Neuregulin (NRG) family is involved in energy metabolism, among which NRG1 is a neuregulin proved to play a protective role in MAFLD cells. But the presice echanism has not been fully illustrated. This study aimed to investigate the role of NRG1 via the ERK/SIRT1 signaling in the pathogenesis of MAFLD. C57BL/6 mice were fed with high-fat diet for 8 weeks, and then injected with NRG1 (0.3 mg/kg/d) and PD98059 (0.3 mg/kg/d) via tail vein for 5 weeks. HepG2 cells induced by oleic acid and palmitic acid were treated with 20ng/mL NRG1 and 10µmol/L PD98059. The changes of histopathological, biochemical indexes, inflammatory factors, lipid metabolism, apoptosis and autophagy parameters were measured. The expressions of NRG1 in MAFLD cell and animal models were significantly lower than that in the control group. After the intervention of ERK inhibitor PD98059, the expression of NRG1 decreased significantly in vivo, but no significant change was observed in vitro. Moreover, NRG1 ameliorated hepatic steatosis, enhanced cell viability, reduced cell apoptosis, and attenuated liver injury both in vitro and in vivo. After NRG1 intervention, the expressions of ERBB2, ERBB3, p-ERK1/2, SIRT1 and p-FOXO1 as well as the LC3II/I ratio in MAFLD cells and liver tissues of MAFLD mice were significantly increased, while the expression of SREBP1c was decreased. The aforementioned therapeutic effect of NRG1 was lost after the intervention of PD98059. NRG1 might play a protective role in the pathogenesis of MAFLD by activating the downstream ERK1/2 through ErbB2-ErbB3, which promotes the expression of SIRT1 and autophagy markers. This study might indicate a new therapeutic strategy for MAFLD.

Previous studies have shown that patients with rosacea tend to have a higher risk of developing cardiovascular diseases (CVDs). However, the potential causal relationship between genetic susceptibility to rosacea and the risk of CVDs remains unclear. Based on summary statistics from publicly available genome-wide association studies (GWASs), we detected the genetic association between rosacea and CVDs by a bidirectional two-sample Mendelian randomization (MR) analysis. The inverse-variance weighted (IVW) method was used as the primary analysis, while weighted median (WM) and MR-Egger were applied as complementary methods. For sensitivity analyses, we applied Cochran’s Q test, the intercept of MR-Egger, MR-Pleiotropy Residual Sum and Outlier (MR-PRESSO), funnel plot, and leave-one-out analysis. The MR analysis revealed that rosacea was associated with an elevated risk of hypertension (HTN) (OR = 1.0032, 95% CI [1.0001–1.0063], P = 0.04). However, no casual relationship was found between rosacea and risk of atrial fibrillation (AF) (OR = 1.0099, 95% CI [0.9823–1.0382], P = 0.49), coronary artery disease (CAD) (OR = 1.0138, 95% CI [0.9824–1.0462], P = 0.39), heart failure (HF) (OR = 0.9965, 95% CI [0.9671–1.0268], P = 0.82), ischemic stroke (IS) (OR = 0.9933, 95% CI [0.9545–1.0337], P = 0.74), or myocardial infarction (MI) (OR = 1.0001, 95% CI [0.9988–1.0013], P = 0.92). In the sensitivity analysis, significant heterogeneity was revealed in the MI subgroup according to the Cochran’s Q test. Other sensitivity analyses indicated the stability of our results. Reverse MR analysis showed no significant genetic effect of cardiovascular disease on rosacea risk. We are the first to use MR analysis to explore the casual relationship between rosacea and the risk of various CVDs, revealing an increased risk of HTN in patients with rosacea.

Background Psoas abscess (PA) is an uncommon disease that has been increasingly reported in the recent years. We reviewed patients with PA and analyzed their clinical characteristics to improve our understanding of this rare disorder.Methods We retrospectively reviewed the clinical presentations, microbiology, and outcomes of patients with PA between 2011 and 2022 at the Zhejiang Provincial People's Hospital in China.Results There were 40 adult patients identified with the discharge diagnosis of PA. The mean age was 60 years, and 67.5% of the patients were male. Primary symptoms were typically nonspecific. In all, 20 abscesses were considered secondary, and the most common was infective spondylitis. The most common causative organism for primary PA was Staphylococcus aureus, followed by Escherichia coli, whereas multiple bacterial species were found in secondary abscesses. The overall in-hospital mortality rate was 5%. Patients with secondary PA had a longer hospital stay.Conclusion PA, as a serious infectious condition, usually presents with nonspecific symptoms and laboratory test results, making early diagnosis difficult. These profiles differed from those reported in the present study. The initial clinical status and subsequent imaging studies can lead to favorable outcomes. What is already known on this topic Psoas abscess (PA) is an uncommon disease with nonspecific symptoms and laboratory test results that few studies were seen. What this study adds Patients with psoas abscess showed clinical characteristics different from previous reports. The causative organism was found to be multiple. How this study might affect research, practice, or policy We suggest that a thorough medical history and subsequent imaging studies can be useful for the diagnosis and treatment.

BACKGROUND:Protothecosis is an infection of humans and animals caused by a rare conditionally pathogenic fungus (prototheca). It can occur in immunocompromised or normal patients.AIMS:To describe the epidemiology of prototheca infection in China.METHODS:We report a case of successful treatment of cutaneous protothecosis with fluconazole and analyzed the epidemiological characteristics, risk factors, clinical manifestations, diagnosis, treatment and prognosis of prototheca infections in China.RESULTS:We describe this case and 29 cases of prototheca infections in China. At present, Prototheca wickerhamii (Pw) infection is the most common infection in China, and single or combined itraconazole is the preferred treatment.CONCLUSIONS:These results provide detailed information and relevant clinical treatment strategies for the diagnosis and treatment of protothecosis in China.

Introduction and Objectives: Autoimmune hepatitis (AIH) is a prevalent noninfectious liver disease. However, there is currently a lack of noninvasive tests appropriate for evaluating liver fibrosis in AIH patients. The objective of this study was to develop and validate a predictive model for noninvasive assessment of significant liver fibrosis (S >= 2) in patients to provide a reliable method for evaluating liver fibrosis in individuals with AIH. Materials and Methods: The clinical data of 374 AIH patients were analyzed. A prediction model was established through logistic regression in the training set, and bootstrap method was used to validate the models internally. In addition, the clinical data of 109 AIH patients were collected for external verification of the model.The model was expressed as a nomogram, and area under the curve (AUC) of the receiver operating characteristic (ROC), calibration curve, and decision curve analysis were used to evaluate the accuracy of the prediction model. Results: Logistic regression analysis revealed that age, platelet count (PLT), and the A/G ratio were identified as independent risk factors for liver fibrosis in AIH patients (P < 0.05). The diagnostic model that was composed of age, PLT and A/G was superior to APRI and FIB-4 in both the internal validation (0.872, 95%CI: 0.819 -0.924) and external validation (0.829, 95%CI: 0.753-0.904). Conclusions: Our predictive model can predict significant liver fibrosis in AIH patients more accurately, simply, and noninvasively. (c) 2024 Fundacion Clinica Medica Sur, A.C. Published by Elsevier Espana, S.L.U. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Chronic hepatitis B virus (HBV) infection remains a serious health issue, and determining the optimal time for antiviral therapy is challenging. We aimed to assess liver histological changes in patients with HBeAg-positive chronic hepatitis B (CHB) and those with HBeAg-negative CHB who had persistently normal alanine aminotransferase and to determine the association between significant liver injury and various clinical parameters. We retrospectively included, in this study, 339 treatment-naïve patients with chronic HBV infections who had persistently normal alanine aminotransferase and underwent liver biopsy from 2013 to 2023. Histologic assessment was based on the Metavir scoring system to evaluate the association between clinical characteristics and the severity of liver inflammation and fibrosis. Among the included participants, 138 were HBeAg-positive and 201 were HBeAg-negative. Lower hepatitis B surface antigen (HBsAg) (P = 0.003) and higher aspartate aminotransferase (AST) (P = 0.002) levels were associated with significant necroinflammation, whereas increasing age (P = 0.004) and lower HBV DNA (P < 0.001) levels were associated with significant fibrosis in HBeAg-positive patients with normal ALT levels. Higher HBV-DNA (P = 0.001) and AST levels(P < 0.001) were associated with significant necroinflammation, and higher AST(P < 0.001) levels were associated with significant fibrosis in HBeAg-negative patients. A substantial proportion of patients with HBV infection who had normal ALT presented significant liver injury. HBsAg and AST were independent predictive factors for evaluating inflammation, while HBV DNA load and age were independent predictive factors for evaluating fibrosis in the HBeAg-positive group. HBV DNA load and AST were independent predictive factors for evaluating inflammation, while AST were independent predictive factors for evaluating fibrosis in the HBeAg-negative group.

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by high blood glucose levels resulting from insulin resistance and impaired insulin secretion. Immune dysregulation-mediated chronic low-grade inflammation is a critical factor that poses a significant risk to the metabolic disorders of T2DM and its related complications. Exosomes, as small extracellular vesicles secreted by various cells, have emerged as essential regulators of intercellular communication and immune regulation. In this review, we summarize the current understanding of the role of exosomes derived from immune and nonimmune cells in modulating immune responses in T2DM by regulating immune cell functions and cytokine production. More importantly, we suggest potential strategies for the clinical applications of exosomes in T2DM management, including biomarkers for disease diagnosis and monitoring, exosome-based therapies for drug delivery vehicles, and targeted therapy for exosomes.

Background: Previous studies on the relationship between systemic lupus erythematosus (SLE) and autoimmune liver diseases (AILDs) are inconclusive. Therefore, we employed Mendelian randomization (MR) to explore the causal associations between SLE and AILDs. Methods: A two -sample MR analysis was performed using summary -level statistics sourced from genome-wide association study (GWAS) datasets. Inverse -variance weighting (IVW), MR-Egger, and weighted median (WM) were further supported by several sensitivity analyses. Results: We detected causal genetic associations between SLE and primary biliary cholangitis (PBC) (odds ratio (OR) = 1.31, 95% CI = 1.15 -1.51, P < 0.01; adjusted OR = 1.63, 95% CI = 1.39 -1.90, P < 0.01) and between SLE and primary sclerosing cholangitis (PSC) (OR = 1.09, 95% CI = 1.01 -1.08, P = 0.03; adjusted OR = 1.10, 95% CI = 1.00 -1.21, P = 0.04). No causal association was found between SLE and autoimmune hepatitis. Conclusions: We are the first to use MR analysis to explore the causal relationships between SLE and various AILDs, revealing an increased risk of PBC and PSC in individuals with SLE.

Objective:To investigate the diagnosis and treatment of granulomatous mastitis with erythema nodosum in lower limbs caused by Corynebacterium tuberculosis.Methods:The diagnosis and treatment process of a patient with granulomatous mastitis caused by Corynebacterium tuberculosis complicated with erythema nodosum in lower limbs admitted to Zhejiang Provincial People’s Hospital on March 28th, 2022 was analyzed and related literatures were reviewed.Results:This case was a 30-year-old young female patient who was admitted to Zhejiang Provincial People’s Hospital for a half-month period of pain due to the left breast mass. The oral cefuroxime axetil had poor anti-infective treatment effect. The diagnosis was confirmed by histopathology, puncture fluid culture and 16S rRNA sequence analysis as granulomatous mastitis caused by Corynebacterium tuberculosis with erythema nodosum in lower limbs. The results of drug sensitivity test showed that vancomycin and linezolid were sensitive. Subsequently, abscess incision and drainage combined with drug treatment (linezolid and prednisone) were performed, and the mass reduced significantly and the inflammation improved, and the patient was discharged.Conclusions:Granulomatous mastitis complicated with erythema nodosum of lower limbs caused by Corynebacterium tuberculosis infection is rare, which is easy to be misdiagnosed and mistreated. Bacterial/fungal culture, 16S rRNA sequence analysis and drug sensitivity test should be combined to identify the pathogenic bacteria and carry out targeted anti-infective treatment.

In China, hepatorenal syndrome is a serious complication in the decompensated stage of hepatitis B cirrhosis, which requires early clinical intervention, so the early diagnosis of hepatorenal syndrome is crucial. This study establishes a new predictive model based on serum biomarkers for the early diagnosis of hepatorenal syndrome. Patients with decompensated hepatitis B cirrhosis who met the inclusion and exclusion criteria were retrospectively enrolled. Patients were randomly assigned to the training dataset and validation dataset at a 7:3 ratio. Univariate and multivariate logistic regression analyses were used to screen the risk factors for hepatorenal syndrome. The identified risk factors were used to establish and verify a model. This study included 255 patients with decompensated hepatitis B cirrhosis, including 184 in the training group and 71 in the validation group. The multivariate logistic regression model was established in the training group and verified in the validation group. Logistic regression showed that hemoglobin (OR 0.938, 95% CI 0.908–0.969), total bilirubin (OR 1.014, 95% CI 1.008–1.021) and creatinine (OR 1.079, 95% CI 1.043–1.117) were independent risk factors for hepatorenal syndrome (P < 0.05). These were used to establish the model. In the training group and the validation group, the area under the ROC curve of the nomogram for the diagnosis of hepatorenal syndrome was 0.968 and 0.980, respectively. The three serum biomarkers, including hemoglobin, total bilirubin and creatinine, can be used as independent early predictors of hepatorenal syndrome in patients with decompensated hepatitis B cirrhosis.

目的 探讨慢性乙肝(CHB)不同免疫自然史阶段肝脂肪变性程度与血清病毒学及肝脏病理的关系.方法 选取2013年10月至2020年9月在浙江省人民医院行肝脏穿刺活检的175例CHB患者为研究对象,根据肝脂肪变性程度分为F0～F1组(无或轻度肝脂肪变性)122例和F2～F4组(中重度肝脂肪变性)53例,比较不同肝脂肪变性程度患者临床资料以及各免疫自然史阶段不同肝脂肪变性程度患者血清病毒学指标.结果 175例CHB患者肝脂肪变性发生率为46.3％.F2～F4组患者BMI、高脂血症占比、血清HBsAg水平均明显高于F0～F1组(均P＜0.05);但两组患者年龄、Hb、PT、ALT、AST、ALP、谷氨酰转肽酶、抗病毒治疗占比、HBVDNA水平、HBeAg水平以及免疫自然史比较,差异均无统计学意义(均P＞0.05).在免疫清除期,G3～G4或S0～S2时F2～F4组血清HBsAg水平均明显高于F0～F1组(均P＜0.05),G3～G4时F2～F4组血清HBeAg水平明显高于F0～F1组(P＜0.05);而G0～G2或S3～S4时不同肝脂肪变性程度患者血清病毒学指标比较,差异均无统计学意义(均P＞0.05).在免疫耐受期、免疫控制期、再活动期,各炎症及纤维化程度分期不同肝脂肪变性程度患者血清病毒学指标比较,差异均无统计学意义(均P＞0.05).结论 在CHB不同免疫自然史阶段,仅发现免疫清除期随着肝脏炎症程度的加重,中重度肝脂肪变性患者血清HBsAg、HBeAg水平明显升高;而随着肝纤维化的加重,中重度肝脂肪变性患者血清HBsAg水平明显降低.

Exosomes, one of three main types of extracellular vesicles, are ~30–100 nm in diameter and have a lipid bilayer membrane. They are widely distributed in almost all body fluids. Exosomes have the potential to regulate unknown cellular and molecular mechanisms in intercellular communication, organ homeostasis, and diseases. They are critical signal carriers that transfer nucleic acids, proteins, lipids, and other substances into recipient cells, participating in cellular signal transduction and material exchange. ncRNAs are non-protein-coding genes that account for over 90% of the genome and include microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs). ncRNAs are crucial for physiological and pathological activities in the liver by participating in gene transcription, posttranscriptional epigenetic regulation, and cellular processes through interacting with DNA, RNA, or proteins. Recent evidence from both clinical and preclinical studies indicates that exosome-derived noncoding RNAs (ncRNAs) are highly involved in the progression of acute and chronic liver diseases by regulating hepatic lipid metabolism, innate immunity, viral infection, fibrosis, and cancer. Therefore, exosome-derived ncRNAs have promising potential and clinical implications for the early diagnosis, targeted therapy, and prognosis of liver diseases.

Background The chronic visceral subtype of acid sphingomyelinase deficiency, commonly known as Niemann Pick disease type B (NPDB), is a relatively rare autosomal recessive genetic disorder that is caused by mutations in the SMPD1 gene. NPDB with sea-blue histiocytes (SBH) clinically mimics Budd-Chiari syndrome (BCS), as it lacks specific clinical characteristics. This makes its diagnosis difficult. Case presentation Here, we report a case of NPDB with SBH that was misdiagnosed as BCS for three years. A 20-year-old female with abdominal distension, hepatosplenomegaly, and haematological anomalies was initially diagnosed with BCS based on her imaging finding of a thin hepatic vein and rapid blood flow at the confluence of the hepatic vein and inferior vena cava. Her bone marrow cytology found sea-blue histiocytes. Liver biopsy showed foamy cytoplasm in hepatocytes surrounded by numerous Kupffer cells. Sequencing analysis of the SMPD1 gene led to the finding of two missense mutations in the heterozygous state: C.829 T > C (p.Trp277Arg) in exon 2 (novel) and c.1805G > A (p.Arg602His) in exon 6 (already described). These findings established the diagnosis of NPDB. Conclusion The patient presented with hepatosplenomegaly, haematological anomalies, and dyslipidaemia. Thus, NPDB should be considered following the exclusion of related diseases. The diagnosis of NPDB was suspected by clinical symptoms and routine laboratory tests and was confirmed by liver biopsy and gene sequencing. The novel mutation c.829 T > C in exon 2 of the SMPD1 gene has never been reported and needs to be further investigated.

Objectives: Here, we retrospectively described the diagnosis and treatment of 32 cases diagnosed with Chlamydia psittaci pneumonia during the COVID-19 pandemic. Methods: Clinical information was collected from all the patients. Reverse transcription–PCR and ELISAs were conducted for the detection of COVID-19 using nasal swabs and bronchoalveolar lavage fluid (BALF) samples. Metagenomic next-generation sequencing (mNGS) was performed for the identification of causative pathogens using BALF, peripheral blood and sputum samples. End-point PCR was performed to confirm the mNGS results. Results: All 32 patients showed atypical pneumonia and had infection-like symptoms that were similar to COVID-19. Results of reverse transcription–PCR and ELISAs ruled out COVID-19 infection. mNGS identified C. psittaci as the suspected pathogen in these patients within 48 hours, which was validated by PCR, except for three blood samples. The sequence reads that covered fragments of C. psittaci genome were detected more often in BALF than in sputum or blood samples. All patients received doxycycline-based treatment regimens and showed favorable outcomes. Conclusion: This retrospective study, with the highest number of C. psittaci pneumonia enrolled cases in China so far, suggests that human psittacosis may be underdiagnosed and misdiagnosed clinically, especially in the midst of the COVID-19 pandemic.

BACKGROUND:Liver cancer is one of the most highly malignant cancers, characterized by easy metastasis and chemoradiotherapy resistance. Emerging evidence indicates that long noncoding RNAs (LncRNAs), including Lnc524369, are highly involved in the initiation, progression, radioresistance, and chemoresistance of hepatocellular carcinoma (HCC). However, the function of Lnc524369 remains unclear.AIM:To explore the function of Lnc524369 in HCC.METHODS:To investigate the effect of Lnc524369, tissue from 41 HCC patients were analyzed using CCK8, migration, and invasion assays. Lnc524369 and YWHAZ (also named 14-3-3ζ) mRNA were detected by qPCR, and YWHAZ and RAF1 proteins were detected by western blot in liver cancer cell lines and human HCC tissues. The Cancer Cell Line Encyclopedia (CCLE) databases, STRING database, Human Protein Atlas database, and the TCGA database were used for bioinformatic analysis.RESULTS:Lnc524369 was significantly upregulated in the nucleus of liver cancer cells and human HCC tissues. Overexpression of Lnc524369 was associated with the proliferation, migration, and invasion of liver cancer cells. YWHAZ and RAF1 proteins and YWHAZ mRNA were overexpressed in liver cancer, which could be attenuated by overexpression of Lnc524369. Lnc524369 and its downstream target YWHAZ and RAF1 proteins were negatively associated with overall survival time.CONCLUSION:Lnc524369 might be a promising target of HCC as it can enhance liver cancer progression and decrease the overall survival time of HCC by activating the YWHAZ/RAF1 pathway.

Abstract Psoas abscess (PA) is an uncommon disease that has been increasingly reported in recent years. We reviewed patients with PA and analysed their clinical characteristics to improve the understanding of this rare disorder. The study retrospectively reviewed the clinical presentations, microbiology, and outcomes of patients with PA between 2011 and 2021 in Zhejiang Provincial People’s Hospital in China. There were 35 cases out of 23057427 hospitalised adult patients; the mean age was 60 years, and 65.7% of the patients were male. Primary symptoms were typically nonspecific. In all, 17 abscesses were considered secondary, and the most common aetiology was infective spondylitis. The most common causative organism for primary PA was Staphylococcus aureus, followed by Escherichia coli, while for secondary abscesses, there were multiple bacterial species. The overall in-hospital mortality rate was 6%. Secondary PA patients had longer hospital stays (mean, 23 vs. 28 days). PAs, as a serious infectious condition, usually present with nonspecific symptoms and laboratory test results, making early diagnosis difficult. The aetiological profiles differed from those reported in our study. Initial clinical status and subsequent imaging studies can lead to favourable outcomes.

BACKGROUNDInborn error of bile acid synthesis type 4 is a peroxisomal disease with impaired bile acid synthesis caused by a-methylacyl-CoA racemase (AMACR) gene mutation.The disease is usually found in children with mild to severe liver disease, cholestasis and poor fat-soluble vitamin absorption.At present, there is no report of inborn errors of bile acid synthesis type 4 in adults with liver disease and poor fat-soluble vitamin absorption. CASE SUMMARYA 71-year-old man was hospitalized in our department for recurrent liver dysfunction.The clinical manifestations were chronic liver disease and yellow skin and sclera.Serum transaminase, bilirubin and bile acid were abnormally increased; and fat-soluble vitamins decreased.Liver cirrhosis and ascites were diagnosed by computed tomography.The patient had poor coagulation function and ascites and did not undergo liver puncture.Genetic testing showed AMACR gene missense mutation.The patient was diagnosed with inborn error of bile acid synthesis type 4.He was treated with ursodeoxycholic acid, liver protection and vitamin supplementation, and jaundice of the skin and sclera was reduced.The indicators of liver function and the quality of life were significantly improved. CONCLUSIONWhen adults have recurrent liver function abnormalities, physicians should be alert to genetic diseases and provide timely treatment.

Liver fibrosis is a necessary stage for patients with chronic hepatitis B to progress to liver cirrhosis or even liver cancer. Detection of early-stage fibrosis is of great clinical significance. Liver biopsy is still the gold standard for hepatic fibrosis, but the clinical application is limited since its invasiveness. Therefore, the method of non-invasive evaluation has been widely used in recent years. This article introduces the progress on serological and imaging evaluation methods of hepatic fibrosis in patients with chronic hepatitis B.

Introduction: Pyogenic liver abscess (PLA) is a serious infectious disease of the liver. Pyogenic liver abscess caused by Fusobacterium nucleatum is extremely rare. Here we report the first case of liver abscess caused by F. nucleatum in China. Case Presentation: The case was a 34-year-old female patient admitted to the hospital due to high fever. The diagnosis of liver abscess was confirmed by imaging studies and liver puncture. We finally confirmed the pathogen as F. nucleatum by next-generation sequencing (NGS). After the targeted anti-infective treatment, the patient recovered and discharged. Conclusions: As a new microbial detection method, NGS can still help in clinical practice. In addition, to improve the positive rate of anaerobic bacteria culture, we should pay attention to avoid contact with air in the process of specimen collection when the pathogenic bacteria are suspected to be anaerobic bacteria.

BACKGROUND Diffuse large B-cell lymphoma (DLBCL) is a common non-Hodgkin's lymphoma. R-CHOP is a protocol for long-term chemotherapy for DLBCL patients. Long-term chemotherapy can lead to low immunity and increase the risk of opportunistic pathogen infections in immunocompromised patients. CASE SUMMARY We report a case of coinfection with Pneumocystis jirovecii (P. jirovecii) and Legionella pneumophila (L. pneumophila) in a patient with DLBCL. The patient was a 40-year-old female who was diagnosed with DLBCL and was admitted due to pulmonary infection. P. jirovecii and L. pneumophila were detected in her bronchoalveolar lavage fluid by hexamine silver staining, isothermal amplification and metagenomic sequencing. CONCLUSION To the best of our knowledge, this is the first case of P. jirovecii and L. pneumophila coinfection found in a DLBCL patient. Clinicians should be aware of the risk of complicated infection in patients undergoing long-term chemotherapy.