Pancreas Cyst Diagnosis and Advances in Cyst Fluid Analysis.

Pancreatic Cystic Neoplasms (PCN) represent a diverse group of tumors, some of which may progress to pancreatic cancer. Considering their high prevalence in the general population, the development of reliable biomarkers is crucial. The ideal biomarker will accurately diagnose the subtype of PCN and assess the risk of high-grade dysplasia or invasive cancer. Cyst fluid analysis has emerged as a promising approach to accomplish this goal, yet no single marker has yet gained unanimous support for routine inclusion in PCN evaluation.

MicroRNA-145 enhances lung cancer cell progression after exposure to lyophilized fertile hydatid cyst fluid of Echinococcus granulosus sensu stricto.

There is increasing evidence that the secretory/excretory antigens of the larval stage of Echinococcus granulosus can induce both anticancer and oncogenic effects between parasite-derived metabolites and various cancer cells. The dual role of miR-145 as either a tumor suppressor or oncogene has already been reported in cancer. However, the mechanism by which miR-145 induces apoptosis in lung cancer cells treated with hydatid cyst fluid (HCF) remains unclear. The fertile HCF was obtained from sheep, purified and lyophilized. H1299 human lung cancer cells were then cultured into two groups: HCF-treated H1299 lung cancer cells and untreated H1299 cancer cells as control cells. Cell viability was assessed using MTT assay to evaluate the effects of HCF on the H1299 cells. Caspase-3 activity was assessed by fluorometric assay. In addition, mRNA expression levels of VGEF, vimentin, caspase-3, miRNA-145, Bax and Bcl-2 genes were quantified by real-time PCR. A scratch test was also performed to assess the effects of HCF on cell migration. The MTT assay revealed that the growth of H1299 cells increased when treated with 60 µg/mL of fertile HCF for 24 h. The fold change of caspase-3, miRNA-145, Bax/Bcl-2 ratio and caspase-3 activity was lower in HCF-treated H1299 cells compared to the control cell. The fold change in VGEF and vimentin gene expression was higher in the HCF-treated H1299 cells than in the control cell. The scratch test results showed that H1299 cell mobility increased 24 and 48 h after exposure to HCF. Our results suggest that the downregulation of miR-145 in HCF-treated H1299 cells may play a role as a possible oncogenic regulator of lung cancer growth. To confirm this assumption, further studies are required to evaluate the microRNA profile and effective oncogenes in vivo.

Pancreas Fine Needle Aspiration: Current and Future Impact on Patient Care.

Pancreatic lesions can be solid or cystic and comprise a wide range of benign, premalignant, and malignant entities. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is the current primary sampling method for the preoperative diagnosis of pancreatic lesions. Optimal handling of cytology/small tissue specimens is critical to ensure that the often-scant diagnostic material is appropriately utilized for ancillary and/or molecular studies when appropriate. Ultimately, evaluation of EUS-FNA cytology and small biopsy material can provide accurate and timely diagnoses to guide patient management and triage them to surveillance or surgical intervention.

Congenital Blood Cyst of a Child: A case report and review of literature.

Blood-filled cysts of the heart valves are frequently reported at postpartum autopsies of infants. They are seen as round nodules mostly in the paediatric age group in infants less than 2 months of age and disappear spontaneously within 6 months of life. We report a unique case of an 11-month-old girl who presented at a tertiary healthcare hospital in 2022 with a blood-filled cyst on the posterior leaflet of the pulmonary valve that was successfully treated. This case report highlights the characteristics and course of a paediatric patient with blood-filled cysts. Further studies are yet needed to better understand the diagnostic approaches to blood-filled cysts as well as treatment modalities to fill the gap in clinical settings.

Activation of cGAS/STING Drives Inflammation and Cellular Senescence of Macrophages in Ovarian Endometrioma Induced by Endometriotic Cyst Fluid.

Ovarian endometrioma (OE) is a common gynecological condition characterized by the formation of "chocolate cysts". Recent research indicates that the cyst fluid acts as a "toxic environment" for the ovary and plays a significant role in the development of OE, with macrophages being pivotal. However, the specific molecular and cellular mechanisms of it are not fully understood. In this study, clinical samples are integrated, single-cell sequencing, in vivo and in vitro experimental models to comprehensively investigate the effects of OE fluid on ovarian function and the mechanisms of it. Combined with bioinformatics analysis and experimental validation, the findings demonstrate that OE fluid can cause ovarian function decline, which associated with inflammatory response, and mitochondrial dysfunction and cellular senescence, while activating the cGAS/STING signaling pathway. As a STING inhibitor, H-151 effectively alleviates ovarian dysfunction, inflammatory state and cell apoptosis induced by OE fluid. Furthermore, it is also discovered that H-151 can inhibit OE fluid-induced mitochondrial dysfunction and cellular senescence. These findings provide important theoretical and experimental foundations for further research and development of STING inhibitors as potential drugs for treating ovarian dysfunction.

Long-Term Outcomes of Endoscopic Ultrasound-Guided Ablation Vs Surgery for Pancreatic Cystic Tumors.

BACKGROUND & AIMS: Endoscopic ultrasound-guided pancreatic cyst ablation (EUS-PCA) is performed as an alternative to surgical resection in selected patients with pancreatic cystic tumors (PCTs). We aimed to directly compare the long-term outcomes between EUS-PCA and surgery for PCTs. METHODS: We reviewed a PCT database to identify patients with unilocular or oligolocular PCTs who underwent EUS-PCA or surgery between January 2004 and July 2019. We performed 1:1 propensity score matching based on potential confounding factors. The primary outcome was long-term morbidities. Secondary outcomes included early (≤14 days) and late (>14 days) major adverse events (MAEs), development of diabetes mellitus, readmission, length of hospital stay, and therapeutic efficacy. RESULTS: A total of 620 patients (EUS-PCA, n = 310; surgery, n = 310) were selected after propensity score matching. The EUS-PCA group showed a lower 10-year rate of cumulative long-term morbidities (1.6% vs 33.5%; P = .001) as well as lower rates of early MAE (1.0% vs 8.7%; P = .001), late MAE (0.3% vs 5.5%; P = .001), and readmission (1.0% vs 15.2%; P = .001). The EUS-PCA group had a shorter hospital stay (3.5 vs 10.3 d; P = .001) and a lower incidence of diabetes mellitus (2.2% vs 22.8%; P = .001), whereas the surgery group had a higher complete resolution rate (76.5% vs 100%; P = .001) and a lower relapse rate (4.6% vs 0.3%; P = .001). CONCLUSIONS: For select patients with PCTs, EUS-PCA showed superior results to surgery in terms of long-term safety profile and preservation of pancreatic function.

Assessing the Potential Apoptotic Effects of Different Hydatid Cyst Fluids on Human Healthy Hepatocytes and Hepatocellular Carcinoma Cells.

Cystic Echinococcosis (CE) is a zoonotic infection caused by the larval form of Echinococcus granulosus in humans. Emerging evidence suggests an intriguing inverse association between E. granulosus infection and the occurrence of cancer. This study aimed to investigate the influence of diverse host-derived hydatid cyst fluids (HCF) with distinct genotypes on human liver hepatocytes (HC) and hepatocellular carcinoma cells (HepG2). Specifically, we examined their effects on cell proliferation, apoptosis sensitivity (BAX/BCL-2), apoptosis-related p53 expression, and the expression of cancer-related microRNA (hsa-miR-181b-3p). Cell proliferation assays, real-time PCR, and ELISA studies were conducted to evaluate potential anti-cancer properties. The findings revealed that animal-origin HCF (G1(A)) induced direct cell death by augmenting the susceptibility of HepG2 cells to apoptosis. Treatment with both G1(A) and G1(H) HCF sensitized HepG2 and HC cell lines to apoptosis by modulating the BAX/BCL-2 ratio, accompanied by upregulation of the p53 gene. Additionally, G1(A) HCF and human-derived HCFs (G1(H), G7(H)) reduced the expression of miR-181b-3p in HepG2 cells. Consequently, this study demonstrates the potential anti-cancer effect of HCF in HepG2 cells and provides the first comparative assessment of HCFs from human and animal sources with diverse genotypes, offering novel insights into this field.

Reliable detection of genetic alterations in cyst fluid DNA for the diagnosis of brain tumors.

PURPOSE: Liquid biopsy of cyst fluid in brain tumors has not been extensively studied to date. The present study was performed to see whether diagnostic genetic alterations found in brain tumor tissue DNA could also be detected in cell-free DNA (cfDNA) of cyst fluid in cystic brain tumors. METHODS: Cyst fluid was obtained from 22 patients undergoing surgery for a cystic brain tumor with confirmed genetic alterations in tumor DNA. Pathological diagnoses based on WHO 2021 classification and diagnostic alterations in the tumor DNA, such as IDH1 R132H and TERT promoter mutation for oligodendrogliomas, were detected by Sanger sequencing. The same alterations were analyzed by both droplet digital PCR (ddPCR) and Sanger sequencing in cyst fluid cfDNA. Additionally, multiplex ligation-dependent probe amplification (MLPA) assays were performed to assess 1p/19q status, presence of CDKN2A loss, PTEN loss and EGFR amplification, to assess whether differentiating between astrocytomas and oligodendrogliomas and grading is possible from cyst fluid cfDNA. RESULTS: Twenty-five genetic alterations were found in 22 tumor samples. All (100%) alterations were detected in cyst fluid cfDNA by ddPCR. Twenty of the 25 (80%) alterations were also detected by Sanger sequencing of cyst fluid cfDNA. Variant allele frequency (VAF) in cyst fluid cfDNA was comparable to that of tumor DNA (R = 0.62, Pearson's correlation). MLPA was feasible in 11 out of 17 (65%) diffuse gliomas, with close correlation of results between tumor DNA and cyst fluid cfDNA. CONCLUSION: Cell-free DNA obtained from cyst fluid in cystic brain tumors is a reliable alternative to tumor DNA when diagnosing brain tumors.

Endoscopic ultrasound-guided fine-needle aspiration for pancreatic cystic lesions: a comprehensive review.

Advancements in diagnostic radiology have amplified the incorporation of these techniques into routine clinical practice. Concurrently, the frequency of incidentally identifying pancreatic cystic lesions (PCLs) has surged. PCLs encompass diverse categories contingent upon their origin. Among them, branch duct-intraductal papillary mucinous neoplasms (BD-IPMN) and mucinous cystic neoplasms (MCN) are categorized as mucinous cystic lesions that have malignant potential. Even solid neoplasms occasionally show cystic degeneration. Therefore, precise differential PCL diagnosis is crucial to optimize clinical management strategies and detect malignant transformations. Endoscopic ultrasound (EUS) affords comprehensive visualization of the pancreas with high-resolution ultrasound, complemented by fine-needle aspiration (FNA) under real-time EUS guidance, which is a minimally invasive procedure for obtaining pathological samples. This synergy has established EUS and EUS-FNA as vital procedures in the management of PCLs, enabling differentiation of PCLs. Cyst fluid analysis has played a pivotal role in deciding the optimal management strategy. The efficacy of cytological analysis is limited by scant cytologic material. The "string sign" test evaluates fluid viscosity, and its simplicity warrants initial consideration. Amylase and tumor markers, such as CEA, have been studied, but they yield varied sensitivity and specificity. Glucose and genetic mutations (KRAS, GNAS) exhibit promise, while comprehensive genomic profiling underscores genetic insights. Through-the-needle biopsy and needle-based confocal laser endomicroscopy also show high diagnostic yield. EUS-FNA, however, entails risks like infection and needle tract seeding, emphasizing the need for proper utilization. Pancreatic cyst fluid analysis augments diagnostic accuracy and informs clinical decisions, making it a valuable adjunct to imaging.

Therapeutic effect of Echinococcus granulosus cyst fluid on bacterial sepsis in mice.

BACKGROUND: The primary pathophysiological process of sepsis is to stimulate a massive release of inflammatory mediators to trigger systemic inflammatory response syndrome (SIRS), the major cause of multi-organ dysfunction and death. Like other helminths, Echinococcus granulosus induces host immunomodulation. We sought to determine whether E. granulosus cyst fluid (EgCF) displays a therapeutic effect on sepsis-induced inflammation and tissue damage in a mouse model. METHODS: The anti-inflammatory effects of EgCF were determined by in vitro culture with bone marrow-derived macrophages (BMDMs) and in vivo treatment of BALB/C mice with cecal ligation and puncture (CLP)-induced sepsis. The macrophage phenotypes were determined by flow cytometry, and the levels of cytokines in cell supernatants or in sera of mice were measured (ELISA). The therapeutic effect of EgCF on sepsis was evaluated by observing the survival rates of mice for 72 h after CLP, and the pathological injury to the liver, kidney, and lung was measured under a microscope. The expression of TLR-2/MyD88 in tissues was measured by western blot to determine whether TLR-2/MyD88 is involved in the sepsis-induced inflammatory signaling pathway. RESULTS: In vitro culture with BMDMs showed that EgCF promoted macrophage polarization to M2 type and inhibited lipopolysaccharide (LPS)-induced M1 macrophages. EgCF treatment provided significant therapeutic effects on CLP-induced sepsis in mice, with increased survival rates and alleviation of tissue injury. The EgCF conferred therapeutic efficacy was associated with upregulated anti-inflammatory cytokines (IL-10 and TGF-ß) and reduced pro-inflammatory cytokines (TNF-α and INF-γ). Treatment with EgCF induced Arg-1-expressed M2, and inhibited iNOS-expressed M1 macrophages. The expression of TLR-2 and MyD88 in EgCF-treated mice was reduced. CONCLUSIONS: The results demonstrated that EgCF confers a therapeutic effect on sepsis by inhibiting the production of pro-inflammatory cytokines and inducing regulatory cytokines. The anti-inflammatory effect of EgCF is carried out possibly through inducing macrophage polarization from pro-inflammatory M1 to regulatory M2 phenotype to reduce excessive inflammation of sepsis and subsequent multi-organ damage. The role of EgCF in regulating macrophage polarization may be achieved by inhibiting the TLR2/MyD88 signaling pathway.

Low pressure headache and cerebral fat embolism from a sacral fracture through a Tarlov cyst: a case report.

BACKGROUND: Here we report the only formally documented case in the United Kingdom, to our knowledge, of a cerebral fat embolism secondary to non-iatrogenic trauma through a Tarlov cyst. This case demonstrates the pathology clearly giving an excellent opportunity to demonstrate a rarely seen pathology as well as illustrating the importance of the patient history to guiding further management. CASE PRESENTATION: A middle-aged patient was admitted on the acute medical take complaining of severe headache with photophobia, having just returned after a skiing holiday. Computerised tomography scan of the head showed fat within the anterior horn of both lateral ventricles, and within the subarachnoid space. Re-discussion with the patient and subsequent MRI (Magnetic Resonance Imaging) of the spine identified the pathogenesis of her symptoms: a sacral insufficiency fracture through a Tarlov cyst, causing subarachnoid fat embolism and symptoms of a low-pressure headaches due to a dural leak. Patient was medically managed and discharged with planned follow-up. Due to the Coronavirus pandemic and resolution of the patient's symptoms, they declined further follow up imaging. CONCLUSIONS: The case demonstrates a rarely seen pathology as cause of a common presenting problem, headache. Emphasizing the importance of history taking and appropriate investigations in medical cases that do not conform to the usual diagnosis.

Using Endoscopy in the Diagnosis of Pancreato-Biliary Cancers.

Pancreatic cancer and cholangiocarcinoma are life threatening oncological conditions with poor prognosis and outcome. Pancreatic cystic lesions are considered precursors of pancreatic cancer as some of them have the potential to progress to malignancy. Therefore, accurate identification and classification of these lesions is important to prevent the development of invasive cancer. In the biliary tract, the accurate characterization of biliary strictures is essential for providing appropriate management and avoiding unnecessary surgery. Techniques have been developed to improve the diagnosis, risk stratification, and management of pancreato-biliary lesions. Endoscopic ultrasound (EUS) and associated techniques, such as elastography, contrasted-enhanced EUS, and EUS-guided needle confocal laser endomicroscopy, may improve diagnostic accuracy. In addition, intraductal techniques applied during endoscopic retrograde cholangiopancreatography (ERCP), such as new generation cholangioscopy and in vivo cellular evaluation through probe-based confocal laser endomicroscopy, can increase the diagnostic yield in characterizing indeterminate biliary strictures. Both EUS-guided and intraductal approaches can provide the possibility for tissue sampling with new tools, such as needles, biopsies forceps, and brushes. At the molecular level, novel biomarkers have been explored that provide new insights into diagnosis, risk stratification, and management of these lesions.

Predictive ability of pancreatic cyst fluid biomarkers: A systematic review and meta-analysis.

BACKGROUND: Mucinous pancreatic cysts harbor the potential to progress to highly lethal pancreatic ductal adenocarcinoma (PDAC). Since these precursor cysts require cancer surveillance or surgical resection, they need to be reliably distinguished from harmless pancreatic cysts. Current clinical and radiographic assessment is imperfect and the value of cyst fluid analysis for differential diagnosis is unclear. Therefore, we set out to investigate the value of cyst fluid biomarkers in distinguishing pancreatic cysts. METHODS: We performed a systematic review of the current literature to identify articles that evaluated the diagnostic performance of clinically relevant and promising candidate cyst fluid biomarkers, with a particular emphasis on DNA-based biomarkers. Meta-analysis was performed for biomarkers targeted at identifying cyst type and presence of high-grade dysplasia or PDAC. RESULTS: Data from a total of 42 studies was analyzed. Mutations in KRAS and/or GNAS allowed identification of mucinous cysts with a sensitivity of 79% and specificity of 98%. This exceeded the performance of the traditional biomarker carcinoembryonic antigen (CEA; sensitivity 58%, specificity 87%). Mutations in VHL were specific for serous cystadenomas (SCAs; sensitivity 56%, specificity 99%) and help to exclude mucinous cysts. Mutations in CDKN2A, PIK3CA, SMAD4, and TP53 each had high specificities of 97%, 97%, 98%, and 95%, respectively, to identify high-grade dysplasia or PDAC in mucinous cysts. CONCLUSIONS: Cyst fluid analysis can be a valuable tool in the characterization of pancreatic cysts, with relevant clinical implications. Our results support the use of DNA-based cyst fluid biomarkers in the multidisciplinary diagnostic work-up of pancreatic cysts.

Pancreatic Cyst Fluid Analysis.

Pancreatic cyst fluid analysis can help diagnose pancreatic cyst type and the risk of high-grade dysplasia and cancer. Recent evidence from molecular analysis of cyst fluid has revolutionized the field with multiple markers showing promise in accurate diagnosis and prognostication of pancreatic cysts. The availability of multi-analyte panels has great potential for more accurate prediction of cancer.

Autosomal Dominant Polycystic Kidney Disease Therapies on the Horizon.

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the formation of numerous kidney cysts which leads to kidney failure. ADPKD is responsible for approximately 10% of patients with kidney failure. Overwhelming evidence supports that vasopressin and its downstream cyclic adenosine monophosphate signaling promote cystogenesis, and targeting vasopressin 2 receptor with tolvaptan and other antagonists ameliorates cyst growth in preclinical studies. Tolvaptan is the only drug approved by Food and Drug Administration to treat ADPKD patients at the risk of rapid disease progression. A major limitation of the widespread use of tolvaptan is aquaretic events. This review discusses the potential strategies to improve the tolerability of tolvaptan, the progress on the use of an alternative vasopressin 2 receptor antagonist lixivaptan, and somatostatin analogs. Recent advances in understanding the pathophysiology of PKD have led to new approaches of treatment via targeting different signaling pathways. We review the new pharmacotherapies and dietary interventions of ADPKD that are promising in the preclinical studies and investigated in clinical trials.

Inhibition of mouse colon cancer growth following immunotherapy with a fraction of hydatid cyst fluid.

BACKGROUND: Hydatid cyst is the larval stage of the tape worm Echinococcus granulosus which is located in human and livestock viscera. There are some scientific evidences indicating that parasitic infections induce antitumor activity against certain types of cancers. In this study, the effects of a fraction of hydatid cyst fluid on colon cancer tumor in BALB/c mice were investigated. MATERIALS AND METHODS: In this experimental work six groups of mice were challenged with mouse colon cancer cells. 5 days later when the sign of tumor growth in mice was seen, group 1-4 were injected with hydatid cyst fluid, the 78 kDa fraction, live protoscolices and BCG respectively. Group five was injected with alum alone and the sixth group left intact without any injection. The size of the tumor was measured and compared in all groups. Then blood samples of mice were evaluated for serum cytokine levels. RESULT: In mice injected with hydatid cyst antigens especially a fraction of hydatid cyst fluid, tumor size was smaller than the that of control groups and the difference of tumor size in cases and control groups was statistically significant. CONCLUSION: The results of this study showed that injection of mice with a fraction of hydatid cyst fluid significantly inhibits the growth of mouse colon cancer and this inhibition may be related to effect of immune response to these antigens.

Validation of combined carcinoembryonic antigen and glucose testing in pancreatic cyst fluid to differentiate mucinous from non-mucinous cysts.

BACKGROUND: More accurate diagnosis of mucinous cysts will reduce the risk of unnecessary pancreatic surgery. Carcinoembryonic antigen (CEA) and glucose in pancreatic cyst fluid (PCF) can differentiate mucinous from non-mucinous pancreatic cystic neoplasms (PCN). The current study assessed the value of combined CEA and glucose testing in PCF. METHODS: Cross-sectional validation study including prospectively collected PCF from patients undergoing endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) and pancreatic surgery. We performed laboratory measurements for CEA and glucose and measured glucose levels by a hand glucometer. Primary outcome was diagnostic accuracy evaluated by receiver operator curves (ROC), sensitivity, specificity, positive, and negative predictive value (PPV, NPV). RESULTS: Overall, PCF was collected from 63 patients, including 33 (52%) with mucinous and 30 (48%) with non-mucinous PCN. Histopathology (n = 36; 57%), cytopathology (n = 2; 3%), or clinical and/or radiological diagnosis (n = 25; 40%) was used as reference standard. Combined CEA (cut-off ≥ 192 ng/ml) and laboratory glucose testing (cut-off ≤ 50 mg/dL) reached 92% specificity and 48% sensitivity, whereas either positive CEA (cut-off ≥ 20 ng/ml) or glucose testing (cut-off ≤ 50 mg/dL) showed 97% sensitivity and 50% specificity. Sensitivity and specificity were 80% and 68% for CEA ≥ 20 ng/mL versus 50% and 93% for CEA ≥ 192 ng/mL (the conventional cut-off level). Laboratory and glucometer glucose both reached 100% sensitivity and 60% and 45% specificity, respectively. None of the biomarkers and cut-offs reached a PPV exceeding 90%, whereas both glucose measurements had a NPV of 100% (i.e., high glucose excludes a mucinous cyst). CONCLUSION: Combined CEA and glucose testing in PCF reached high specificity and sensitivity for differentiating mucinous from non-mucinous PCN. Glucose testing, whether alone or combined with the new CEA cut-off (≥ 20 ng/mL), reached > 95% sensitivity for mucinous cysts, whereas only glucose reached a NPV > 95%.

Molecular Analysis of Pancreatic Cyst Fluid for the Management of Intraductal Papillary Mucinous Neoplasms.

Pancreatic cancer is one of the most lethal human cancers. Early detection and diagnosis of precursor lesions for pancreatic malignancy is essential to improve the morbidity and mortality associated with this diagnosis. Of the cystic precursor lesions, branch duct intraductal papillary mucinous neoplasm (IPMN) is the most frequently identified lesion and has a wide range of malignant potential. Currently, Carcinogenic embryonic antigen (CEA) levels in the cyst fluid and cytology are the two most often utilized tools to diagnose these lesions; however, their diagnostic and risk stratification capabilities are somewhat limited. Within the last decade, the use of endoscopic ultrasound-guided fine-needle aspiration has opened the door for molecular analysis of cystic fluid as an option to enhance both the diagnosis and risk stratification of these lesions. The first step is to differentiate branch duct IPMNs from other lesions. KRAS and GNAS alterations have been shown to be accurate markers for this purpose. Following cyst type identification, mutational analysis, telomere fusion, microRNAs, long non-coding RNA, and DNA methylation have been identified as potential targets for stratifying malignant potential using the cystic fluid. In this review, we will examine the various targets of cyst fluid molecular analysis and their utility in the diagnosis and risk stratification of branch duct IPMNs.

A Comparative Evaluation of Four Different Immunoassays in the Diagnosis of Cystic Echinococcosis Using a Crude and Purified Hydatid Cyst Fluid Antigen.

PURPOSE: Cystic echinococcosis (CE) is one of the most neglected tropical diseases as per WHO which has an immense public health significance. Diagnosis of CE is difficult as specific clinical signs are manifested only after the hydatid cyst attains a considerable size. Immunodiagnosis is a reliable method of diagnosing CE. METHODS: SDS-PAGE was performed for the hydatid cyst fluid antigens. The antigen purity was tested by Western blotting and four different immunoassays were evaluated using these two antigens in sheep and buffalo in diagnosis of CE. RESULTS: SDS-PAGE revealed four bands of 72, 64, 48 and 24 kDa for crude antigen and a single 72 kDa band for purified antigen. Among sheep sera, ELISA was most sensitive (70%) using crude antigen and also while using the purified antigen (80%). In case of buffaloes, ELISA, DID and CIEP were more sensitive (83.3%) using crude antigen, whereas DID and CIEP were more sensitive (83.3%) using purified antigen. CONCLUSION: In sheep, while using the crude antigen ELISA was the most sensitive assay and IHA was the least sensitive assay. While using the purified antigen also, ELISA was the most sensitive and others were absolutely specific except for IHA being less sensitive. In buffaloes, using crude antigen, all the immunoassays CIEP, DID and ELISA were highly sensitive in diagnosing CE infection except IHA, whereas using the purified antigen, both CIEP and DID were more sensitive than ELISA and IHA which were comparatively less sensitive in detecting CE in buffalo sera.