Polymeric nanocapsules loaded with poly(I:C) and resiquimod to reprogram tumor-associated macrophages for the treatment of solid tumors

Background

In the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play a key immunosuppressive role that limits the ability of the immune system to fight cancer. Toll-like receptors (TLRs) ligands, such as poly(I:C) or resiquimod (R848) are able to reprogram TAMs towards M1-like antitumor effector cells. The objective of our work has been to develop and evaluate polymeric nanocapsules (NCs) loaded with poly(I:C)+R848, to improve drug stability and systemic toxicity, and evaluate their targeting and therapeutic activity towards TAMs in the TME of solid tumors.

Methods

NCs were developed by the solvent displacement and layer-by-layer methodologies and characterized by dynamic light scattering and nanoparticle tracking analysis. Hyaluronic acid (HA) was chemically functionalized with mannose for the coating of the NCs to target TAMs. NCs loaded with TLR ligands were evaluated in vitro for toxicity and immunostimulatory activity by Alamar Blue, ELISA and flow cytometry, using primary human monocyte-derived macrophages. For in vivo experiments, the CMT167 lung cancer model and the MN/MCA1 fibrosarcoma model metastasizing to lungs were used; tumor-infiltrating leukocytes were evaluated by flow cytometry and multispectral immunophenotyping.

Results

We have developed polymeric NCs loaded with poly(I:C)+R848. Among a series of 5 lead prototypes, protamine-NCs were selected based on their physicochemical properties (size, charge, stability) and in vitro characterization, showing good biocompatibility on primary macrophages and ability to stimulate their production of T-cell attracting chemokines (CXCL10, CCL5) and to induce M1-like macrophages cytotoxicity towards tumor cells. In mouse tumor models, the intratumoral injection of poly(I:C)+R848-protamine-NCs significantly prevented tumor growth and lung metastasis. In an orthotopic murine lung cancer model, the intravenous administration of poly(I:C)+R848-prot-NCs, coated with an additional layer of HA-mannose to improve TAM-targeting, resulted in good antitumoral efficacy with no apparent systemic toxicity. While no significant alterations were observed in T cell numbers (CD8, CD4 or Treg), TAM-reprogramming in treated mice was confirmed by the relative decrease of interstitial versus alveolar macrophages, having higher CD86 expression but lower CD206 and Arg1 expression in the same cells, in treated mice.

Conclusion

Mannose-HA-protamine-NCs loaded with poly(I:C)+R848 successfully reprogram TAMs in vivo, and reduce tumor progression and metastasis spread in mouse tumors.

Synthetic peptides of IL-1Ra and HSP70 have anti-inflammatory activity on human primary monocytes and macrophages: Potential treatments for inflammatory diseases

Chronic inflammatory diseases are increasing in developed societies, thus new anti-inflammatory approaches are needed in the clinic. Synthetic peptides complexes can be designed to mimic the activity of anti-inflammatory mediators, in order to alleviate inflammation. Here, we evaluated the anti-inflammatory efficacy of tethered peptides mimicking the interleukin-1 receptor antagonist (IL-1Ra) and the heat-shock protein 70 (HSP70). We tested their biocompatibility and anti-inflammatory activity in vitro in primary human monocytes and differentiated macrophages activated with two different stimuli: the TLR agonists (LPS + IFN-γ) or Pam3CSK4. Our results demonstrate that IL-1Ra and HSP70 synthetic peptides present a satisfactory biocompatible profile and significantly inhibit the secretion of several pro-inflammatory cytokines (IL-6, IL-8, IL-1β and TNFα). We further confirmed their anti-inflammatory activity when peptides were coated on a biocompatible material commonly employed in surgical implants. Overall, our findings support the potential use of IL-1Ra and HSP70 synthetic peptides for the treatment of inflammatory conditions.

An in vitro model for osteoarthritis using long-cultured inflammatory human macrophages repeatedly stimulated with TLR agonists

Osteoarthritis (OA) is characterized by an abundance of inflammatory M1-like macrophages damaging local tissues. The search for new potential drugs for OA suffers from the lack of appropriate methods of long-lasting inflammation. Here we developed and characterized an in vitro protocol of long-lasting culture of primary human monocyte-derived macrophages differentiated with a combination of M-CSF+GM-CSF that optimally supported long-cultured macrophages (LC-Mϕs) for up to 15 days, unlike their single use. Macrophages repeatedly stimulated for 15 days with the TLR2 ligand Pam3CSK4 (LCS-Mϕs), showed sustained levels over time of IL-6, CCL2, and CXCL8, inflammatory mediators that were also detected in the synovial fluids of OA patients. Furthermore, macrophages isolated from the synovia of two OA patients showed an expression profile of inflammation-related genes similar to that of LCS-Mϕs, validating our protocol as a model of chronically activated inflammatory macrophages. Next, to confirm that these LCS-Mϕs could be modulated by anti-inflammatory compounds, we employed dexamethasone and/or celecoxib, two drugs widely used in OA treatment, that significantly inhibited the production of inflammatory mediators. This easy-to-use in vitro protocol of long-lasting inflammation with primary human macrophages could be useful for the screening of new compounds to improve the therapy of inflammatory disorders.

Mannose-modified hyaluronic acid nanocapsules for the targeting of tumor-associated macrophages

Tumor-associated macrophages (TAMs), a class of immune cells that play a key role in tumor immunosuppression, are recognized as important targets to improve cancer prognosis and treatment. Consequently, the engineering of drug delivery nanocarriers that can reach TAMs has acquired special relevance. This work describes the development and biological evaluation of a panel of hyaluronic acid (HA) nanocapsules (NCs), with different compositions and prepared by different techniques, designed to target macrophages. The results showed that plain HA NCs did not significantly influence the polarization of M0 and M2-like macrophages towards an M1-like pro-inflammatory phenotype; however, the chemical functionalization of HA with mannose (HA-Man) led to a significant increase of NCs uptake by M2 macrophages in vitro and to an improved biodistribution in a MN/MNCA1 fibrosarcoma mouse model with high infiltration of TAMs. These functionalized HA-Man NCs showed a higher accumulation in the tumor compared to non-modified HA NCs. Finally, the pre-administration of the liposomal liver occupying agent Nanoprimer™ further increased the accumulation of the HA-Man NCs in the tumor. This work highlights the promise shown by the HA-Man NCs to target TAMs and thus provides new options for the development of nanomedicine and immunotherapy-based cancer treatments.

Important functional role of the protein osteopontin in the progression of malignant pleural mesothelioma

Background

Malignant Pleural Mesothelioma (MPM) is an aggressive cancer of the mesothelial lining associated with exposure to airborne non-degradable asbestos fibers. Its poor response to currently available treatments prompted us to explore the biological mechanisms involved in its progression. MPM is characterized by chronic non-resolving inflammation; in this study we investigated which inflammatory mediators are mostly expressed in biological tumor samples from MPM patients, with a focus on inflammatory cytokines, chemokines and matrix components.

Methods

Expression and quantification of Osteopontin (OPN) was detected in tumor and plasma samples of MPM patients by mRNA, immunohistochemistry and ELISA. The functional role of OPN was investigated in mouse MPM cell lines in vivo using an orthotopic syngeneic mouse model.

Results

In patients with MPM, the protein OPN was significantly more expressed in tumors than in normal pleural tissues and predominantly produced by mesothelioma cells; plasma levels were elevated in patients and associated with poor prognosis. However, modulation of OPN levels was not significantly different in a series of 18 MPM patients receiving immunotherapy with durvalumab alone or with pembrolizumab in combination with chemotherapy, some of whom achieved a partial clinical response. Two established murine mesothelioma cell lines: AB1 and AB22 of sarcomatoid and epithelioid histology, respectively, spontaneously produced high levels of OPN. Silencing of the OPN gene (Spp1) dramatically inhibited tumor growth in vivo in an orthotopic model, indicating that OPN has an important promoting role in the proliferation of MPM cells. Treatment of mice with anti-CD44 mAb, blocking a major OPN receptor, significantly reduced tumor growth in vivo.

Conclusion

These results demonstrate that OPN is an endogenous growth factor for mesothelial cells and inhibition of its signaling may be helpful to restrain tumor progression in vivo. These findings have translational potential to improve the therapeutic response of human MPM.

Abstract 5140: Combined administration of poly(I:C) and resiquimod triggers effective antitumoral response in mouse models of pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) represents one of the deadliest malignancies worldwide. The lack of clinical symptoms in the early stages of the disease and the poor immunogenicity of PDAC are two major causes of late diagnosis and inefficient therapies. The tumor microenvironment of PDAC is rich in stromal cells inducing desmoplasia, complicating the arrival of medical compounds, as well as in immune cells, that are suppressed by several mediators produced by cancer cells. In this setting, it has been shown that some medications can restore the antitumoral activity of innate immune cells that, in turn, re-activate also adaptive immune cells. In this study, we present the combination of the TLR agonists poly(I:C) (pIC - TLR3) and resiquimod (R848 - TLR7/8) as an immunotherapeutic tool in PDAC. In a subcutaneous model of PDAC (K8484 cells, isolated from KPC mice that spontaneously develop PDAC and recapitulate the features of human pancreatic cancer), the intratumoral administration of pIC+R848 for 5 times every 2-3 days led to the complete regression of the tumor in 100% of the treated mice. Moreover, all mice were protected from a second and a third rechallenge with the same cell line, performed months after the first treatments. Mechanistic studies performed on the tumors with flow cytometry demonstrated an increase of MHC-II positive cells in the monocytic (Ly6C+) compartment, as well as an increase in the number of mature CD8+ T cells and NK cells. Similar findings were demonstrated also in another heterotopic model obtained injecting Panc02 cells, another cell line with a sarcomatous phenotype. Consistently with the flow cytometry data, the depletion of CD4+ and CD8+ T cells abolished the antitumoral efficacy of pIC+R848, while the depletion of NK cells and CSF-1R+ cells was not sufficient to abolish the antitumoral response, suggesting a strong involvement of the adaptive immunity. In line with these findings, the intratumoral administration of pIC+R848 in mice unable to produce IFN-γ failed to reduce the tumor growth. In conclusion, our work clearly demonstrates that pIC+R848 are an effective treatment for PDAC when injected intratumorally and that this activity strongly relies on IFN-γ and adaptive immunity. Further investigations are ongoing to assess their potential in orthotopic models using different routes of administration, in a setting closer to the real clinical situation.

Citation Format: Aldo Ummarino, Clément Anfray, Andrea Mariancini, Domenico Supino, Cecilia Garlanda, Fernando Torres Andòn, Alberto Mantovani, Paola Allavena. Combined administration of poly(I:C) and resiquimod triggers effective antitumoral response in mouse models of pancreatic adenocarcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5140.

In Vitro Methods to Evaluate Macrophage Polarization and Function in Cancer

Tumor-associated macrophages (TAMs) play a key immunosuppressive role that limits the ability of the immune system to fight cancer and hinder the anti-tumoral efficacy of most treatments currently applied in the clinic. However, a key feature of macrophages is their phenotypical and functional plasticity, which called their attention as promising targets for therapeutic intervention based on their elimination or reprogramming toward M1-like cytotoxic effector cells, with anti-tumor functions. This polarization status of macrophages can be studied in terms of molecular markers and functional activities, using an appropriate combination of experimental methodologies, both in vitro and in vivo. Here we focus on describing in vitro protocols to isolate primary monocytes from buffy coats and to study macrophage phenotype and function, after exposure to new therapies, by a combination of flow cytometry, RT-PCR, and ELISA analysis. We also provide the methodology to evaluate in vitro the cytotoxic activity of treated macrophages toward cancer cells.

A PCR-based method for the diagnosis of Enterobius vermicularis in stool samples, specifically designed for clinical application

BACKGROUND

Enterobius vermicularis (E. vermicularis) is a nematode that infects up to 200 million people worldwide, despite effective medications being available. Conventional diagnostic tests are hindered by low sensitivity and poor patient compliance. Furthermore, no biomolecular techniques are available for clinical application. The aim of this study was to develop a procedure specifically designed for clinical application to detect E. vermicularis by means of PCR.

MATERIALS AND METHODS

Two subject groups were taken into account: a group of 27 infected patients and a control group of 27 healthy subjects. A nested-PCR was performed on fecal samples to detect E. vermicularis. Due to the intrinsic difficulties of the fecal matrix, several countermeasures were adopted to ensure the efficient performance of the method: (a) a large amount of feces for the extraction process (20 g instead of 200 mg); (b) a combination of chemical and physical treatments to grind the fecal matrix; (c) an additional purification process for the negative samples after the first nested-PCR; and (d) the selection of a very specific target region for the PCR.

RESULTS

Due to the lack of overlap with other organisms, a sequence of the 5S ribosomal DNA (rDNA) spacer region including the tract SL1 was chosen to design appropriate external and internal primers. The first nested-PCR detected E.vermicularis in 19/27 samples from infected patients. After further purification, 5/8 of the negative samples resulted positive at the second PCR. Conversely, all the samples from healthy controls resulted negative to both PCRs. Sensitivity and specificity of the method were, respectively, 88.9% and 100%.

CONCLUSION

The results prove the high diagnostic accuracy of the proposed method, addressing and overcoming the challenges posed by both conventional tests and PCR-based approaches. Therefore, the method can be proposed for clinical application.

Innate and Adaptive Responses of Intratumoral Immunotherapy with Endosomal Toll-Like Receptor Agonists

Toll-like receptors (TLRs) are natural initial triggers of innate and adaptive immune responses. With the advent of cancer immunotherapy, nucleic acids engineered as ligands of endosomal TLRs have been investigated for the treatment of solid tumors. Despite promising results, their systemic administration, similarly to other immunotherapies, raises safety issues. To overcome these problems, recent studies have applied the direct injection of endosomal TLR agonists in the tumor and/or draining lymph nodes, achieving high local drug exposure and strong antitumor response. Importantly, intratumoral delivery of TLR agonists showed powerful effects not only against the injected tumors but also often against uninjected lesions (abscopal effects), resulting in some cases in cure and antitumoral immunological memory. Herein, we describe the structure and function of TLRs and their role in the tumor microenvironment. Then, we provide our vision on the potential of intratumor versus systemic delivery or vaccination approaches using TLR agonists, also considering the use of nanoparticles to improve their targeting properties. Finally, we collect the preclinical and clinical studies applying intratumoral injection of TLR agonists as monotherapies or in combination with: (a) other TLR or STING agonists; (b) other immunotherapies; (c) radiotherapy or chemotherapy; (d) targeted therapies.

Structural-Equation-Modelling (SEM) to analyze climatic factor's role on COVID-19 spreading

Purpose

Climate seems to influence the COVID-19 spreading, but the results of the published studies are conflicting. Aim of this study was to perform a world-wide investigation to analyze the role of all the main climatic factors (CF), trying to identify the causes that led to the discrepancy of the results.

Methods & Materials

134,871 data (from 209 countries) were used for the analysis. These were extrapolated from an initial data-set of 1.200.000 data. To avoid biases present in most of the previously studies, a set of specific requirements was adopted: long observation period (16 weeks),

• the use of a relative time scale to synchronize the beginning of the outbreak among the countries,

• multiple data collection points (up to 4 cities/per country) to overcome the problem of climate variability within a country,

• the use of an appropriate technique to test the relationships among interdependent variables,

• the use of a lag-period to compensate the shift between the infection exposure and the diagnosis’ confirmation.

Data's analysis was performed with SEM, a flexible statistical technique for modeling causal chain of effects simultaneously. Using hypothesis-testing, this technique examines the relationships between observed variables and latent variables, in turn linked to observed variables, their indicators. With this statistical model it was possible to consider the integrated effects of all the CF on COVID-19 and, at the same time, to investigate the effects of population density (PD) too.

Results

The results of the analysis showed that both climate and population density significantly influence the spread of COVID-19 (p<0.001; p<0.01, respectively). Overall, climate outweighs population density (path coefficients: climate vs incidence=0.18, climate vs prevalence=0.11, PD vs incidence=0.04, PD vs prevalence=0.05). Among the climatic factors, irradiation plays the most relevant role, with a factor-loading of -0.77, followed by temperature (-0.56), humidity (0.52), precipitation (0.44), and pressure (0.073); for all p<0.001. Fit indices demonstrated a good fit of the model (determination-coefficient=0.826, Root-Mean-Square-Error-of-Approximation=0.088, Standardized-Root-Mean-Square-Residual=0.078).

Conclusion

This study demonstrates that CF significantly influence the spread of SARS-CoV-2. However, demographic factors, together with other determinants, can affect the transmission, overcoming the protective effect of climate, where favourable.

Intratumoral combination therapy with poly(I:C) and resiquimod synergistically triggers tumor-associated macrophages for effective systemic antitumoral immunity

Background

Tumor-associated macrophages (TAMs) play a key immunosuppressive role that limits the ability of the immune system to fight cancer and hinder the antitumoral efficacy of most treatments currently applied in the clinic. Previous studies have evaluated the antitumoral immune response triggered by (TLR) agonists, such as poly(I:C), imiquimod (R837) or resiquimod (R848) as monotherapies; however, their combination for the treatment of cancer has not been explored. This study investigates the antitumoral efficacy and the macrophage reprogramming triggered by poly(I:C) combined with R848 or with R837, versus single treatments.

Methods

TLR agonist treatments were evaluated in vitro for toxicity and immunostimulatory activity by Alamar Blue, ELISA and flow cytometry using primary human and murine M-CSF-differentiated macrophages. Cytotoxic activity of TLR-treated macrophages toward cancer cells was evaluated with an in vitro functional assay by flow cytometry. For in vivo experiments, the CMT167 lung cancer model and the MN/MCA1 fibrosarcoma model metastasizing to lungs were used; tumor-infiltrating leukocytes were evaluated by flow cytometry, RT-qPCR, multispectral immunophenotyping, quantitative proteomic experiments, and protein–protein interaction analysis.

Results

Results demonstrated the higher efficacy of poly(I:C) combined with R848 versus single treatments or combined with R837 to polarize macrophages toward M1-like antitumor effectors in vitro. In vivo, the intratumoral synergistic combination of poly(I:C)+R848 significantly prevented tumor growth and metastasis in lung cancer and fibrosarcoma immunocompetent murine models. Regressing tumors showed increased infiltration of macrophages with a higher M1:M2 ratio, recruitment of CD4⁺ and CD8⁺ T cells, accompanied by a reduction of immunosuppressive CD206⁺ TAMs and FOXP3⁺/CD4⁺ T cells. The depletion of both CD4⁺ and CD8⁺ T cells resulted in complete loss of treatment efficacy. Treated mice acquired systemic antitumoral response and resistance to tumor rechallenge mediated by boosted macrophage cytotoxic activity and T-cell proliferation. Proteomic experiments validate the superior activation of innate immunity by poly(I:C)+R848 combination versus single treatments or poly(I:C)+R837, and protein–protein-interaction network analysis reveal the key activation of the STAT1 pathway.

Discussion

These findings demonstrate the antitumor immune responses mediated by macrophage activation on local administration of poly(I:C)+R848 combination and support the intratumoral application of this therapy to patients with solid tumors in the clinic.

Drug Delivery Systems for the Treatment of Knee Osteoarthritis: A Systematic Review of In Vivo Studies

Many efforts have been made in the field of nanotechnology to improve the local and sustained release of drugs, which may be helpful to overcome the present limitations in the treatment of knee OA. Nano-/microparticles and/or hydrogels can be now engineered to improve the administration and intra-articular delivery of specific drugs, targeting molecular pathways and pathogenic mechanisms involved in OA progression and remission. In order to summarize the current state of this field, a systematic review of the literature was performed and 45 relevant studies were identified involving both animal models and humans. We found that polymeric nanoparticles loaded with anti-inflammatory drugs (i.e., dexamethasone or celecoxib) are the most frequently investigated drug delivery systems, followed by microparticles and hydrogels. In particular, the nanosystem most frequently used in preclinical research consists of PLGA-nanoparticles loaded with corticosteroids and non-steroidal anti-inflammatory drugs. Overall, improvement in histological features, reduction in joint inflammation, and improvement in clinical scores in patients were observed. The last advances in the field of nanotechnology could offer new opportunities to treat patients affected by knee OA, including those with previous meniscectomy. New smart drug delivery approaches, based on nanoparticles, microparticles, and hydrogels, may enhance the therapeutic potential of intra-articular agents by increasing the permanence of selected drugs inside the joint and better targeting specific receptors and tissues.

Structural equation modeling to shed light on the controversial role of climate on the spread of SARS-CoV-2

Climate seems to influence the spread of SARS-CoV-2, but the findings of the studies performed so far are conflicting. To overcome these issues, we performed a global scale study considering 134,871 virologic-climatic-demographic data (209 countries, first 16 weeks of the pandemic). To analyze the relation among COVID-19, population density, and climate, a theoretical path diagram was hypothesized and tested using structural equation modeling (SEM), a powerful statistical technique for the evaluation of causal assumptions. The results of the analysis showed that both climate and population density significantly influence the spread of COVID-19 (p < 0.001 and p < 0.01, respectively). Overall, climate outweighs population density (path coefficients: climate vs. incidence = 0.18, climate vs. prevalence = 0.11, population density vs. incidence = 0.04, population density vs. prevalence = 0.05). Among the climatic factors, irradiation plays the most relevant role, with a factor-loading of - 0.77, followed by temperature (- 0.56), humidity (0.52), precipitation (0.44), and pressure (0.073); for all p < 0.001. In conclusion, this study demonstrates that climatic factors significantly influence the spread of SARS-CoV-2. However, demographic factors, together with other determinants, can affect the transmission, and their influence may overcome the protective effect of climate, where favourable.

Therapeutic Manipulation of Tumor-associated Macrophages: Facts and Hopes from a Clinical and Translational Perspective

The stroma of most solid tumors is populated by myeloid cells, which mostly represent macrophages. Tumor-associated macrophages (TAMs), strongly influenced by cancer cell-derived factors, are key drivers of immunosuppression and support tumor growth and spread to distant sites. Their accurate quantification and characterization in the tumor microenvironment are gaining prognostic value: increasing evidence demonstrates their ability to hamper cancer patients' response to chemotherapy, as well as to immunotherapies based on checkpoint inhibition. Therefore, strategies to counteract their negative effects are nowadays gaining momentum at preclinical, translational, and clinical levels. Our knowledge of the biology of TAMs has greatly advanced in the last years; several strategies to target and reprogram their functions to become antitumor effectors have proven successful in experimental preclinical tumor models; on the other hand, few approaches have so far been effectively translated into clinic practice. A growing interest in the therapeutic manipulation of TAMs is evidenced by numerous early-phase clinical trials, which are continuously fueled by new discoveries from basic research. This gives us hope that the targeting and sustained reprogramming of TAMs will be more specific to synergize with current therapies and maximize antitumor responses in patients.

Value of real-time gastric juice analysis in upper gastrointestinal endoscopy

AIM

Esophagogastroduodenoscopy (EGDS) cannot identify microscopic lesions. We determined the contribution of real-time gastric juice analysis in detecting lesions non-detectable with the simple endoscopic inspection.

METHODS

Endoscopy, histology and gastric juice analysis were performed in 216 patients. We assessed six diagnostic strategies: EGDS (strategy-1), EGDS with antral biopsies (hematoxylin-eosin staining) in hypochlorhydrics (strategy-2) or all patients (strategy-3), EGDS with antral and fundic biopsies (hematoxylin-eosin staining) in hypochlorhydrics (strategy-4) or all patients (strategy-5), EGDS with antral and fundic biopsies (hematoxylin-eosin + immunohistochemical staining) in hypochlorhydrics (strategy-6). Then, we determined how many of the pathological conditions identified by the complete histological evaluation would have been detected by each strategy.

RESULTS

In total, 220 pathological conditions were identified. Hypochlorhydria was correlated (r=0.67; P<0.01) with histological lesions (85% lesions were detected in hypochlorhydrics) and high ammonium levels, with H.pylori infection (r=0.69; P<0.01). Strategy-1 identified only 5% conditions, while strategies 3 and 5 detected 68.6% and 83.2% conditions, respectively. Strategies 2, 4 and 6 (based on gastric juice analysis) yielded detection rates (61.4%, 75.5%, 90.9%) similar to or better than those of strategies 3 and 5.

CONCLUSION

Real-time gastric juice analysis provided information about the presence of gastric lesions in an otherwise "normal" stomach at EGDS. It improved the diagnostic yield and optimized resource utilization without any additional effort by the endoscopist.

Perendoscopic real-time assessment of pH improves detection of gastric preneoplastic conditions

AIM

Gastric juice may constitute a precious source of clinicopathological information. We assessed the usefulness of real-time, perendoscopic, gastric juice pH determination in identifying preneoplastic conditions of the stomach, that often escape the mere endoscopic evaluation.

METHODS

The study included 245 patients (115M; 130F; age 47±17). In each of them perendoscopic gastric juice pH was assessed by means of an innovative device, the Endofaster, and the results were correlated with histological evaluation (H&E, immunohistochemistry, argyrophil stains), and gastric acid secretion (BAO-PAO), and serum gastrin levels. The conditions evaluated were: atrophy, intestinal metaplasia, endocrine cell hyperplasia, hypergastrinemia.

RESULTS

A total of 136 pathological conditions were detected and these resulted to be correlated with pH (r=0.67; P<0.01). The rate of pathological conditions was low in normochlorhydric patients (14.1%); most of these conditions were concentrated in patients with hypochlorhydria (85.9%) (P<0.001). Specifically, the number of patients with one or more pathological conditions increased proportionately with the rise in pH levels. An inverse correlation was detected between gastric juice pH and basal acid output (BAO) (r=-0.72; P<0.01). Endoscopic feature was normal/mild in most of patients with pathological conditions.

CONCLUSION

Hypochlorhydria is a sensitive indicator of gastric risk conditions. Perendoscopic real-time assessment of pH can improve and extend optical analysis by allowing the detection of pathological conditions (either preneoplastic or not) that often escape diagnosis because not correlated with specific endoscopic pattern.