Gumus Tufan, Ece Deniz, Muftuoglu Can, Mert Ufuk, Kalemoglu Ecem, Akpinar Goksever, Asadi Milad, Coskun Tolga, Alizadeh Hamid, Uguz Alper, Caner Ayse
Department of General Surgery, Faculty of Medicine, Ege University, Turkey.
Department of Basic Oncology, Ege University, Institute of Health Sciences, Izmir, Turkey.
Acta Trop. 2025 Oct;270:107804. doi: 10.1016/j.actatropica.2025.107804. Epub 2025 Aug 25.
Cryptosporidium spp. is a protozoan parasite known to cause gastrointestinal infections, particularly in immunocompromised individuals such as cancer patients. It typically infects the small intestine but has been reported in extraintestinal sites, including the biliary tract, and lungs. While Cryptosporidium has been implicated in the pathogenesis of several gastrointestinal cancers, there is very limited data its association with pancreatic ductal adenocarcinoma (PDAC). This study aimed to investigate the presence of Cryptosporidium in pancreatic tissue and saliva samples from PDAC patients using digital PCR (dPCR), a highly sensitive diagnostic tool, and to compare findings with those in distal cholangiocarcinoma (DCC) patients and healthy controls.
A total of 50 participants were enrolled, including 20 PDAC patients, 10 DCC patients, and 20 healthy controls. Pancreatic tissue and saliva samples were collected from PDAC and DCC patients, while only saliva was collected from healthy controls. DNA was extracted from all samples, and the presence of Cryptosporidium was investigated using both quantitative PCR (qPCR) and dPCR. Cancer patients were also analyzed for clinical findings and patients positive for Cryptosporidium spp. in saliva and tissue samples were evaluated clinically.
Cryptosporidium DNA was detected by qPCR in the saliva of one DCC patient. In contrast, dPCR revealed Cryptosporidium spp. in the saliva of one PDAC and two DCC patients (one overlapping with qPCR), and in the pancreatic tissue of two PDAC patients (whose saliva was negative). No Cryptosporidium spp. was detected in the healthy control group. Although the differences between groups were not statistically significant, the presence of Cryptosporidium in pancreatic tissue was demonstrated for the first time using dPCR. Some positive patients showed respiratory symptoms or were asymptomatic, raising the possibility of subclinical or extraintestinal infection.
This study provides the first dPCR-based evidence of Cryptosporidium in pancreatic tissue, suggesting its potential for extraintestinal dissemination in cancer patients. The findings highlight the superiority of dPCR over qPCR for detecting low-abundance pathogens in clinical samples. Although no direct causal link with PDAC was established, the detection of Cryptosporidium in pancreatic tissues warrants further investigation into its potential role in pancreatic carcinogenesis.
隐孢子虫属是一种原生动物寄生虫，已知可引起胃肠道感染，尤其是在免疫功能低下的个体（如癌症患者）中。它通常感染小肠，但也有在包括胆道和肺部在内的肠外部位的报道。虽然隐孢子虫与几种胃肠道癌症的发病机制有关，但其与胰腺导管腺癌（PDAC）的关联数据非常有限。本研究旨在使用数字PCR（dPCR，一种高度灵敏的诊断工具）调查PDAC患者胰腺组织和唾液样本中隐孢子虫的存在情况，并将结果与远端胆管癌（DCC）患者和健康对照进行比较。
共招募了50名参与者，包括20名PDAC患者、10名DCC患者和20名健康对照。从PDAC和DCC患者中采集胰腺组织和唾液样本，而健康对照仅采集唾液。从所有样本中提取DNA，并使用定量PCR（qPCR）和dPCR调查隐孢子虫的存在情况。还对癌症患者进行了临床检查，并对唾液和组织样本中隐孢子虫属阳性的患者进行了临床评估。
通过qPCR在一名DCC患者的唾液中检测到隐孢子虫DNA。相比之下，dPCR在一名PDAC患者和两名DCC患者的唾液中发现了隐孢子虫属（其中一名与qPCR结果重叠），以及在两名PDAC患者的胰腺组织中发现了隐孢子虫属（其唾液为阴性）。健康对照组未检测到隐孢子虫属。尽管各组之间的差异无统计学意义，但首次使用dPCR在胰腺组织中证实了隐孢子虫的存在。一些阳性患者表现出呼吸道症状或无症状，提示存在亚临床或肠外感染的可能性。
本研究提供了基于dPCR的胰腺组织中隐孢子虫的首个证据，表明其在癌症患者中存在肠外传播的可能性。研究结果突出了dPCR在检测临床样本中低丰度病原体方面优于qPCR。虽然未建立与PDAC的直接因果关系，但在胰腺组织中检测到隐孢子虫值得进一步研究其在胰腺癌发生中的潜在作用。
