Fat Diet Management Strategy in patients with Chylothorax following pulmonary resection.

BACKGROUND: Chylothorax is a postoperative complication in patients with lung cancer. Diet-control approaches have been the mainstay for managing this condition. However, a surgical intervention is needed for the patients if conservative treatment is ineffective. Because of the lack of accurate indicators to assess the prognosis of the postoperative complication at an early stage, the criteria of surgical treatment were not consistent. METHODS: We reviewed 2942 patients who underwent pulmonary resection and lymph node dissection for primary lung cancer at our hospital between March 2021 and December 2022. The prognostic implications of clinical indicators were assessed in patients with postoperative chylothorax who were managed with a low-fat diet. Binary logistic regression was used to explore the predictive value of these indicators for patient prognosis. RESULTS: Postoperative chylothorax occurred in 108 patients and 79 patients were treated with a low-fat diet management while 29 patients were managed with TPN. In contrast to drainage volume, the pleural effusion triglyceride level after 2 days of low-fat diet exhibited enhanced predictive efficacy in predicting patient prognosis. When the pleural fluid triglyceride level of 1.33 mmol/L was used as the diagnostic threshold for prognosis, the sensitivity and specificity reached 100% and 80.6%, respectively. CONCLUSIONS: The pleural effusion triglyceride level after 2 days of low-fat diet can serve as a valuable prognostic indicator in patients undergoing lung surgery and experiencing chylothorax. This predictive approach will help thoracic surgeons to identify patients with poor prognosis in a timely manner and make decision to perform necessary surgical interventions.

Control of pleural effusion with prednisolone in a patient with yellow nail syndrome: A case report.

Yellow nail syndrome (YNS) can induce bilateral exudative pleural effusion; however, to the best of our knowledge, no standard treatment for YNS has been established. The present study describes a patient with YNS for whom the pleural effusion was controlled by prednisolone. A 73-year-old man was referred to the University of Tsukuba Hospital (Ibaraki, Japan) complaining of shortness of breath, which was diagnosed as being due to bilateral pleural effusion. Based on the presence of yellowing and growth retardation of the toenails, lymphedema, bilateral exudative pleural fluid of unknown etiology, and lymphatic congestion on lymphoscintigraphy, the patient was diagnosed with YNS. The pleural fluid was predominantly lymphocytic and responded to systemic steroid administration [prednisolone 30 mg/day (0.5 mg/kg) for 2 weeks, with subsequent weekly tapering]. The general condition of the patient and their dyspnea also improved with treatment. These findings indicated that systemic steroid administration should be considered as one of the treatment options for patients with YNS who are reluctant to undergo chest drainage or pleurodesis due to the potential for a decrease in their ability to perform daily activities and respiratory function.

Cytomorphology of metastatic malignant peripheral nerve sheath tumour present in pleural fluid: Case study and literature review.

The cytomorphology of MPNST in effusion specimens is rarely described. In this paper, the detailed cytopathological and immunohistochemical characteristics of metastatic MPNST has been described in pleural effusion. Patients' medical history and the judicious utilization of ancillary studies contribute to ensure precise cytological diagnoses. The cytomorphology of malignant peripheral nerve sheath tumour (MPNST) in effusion specimens can be diagnostically challenging. The author presents detailed cytopathological and immunohistochemical characteristics of a case of metastatic MPNST in pleural effusion.

Isolated Malignant Pleural Effusion in a Child: Unusual Presentation of Acute Leukemia.

Pleural effusion in the pediatric population is an abnormal pathology characterized by the accumulation of fluids between the parietal and visceral pleura. The etiology of this excessive fluid accumulation can be attributed to both infectious and non-infectious factors. Notably, Streptococcus pneumoniae stands out as the predominant infectious agent responsible for this condition. Non-infectious causative factors encompass hematolymphoid malignancies, congestive heart failure, hemothorax, hypoalbuminemia, and iatrogenic causes. Among the hematolymphoid malignancies, lymphoma emerges as the most prevalent malignancy associated with pleural effusion. It is followed by T-cell lymphoblastic leukemia, germ cell tumor, neurogenic tumor, chest wall and pulmonary malignancy, carcinoid tumor, pleuro-pulmonary blastoma, and Askin's tumor, among others. Malignant pleural effusion is predominantly linked to T-cell lymphoblastic malignancies. In the context of acute lymphoblastic leukemia (ALL), cases where T-cell presentation is accompanied by leukemic pleural effusion are commonly associated with either a mediastinal mass or significant lymphadenopathy. Here, we describe a case of a four-year-old male child who exhibited a brief history of febrile illness. Notably, this case was characterized by isolated pleural effusion, devoid of any mediastinal mass or lymphadenopathy. Pathological investigations of pleural fluid analysis revealed the presence of malignant cells, facilitating an expedited diagnosis.

Diagnostic analysis of pleural fluid cell blocks using relevant immunohistochemical markers in clinically suspicious cases of malignancy.

Objective: Thoracocentesis is a less invasive and expensive procedure than pleural biopsy, enabling sample collection for cytological evaluation. Cell blocks prepared from these samples provide histopathological diagnoses; further, immunohistochemistry (IHC) can be performed for subtyping malignancies, guiding the clinician in choosing the appropriate treatment modality for the patient. We aimed to determine the various histological subtypes of malignancies using cell block IHC and compare the cell block and conventional cytology methods for diagnosing malignant pleural effusion. Material and Methods: All pleural fluid samples from the clinically suspicious cases of malignancy collected at the Department of Pathology, Government Medical College Kottayam, India, during 18 months, except duplicate and inadequate samples, were included in this prospective observational study. IHC was performed on cell blocks that were positive for malignancy. Results: This study analyzed 630 samples, of which 121 cell blocks demonstrated the presence of malignancy. Overall, 80%, 13%, and 7% of cases were negative, suspicious, and positive for malignancy based on conventional cytology, and 81%, 0%, and 19% were negative, suspicious, and positive for malignancy based on cell blocks, respectively. Among all malignancies, adenocarcinomas from the lung (56%) were the most common, followed by adenocarcinomas from the breast (6%), squamous cell carcinomas (5%), and adenocarcinomas from the ovary (3%). Cell blocks helped detect more malignancies (19%) than conventional cytology (7%), despite a moderate agreement between both methods. Conclusion: Adenocarcinomas were the most common cause of malignant pleural effusions, and the most frequent site of origin was the lungs. Cell blocks helped diagnose more malignancies than conventional cytology.

Multiple Myeloma: A Rare Presentation As Unilateral Pleural Effusion.

Multiple myeloma (MM) is a hematologic malignancy characterized by the clonal proliferation of plasma cells in the bone marrow. It commonly presents with bone pain, anemia, renal failure, and hypercalcemia. Pleural effusion in MM usually has multiple causes, but it is rare for the effusion to be due to myelomatous deposition of the pleura. Here, we present a rare case in which the patient presented to the outpatient department with a dry cough, breathlessness, and generalized weakness. The patient was diagnosed with MM with myelomatous pleural effusion (MPE), highlighting the importance of considering MM as a differential diagnosis in patients with atypical presentations. MPE indicates a poor prognosis, and early consideration of MPE can lead to an earlier diagnosis and a more effective treatment of MM.

Clinical impact of pleural fluid carcinoembryonic antigen on therapeutic strategy and efficacy in lung adenocarcinoma patients with malignant pleural effusion.

BACKGROUND/AIMS: Epidermal growth factor receptor (EGFR) mutation is important in determining the treatment strategy for advanced lung cancer patients with malignant pleural effusion (MPE). Contrary to serum carcinoembryonic antigen (S-CEA) levels, the associations between pleural fluid CEA (PF-CEA) levels and EGFR mutation status as well as between PF-CEA levels and treatment efficacy have rarely been investigated in lung adenocarcinoma patients with MPE. METHODS: This retrospective study enrolled lung adenocarcinoma patients with MPE and available PF-CEA levels and EGFR mutation results. The patients were categorized based on PF-CEA levels: < 10 ng/mL, 10-100 ng/mL, 100-500 ng/mL, and ≥ 500 ng/mL. The association between PF-CEA levels and EGFR mutation status as well as their therapeutic impact on overall survival was compared among the four groups. RESULTS: This study included 188 patients. PF-CEA level was found to be an independent predictor of EGFR mutation but not S-CEA level. The EGFR mutation rates were higher as the PF-CEA levels increased, regardless of cytology results or sample types. Among EGFR-mutant lung adenocarcinoma patients receiving EGFR-tyrosine kinase inhibitor (TKI) treatment, those with high PF-CEA levels had significantly better survival outcomes than those with low PF-CEA levels. CONCLUSION: High PF-CEA levels were associated with high EGFR mutation rate and may lead to a favorable clinical outcome of EGFR-TKI treatment in EGFR-mutant lung adenocarcinoma patients with MPE. These findings highlight the importance of actively investigating EGFR mutation detection in patients with suspected MPE and elevated PF-CEA levels despite negative cytology results.

Disseminated thymoma in pleural fluid: An unusual case.

Thymic epithelial tumours show characteristic cytological features on fine-needle aspiration cytology, however the cytological features of thymoma in fluid cytology are not well described. We present the case of a 77 year-old-woman with known pleural dissemination of type B2/B3 thymoma presenting with shortness of breath and orthopnoea due to a pleural effusion. Cytological evaluation of the pleural fluid showed cellular smears composed of numerous small lymphocytes with small numbers of admixed mesothelial cells. There was no epithelial component. On immunohistochemical (IHC) staining the lymphocytes were T cells which were positive for CD3. CD1a and terminal deoxynucleotide transferase (TdT) were also positive, consistent with immature lymphocytes of thymic origin. Despite the lack of an epithelial component, this case was diagnosed as suspicious for recurrent/ metastatic thymoma. This is only the second published case of thymoma identified on pleural fluid cytology, and to our knowledge the first case describing thymoma in pleural fluid with no epithelial component, a potential pitfall with the more common differential diagnosis of a reactive lymphocytic effusion.

Pleural effusion due to lymphangiomatosis and the role of sirolimus: A case report.

Introduction: Lymphangiomatosis is a rare abnormal proliferation of lymphatic vessels involving multiple organs like the brain, lung, heart, spleen, liver, and bones. Lymphangiomas constitute 5.6% of all benign tumors in infancy and adulthood. Case presentation: We report a case of a young lady who presented with constitutional symptoms and progressive dyspnea. Her medical history is significant for muco-cutaneous albinism, diffuse hemangiomas of the bone and viscera, and consumptive coagulopathy status post-splenectomy. After initial investigations, she was found to have right-sided pleural effusion. Pleural fluid analysis indicated chylothorax. She had multiple drainages of the pleural fluid done, and afterward, ligation of the right thoracic duct was performed with a trial of sirolimus, which improved her chylothorax. Clinical discussion: Several case reports have reported positive outcomes with sirolimus in the treatment of lymphangiomatosis. However, larger controlled studies are needed to confirm these findings. Conclusion: Sirolimus is promising as a medical treatment for diffuse pulmonary lymphangiomatosis.

Evaluation of DiaSorin Liaison® calprotectin fecal assay adapted for pleural effusion.

Objectives: Calprotectin (CP) is a calcium and zinc binding protein that is widely measured on faecal samples but its determination in other biological fluids might be of interest. The aim of this work was to validate the measurement of CP in pleural fluid by chemiluminescence. Methods: LIAISON®XL, a fully automated chemiluminescence analyzer, was used for CP quantification on pleural fluid. A validation protocol was designed using both quality control materials provided by the manufacturer and pools of pleural fluid samples. Stability, imprecision, bias, linearity, detection capability and carry over effect were evaluated. Results: CP was stable on pleural fluid at least one week, under refrigerated conditions, and four weeks at -80 °C. The observed intra- and inter-day imprecision was between 2.2 and 6.49 %, with a negative bias under 5.51 %. The linearity of the method was verified up to 2,000 ng/mL. The LoQ for the assay was 48.52 ng/mL. A statistically significant carry-over effect was observed after measuring CP concentrations above the upper limit of linearity, but given the observed magnitude, a clinically relevant impact should not be expected. Conclusions: DiaSorin Liaison® calprotectin assay allows reliable measurement of CP in pleural fluid.

Bode Phase Angle Signaling of a TB Disease Biomarker.

Tuberculosis (TB) is a worldwide burden whose total control and eradication remains a challenge due to factors including false positive/negative diagnoses associated with the poor sensitivity of the current diagnostics in immune-compromised and post-vaccinated individuals. As these factors complicate both diagnosis and treatment, the early diagnosis of TB is of pivotal importance towards reaching the universal vision of a TB-free world. Here, an aptasensor for signaling an interferon gamma (IFN-γ) TB biomarker at low levels is reported. The aptasensor was assembled through gold-thiol interactions between poly(3,4-propylenedioxythiophene), gold nanoparticles, and a thiol-modified DNA aptamer specific to IFN-γ. The aptasensor sensitively detected IFN-γ in spiked pleural fluid samples with a detection limit of 0.09 pg/mL within a linear range from 0.2 pg/mL to 1.2 pg/mL. The good performance of the reported aptasensor indicates that it holds the potential for application in the early diagnosis of, in addition to TB, various diseases associated with IFN-γ release in clinical samples.

Role of RAPID score and surgery in the management of pleural infection: a single center retrospective study.

Background: The RAPID [Renal (urea level), Age, Pleural fluid purulence, source of Infection and Denutrition (albumin level)] score classifies patients with pleural infection according to mortality risk at 3 months. This study aims to assess the applicability of this score in a thoracic surgery department and to determine the impact of surgery in the management of pleural infection depending on the Rapid score. Methods: In this single center retrospective study, patients managed for pleural infection, from January 1st 2013 to June 30th 2019, were included. The primary endpoint was the probability of survival at 6 months and 12 months depending on the RAPID score. Secondary endpoint was the probability of survival at 6 and 12 months in patients who had surgeries (surgical treatment group) and patients who didn't have surgery (medical treatment group). Results: Seventy-four patients were included, with a median age of 54.5 years. According to the RAPID score, the low-, medium- and high-risk groups had 30, 30 and 14 patients respectively. The probability of survival at 6 and 12 months in the low- and medium-risk groups were both 0.967 [95% confidence index (CI95): 0.905-1] whereas, the probabilities of survival at 6 and 12 months in the high-risk group was significantly lower at 0.571 (CI95: 0.363-0.899) and 0.357 (CI95: 0.177-0.721) respectively (P<0.0001). The probabilities of survival at 6 months and 12 months in the medical treatment group was 0.875 (CI95: 0.786-0.974) and 0.812 (CI95: 0.704-0.931) respectively compared to the surgical treatment group where probabilities of survival at 6 and 12 months were both 0.923 (CI95: 0.826-1) (P=0.26). Conclusions: In our study, patients with pleural infection, classified as high-risk according to the RAPID score, had a lower survival rate compared to low- and medium-risk patients. No difference in survival rate was found between patients classified as low- and medium-risk. In selected patients, surgical management seems to decrease mortality compared to exclusive medical management: this result should be confirmed in larger prospective studies.

Pericardial Effusion and Progressive Bilateral Effusion as Rare Presentations of Idiopathic Hypereosinophilic Syndrome.

Hypereosinophilic syndrome (HES) is a rare disease with peripheral blood eosinophils >1500/µL and end-organ damage. We encountered a case of idiopathic HES in a woman in her 60s who presented with dyspnea due to cardiac effusion and bilateral pleural effusions. At first, the patient did not have eosinophilia in the peripheral blood, and the presence of serum pericardial fluid and pleural effusion led to suspicion of carcinomatous pericarditis and pleurisy. One month later after onset, eosinophilia in the peripheral blood was observed, and HES was suspected for the first time. However, inflammatory cell infiltration by eosinophils has been observed in the pleural fluid specimen before eosinophilia in the peripheral blood. Prednisolone was administered, and the pleural effusion and respiratory failure quickly abated. This case provided an educational illustration of a unique manifestation of cardiac tamponade and HES, characterized by the absence of peripheral blood eosinophilia at the initial presentation.

Pleural penetration of amoxicillin and metronidazole during pleural infection: An ambispective cohort study.

OBJECTIVES: The pharmacokinetics of antibiotics in pleural fluid during pleural infections has been poorly described. This study aimed to explore amoxicillin and metronidazole diffusion into the pleural space. METHODS: This was an ambispective, single-centre study that included patients with complicated parapneumonic effusion or pleural empyema managed with repeated therapeutic thoracentesis as first-line treatment between 2014 and 2022. Pleural steady-state or trough concentrations of amoxicillin and metronidazole were measured, with a lower limit of quantification of 5 mg/L. RESULTS: Seventy paired blood and pleural samples were analysed from 40 patients. The median (interquartile range) patient age was 55 years (45-67 years) and 88% were male. The median patient weight was 65.8 kg (57.3-82 kg) and median plasma albumin concentration was 29.7 g/L (23.7-33.9 g/L). Median creatinine clearance was 106 mL/min (95-117 mL/min). Median amoxicillin pleural concentrations in patients treated with oral, bolus and continuous intravenous administrations (6 g/day) were, respectively, 5.2 (<5-6.4), 9.4 (8-13.1) and 10.8 (7.1-13.1) mg/L. Pleural concentrations were <5 mg/L in 5/11 samples (45%) with oral treatment and 6/59 (10%) with intravenous treatment. Median metronidazole pleural concentrations were 18.4 (15.7-22.8) mg/L, with all patients being treated orally (1.5 g/day). CONCLUSIONS: Oral metronidazole (1.5 g/day) and intravenous amoxicillin (6 g/day) achieved therapeutic targets in pleural fluid in most cases, but oral amoxicillin did not.

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.

Immunoassay with Novel Paired Antibodies for Detection of Lipoarabinomannan in the Pleural Fluid and Plasma of Patients with Tuberculous Pleurisy.

Tuberculous pleurisy (TP) is one of the most common forms of extrapulmonary tuberculosis, but its diagnosis is challenging. Lipoarabinomannan (LAM) antigen is a biomarker for Mycobacterium tuberculosis (Mtb) infection. LAM detection has potential as an auxiliary diagnostic method for TP. We have successfully generated five rabbit anti-LAM monoclonal antibodies (BJRbL01, BJRbL03, BJRbL20, BJRbL52, and BJRbL76). Here, anti-LAM antibodies were tested to detect LAM in the pleural fluid and plasma of patients with TP by sandwich enzyme-linked immunosorbent assays (ELISAs). The results revealed that all of the anti-LAM antibodies were successfully used as capture and detection antibodies in sandwich ELISAs. The BJRbL01/BJRbL01-Bio pair showed better performance than the other antibody pairs for detecting mycobacterial clinical isolates and had a limit of detection of 62.5 pg/mL for purified LAM. LAM levels were significantly higher in the pleural fluid and plasma of patients with TP than in those of patients with malignant pleural effusion or the plasma of non-TB, and LAM levels in the pleural fluid and plasma were positively correlated. Moreover, LAM levels in the pleural fluid sample were significantly higher in confirmed TP patients than in clinically diagnosed TP patients. Our studies provide novel LAM detection choices in the pleural fluid and plasma of TP patients and indicate that LAM detection assay has an auxiliary diagnostic value for TP, which may help to improve the diagnosis of TP.