ABSTRACT
OBJECTIVE: Exocrine pancreatic insufficiency (EPI) is a common manifestation of chronic pancreatitis (CP) and autoimmune pancreatitis (AIP). This study aimed to estimate the presence of EPI in patients with CP or AIP using alternative clinical markers. MATERIALS AND METHODS: A machine learning analysis employing a decision tree model was conducted on a retrospective training cohort comprising 57 patients with CP or AIP to identify EPI, defined as fecal elastase-1 levels less than 200 µg/g. The outcomes were then confirmed in a validation cohort of 26 patients. RESULTS: Thirty-nine patients (68%) exhibited EPI in the training cohort. The decision tree algorithm revealed body mass index (≤21.378 kg/m 2 ) and total protein level (≤7.15 g/dL) as key variables for identifying EPI. The algorithm's performance was assessed using 5-fold cross-validation, yielding area under the receiver operating characteristic curve values of 0.890, 0.875, 0.750, 0.625, and 0.771, respectively. The results from the validation cohort closely replicated those in the training cohort. CONCLUSIONS: Decision tree analysis revealed that EPI in patients with CP or AIP can be identified based on body mass index and total protein. These findings may help guide the implementation of appropriate treatments for EPI.
Subject(s)
Autoimmune Pancreatitis , Exocrine Pancreatic Insufficiency , Pancreatitis, Chronic , Humans , Autoimmune Pancreatitis/complications , Autoimmune Pancreatitis/diagnosis , Retrospective Studies , Pancreatitis, Chronic/complications , Pancreatitis, Chronic/diagnosis , Exocrine Pancreatic Insufficiency/diagnosis , Exocrine Pancreatic Insufficiency/etiology , Decision TreesABSTRACT
This case report describes a 73-year-old woman with pancreatic adenocarcinoma who had undergone a colectomy for colorectal cancer in 1995 and a right mastectomy and axillary dissection for breast cancer in 2013. In January 2019, a tumor, approximately 20mm in diameter, was detected in the pancreatic body. It contained a cyst noted to have delayed perfusion towards the center on abdominal computed tomography. On T1-weighted magnetic resonance imaging (MRI), almost the entire tumor exhibited low intensity. On T2-weighted MRI, however, the tumor center displayed high intensity, the tumor wall displayed low intensity, and the outermost layer displayed high intensity. On endoscopic ultrasound, the tumor center displayed low echo density, the tumor wall had a slightly elevated echo density, and the outermost layer had a low echo density. A distal pancreatectomy was performed for a suspected metastatic pancreatic cancer, pancreatic neuroendocrine neoplasm, or invasive ductal carcinoma without tubular adenocarcinoma. Histopathological examination revealed that the tumor cells had formed atypical tubular gland ducts with a fibrous stroma in the background. The lesion differed from the histopathological findings of her previous colorectal and breast cancers, and it was ultimately diagnosed as a pancreatic ductal adenocarcinoma. The lumen of the cyst was covered with tumor cells identical to those of the atypical tubular gland ducts in the tumor parenchyma, suggesting that the cyst was a dilated tubular gland duct.
Subject(s)
Adenocarcinoma , Breast Neoplasms , Carcinoma, Pancreatic Ductal , Cysts , Pancreatic Neoplasms , Adenocarcinoma/diagnostic imaging , Adenocarcinoma/surgery , Aged , Carcinoma, Pancreatic Ductal/diagnostic imaging , Carcinoma, Pancreatic Ductal/surgery , Female , Humans , Mastectomy , Pancreatectomy , Pancreatic Ducts , Pancreatic Neoplasms/diagnostic imaging , Pancreatic Neoplasms/surgeryABSTRACT
BACKGROUND/OBJECTIVES: Patients with autoimmune pancreatitis (AIP) sometimes progress to chronic pancreatitis (CP). We evaluated the ability of corticosteroids to prevent the progression to CP. METHODS: We defined patients with definitive findings of CP (stones in the main pancreatic duct [MPD] or multiple pancreatic calcifications) as having severe calcification (SC). A total of 145 AIP patients were enrolled. We measured the duration between AIP diagnosis and SC development and retrospectively compared the time to SC development between patients with and without steroids. Multivariate analysis for factors associated with SC were performed. RESULTS: Nineteen (13%) patients progressed to SC. Since 95 patients had pancreatic head swelling and SC was found in these patients only, our analysis focused mainly on these at-risk populations. In Kaplan-Meier analysis limited to patients with pancreatic head swelling, the incidence of SC was significantly lower in patients with steroids than in those without (hazard ratio [HR] 0.18, 95% confidence interval [CI] 0.07-0.52; p < 0.001). Multivariate testing of patients with pancreatic head swelling confirmed that steroid therapy was significantly associated with a lower incidence of SC (HR 0.11, 95% CI 0.03-0.34; p < 0.001), while MPD dilation at AIP diagnosis was related to a higher incidence of SC (HR 4.02, 95% CI 1.43-11.7; p = 0.009). CONCLUSIONS: Corticosteroids appeared to prevent progression to CP in AIP patients, especially in those with pancreatic head swelling. Patients with both pancreatic head swelling and MPD dilation at diagnosis have a higher incidence of progression to CP. Steroid therapy is suggested for these high-risk cases.
Subject(s)
Adrenal Cortex Hormones/therapeutic use , Autoimmune Pancreatitis/drug therapy , Pancreatitis, Chronic/prevention & control , Adult , Aged , Aged, 80 and over , Calcinosis/drug therapy , Calcinosis/etiology , Disease Progression , Female , Humans , Incidence , Kaplan-Meier Estimate , Male , Middle Aged , Pancreas/pathology , Pancreatic Ducts , Pancreatitis, Chronic/epidemiology , Retrospective Studies , Treatment OutcomeABSTRACT
Quantifying myocardial T1 values has been useful for detecting and characterizing fibrotic appearance in myocardial infarction, focal scars, and non-ischemic cardiomyopathies. Since pancreatic exocrine function decreases with chronic pancreatic fibrosis advancement, this study examined the correlation between pancreatic T1 values and pancreatic exocrine and endocrine insufficiency. METHODS: Thirty-two patients underwent abdominal contrast-enhanced MRI in our department between October 2017 and February 2019. We evaluated the T1 values of the pancreas using a modified Look-Locker inversion recovery sequence (MOLLI), pancreatic exocrine insufficiency (PEI) by fecal elastase 1 (FE1) values, and pancreatic endocrine insufficiency using fasting insulin and blood glucose levels to calculate the HOMA-ß. This trial is registered in the UMIN Clinical Trials Registry as UMIN 000030067. RESULTS: The median cohort (9 males and 23 females) age was 71 (range: 49-84) years. Eighteen patients had pancreatic cysts, three had alcohol-induced chronic pancreatitis, three had pancreatic cancer, and eight possessed other pancreatic features (two patients each with autoimmune pancreatitis, acute pancreatitis, or a bile duct tumor, one with idiopathic chronic pancreatitis, and one healthy control with negative findings). The median pancreatic T1 value measured by the MOLLI was 857.5 ms (597-2569). A significant negative correlation was found between the T1 mapping and FE1 values (r = 0.69, p < 0.01), with none for the T1 with HOMA-ß or serum albumin, triglycerides, or body mass index. CONCLUSIONS: the pancreatic T1 values correlated significantly with pancreatic exocrine function and might be useful in PEI diagnosis.
ABSTRACT
Mixed connective tissue disease (MCTD) causes multiple organ dysfunctions, such as joint swelling, pulmonary fibrosis and hypertension, and serositis, but hepatopancreatic complications are rare. Here, we report a case of young man who exhibited acute severe liver dysfunction. He also had impaired cardiac function: both ventriculi were hypokinetic, but pulmonary hypertension and pericarditis were not observed. Since his liver and cardiac function markedly improved after commencing furosemide and carperitide, we considered congestive hepatopathy due to MCTD and accompanying heart failure. Heart failure and congestive hepatopathy recurred and he was treated with diuretics and prednisolone, but he passed away by co-occurrence of acute hemorrhagic pancreatitis. Necropsy revealed chronic hepatic congestion but not accompanying autoimmune hepatitis and hepatic vasculitis. We should consider congestive hepatopathy and hemorrhagic pancreatitis as serious complications of MCTD.
Subject(s)
Liver Diseases/etiology , Mixed Connective Tissue Disease/complications , Pancreatitis/etiology , Adult , Fatal Outcome , Heart Failure/etiology , Humans , Liver/pathology , Liver Diseases/diagnostic imaging , Liver Diseases/pathology , Male , Mixed Connective Tissue Disease/pathology , Pancreatitis/diagnostic imaging , Skin/pathology , Tomography, X-Ray ComputedABSTRACT
Objectives: Autoimmune pancreatitis (AIP) sometimes becomes complicated with pancreatic cysts, although their detailed characteristics and management strategy have not been fully determined. We aimed to clarify the efficiency of steroid therapy and the risk factors for cyst formation and cyst-related complications. Methods: One hundred sixty-three AIP patients were retrospectively analyzed for relevant factors of cyst formation. We compared subjects with and without steroids to evaluate drug effectiveness on cyst size change and investigated the factors associated with cyst-related complications. Results: Thirty-two patients (19.6%) had complicating pancreatic cyst formation, and 40 cystic lesions of ≥10 mm in size were detected. Multivariate analysis revealed a drinking habit, abdominal/back pain, and elevated serum amylase to be significantly associated with cyst formation. Steroid-treated cysts became significantly reduced in size in the short-term and disappeared significantly more frequently within 1-year as compared with non-treated ones, which was confirmed by multivariate analysis. Six of 40 cysts exhibited cyst-related complications significantly associated with multilocular morphology and larger size. Conclusions: Steroid therapy is an effective choice for cysts developing in AIP to promote the release of pancreatic juice stasis. Larger lesions with multilocular morphology should be monitored closely for cyst-related complications and be considered strong candidates for steroid therapy.
Subject(s)
Autoimmune Pancreatitis/complications , Pancreatic Cyst/drug therapy , Pancreatic Cyst/etiology , Steroids/therapeutic use , Adult , Aged , Aged, 80 and over , Female , Humans , Japan , Logistic Models , Male , Middle Aged , Multivariate Analysis , Retrospective Studies , Risk Factors , Treatment OutcomeABSTRACT
OBJECTIVES: Because several studies for autoimmune pancreatitis (AIP) have revealed pancreatic calcification resembling that in chronic pancreatitis (CP), we sought to clarify whether AIP could transform into chronic features similar to advanced CP with severe pancreatic dysfunction. METHODS: Pancreatic functions of 92 AIP patients, 47 definite CP patients, and 30 healthy controls were assessed by fecal elastase-1 concentration (FEC), fasting immunoreactive insulin (IRI), and homeostatic model assessment (HOMA)-R. RESULTS: The 92 AIP patients included 17 (18%) with severe calcification (SC) and 75 without. The FEC levels in AIP and CP patients were significantly lower than that in controls. Exocrine insufficiency defined as FEC less than 200 µg/g was 39% in AIP without SC, 56% in AIP with SC, and 74% in CP. Fasting IRI and C-peptide reactivity values in CP were significantly lower than those in AIP, with no significant differences between AIP subgroups. The prevalence of endocrine insufficiency according to fasting IRI less than 5.0 µU/mL was 26% in AIP without SC, 31% in AIP with SC, and 59% in CP, respectively. HOMA-R values were significantly higher in all AIP groups than in CP. CONCLUSIONS: Autoimmune pancreatitis can transform into a state of pancreatic insufficiency after calcification that is less severe than that in definite CP.
Subject(s)
Autoimmune Diseases , C-Peptide , Calcinosis , Humans , Pancreas , Pancreatitis , Pancreatitis, ChronicABSTRACT
OBJECTIVE: Because it is uncertain whether immunoglobulin G4-related disease (IgG4-RD) is associated with malignancy, we evaluated the incidence of cancer development in a large cohort of patients with IgG4-RD. METHODS: The study enrolled 158 patients diagnosed as having IgG4-RD between 1992 and 2012. We calculated the standardized incidence ratio (SIR) and cumulative rate of malignancies in this group and searched for risk factors associated with the occurrence of tumors. RESULTS: A total of 34 malignancies were observed in the patients with IgG4-RD over a mean followup period of 5.95 ± 4.48 years. The overall SIR of malignancies was 2.01 (95% CI 1.34-2.69). The SIR of patients who exhibited a tumor within 1 year after IgG4-RD diagnosis was 3.53 (95% CI 1.23-5.83), while that of subjects forming a malignancy in subsequent years was 1.48 (95% CI 0.99-1.98). The cumulative rate of malignancy development was significantly higher in patients with IgG4-RD within 12 years after diagnosis than in the Japanese general population. Comparable results were obtained for an autoimmune pancreatitis subgroup. The serum concentrations of several disease activity markers at diagnosis were significantly higher in patients with malignancies than in those without. CONCLUSION: We identified a close association between IgG4-RD and malignancy formation within 12 years after diagnosis, particularly during the first year. An active IgG4-RD state is presumed to be a strong risk factor for malignancy development.
Subject(s)
Autoimmune Diseases/diagnosis , Immunoglobulin G/biosynthesis , Neoplasms/epidemiology , Neoplasms/immunology , Age Distribution , Aged , Aged, 80 and over , Autoimmune Diseases/epidemiology , Cohort Studies , Female , Follow-Up Studies , Humans , Incidence , Japan/epidemiology , Male , Neoplasms/diagnosis , Pancreatic Neoplasms/diagnosis , Pancreatic Neoplasms/epidemiology , Pancreatic Neoplasms/immunology , Retrospective Studies , Severity of Illness Index , Sex Distribution , Time FactorsABSTRACT
BACKGROUND: Although most patients with autoimmune pancreatitis (AIP) respond favorably to prednisolone therapy, some individuals who later suffer from pancreatic calculi may require additional extracorporeal shock wave lithotripsy (ESWL) treatment. This study compares the efficacy of ESWL for calculi in AIP with that in ordinary chronic pancreatitis (CP) and proposes a new treatment approach for pancreatic duct stones occurring in AIP. METHODS: We examined the clinical records of 8 patients with chronic stage AIP and 92 patients with ordinary CP who received ESWL for pancreatic calculi. RESULTS: The AIP group was significantly older than the CP group (69.0 vs. 56.5 years, P = 0.018). With regard to the indications for ESWL, chronic pain was significantly less frequent in the chronic stage AIP group (0% vs. 45.7%, P = 0.001), whereas preservation of pancreatic function was significantly more frequent (75% vs. 19.6%, P = 0.001). Compared with the CP group, the AIP group tended to exhibit pancreatic duct stenosis proximal to pancreatic calculi and had a lower rate of complete extraction of stones from the main pancreatic duct. Histopathological analysis of a patient with chronic stage AIP revealed widely distributed nodular pancreatitis, which was characteristic of ordinary CP, along with isolated areas of lymphoplasmacytic sclerosing pancreatitis. CONCLUSIONS: Different approaches are needed for the treatment of pancreatic calculi in chronic stage AIP and ordinary CP. Specifically, it appears that intensive ESWL therapy can be avoided or delayed in AIP if the patient displays: (1) advanced age, (2) little or no chronic pain or pancreatitis, and (3) pancreatic duct stenosis proximal to pancreatic stones. In such cases, the benefit of ESWL treatment may be outweighed by the risks involved in this procedure.
Subject(s)
Autoimmune Diseases/complications , Calculi/therapy , Lithotripsy , Pancreatic Diseases/therapy , Pancreatitis, Chronic/complications , Adult , Aged , Aged, 80 and over , Autoimmune Diseases/pathology , Calculi/complications , Chronic Pain/etiology , Constriction, Pathologic/etiology , Female , Humans , Male , Middle Aged , Pancreatic Diseases/complications , Pancreatic Ducts/pathology , Pancreatitis, Chronic/immunology , Pancreatitis, Chronic/pathology , Retrospective Studies , Treatment Outcome , Young AdultABSTRACT
BACKGROUND: Among the intrahepatic bile ducts, the biliary system of the left medial sectional bile duct (B4) is known to have relatively complex patterns. METHODS: The records of 500 patients who had been diagnosed as having hepato-pancreatico-biliary disease were retrospectively studied for anatomical biliary variations of the left liver with special reference to the drainage system of B4 using magnetic resonance images. RESULTS: The left hepatic duct was present in 494 patients (98.8%), whereas it was lacking in 6 patients (1.2%), and these patients exhibited the following B4 confluence patterns: B4 drained into the common hepatic duct in 2 patients (.4%), the right anterior sectional bile duct in 3 patients (.6%), and the right posterior sectional bile duct in 1 patient (.2%). The left hepatic duct was absent more frequently in patients with portal venous variations than in patients with a common branching pattern (8.2% vs .4%, P = .0011). CONCLUSION: The presently reported data are useful for obtaining a better understanding of the surgical anatomy of the biliary system of the left liver.
Subject(s)
Anatomic Variation , Bile Ducts, Intrahepatic/anatomy & histology , Magnetic Resonance Imaging , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Liver , Male , Middle Aged , Retrospective Studies , Young AdultSubject(s)
Autoimmune Diseases/immunology , Cholangitis, Sclerosing/immunology , Immunoglobulin G/immunology , Pancreatitis/immunology , Autoimmune Diseases/diagnosis , Autoimmune Diseases/pathology , Cholangitis, Sclerosing/diagnosis , Cholangitis, Sclerosing/pathology , Humans , Pancreatitis/diagnosis , Pancreatitis/pathologyABSTRACT
Autoimmune pancreatitis (AIP) has been recognized as a distinct type of pancreatitis that is possibly caused by autoimmune mechanisms. AIP is characterized by high serum IgG4 and IgG4-positive plasma cell infiltration in affected pancreatic tissue. Acute phase AIP responds favorably to corticosteroid therapy and results in the amelioration of clinical findings. However, the long-term prognosis and outcome of AIP remain unclear. We have proposed a working hypothesis that AIP can develop into ordinary chronic pancreatitis resembling alcoholic pancreatitis over a long-term course based on several clinical findings, most notably frequent pancreatic stone formation. In this review article, we describe a series of study results to confirm our hypothesis and clarify that: 1) pancreatic calcification in AIP is closely associated with disease recurrence; 2) advanced stage AIP might have earlier been included in ordinary chronic pancreatitis; 3) approximately 40% of AIP patients experience pancreatic stone formation over a long-term course, for which a primary risk factor is narrowing of both Wirsung's and Santorini's ducts; and 4) nearly 20% of AIP patients progress to confirmed chronic pancreatitis according to the revised Japanese Clinical Diagnostic Criteria, with independent risk factors being pancreatic head swelling and non-narrowing of the pancreatic body duct.
Subject(s)
Autoimmune Diseases/physiopathology , Pancreatitis/physiopathology , Aged , Aged, 80 and over , Calcinosis , Chronic Disease , Female , Humans , Male , Middle Aged , Prognosis , Recurrence , Risk FactorsABSTRACT
BACKGROUND AND STUDY AIMS: Although colonic diverticular hemorrhage is a common cause of lower gastrointestinal bleeding, the low rate of detection of the diverticula responsible for bleeding, together with inadequate evaluation of endoscopic hemostasis, remain unsatisfactory. PATIENTS AND METHODS: Over 3 years, we employed the hood method to diagnose diverticular hemorrhage in 53 patients and applied endoscopic band ligation (EBL) for hemostasis in 27 patients with responsible diverticula. RESULTS: The hood method revealed active bleeding in 13 patients (24.5%), nonbleeding visible vessels in 14 patients (26.4%), and presumptive diverticular hemorrhage in 26 patients (49.1%). The nonbleeding visible vessels were located in the diverticular dome in 13 patients and at the diverticular orifice in one patient. EBL was performed in 27 patients, and a hemostasis rate of 96.3% was achieved. In 9 of 12 patients treated with EBL, follow-up colonoscopy revealed resolution of the responsible diverticula. CONCLUSIONS: The hood method improves the detection rate of diverticula responsible for bleeding by revealing potential nonbleeding visible vessels in the diverticular dome. EBL may become an effective procedure for hemostasis of colonic diverticular hemorrhage.
Subject(s)
Colonoscopy/methods , Diverticulum, Colon/diagnosis , Gastrointestinal Hemorrhage/therapy , Hemostasis, Endoscopic , Diverticulum, Colon/complications , Gastrointestinal Hemorrhage/etiology , Humans , LigationABSTRACT
Objectives. The recent International Consensus Diagnostic Criteria (ICDC) for autoimmune pancreatitis (AIP) and its Japanese amendment developed by the Japanese Pancreas Society (JPS 2011) may have overcome the drawbacks of earlier criteria and achieved a higher diagnostic ability for AIP. The aim of the present study is to evaluate this possibility and identify the underlying causes of this change. Methods. We compared the diagnostic abilities of the ICDC and JPS 2011 with those of the Japanese diagnostic criteria 2006 (JPS 2006), Korean diagnostic criteria (Korean), Asian diagnostic criteria (Asian), and HISORt diagnostic criteria in 110 patients with AIP and 31 patients with malignant pancreatic cancer. Results. The ICDC achieved the highest diagnostic ability in terms of accuracy (95.0%), followed by JPS 2011 (92.9%), Korean (92.2%), HISORt (88.7%), Asian (87.2%), and JPS 2006 (85.1%). Nearly all criteria systems exhibited a high specificity of 100%, indicating that the enhanced diagnostic ability of the ICDC and JPS 2011 likely stemmed from increased sensitivity brought about by inclusion of diagnostic items requiring no endoscopic retrograde pancreatography. The diagnostic ability of JPS 2011 was nearly equivalent to that of the ICDC. Conclusions. The ICDC and JPS 2011 have improved diagnostic ability as compared with earlier criteria sets because of an increase in sensitivity.
ABSTRACT
Type 1 autoimmune pancreatitis (AIP) is characterized by a high serum IgG4 concentration and is closely associated with the HLA-DRB1(*)04:05-DQB1(*)04:01 haplotype, for which family studies may disclose its immunogenetic significance. In the present study, we encountered two male siblings with type 1 AIP who exhibited diffuse pancreatic swelling with a capsule-like rim and diffuse pancreatic duct stricture. The younger brother also displayed characteristic IgG4-related sialadenitis and retroperitoneal fibrosis. Contrary to our expectations, the siblings showed only normal or slightly elevated values of serum IgG4 and no HLA DRB1(*)04:05-DQB1(*)04:01 haplotype, suggesting that type 1 autoimmune pancreatitis is associated with multiple immunogenetic factors.
Subject(s)
Autoimmune Diseases/classification , Autoimmune Diseases/genetics , Pancreatitis/classification , Pancreatitis/genetics , Siblings , Autoimmune Diseases/immunology , HLA-DRB1 Chains/genetics , HLA-DRB1 Chains/immunology , Humans , Male , Middle Aged , Pancreatitis/immunologyABSTRACT
A major form of proteasome activator PA28 is a heteroheptamer composed of interferon-γ-inducible α and ß subunits, which share approximately 50% amino acid identity and possess distinct insert loops. This activator forms a complex with the 20S proteasome and thereby stimulates proteasomal degradation of peptides in an ATP-independent manner, giving rise to smaller antigenic peptides presented by major histocompatibility complex class I molecules. In this study, we performed biophysical and biochemical characterization of the structure and function of the PA28 hetero-oligomer. Deuteration-assisted small-angle neutron scattering demonstrated three α and four ß subunits are alternately arranged in the heptameric ring. In this arrangement, PA28 loops surround the central pore of the heptameric ring (site for peptide entry). Activating the 20S proteasome with a PA28 mutant that lacked the α subunit loops cleaved model substrates longer than a nonapeptide with better efficiency when compared to wild-type PA28. Based on these data, we hypothesize that the flexible PA28 loops act as gatekeepers, which function to select the length of peptide substrates to be transported between the proteolytic chamber and the extra-proteasomal medium.
Subject(s)
Proteasome Endopeptidase Complex/chemistry , Proteasome Endopeptidase Complex/metabolism , Animals , Mice , Peptides/chemistry , Protein Conformation , Protein Multimerization , Protein Subunits/chemistry , Protein Subunits/metabolism , ProteolysisABSTRACT
In order to evaluate the biochemical characteristics of 14 substrains of Mycobacterium bovis bacillus Calmette Guérin (BCG) - Russia, Moreau, Japan, Sweden, Birkhaug, Danish, Glaxo, Mexico, Tice, Connaught, Montreal, Phipps, Australia and Pasteur - we performed eight different biochemical tests, including those for nitrate reduction, catalase, niacin accumulation, urease, Tween 80 hydrolysis, pyrazinamidase, p-amino salicylate degradation and resistance to thiophene 2-carboxylic acid hydrazide. Catalase activities of the substrains were all low. Data for nitrate reduction, niacin accumulation, Tween 80 hydrolysis, susceptibility to hydrogen peroxide and nitrate, and optimal pH for growth were all variable among these substrains. These findings suggest that the heterogeneities of biochemical characteristics are relevant to the differences in resistance of BCG substrains to environmental stress. The study also contributes to the re-evaluation of BCG substrains for use as vaccines.
Subject(s)
Genetic Variation , Mycobacterium bovis/classification , Mycobacterium bovis/physiology , Animals , Bacterial Typing Techniques , Cell Line , Female , Humans , Macrophages/microbiology , Mice , Mice, Inbred C57BL , Microbial Viability , Monocytes/microbiology , Mycobacterium bovis/growth & development , Mycobacterium bovis/metabolismABSTRACT
During the serial passage of Mycobacterium bovis bacillus Calmette-Guérin (BCG) in different countries after initial seed distribution from the Pasteur Institute, specific insertions and deletions in the genome among BCG substrains were observed and speculated to result in differences in immunological activities. 'Early-shared strains' of BCG (Russia, Moreau, Japan, Sweden, Birkhaug), distributed by the Pasteur Institute, which conserve three types of mycolate (alpha, methoxy, keto) in cell wall, exhibited stronger activities of induction of nitric oxide, interleukin-1beta (IL-1beta), IL-6, IL-8, IL-12 and tumor necrosis factor (TNF)-alpha, from human epithelial cell line A549, human myelomonocytic cell line THP-1 and mouse bone marrow cells in the presence of interferon-gamma (IFN-gamma) than did 'late-shared strains' of BCG (Danish, Glaxo, Mexico, Tice, Connaught, Montreal, Phipps, Australia, Pasteur). The stronger induction of IL-12 and TNF-alpha in the presence of IFN-gamma was also observed by trehalose 6,6'-dimycolate (TDM) extracted from BCG-Japan than by TDM from BCG-Connaught, which lacks the methoxymycolate residue. These results suggest that 'early-shared strains' are more potent immunostimulating agents than 'late-shared strains', which could be attributed partially to methoxymycolate. Our study provides the basic information for immunological characterization of various BCG strains and may contribute to a re-evaluation of them as a reference strain for vaccination against tuberculosis.