Precision medicine translates through molecular assays and in minimally invasive diagnosis, evident in analyses of effusions that serve therapeutic and diagnostic purposes. This cost-effective and low-risk approach provides advantages, playing a pivotal role in late-stage oncology and frequently standing as the primary resource for cancer diagnosis and treatment pathways. This article outlines the workflow for managing serous fluid and explores how cytology effusion analysis extends beyond immunocytological diagnosis. Combined with current molecular tests it showcases the potential to be a skillful tool in precision cytopathology.

BACKGROUND: The distinction between complicated and uncomplicated acute appendicitis (AA) is important as it guides postoperative antibiotic treatment. A diagnosis based on intraoperative findings is imprecise and standard cultivation of peritoneal fluid is generally time-consuming with little clinical benefit. The aim of this study was to examine if cultivation of peritoneal fluid in acute appendicitis could reliably detect bacteria within 24 h.
METHODS: Patients older than 18 years undergoing laparoscopic appendectomy were prospectively enrolled at two surgical departments after informed consent was obtained. Periappendicular fluid was collected prior to appendectomy and sent for cultivation. Sensitivity, specificity and positive and negative predictive values were calculated with 95% confidence intervals (CIs) using 72-hour cultivation results as the gold standard. Patients with complicated AA as determined by the surgeon, received a three-day course of oral antibiotics. Postoperative infectious complications within 30 days after surgery were registered.
RESULTS: From July 2020 to January 2021, 101 patients were included. The intraoperative diagnosis was complicated AA in 34 cases. Of these patients, six (17.6%) had bacteria cultured within 24 h after surgery, leading to a sensitivity of 60% and a specificity of 100%. The positive and negative predictive values were 1.00 and 0.96, respectively. Seven patients developed a postoperative infection (five superficial wound infections and two intra-abdominal abscess). In all cases with a positive cultivation result, the intraoperative diagnosis was complicated appendicitis and a postoperative course of antibiotics prescribed.
CONCLUSIONS: Twenty-four-hour cultivation of the peritoneal fluid in acute appendicitis is a valid indicator for peritoneal bacterial contamination. Randomized studies are necessary to determine if this approach is suitable for targeting postoperative antibiotic treatment as a means to prevent overtreatment without increasing the risk of infectious complications.

Side effects and low efficacy of current anti-toxoplasmosis therapeutics against encysted bradyzoites necessitate research into alternative safe therapeutic options. The safety, immunostimulatory, and antimicrobial properties of alginate nanoparticle formulation (Alg-NP) highlight its potential as an oral therapy against acute toxoplasmosis. In the current study, Alg-NP was formulated and characterized and then assessed for its anti-Toxoplasma effects using parasitological, ultrastructural, immunological, and histopathological studies. Treatment with Alg-NP significantly prolonged mice survival and reduced the parasite burden in both peritoneal fluid and tissue impression smears. In addition, it altered parasite viability and caused severe tachyzoite deformities as evidenced by ultrastructural studies. Alg-NP induced high levels of serum IFN-γ in infected mice with significant amelioration in histopathological changes in both hepatic and splenic tissue sections. In conclusion, Alg-NP could be considered a promising therapeutic agent against acute murine toxoplasmosis, and owing to its safety, it could potentially be enlisted for human use.

Endometriosis is an estrogen-dependent inflammatory gynecological disease whose pathogenesis is unclear. C-C motif chemokine ligand 18 (CCL18), a chemokine, is involved in several inflammatory diseases. In this study, we aimed to investigate the role of CCL18 in endometriosis and its underlying mechanisms. Human endometrium and peritoneal fluid were obtained from women with and without endometriosis for molecular studies. The expression level of CCL18 in each tissue sample was examined by RNA sequencing analysis, quantitative PCR analysis and immunohistochemistry staining. The effects of CCL18 on cell migration, tube formation and neurite growth were investigated in vitro using primary endometrial cells, human umbilical vein endothelial cells (HUVECs) and dorsal root ganglion (DRG) neurons, respectively. Moreover, the development of endometriosis in mice was studied in vivo by blocking CCL18. CCL18 was shown to be overexpressed in endometrial foci and peritoneal fluid in women with endometriosis and was positively correlated with endometriosis pain. In vitro, CCL18 promoted the migration of ectopic endometrial cells, tube formation of HUVECs, and nerve outgrowth of DRG neurons. More importantly, inhibition of CCL18 significantly suppressed lesion development, angiogenesis, and nerve infiltration in a mouse model of endometriosis. In conclusion, CCL18 may play a role in the progression of endometriosis by increasing endometrial cell migration and promoting neuroangiogenesis.

Objective: To investigate the importance of cell block and immunohistochemistry in the accurate diagnosis of serous effusion. Methods: A retrospective study was conducted on 3 124 cases of serous effusion from the Department of Pathology, Beijing Hospital from 2018 to 2022, include 2 213 cases of pleural effusion, 768 cases of peritoneal effusion, 143 cases of pericardial effusion. There were 1 699 males (54.4%) and 1 425 females (45.6%), average age 69 years old. Of which 1 292 cases were prepared with cell blocks and examined with immunohistochemical stain. Results: The percentage of malignant diagnosis increased from 64.9% (839/1 292) to 84.0% (1 086/1 292) after cell block preparation, and 1 086 cases were accurately diagnosed with histological type and/or origin of primary tumor. The undetermined diagnosis of suspected malignancy decreased from 13.3% (172/1 292) to 0.1% (1/1 292) and that of atypical hyperplasia from 18.8% (243/1 292) to 0.4% (5/1 292). The negative result for malignancy rate increased from 3.0% (38/1 292) to 15.5% (200/1 292). The differences highlighted above were statistically significant (Pearson\'s chi-squared test=12.739, P<0.01). Conclusion: Application of immunohistochemistry based on cell block can significantly improve malignant diagnosis in serous effusion, identify tumor origin and histological type as well as decrease the uncertain diagnosis.
目的： 探讨细胞蜡块及免疫组织化学对浆膜腔积液精准诊断的重要性。 方法： 回顾性研究2018—2022年北京医院病理科浆膜腔积液标本3 124例，包括胸腔积液2 213例，腹腔积液768例，心包积液143例。男性1 699例（54.4%），女性1 425例（45.6%）；平均年龄69岁。其中1 292例制作了细胞蜡块，并行免疫组织化学检查。 结果： 诊断恶性肿瘤百分比从细胞蜡块制作前64.9%（839/1 292）提高到制作后84.0%（1 086/1 292），其中1 086例恶性肿瘤明确了组织类型和/或来源；不明确的诊断包括可疑恶性及不典型增生，分别从13.3%（172/1 292）和18.8%（243/1 292）降低到0.1%（1/1 292）和0.4%（5/1 292）；阴性率从3.0%（38/1 292）升高到15.5%（200/1 292），差异具有统计学意义（Pearson卡方=12.739，P<0.01）。 结论： 以细胞蜡块制作为基础的免疫组织化学检查显著提高了浆膜腔积液恶性诊断率，同时可鉴别组织类型和肿瘤来源，减少不明确的诊断。.

Background: Immunological imbalances characteristic of endometriosis may develop as early as the primary manifestations of the disease in adolescence. Objective: To evaluate subpopulation dynamics of monocytes and lymphocytes in peripheral blood and peritoneal fluid of adolescents with peritoneal endometriosis at diagnosis and after 1-year progestogen therapy. Methods: This study included 70 girls, 13-17 years old, diagnosed laparoscopically with peritoneal endometriosis (n = 50, main group) or paramesonephric cysts (n = 20, comparison group). Phenotypes of monocytes and lymphocytes of the blood and macrophages of the peritoneal fluid were analyzed by flow cytometry at diagnosis and during progestogen therapy. Results: Differential blood counts of CD16+ (p < 0.001) and CD86+ (p = 0.017) monocytes were identified as independent risk factors for peritoneal endometriosis in adolescents. During the treatment, cytotoxic lymphocytes CD56dimCD16bright (p = 0.049) and CD206+ monocytes (p < 0.001) significantly increased while CD163+ monocytes decreased in number (p = 0.017). The CD56dimCD16bright blood counts before (p < 0.001) and during progestogen therapy (p = 0.006), as well as CD206+ blood counts during the treatment (p = 0.038), were associated with the efficacy of pain relief after 1-year progestogen therapy. Conclusions: Adolescents with peritoneal endometriosis have altered counts of pro- and anti-inflammatory monocytes and lymphocytes both before and after 1-year progestogen therapy, correlating with treatment efficacy and justifying long-term hormonal therapy.

BACKGROUND: Diagnosing peritoneal tuberculosis is challenging due to unspecific clinical manifestations, particularly in immunocompromised patients with HIV/AIDS and tuberculosis infections.
METHODS: An Indonesian man, 26-years-old, complained of mid-abdominal colic and constipation. The patient\'s present state exhibited symptoms of weakness and paleness, oral candidiasis, a bloated abdomen, palpable discomfort, and shifting dullness. The ascitic fluid analysis showed increased ADA (709 U/L), and detected Mycobacterium tuberculosis using GeneXpert MTB/RIF. Radiographic examination from abdominal x-ray and CT scan revealed a small bowel obstruction. He received intestinal decompression, pain control, intravenous fluid resuscitation, and correction of electrolyte imbalance for small bowel obstruction without any indication for surgical intervention. He also receive first-line ATD for 2 months during intensive phase and 4 months for continuous phase. After a period of 2 weeks following the ATD administration, the patient began taking ARV medication on a daily basis. He showed a good prognosis 6 months following.
CONCLUSIONS: The diagnosis of peritoneal tuberculosis is challenging due to its unspecific manifestation and some cases are identified when complications such as small bowel obstruction appear. The ADA test and GenExpert MTB/RIF are useful instruments for promptly diagnosing tuberculosis. It is suggested to use ARV treatment in individuals with HIV/AIDS who have peritoneal tuberculosis, starting 2 weeks following ATD treatments.
CONCLUSIONS: Peritoneal tuberculosis with small bowel obstruction and HIV/AIDS infection is a rare case in which early diagnosis and monitoring play an important role in successful treatment.

UNASSIGNED: Peritoneal metastasis (PM) is the most prevalent type of metastasis in patients with gastric cancer (GC) and has an extremely poor prognosis. The detection of free cancer cells (FCCs) in the peritoneal cavity has been demonstrated to be one of the worst prognostic factors for GC. However, there is a lack of sensitive detection methods for FCCs in the peritoneal cavity. This study aimed to use a new peritoneal lavage fluid cytology examination to detect FCCs in patients with GC, and to explore its clinical significance on diagnosing of occult peritoneal metastasis (OPM) and prognosis.
UNASSIGNED: Peritoneal lavage fluid from 50 patients with GC was obtained and processed via the isolation by size of epithelial tumor cells (ISET) method. Immunofluorescence and fluorescence in situ hybridization (FISH) were used to identify FCCs expressing chromosome 8 (CEP8), chromosome 17 (CEP17), and epithelial cell adhesion molecule (EpCAM).
UNASSIGNED: Using a combination of the ISET platform and immunofluorescence-FISH, the detection of FCCs was higher than that by light microscopy (24.0% vs. 2.0%). Samples were categorized into positive and negative groups, based on the expressions of CEP8, CEP17, and EpCAM. Statistically significant relationships were demonstrated between age (P = 0.029), sex (P = 0.002), lymphatic invasion (P = 0.001), pTNM stage (P = 0.001), and positivity for FCCs. After adjusting for covariates, patients with positive FCCs had lower progression-free survival than patients with negative FCCs.
UNASSIGNED: The ISET platform highly enriched nucleated cells from peritoneal lavage fluid, and indicators comprising EpCAM, CEP8, and CEP17 confirmed the diagnosis of FCCs. As a potential detection method, it offers an opportunity for early intervention of OPM and an extension of patient survival.

UNASSIGNED: Spontaneous bacterial peritonitis is a frequent severe complication in cirrhotic patients with ascites. Carbapenem antibiotics are currently the treatment of choice for patients with hospital-acquired or healthcare-related infections. However, there is limited evidence available on the efficacy of ertapenem in cirrhotic patients with spontaneous bacterial peritonitis. As a result, the pharmacokynetics and pharmacodynamics of this antibiotic are still unknown. The objective of this study was to develop and validate measurement procedures based on liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) to determine ertapenem concentrations in plasma and ascitic fluid.
UNASSIGNED: Samples were pretreated by acetronile protein-precipitation. Chromatographic separation is performed on a C18 reversed-phase Acquity®-UPLC®-BEHTM column (2.1 × 100 mm id, 1.7 µm) using a non-linear gradient of water/acetonitrile containing 0.1 % of formic acid at a flow rate of 0.4 mL/min. Ertapenem and its internal standard (ertapenem-D4) are detected by tandem mass spectrometry using positive electrospray ionization and multiple reaction monitoring, and using 476.2 → 346.0/432.2 as mass transition for ertapenem and 480.2 → 350.0 for its internal standard.
UNASSIGNED: No significant interferences or carry-over contamination were observed. Imprecisions, absolute relative bias, matrix effects and normalized recoveries were ≤14.5 %, ≤9.3 % (92.8-104.5) % and (98.8-105.8) %, respectively. Chromatographic measurement procedures were linear from (0.50-100) mg/L.
UNASSIGNED: The measurement procedures based on UHPLC-MS/MS developed and validated in this study could be useful in pharmacokynetic and pharmacodynamic studies in subjects with liver cirrhosis who develop spontaneous bacterial peritonitis treated with ertapenem.

OBJECTIVE: Endometriosis is a prevalent chronic gynecological disease linked to immune dysfunction. The protein T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) plays a crucial role in immune system balance. Malfunction of TIM-3 may result in excessive immune activation and inflammatory tissue damage. Given TIM-3\'s established role in the development of cancer and autoimmune diseases, we decided to study its role in women suffering from endometriosis.
METHODS: We included a total of 62 female patients, all of whom had undergone laparoscopic surgery. Of these, 47 had endometriosis and 15 did not. During surgery, we collected peritoneal fluid (PF) and peripheral blood (PB) samples from every patient for analysis using flow cytometry. To mark the samples, we used a panel of monoclonal antibodies and examined TIM-3 expression in their immune cells.
RESULTS: Endometriosis patients in PB demonstrated a significantly lower percentage of CD56+ T cells with TIM-3 expression. As endometriosis progressed through its stages, this expression lessened. This decrease was particularly notable in women with stage III/IV endometriosis. Additionally, both women diagnosed with intestinal endometriosis and those with recent endometriosis diagnoses showed a significantly reduced percentage of CD56+ T cells expressing TIM-3.
CONCLUSIONS: Patients with endometriosis exhibit diminished TIM-3 expression within circulating T cells. This warrants further investigation to discern whether it contributes to the progression of endometriosis, potentially through the amplification of autoreactive T cells and inflammation.