Detection of specific Atlantic salmon antibodies against salmonid alphavirus using a bead-based immunoassay

Salmonid alphavirus (SAV) is the etiological cause of pancreas disease (PD) in Atlantic salmon (Salmo salar). Several vaccines against SAV are in use, but PD still cause significant mortality and concern in European aquaculture, raising the need for optimal tools to monitor SAV immunity. To monitor and control the distribution of PD in Norway, all salmonid farms are regularly screened for SAV by RT-qPCR. While the direct detection of SAV is helpful in the early stages of infection, serological methods could bring additional information on acquired SAV immunity in the later stages. Traditionally, SAV antibodies are monitored in neutralization assays, but they are time-consuming and cumbersome, thus alternative assays are warranted. Enzyme-linked immunosorbent assays (ELISAs) have not yet been successfully used for anti-SAV antibody detection in aquaculture. We aimed to develop a bead-based immunoassay for SAV-specific antibodies. By using detergent-treated SAV particles as antigens, we detected SAV-specific antibodies in plasma collected from both a SAV challenge trial and a field outbreak of PD. Increased levels of SAV-specific antibodies were seen after most fish had become negative for viral RNA. The bead-based assay is time saving compared to virus neutralization assays, and suitable for non-lethal testing due to low sample size requirements. We conclude that the bead-based immunoassay for SAV antibody detection is a promising diagnostic tool to complement SAV screening in aquaculture.

Hyaluronan deposition in islets may precede and direct the location of islet immune-cell infiltrates

AIMS/HYPOTHESIS

Substantial deposition of the extracellular matrix component hyaluronan (HA) is characteristic of insulitis in overt type 1 diabetes. We investigated whether HA accumulation is detectable in islets early in disease pathogenesis and how this affects the development of insulitis and beta cell mass.

METHODS

Pancreas tissue from 15 non-diabetic organ donors who were positive for islet autoantibodies (aAbs) and from 14 similarly aged aAb^- control donors were examined for the amount of islet HA staining and the presence of insulitis. The kinetics of HA deposition in islets, along with the onset and progression of insulitis and changes in beta cell mass, were investigated in BioBreeding DRLyp/Lyp rats (a model of spontaneous autoimmune diabetes) from 40 days of age until diabetes onset.

RESULTS

Abundant islet HA deposits were observed in pancreas tissues from n = 3 single- and n = 4 double-aAb⁺ donors (aAb⁺HA^high). In these seven tissues, the HA-stained areas in islets measured 1000 ± 240 μm² (mean ± SEM) and were fourfold larger than those from aAb^- control tissues. The aAb⁺HA^high tissues also had a greater prevalence of islets that were highly rich in HA (21% of the islets in these tissues contained the largest HA-stained areas [>2000 μm²] vs less than 1% in tissues from aAb^- control donors). The amount of HA staining in islets was associated with the number of aAbs (i.e. single- or double-aAb positivity) but not with HLA genotype or changes in beta cell mass. Among the seven aAb⁺HA^high tissues, three from single- and one from double-aAb⁺ donors did not show any islet immune-cell infiltrates, indicating that HA accumulates in aAb⁺ donors independently of insulitis. The three aAb⁺HA^high tissues that exhibited insulitis had the largest HA-stained areas and, in these tissues, islet-infiltrating immune cells co-localised with the most prominent HA deposits (i.e. with HA-stained areas >2000 μm²). Accumulation of HA in islets was evident prior to insulitis in 7-8-week-old presymptomatic DRLyp/Lyp rats, in which the islet HA-stained area measured 2370 ± 170 μm² (mean ± SEM), which was threefold larger than in 6-week-old rats. This initial islet HA deposition was not concurrent with beta cell loss. Insulitis was first detected in 9-10-week-old rats, in which the HA-stained areas were 4980 ± 500 μm². At this age, the rats also exhibited a 44% reduction in beta cell mass. Further enlargement of the HA-positive areas (mean ± SEM: 7220 ± 880 μm²) was associated with invasive insulitis. HA deposits remained abundant in the islets of rats with destructive insulitis, which had lost 85% of their beta cells.

CONCLUSIONS/INTERPRETATION

This study indicates that HA deposition in islets occurs early in type 1 diabetes and prior to insulitis, and points to a potential role of HA in triggering islet immune-cell infiltration and the promotion of insulitis.

The effect of the proteolisis' system activity for the trophological status of patients with osteoarthrosis and excretory insufficiency of pancreas

OBJECTIVE

Introduction:The excretory insufficiency of pancreas in patients with primary osteoarthrosis is formed at the comorbid pathologies and as a result of long-term treatment of osteoarthrosis using the non-steroidal anti-inflammatory drugs, steroids, chondroprotectors and chondrostimulators etc. The aim: to study the state of the proteolysis system and immune status, the presence and depth of the dysbiosis of colon in patients with primary osteoarthrosis against a violation of their excretory insufficiency of pancreas.

PATIENTS AND METHODS

Materials and methods: There were 64 outpatients with primary OA (group 1) and 74 patients with primary OA in combination with diseases associated with EIP (group 2). The control group consisted of 30 healthy people.The age of the patients ranged from 29 to 74 years. The diagnosis of primary OA was established on the basis of unified diagnostic criteria, the X-ray stage of the primary OA, according to J. H. Kellgren and J. S. Lawrence.

RESULTS

Results: It was proved that there is a deeper excitation of the excretory function of the pancreas in patient with osteoarthrosis and comorbid pathologies of the gastrointestinal tract with the excretory insufficiency of pancreas, as well as the presence of the excretory insufficiency of pancreas in patients with primary osteoarthrosis without the clinically available the excretory insufficiency of pancreas. In patients with primary osteoarthrosis that went through the isolation or in combination with the diseases accompanied by theexcretory insufficiency of pancreas, a statistically significant activation of the total proteolysis by the level of the proteolytic activity of the plasma was established. In group 2, dysbiotic changes were significantly deeper than in group 1. The obtained results indicate the presence of secondary immune deficiency in patients and non-specific activation of the humoral part of the immune system and the inflammatory process.

CONCLUSION

Conclusion: Statistically more significant changes were observed in group 2, indicating the progression of the detected changes in comorbidity conditions.

Type 1 Diabetes and Type 1 Interferonopathies: Localization of a Type 1 Common Thread of Virus Infection in the Pancreas

Type 1 diabetes (T1D) has been associated with both genetic and environmental factors. Increasing incidence of T1D worldwide is prompting researchers to adopt different approaches to explain the biology of T1D, beyond the presence and activity of autoreactive lymphocytes. In this review, we propose inflammatory pathways as triggers for T1D. Within the scope of those inflammatory pathways and in understanding the pathogenesis of disease, we suggest that viruses, in particular Coxsackieviruses, act by causing a type 1 interferonopathy within the pancreas and the microenvironment of the islet. As such, this connection and common thread represents an exciting platform for the development of new diagnostic, treatment and/or prevention options.

Immune gene profiles in Atlantic salmon (salmo salar L.) post-smolts infected with SAV3 by bath-challenge show a delayed response and lower levels of gene transcription compared to injected fish

Salmonid alphavirus (SAV) causes pancreatic disease (PD) in salmonids in Northern Europe which results in large economic losses within the aquaculture industry. In order to better understand the underlying immune mechanisms during a SAV3 infection Atlantic salmon post-smolts were infected by either i.m.-injection or bath immersion and their immune responses compared. Analysis of viral loads showed that by 14 dpi i.m.-injected and bath immersion groups had 95.6% and 100% prevalence respectively and that both groups had developed the severe pathology typical of PD. The immune response was evaluated by using RT-qPCR to measure the transcription of innate immune genes involved in the interferon (IFN) response as well as genes associated with inflammation. Our results showed that IFNa transcription was only weakly upregulated, especially in the bath immersion group. Despite this, high levels of the IFN-stimulated genes (ISGs) such as Mx and viperin were observed. The immune response in the i.m.-injected group as measured by immune gene transcription was generally faster, and more pronounced than the response in the bath immersion group, especially at earlier time-points. The response in the bath immersion group started later as expected and appeared to last longer often exceeding the response in the i.m-injected fish at later time-points. High levels of transcription of many genes indicative of an active innate immune response were present in both groups.

Common autoimmune biomarkers, thyroid hormonal abnormalities, and beta cells dysfunction in patients with latent autoimmune diabetes in adults with type II diabetes mellitus

AIM

Latent autoimmune diabetes in adults (LADA) is autoimmune diabetes with a slow progression characterized by the presence of antibodies associated with Type I diabetes. The present study aimed to assess autoimmune characteristics in patients with LADA in Iran. We attempted to obtain a clear view of autoimmune conditions in LADA among our population.

METHODS

This study was sourced from the population-based survey of KERCARDS aiming assessment of cardiovascular risk factors among a great sample of Iranian population who were resident in Kerman, a great province in southern Iran. Among all diabetic patients who were negative for Anti Glutamic Acid Decarboxylase (GAD) antibody test, 120 were selected as the controls and among 80 patients who were positive for this test diagnosed as LADA, the recorded files of 57 patients were complete considered as the cases.

RESULTS

The level of thyroxin is significantly lower in patients with LADA compared with the controls so 73.7% and 45% of patients had normal level of thyroxin, respectively. Also, those with LADA had considerably lower levels of both thyroid peroxydaseantibody (TPO-Ab) and C-peptide when compared with non-LADA group. Using multivariate analyses and with the presence of baseline variables including gender, age, and duration of disease, the diagnosis of LADA was associated with lower serum levels of Anti-TPO, C-peptide, and thyroxin, but not associated with the level of Anti-TTG in serum.

CONCLUSION

LADA patients may face with lower serum levels of C-peptide and thyroid-specific antibodies indicating insulin therapy requirement and authoimmune fundaments of the disease, respectively.

Comparison of transcriptomic responses to pancreas disease (PD) and heart and skeletal muscle inflammation (HSMI) in heart of Atlantic salmon (Salmo salar L)

Pancreas disease (PD) and heart and skeletal muscle inflammation (HSMI) are viral diseases associated with SAV (salmonid alphavirus) and PRV (piscine reovirus), which induce systemic infections and pathologies in cardiac and skeletal muscle tissue of farmed Atlantic salmon (Salmo salar L), resulting in severe morbidity and mortality. While general features of the clinical symptoms and pathogenesis of salmonid viral diseases are relatively well studied, much less is known about molecular mechanisms associated with immunity and disease-specific changes. In this study, transcriptomic analyses of heart tissue from PD and HSMI challenged Atlantic salmon were done, focusing on the mature phases of both diseases at respectively 28-35 and 42-77 days post infection. A large number of immune genes was activated in both trials with prevalence of genes associated with early innate antiviral responses, their expression levels being slightly higher in PD challenged fish. Activation of the IFN axis was in parallel with inflammatory changes that involved diverse humoral and cellular factors. Adaptive immune response genes were more pronounced in fish with HSMI, as suggested by increased expression of a large number of genes associated with differentiation and maturation of B lymphocytes and cytotoxic T cells. A similar down-regulation of non-immune genes such as myofiber and mitochondrial proteins between diseases was most likely reflecting myocardial pathology. A suite of genes important for cardiac function including B-type natriuretic peptide and four neuropeptides displayed differential expression between PD and HSMI. Comparison of results revealed common and distinct features and added to the understanding of both diseases at their mature phases with typical clinical pictures. A number of genes that showed disease-specific changes can be of interest for diagnostics.

IgG4-unrelated type 1 autoimmune pancreatitis

A 50-year-old male was referred to our hospital for the evaluation of hyperproteinemia. Fluorodeoxyglucose positron emission tomography revealed high fluorodeoxyglucose uptake in the pancreas, bilateral lacrimal glands, submandibular glands, parotid glands, bilateral pulmonary hilar lymph nodes, and kidneys. Laboratory data showed an elevation of hepatobiliary enzymes, renal dysfunction, and remarkably high immunoglobulin (Ig) G levels, without elevated serum IgG4. Abdominal computed tomography revealed swelling of the pancreatic head and bilateral kidneys. Endoscopic retrograde cholangiopancreatography showed an irregular narrowing of the main pancreatic duct in the pancreatic head and stricture of the lower common bile duct. Histological examination by endoscopic ultrasonography-guided fine-needle aspiration revealed findings of lymphoplasmacytic sclerosing pancreatitis without IgG4-positive plasma cells. Abnormal laboratory values and the swelling of several organs were improved by the treatment with steroids. The patient was diagnosed as having type 1 autoimmune pancreatitis (AIP) based on the International Consensus Diagnostic Criteria. Therefore, we encountered a case of compatible type 1 AIP without elevated levels of serum IgG4 or IgG4-positive plasma cells. This case suggests that AIP phenotypes are not always associated with IgG4.

Isolated intrapancreatic IgG4-related sclerosing cholangitis

Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) is frequently associated with type 1 autoimmune pancreatitis (AIP). Association with AIP can be utilized in the diagnosis of IgG4-SC. However, some cases of IgG4-SC are isolated from AIP, which complicates the diagnosis. Most of the reported cases of isolated IgG4-SC displayed hilar biliary strictures, whereas isolated IgG4-SC with intrapancreatic biliary stricture is very rare. Recently, we have encountered 5 isolated intrapancreatic IgG4-SC cases that were not associated with AIP, three of which were pathologically investigated after surgical operation. They all were males with a mean age of 74.2 years. The pancreas was not enlarged in any of these cases. No irregular narrowing of the main pancreatic duct was found. Bile duct wall thickening in lesions without luminal stenosis was detected by abdominal computed tomography in all five cases, by endoscopic ultrasonography in two out of four cases and by intraductal ultrasonography in all three cases. In three cases, serum IgG4 levels were within the normal limits. The mean serum IgG4 level measured before surgery was 202.1 mg/dL (4 cases). Isolated intrapancreatic IgG4-SC is difficult to diagnose, especially if the IgG4 level remains normal. Thus, this type of IgG4-SC should be suspected in addition to cholangiocarcinoma and pancreatic cancer if stenosis of intrapancreatic bile duct is present.

Pancreatic mass as an initial manifestation of polyarteritis nodosa: A case report and review of the literature

Classic polyarteritis nodosa (PAN) that targets medium-sized muscular arteries and microscopic polyangiitis (MPA), characterized by inflammation of small-caliber vessels and the presence of circulating myeloperoxidase anti-neutrophil cytoplasmic antibodies (MPO-ANCA), are distinct clinicopathological entities of systemic vasculitis. A 66-year-old woman presented with fever, cholestasis and positive MPO-ANCA. Radiological examination showed a pancreatic mass compressing the bile duct. Therefore, we performed pancreatoduodenectomy. Histopathological examination revealed that necrotizing vasculitis predominantly affecting the medium-sized vessels, spared arterioles or capillaries in the pancreas, a finding consistent with PAN. Unexpectedly, renal biopsy revealed small-caliber vasculitis and glomerulonephritis, supporting MPA. The initial manifestation of a pancreatic mass associated with vasculitis has only been reported in 7 articles. Its diagnosis is challenging because no reliable clinico-radiological findings have been observed. Clinicians should be aware of such cases and early diagnosis followed by immunosuppression is mandatory. Our findings may reflect a polyangiitis overlap syndrome coexisting between pancreatic PAN and renal MPA.

Autoimmune pancreatitis in the context of IgG4-related disease: Review of imaging findings

Current understanding of autoimmune pancreatitis (AIP) recognizes a histopathological subtype of the disease to fall within the spectrum of IgG4-related disease. Along with clinical, laboratory, and histopathological data, imaging plays an important role in the diagnosis and management of AIP, and more broadly, within the spectrum of IgG4-related disease. In addition to the defined role of imaging in consensus diagnostic protocols, an array of imaging modalities can provide complementary data to address specific clinical concerns. These include contrast-enhanced computed tomography (CT) and magnetic resonance (MR) imaging for pancreatic parenchymal lesion localization and characterization, endoscopic retrograde and magnetic resonance cholangiopancreatography (ERCP and MRCP) to assess for duct involvement, and more recently, positron emission tomography (PET) imaging to assess for extra-pancreatic sites of involvement. While the imaging appearance of AIP varies widely, certain imaging features are more likely to represent AIP than alternate diagnoses, such as pancreatic cancer. While nonspecific, imaging findings which favor a diagnosis of AIP rather than pancreatic cancer include: delayed enhancement of affected pancreas, mild dilatation of the main pancreatic duct over a long segment, the “capsule” and “penetrating duct” signs, and responsiveness to corticosteroid therapy. Systemic, extra-pancreatic sites of involvement are also often seen in AIP and IgG4-related disease, and typically respond to corticosteroid therapy. Imaging by CT, MR, and PET also play a role in the diagnosis and monitoring after treatment of involved sites.

Immune parameters correlating with reduced susceptibility to pancreas disease in experimentally challenged Atlantic salmon (Salmo salar)

Two strains of Atlantic salmon (Salmon salar) with different susceptibility to infectious salmon anaemia (ISA) were challenged with salmon pancreas disease virus (SPDV), the etiological agent of salmon pancreas disease (PD), by cohabitation. Serum and tissues were sampled at 0, 1, 3, 6 and 8 weeks post-challenge. Experimental challenge with SAV did not cause mortality, but virus loads and assessment of histopathology indicated that the fish more resistant to ISAV (ISAHi) also was more resistant to PD. Eight weeks post-challenge, the ISAHi strain had higher titres of SAV-neutralising antibodies than the less resistant strain (ISALo). Transcript levels of four adaptive and six innate immune parameters were analysed by real-time RT-PCR in heart, head kidney (HK) and gills of both strains. Secretory IgM (sIgM) and CD8 levels differed most between the two salmon strains. The ISAHi strain had significantly higher levels of sIgM in HK at all samplings, and significantly higher CD8 levels in gills at most samplings. In heart, both sIgM and CD8 levels increased significantly during the challenge, but the increase appeared earlier for the ISALo strain. By hierarchical clustering analysis of mRNA levels, a clear segregation was observed between the two strains prior to the virus challenge. As the viral infection developed, the clustering divide between fish strains disappeared, first for innate and later for adaptive parameters. At eight weeks post-challenge, the divide had however reformed for adaptive parameters. Possible pair-wise correlation between transcript levels of immune parameters was evaluated by a non-parametric statistical test. For innate parameters, the extent of correlation peaked at 3 wpc in all tissues; this came rapidly for ISALo and more gradual for ISAHi. The ISAHi strain tended to show higher correlation for innate parameters in heart and gill than ISALo at early sampling times. For adaptive immune parameters, little correlation was observed in general, except for ISAHi in heart at 6 wpc. Overall, the observed differences in immune parameters may provide important clues to the causes underlying the observed difference in susceptibility to PD.

Stress-induced reversion to virulence of infectious pancreatic necrosis virus in naïve fry of Atlantic salmon (Salmo salar L.)

We have studied stress-induced reversion to virulence of infectious pancreatic necrosis virus (IPNV) in persistently infected Atlantic salmon (Salmo salar L.) fry. Naïve fry were persistently infected with a virulent strain (T₂₁₇A₂₂₁ of major structural virus protein 2, VP2) or a low virulent (T₂₁₇T₂₂₁) variant of IPNV. The fry were infected prior to immunocompetence as documented by lack of recombination activating gene-1, T-cell receptor and B-cell receptor mRNA expression at time of challenge. The fish were followed over 6 months and monitored monthly for presence of virus and viral genome mutations. No mutation was identified in the TA or TT group over the 6 months period post infection. Six months post infection TA and TT infected groups were subject to daily stress for 7 days and then sampled weekly for an additional period of 28 days post stress. Stress-responses were documented by down-regulation of mRNA expression of IFN-α1 and concomitant increase of replication levels of T₂₁₇T₂₂₁ infected fish at day 1 post stress. By 28 days post stress a T221A reversion was found in 3 of 6 fish in the T₂₁₇T₂₂₁ infected group. Sequencing of reverted isolates showed single nucleotide peaks on chromatograms for residue 221 for all three isolates and no mix of TA and TT strains. Replication fitness of reverted (TA) and non-reverted (TT) variants was studied in vitro under an antiviral state induced by recombinant IFN-α1. The T₂₁₇A₂₂₁ reverted variant replicated to levels 23-fold higher than the T₂₁₇T₂₂₁ strain in IFN-α1 treated cells. Finally, reverted TA strains were virulent when tested in an in vivo trial in susceptible salmon fry. In conclusion, these results indicate that stress plays a key role in viral replication in vivo and can facilitate conditions that will allow reversion from attenuated virus variants of IPNV.

No signs of progressive beta cell damage during 20 years of prospective follow-up of autoantibody-negative diabetes

Both type 1 and type 2 diabetes are considered to be associated with different degrees of progressive beta cell damage. However, few long-term studies have been made. Our aim was to study the clinical course of 20 years of diabetes disease, including diabetes progression, comorbidity, and mortality in a prospectively studied cohort of consecutively diagnosed diabetic patients. Among all 233 patients diagnosed with diabetes during 1985-1987 in Malmö, Sweden, 50 of 118 surviving patients were followed-up after 20 years. The age at diagnose was 42.3 ± 23.1 and 57.5 ± 13.6 years for antibody-positive and antibody-negative patients, respectively. HbA1c and plasma lipids were analyzed with regard to metabolic control. Islet antibody-negative patients at diagnosis had highly preserved C-peptide levels after 20 years in contrast to antibody-positive patients (antibody negative: C-peptide 0 years 0.78 ± 0.47 and 20 years 0.70 ± 0.46 (nmol/l), P = 0.51 and antibody positive: C-peptide 0 years 0.33 ± 0.35 and 20 years 0.10 ± 0.18; P < 0.001. Islet antibodies but not age, BMI, or C-peptide at diagnosis were predictors of C-peptide levels at 20 years when analyzed by logistic regression (P < 0.05). HbA1c did not differ between the groups after 20 years. The 20-year mortality was higher among antibody-negative patients, dependent on the higher age at diagnosis in this group (number of deaths: antibody positive: 18 of 56 vs. antibody negative: 109 of 188, P < 0.001). Of the deceased, 79% had died from diseases or complications that may be associated with diabetes. We found no progressive beta cell damage in autoantibody-negative diabetes at a 20-year follow-up of the clinical course of diabetes.

Formulations combining CpG containing oliogonucleotides and poly I:C enhance the magnitude of immune responses and protection against pancreas disease in Atlantic salmon

Both CpG oligodeoxynucleotides and double-stranded RNA (poly I:C) have documented effects as treatments against several viral diseases in fish. However, as stand-alone treatments their effects have been modest. We have tested here whether CpG and poly I:C, alone or in combination induce protection against Salmonid Alphavirus (SAV), the causative agent of pancreas disease in Atlantic salmon. Our results revealed a significant reduction of viraemia 2 weeks after ip injection of the combined treatment and 1 week after challenge with SAV subtype 3, followed by reduced SAV induced heart pathology 3 weeks later. The SAV titers in blood samples from the combination group were lower as compared to single treatments with either CpG or poly I:C. Surprisingly, reduced SAV levels could also be found in fish as long as 7 weeks after receiving the combination treatment. The expression of IFNγ and to a lesser extent IFNa and Mx was up-regulated in head kidney and spleen 5 days after the fish had been treated with CpG and poly I:C. Furthermore, the complement factor C4 was depleted in serum 8 weeks post treatment, suggesting complement activation leading to C4 consumption. We hypothesize that the CpG/poly I:C-induced protection against SAV3 is mediated by mechanisms involving type I and type II IFN induced antiviral activity and complement mediated protective responses.

Lack of evidence for vertical transmission of SAV 3 using gametes of Atlantic salmon, Salmo salar L., exposed by natural and experimental routes

Pancreas disease (PD) is an important cause of losses in farmed salmonids in Norway, the United Kingdom and Ireland. As the spread of salmonid alphavirus (SAV), the causal agent, to naïve populations is of major concern to the farming industry, it is important to uncover the transmission routes of the virus. This study was conducted to investigate the potential for vertical transmission of SAV subtype 3. Progeny of broodstock with signs of late-stage PD and persistent RT-PCR signals for SAV were followed from fertilization to smoltification in an experimental facility. Fertilized ova were either not disinfected or taken through one of three different disinfection regimes. Also, ova and milt from uninfected broodfish from a different population were exposed to a cell-cultured strain of SAV 3 immediately before fertilization to simulate a viraemic phase in parent fish. A group of uninfected controls were also included in the study. Fertilized ova from bath exposed and negative control groups were double disinfected. Following fertilization, experimental fish went through a normal freshwater phase. However, fry were stressed at first feeding to enhance replication of possibly latent virus. Smoltification was induced by an artificial light regime, and experimental fish were followed to the late smoltification phase. Selected samples were investigated by real-time RT-PCR for SAV, by histology for evidence of PD and by serology for neutralising antibodies against SAV. All analysed samples of progeny were negative. This result shows that SAV 3 is not readily transmitted vertically from parents to offspring. Additional negative PCR results from salmon sampled in commercial hatcheries support these findings. Also, recent studies have shown that risk factors for the horizontal transmission route explain the vast majority of PD outbreaks in Norway. It is concluded that if it happens at all, vertical transmission is of minor importance in the spread of SAV 3.

Inflammatory pseudotumors of the pancreas and liver with infiltration of IgG4-positive plasma cells

Recently, it has been reported that autoimmune pancreatitis (AIP) can be complicated with various extrapancreatic lesions. Here, we report a very rare case of pancreatic and hepatic inflammatory pseudotumor (IPT) with the infiltration of IgG4-positive plasmacytes. The patient showed pancreatic and hepatic masses with elevated levels of serum IgG4. Endoscopic retrograde cholangiopancreatography revealed narrowing of the intrapancreatic bile duct. Fluorine-18fluorodeoxyglucose positron emission tomography suggested pancreatic cancer with hepatic metastasis. Histopathologic findings showed fibrosis and infiltration of IgG4-positive plasmacytes, suggesting IPT. The present case suggests a possible common mechanism in the development of AIP and IPT of the liver.

Reovirus delays diabetes onset but does not prevent insulitis in nonobese diabetic mice

Mice infected with reovirus develop abnormalities in glucose homeostasis. Reovirus strain type 3 Abney (T3A) was capable of systemic infection of nonobese diabetic (NOD) mice, an experimental model of autoimmune diabetes. Reovirus antigen was detected in pancreatic islets of T3A-infected mice, and primary cultures of pancreatic islets from NOD mice supported T3A growth. Significantly fewer T3A-infected animals compared to uninfected controls developed diabetes. However, despite the alteration in diabetes penetrance, insulitis was evident in T3A-infected mice. These results suggest that viral infection of NOD mice alters autoimmune responses to beta-cell antigens and thereby delays development of diabetes.

Serum IgG4 concentrations in pancreatic and biliary diseases

BACKGROUND

Recently, it has been reported that the serum concentration of IgG4, a minor component of IgG subclasses, is increased in autoimmune pancreatitis. However, data regarding IgG4 concentrations in other pancreatic or biliary diseases have been insufficient.

METHODS

Serum IgG4 was measured in 116 patients with pancreatic or biliary diseases (35 autoimmune pancreatitis, 24 chronic pancreatitis except autoimmune pancreatitis, 11 primary sclerosing cholangitis, 23 pancreatic cancer, 3 islet cell tumor, 2 papilla cancer, 15 bile duct cancer, and 3 gallbladder cancer patients). The cut-off concentration of IgG4 was 135 mg/dl.

RESULTS

Increased serum IgG4 was observed in 33 of 35 patients with autoimmune pancreatitis, 0 of 24 with chronic pancreatitis, 4 of 11 with primary sclerosing cholangitis, 0 of 23 with pancreatic cancer, 0 of 3 with islet cell tumor, 0 of 2 with duodenal papilla cancer, 0 of 15 with bile duct cancer and 0 of 3 with gallbladder cancer patients.

CONCLUSIONS

Serum IgG4 was increased in autoimmune pancreatitis and was within normal limits for other pancreatic or biliary diseases except primary sclerosing cholangitis.

Transforming growth factor-beta pathway: role in pancreas development and pancreatic disease

The pancreas is a complex exocrine and endocrine gland that controls many homeostatic functions. The exocrine pancreas produces and secretes digestive enzymes, whereas, the endocrine pancreas produces four distinct hormones, chief among them being the glucose regulating hormone-insulin. Diabetes, pancreatitis and pancreatic cancer are some of the main afflictions that result from pancreas dysfunction. Transforming growth factor-beta (TGF-beta) proteins are central regulators of pancreas cell function, and have key roles in pancreas development and pancreatic disease. Since expression levels and kinase activities of components of TGF-beta signaling are aberrantly altered in diseases of the pancreas, modulating the activity of TGF-beta provides a unique and rational opportunity for therapeutic intervention. Although TGF-beta still remains elusive in terms of our understanding of its multifunctional modes of action, research is moving closer to the design of approaches directed toward modulating its activities for therapeutic benefit.

Immunokinetics of autoreactive CD4 T cells in blood: a reporter for the “hit-and-run” autoimmune attack on pancreas and diabetes progression

Little is known about the fate of autoreactive CD4 T cells in blood. Using a mouse model for spontaneous autoimmune diabetes we demonstrated that the status of the autoimmune process in pancreas could be pictured through the frequency and phenotype of autoreactive CD4 T cells in the blood. Early during the prediabetic stage, the frequency of these cells in blood decreased as a consequence of their recruitment in the pancreas. This was followed by an imbalance between CD4(+)CD25(+) and CD4(+)CD69(+) T cells in the pancreas that was mirrored in the phenotype of autoreactive T cells in the blood. Waves of activated CD4(+)CD69(+) T cells in blood preceded the disease onset suggesting that the autoimmune attack on pancreas is a discontinuous "hit-and-run" rather than a continuous process. Tracking autoreactive CD4 T cells in blood may help in identifying prediabetic humans and monitoring the disease progression during therapeutic interventions.

Oligoclonal T-cell populations in an inflammatory pseudotumor of the pancreas possibly related to autoimmune pancreatitis: an immunohistochemical and molecular analysis

Inflammatory pseudotumors (IPT), also known as inflammatory myofibroblastic tumors (IMT), are benign inflammatory processes that may have an infectious etiology and are very rare in the pancreatico-biliary region. Recent studies suggest a biological distinction between IPT and IMT, the latter being a true neoplastic process. We describe a case of pancreatic IPT, originally diagnosed as malignancy, which presumably recurred 4 months after the operation. Histologically, the tumor consisted of a smooth muscle actin and CD68-positive spindle cell population and a more abundant mononuclear inflammatory cell population, primarily composed of macrophages and T-lymphocytes. Inflammatory cells were the source of connective tissue growth factor and transforming growth factor-beta1 and tended to accumulate around nerves and blood vessels, as well as around residual pancreatic parenchymal elements, where an intense angiogenetic response was detected. Comparative genomic hybridization analysis of the tumor showed no chromosomal imbalances. Polymerase chain reaction-based analysis of T-cell receptor gamma gene rearrangement revealed an oligoclonal pattern. These findings suggest that the pathogenesis of aggressive cases of IPT could be related to the development of an intense and self-maintaining immune response, with the emergence of clonal populations of T-lymphocytes. The relation of the pancreatic IPT to autoimmune pancreatitis is emphasized.

[Effect of early enteral feeding on immune status in the immediate postoperative period]

The effect of the balanced feeding formulas "Peptamen" and "Nutren" ("Nestle Swisse", Switzerland) on the immune status was studied in 30 patients immediately after pancreas surgery. 15 patients with full-fledged parenteral alimentation were controls. The catabolic trend of metabolic processes was detected in the early postoperative period. The use of "Peptamen" and "Nutren" inverts metabolism towards anabolism. Profound immunologic disorders were observed both in the cellular and humoral chains immediately after surgery. The early enteral feeding normalized, first, the immunity humoral chain (from the 1st postoperative day) and, then, the immunity cellular chain (by the 6th postoperative day).

Tuberculosis of pancreas and peripancreatic lymph nodes in immunocompetent patients: experience from China

AIM: To determine the clinical, radiographic and laboratory characteristics, diagnostic methods, and therapeutic variables in immunocompetent patients with tuberculosis (TB) of the pancreas and peripancreatic lymph nodes.

METHODS: The records of 16 patients (6 male, 10 female; mean age 37 years, range 18-56years) with tuberculosis of the pancreas and peripancreatic lymph nodes from 1983 to 2001 in the Southwest Hospital were analyzed retrospectively. In addition, 58 similar cases published in Chinese literature were reviewed and summarized. We reviewed the clinical, radiographic and laboratory findings, diagnostic methods, therapeutic approaches, and outcome in the patients. Criteria for the diagnosis of pancreatic tuberculosis were the presence of granuloma in histological sections or the presence of Mycobacterium tuberculosis DNA by polymerase chain reaction (PCR).

RESULTS: Predominant symptoms consisted of abdominal nodule and pain (75%), anorexia/weight loss (69%), malaise/weakness (64%), fever and night sweats (50%), back pain (38%) and jaundice (31%). Swelling of the head of the pancreas with heterogeneous attenuation echo was detected with ultrasound in 75% (12/16). CT scan showed pancreatic mass with heterogeneous hypodensity focus in all patients, with calcification in 56% (9/16) patients, and peripancreatic nodules in 38% (6/16) patients. Anemia and lymphocytopenia were seen in 50% (8/16) patients, and pancytopenia occurred in 13% (2/16) patients. Hypertransaminasemia, elevated alkaline phosphatase (AP) and GGT were seen in 56% (9/16) patients. The erythrocyte sedimentation rate (ESR) was elevated in 69% (11/16) cases. Granulomas were found in 75% (12/16) cases, and in 38% (6/16) cases caseous necrosis tissue was found. Laparotomy was performed in 75% (12/16) cases, and ultrasound-guided fine needle aspiration (FNA) was done in 63% (10 of 16). The most commonly used combinations of medications were isoniazid/rifampin/streptomycin (63%, n = 10) and isoniazid/rifampin pyrazinamide/streptomycin or ethambutol (38%, n = 6). The duration of treatment lasted for half or one year and treatment was successful in all cases. The characteristics of 58 cases from Chinese literature were also summarized.

CONCLUSION: Tuberculosis of the pancreas and peripancreatic lymph nodes should be considered as a diagnostic possibility in patients presenting with a pancreatic mass, and diagnosis without laparotomy is possible if only doctors are aware of its clinical features and investigate it with appropriate modalities. Pancreatic tuberculosis can be effectively cured by antituberculous drugs.

Rheumatologic manifestations of hepatic diseases

A possible link is suggested between hepatic diseases and rheumatic disease. Polyarthralgia and polyarthritis may be seen during the prodromal period of acute viral hepatitis, especially in hepatitis B virus (HBV). The symptoms of arthritis, mild, localized or generalized, mostly involve the small joints of hands. Joint symptoms frequently precede the onset of jaundice, no residual joint deformities. Circulating immune complexes are believed to play a causative role in the development of vasculitis and arthritis. Hemochromatosis is an antosomal recessive disorder of iron. About 43%-81% of patients with hemochromatosis have arthritis. The common extrahepatic manifestations of autoimmune hepatitis are arthralgia and skin rash. The reported prevalence of symptomatic inflammatory arthropathy in patients with primary biliary cirrhosis ranges from 4% to 50%. Skeletal involvement with Wilson's disease is common. Such patients may complain of pain and stiffness, mainly in the knee, wrist, or other large joints. Shwachman's syndrome is a disorder of pancreatic exocrine. Symmetric bone lesions have been reported in 10% to 15% of patients. They are involved predominantly at the femoral neck. Rheumatic symptoms are seen in one third of adult patients with cystic fibrosis and arthritis in 2.5% to 12% of patients. The arthritis caused by pancreatic panniculitis is usually symmetrical and involves the small joints of the hand, wrist, and feet, but may involve such larger joints as the elbow, ankle, and knee.

Functional IL-18 Is produced by primary pancreatic mouse islets and NIT-1 beta cells and participates in the progression towards destructive insulitis

BACKGROUND

Preclinical stages of type 1 diabetes are characterized by infiltrating T cells and by the peri- and intra-islet accumulation of pro-inflammatory mediators, such as IFNgamma.

METHODS/RESULTS

Using quantitative PCR we demonstrated that mRNA specific for the IFNgamma-inducing cytokine IL-18 is upregulated in NIT-1 beta cells and intact mouse islets upon exposure to IL-1beta, IFNgamma and TNFalpha. The biological activity of IL-18 was blocked using caspase inhibitors and anti-IL-18 antibodies. Increased IL-18 expression was also detected in islets during advanced stages of insulitis and correlated with elevated transcripts for IFNgamma and for the IL-18 receptor.

CONCLUSION

Thus, beta cells produce bioactive IL-18 in the course of insulitis and actively contribute to the exacerbation of inflammation leading to their own demise.

Antibodies to soluble liver antigen/liver pancreas and HLA risk factors for type 1 autoimmune hepatitis

OBJECTIVE

Antibodies to soluble liver antigen/liver-pancreas are highly specific markers of type 1 autoimmune hepatitis that have been associated with relapse. Our aim was to determine if these antibodies are reflective of a genetic predisposition for recrudescent disease.

METHODS

One hundred forty-four white North American patients were evaluated by an enzyme immunoassay and by Western blot using recombinant soluble liver antigen/liver-pancreas; 122 were assessed for class II human leukocyte antigens (HLAs).

RESULTS

Twenty-two patients (15%) had antibodies to soluble liver antigen/liver-pancreas. These patients were indistinguishable from seronegative patients by clinical, laboratory, and histological features at presentation. Patients with antibodies to soluble liver antigen/liver pancreas had HLA DR3 (79% vs 50%, p = 0.02) more commonly and HLA DR4 less often (16% vs 47%, p = 0.02) than patients with smooth muscle antibodies and/or antinuclear antibodies. Seropositivity was associated with DRB1*0301 and seronegativity was associated with DRB1*0401. Relapse after drug withdrawal occurred in all patients with antibodies to soluble liver antigen/liver-pancreas and at a higher frequency than in patients with conventional antibodies (100% vs 78%, p = 0.05).

CONCLUSIONS

Antibodies to soluble liver antigen/liver pancreas are associated with HLA DR3 and the susceptibility allele, DRB1*0301. Antibodies to soluble liver antigen/liver-pancreas may be surrogate markers of a genetic propensity for recrudescent disease or the target autoantigen. They may be complementary to antinuclear antibodies and smooth muscle antibodies in diagnosis and management.

Pathogenesis and immune response in Atlantic salmon (Salmo salar L.) parr experimentally infected with salmon pancreas disease virus (SPDV)

Atlantic salmon parr were injected intraperitoneally with salmon pancreas disease virus (SPDV) grown on CHSE-214 cells. The viraemia, the histopathological changes in target organs and some immune parameters were taken at intervals up to 30 days post-infection (dpi). The earliest kind of lesion was necrosis of exocrine pancreas, appearing as soon as 2 dpi. It progressed towards complete tissue breakdown at 9 dpi before resolving gradually. Concurrent to this necrosis, a strong inflammatory response was in evidence from 9 dpi in the pancreatic area for a majority of fish. A necrosis of the myocardial cells of the ventricle occurred in infected fish mainly at 16 dpi and it faded thereafter. The monitoring of the plasma viral load showed a rapid haematogenous spreading of SPDV, peaking at 4 dpi, but also the absence of a secondary viraemia. No interferon (IFN) was detected following the infection of parr with SPDV, probably owing to an IFN activity in Atlantic salmon below the detection level of the technique. Neutralising antibodies against SPDV were in evidence from 16 dpi and they showed a time-related increasing titre and prevalence. The phagocytic activity in head-kidney leucocytes was always significantly higher in the infected fish than in the control fish, being particularly high by 9 dpi. Lysozyme and complement levels were both increased and they peaked significantly in the infected fish at 9 and 16 dpi respectively. These results demonstrated that an experimental infection of Atlantic salmon parr with SPDV provoked a stimulation of both specific and non-specific immunity with regards to the viraemia and the histopathology.

Production and characterisation of monoclonal antibodies to salmon pancreas disease virus

Six mouse monoclonal antibodies (mAbs) specific to salmon pancreas disease virus (SPDV) were produced following immunisation with purified virus preparations. These mAbs and 2 mAbs resulting from an earlier investigation were characterised. None of the mAbs possessed virus neutralising activity but all reacted with 4 geographically different SPDV isolates as determined by indirect immunofluorescence. Three mAbs produced positive immunostaining with Western blots of SPDV proteins. The 4H1 mAb reacted with the 53 kDa structural E1 glycoprotein present in virus-infected cells and in gradient-purified virus. Two mAbs, 5A5 and 7B2, which exhibited unusual immunofluorescence staining of the nuclear margin, reacted with a 35 kDa protein, which is present in gradient-purified virus and which is considered to be the capsid protein. A sandwich ELISA, based on the use of mAb 2D9 for capture and a biotinylated conjugate of mAb 7A2 for detection, detected SPDV antigen in virus-infected Chinook salmon embryo-214 cells and gradient-purified virus. These mAbs may be of use in pathogenesis studies and in diagnostic test development.

Immune function in patients with Shwachman-Diamond syndrome

Shwachman-Diamond syndrome (SDS) is an inherited multisystem disorder characterized by exocrine pancreatic dysfunction and varying degrees of cytopenia. In addition, various immunological abnormalities have been noted. To clarify the issue of immunological competence or incompetence in SDS, we prospectively studied immune function in 11 patients with SDS. Seven suffered from recurrent bacterial infections and six from recurrent viral infections. Varying degrees of impairment were readily identified. All patients had neutropenia; total lymphocyte counts, however, were normal in all except one patient. Nine patients had B-cell defects comprising one or more of the following abnormalities: low IgG or IgG subclasses, low percentage of circulating B lymphocytes, decreased in vitro B-lymphocyte proliferation and a lack of specific antibody production. Seven out of nine patients studied had at least one T-cell abnormality comprising a low percentage of total circulating T lymphocytes or CD3+/CD4+ cell subpopulations or decreased in vitro T-lymphocyte proliferation. Five out of six patients studied had decreased percentages of circulating natural killer cells. Moreover, neutrophil chemotaxis was significantly low in all the patients studied. These data point to a major immunodeficiency component in SDS that places patients at heightened risk of infections, even if neutrophil numbers are protective. This finding broadens the definition of the syndrome substantially: it suggests that the SDS marrow defect occurs at the level of an early haematological-lymphocytic stem cell or that a combined marrow and thymic stromal defect accounts for the aberrant function of haematopoietic and lymphopoietic lineages.

Isolation of salmon pancreas disease virus (SPDV) in cell culture and its ability to protect against infection by the 'wild-type' agent

A Scottish salmon pancreas disease virus (SPDV) has been isolated and its optimum growth conditions determined. Although several fish cell lines have been tested, successful culture was achieved only with CHSE-214 cells. Cytopathic effects were observed after 5 days. The highest virus titres, calculated by microtitration assay, were reached at 15 degrees C. After 7-9 days post-inoculation, CHSE-214 cell supernatants contained between 10(7)-10(5) TCID50 ml(-1) The cultured isolate is chloroform- and pH 3.0-sensitive, and virions are 50-60 nm in diameter. These characteristics are similar to the Irish SPDV isolates. The culture isolate induced typical pancreas disease (PD) lesions in experimentally infected Atlantic salmon and convalescent fish were resistant to experimental infection with PD-infective kidney homogenates obtained by serial in vivo passages from a PD-infected farmed salmon (termed wild-type SPDV). Furthermore, fish immunised with the inactivated cultured virus were protected against a cohabitation challenge with the wild-type virus. Immunised fish sera showed virus-neutralising activity before challenge (7 weeks post-immunisation) and from 3-6 weeks post-challenge, when sera from non-immunised fish did not neutralise the virus. At 6 weeks post-cohabitation challenge, previously immunised fish had neutralising titres of up to 1:65. Following intraperitoneal (i.p.) challenge, immunised fish showed neutralising titres as high as 1:226 at 8 weeks post-challenge. Non-immunised fish injected i.p. with the wild-type virus developed serum-neutralising activity against the cultured isolate when sampled 8 weeks after infection, confirming an antigenic relationship between the wild-type and cultured virus. The results demonstrate that the tissue culture-adapted isolate of SPDV could be successfully used to protect against challenge by the wild-type virus and could therefore have potential use as an inactivated vaccine against PD.

Islet cell autoimmunity in youth onset diabetes mellitus in Northern India

We characterised a consecutive cohort of 132 youth onset diabetic individuals (age at onset<30 years, mean duration of disease 5.5+/-6.0 years) from North India, by serological determination of the determination of the islet cell autoantibodies, GAD(65) and IA2, and clinically for coexisting autoimmune thyroid disease, malnutrition and pancreatic calcification. Five types of diabetes were delineated: Type 1 (37%), ketosis resistant (32%), Type 2 (13%), fibrocalculous pancreatopathy (11%) and autoimmune polyglandular syndrome (7%). C-peptide response to glucagon was assessed in a representative subset of 50 patients with Type 1, ketosis resistant, and autoimmune polyglandular syndrome. A total of 22.4% of Type 1 and 30% of autoimmune polyglandular syndrome subjects showed both GAD(65) plus IA-2 autoantibody positivity, significantly more than the 4.7% positivity shown by the ketosis resistant type. However, GAD(65) antibody positivity alone was seen in 38% of ketosis resistant subjects which was significantly more than the 14.2 and 10% positivity seen in Type 1 and autoimmune polyglandular groups, respectively. The fibrocalculous pancreatopathy group showed GAD(65) plus IA-2 autoantibody positivity in 14.2% and GAD(65) autoantibody alone positivity in 7.1%. 26 and 60%, respectively, of the Type 1 and autoimmune polyglandular syndrome groups had thyroid microsomal autoantibody positivity. Type 1 showed significantly less C-peptide response to glucagon when compared to the ketosis resistant and autoimmune polyglandular syndrome groups. The controls and Type 2 diabetic individuals tested negative for islet cell autoimmunity markers. These findings demonstrate a role of islet cell autoimmunity in the pathogenesis of four out of the five clinical types of youth onset diabetes seen in North India.

Antibodies to diabetes-associated autoantigens in Indian patients with Type 1 diabetes: prevalence of anti-ICA512/IA2 and anti-SOX13

We ascertained frequencies of autoantibodies to a suite of islet cell antigens including ICA512/IA2 and SOX13 in Asian Indians with Type 1 diabetes and in other forms of diabetes. Autoantibodies to ICA512/IA2 and SOX13 were tested by radioimmunoprecipitation assay, and results were amalgamated with previous data on antibodies to glutamic acid decarboxylase (GAD) and to islet cell cytoplasmic antigens (ICA). The frequency of anti-SOX13 was higher in Asian Indians than in Europids. Overall, the combined frequency for all autoantibodies to diabetes-associated antigens in Type 1 diabetes in Indians approached the frequency reported for Europids. There was an unexpectedly high frequency of autoantibody reactions to any one of the autoantigens tested (24%) in fibrocalculous pancreatic diabetes, however, individual autoantibody frequencies were relatively low. Our data indicate that, whatever the population studied, testing for multiple autoantigenic reactivities is more informative than more limited testing, and that there may be regional (presumably ethnically based) differences in levels of particular autoantibodies in cases of Type 1 diabetes.

[An analysis of the immunity indices of patients with indurative diseases of the head of the pancreas]

Based on an analysis of dynamics of immunity indices the authors have revealed differences in the character of their changes in nontumoral and tumoral diseases and in relation to the stage of the malignant process. The optimal minimum of indices of the immunity status in indurative diseases of the pancreas head is proposed which is of significance for differential diagnosis and determination of resectability of the tumor.

Distribution of autoantibodies to glutamic acid decarboxylase across the spectrum of diabetes mellitus seen in South Africa

AIMS

This study investigated the association between glutamic acid decarboxylase antibodies (GAD-AB) and Type 1, Type 2, pancreatic and lipoatrophic diabetes mellitus (DM) in South African patients.

METHODS

Four groups were selected: group A, 100 Black Type 1 DM patients (age at onset < 35 years, body mass index (BMI) < 27 kg/m2 and insulin dependent within 1 year of presentation); group B, 80 Black Type 2 DM patients (age at onset > 35 years, BMI > 27 kg/m2 and controlled on oral hypoglycaemic agents for at least 1 year after presentation); group C, 10 patients of varying ethnicity with DM or impaired glucose tolerance secondary to chronic pancreatitis; group D, five patients of varying ethnicity with DM associated with total lipodystrophy. Fifty healthy Black control subjects were also studied (group E). Serum GAD-AB and random C-peptide levels were measured by radioimmunoassay.

RESULTS

Mean C-peptide concentration was significantly lower in Type 1 DM patients than Type 2 DM patients (P < 0.00001). Forty-four patients with Type 1 DM were GAD-AB-positive compared to two patients with Type 2 DM. Two control subjects were also GAD-AB-positive. No patient in the other groups had a titre > 1 U/ml. Type 1 DM patients who were GAD-AB-positive did not differ from those who were GAD-AB-negative for age at onset, duration of DM or C-peptide concentrations.

CONCLUSIONS

Auto-immune beta-cell destruction has an important role in the pathogenesis of Type 1 DM amongst African patients. However, Type 2 African DM patients and other diabetes subtypes are largely GAD-AB-negative.

Differential protection in two transgenic lines of NOD/Lt mice hyperexpressing the autoantigen GAD65 in pancreatic beta-cells

Although expressed at very low levels in islets of NOD mice, GAD65 is a candidate islet autoantigen. Two transgenic lines of NOD/Lt mice expressing high levels of human GAD65 from a rat insulin promoter were generated. Transgenes were integrated on proximal chromosome 15 of the A line and on the Y chromosome of the Y line. Transgenic A-line mice were obligate hemizygotes, since homozygous expression resulted in developmental lethality. A twofold higher level of hGAD65 transcripts in A-line islets from young donors was associated with higher GAD protein and enzyme activity levels. Y-line males developed diabetes at a similar rate and incidence as standard NOD/Lt males. In contrast, A-line mice of both sexes exhibited a markedly lowered incidence of diabetes. Insulitis, present in both transgenic lines, developed more slowly in A-line mice and correlated with a reduction in the ratio of gamma-interferon to interleukin-10 transcripts. Splenic leukocytes from young A-line donors transferred diabetes into NOD-scid recipients at a retarded rate compared with those from nontransgenic donors. Further, nontransgenic NOD T-cells transferred diabetes more slowly in NOD-scid recipients that were congenic for A-line transgenes as compared with standard NOD-scid recipients. Primed T-cell responses and spontaneous humoral reactivity to GAD65 failed to distinguish transgenic from nontransgenic mice. Quantitative differences in expression level or insertional mutagenesis are possible mechanisms of protection in the A line.

Antibodies to pancreatic islet cell antigens in diabetes seen in Southern India with particular reference to fibrocalculous pancreatic diabetes

Fibrocalculous pancreatic diabetes (FCPD) is a type of diabetes secondary to tropical chronic non-alcoholic pancreatitis. Little is known about the aetiopathogenesis of FCPD. We studied glutamic acid decarboxylase antibodies (GAD-Ab) and islet cell antibodies (ICA) in patients with FCPD and compared the results with Type 1 (insulin dependent) diabetes mellitus, Type 2 (non-insulin-dependent) diabetes mellitus and non-diabetic subjects in Southern India. The prevalence of GAD-Ab was 7.0% (95% Confidence Interval (CI) 1.9-17.2) in FCPD, 47.5% (CI 31.4-64.0) in Type 1 (p < 0.001 compared to FCPD), 5.6% (CI 1.5-13.9) in Type 2 (non-significant (NS) compared to FCPD) and 0% in controls. The prevalence of ICA was 6.3% (CI 1.2-17.4) in FCPD, 53.8% (CI 37.1-70.0) in Type 1 (p < 0.001 compared to FCPD), 9.9% (CI 4.0-19.4) in Type 2 (NS compared to FCPD) and 4.7% (CI 0.4-16.1) in controls. The data suggest that in FCPD, the frequency of auto-antibodies is low and its aetiology is probably not linked to autoimmunity in the majority of the patients.

CD40 ligand-CD40 interactions are necessary for the initiation of insulitis and diabetes in nonobese diabetic mice

The nonobese diabetic (NOD) mouse spontaneously develops T cell-dependent autoimmune diabetes. Here, we investigate the role of CD40 ligand (CD40L)-CD40 costimulation in the initiation and progression of this disease. Anti-CD40L mAb treatment of 3- to 4-wk-old NOD females (the age at which insulitis typically begins) completely prevented the insulitis and diabetes. In contrast, treatment of such mice with anti-CD40L at >9 wk of age did not inhibit the disease process. These results suggest that a costimulatory signal by CD40L is required early but not in the effector phase of disease development. Anti-CD40L treatment affected the priming of islet Ag-specific T cell responses in vivo. Cytokine analysis revealed a dramatic decrease in IFN-gamma and IL-2 release without a concomitant increase in IL-4 production by T cells from anti-CD40L-treated mice. Thus, anti-CD40L impaired the islet Ag-specific Th1 cell response in vivo, and the prevention of diabetes by anti-CD40L was not associated with switching of the response from a Th1 to a Th2 profile. Cotransfer of splenocytes from anti-CD40L-treated mice with splenocytes from diabetic NOD mice into NOD/scid mice did not inhibit the transfer of disease, indicating that anti-CD40L does not prevent the disease by inducing regulatory cells. Since anti-CD40L clearly prevented the insulitis by inhibiting the development and further accumulation of pathogenic Th1 cells to islets of Langerhans, we conclude that CD40L-CD40 costimulation is required for early events in the development of spontaneous autoimmune diabetes.

Direct evidence for the contribution of B cells to the progression of insulitis and the development of diabetes in non-obese diabetic mice

The non-obese diabetic (NOD) mouse is an excellent animal model of autoimmune diabetes associated with insulitis. The progression of insulitis causes the destruction of pancreatic beta cells, resulting in the development of hyperglycemia. Although it has been well documented that T cells are required for the development of insulitis and diabetes in NOD mice, the importance of B cells remains unclear. To clarify the role of B cells in the pathogenesis of NOD mice, we therefore generated B cell-deficient NOD (B-NOD) mice. Surprisingly, none (of 13) of the B-NOD mice developed diabetes by 40 weeks of age, while the control littermates with B cells (B+NOD) suffered from a high proportion (43 of 49) of diabetes. The insulin reactivity of B+NOD mice was significantly impaired, while the B-NOD mice showed a good insulin response, thus suggesting the pancreatic beta cell function to be well preserved in B-NOD mice. Although B-NOD mice did develop insulitis, the extent of insulitis was significantly suppressed. These data thus provide the direct evidence that B cells are essential for the progression of insulitis and the development of diabetes in NOD mice.

Transgenic monocyte chemoattractant protein-1 (MCP-1) in pancreatic islets produces monocyte-rich insulitis without diabetes: abrogation by a second transgene expressing systemic MCP-1

Monocyte chemoattractant protein-1 (MCP-1) is a CC chemokine that attracts monocytes and T lymphocytes in vitro; however, its in vivo functions are poorly understood. To address this question, we constructed transgenic mice expressing MCP-1 controlled by an insulin promoter. These mice developed a chronic insulitic infiltrate composed of F4/80+ monocytes with minor populations of CD4+, CD8+, and B220+ cells. Despite persistent transgene expression, the insulitis never progressed, and blood glucose levels remained normal. Thus, MCP-1 alone is sufficient to elicit a monocytic infiltrate, but not to activate elicited cells. These results differ from those obtained with another transgenic model using the mouse mammary tumor virus long terminal repeat, in which mice expressed substantial MCP-1 in several organs but had no infiltrates. However, mice expressing both transgenes had minimal insulitis, indicating that high systemic levels of MCP-1 prevented monocytes from responding to local MCP-1. Thus, the ability of MCP-1 to elicit monocytic infiltration depends on its being expressed at low levels in an anatomically restricted area.

Immunization with viral antigens: infectious pancreatic necrosis

Clinical IPN has traditionally been observed in brook trout (Salvelinus fontinalis) and rainbow trout (Oncorhynchus mykiss). However, during the past 10 years outbreaks of IPN have been reported frequently in farmed Atlantic salmon (Salmo salar L.) in Norway. Acute IPN with high mortality is observed in fry at start feeding and in smolt in the first six months after transfer to seawater. Today IPN is the most important infectious disease in Norway in farmed fish, giving economic losses of about 60 million USD yearly. A prophylactic strategy against this disease is strongly needed. Different strategies for developing IPN vaccines have been tested since the virus was first isolated in 1960. Vaccination with live virus has not been successful and is probably not an acceptable strategy for environmental risk reasons. Vaccination with inactivated virus has been tested in rainbow trout given by the oral route, by immersion and injection. Protection against challenge was obtained only by injection. IPN vaccines based on inactivated virus may be effective but are expensive. A subunit vaccine produced by fermentation is a more realistic strategy for fish vaccine production if the actual protective epitopes can be identified. Protective IPNV epitopes may include both B- and T-cell epitopes, but only B-cell epitopes have been examined so far. Epitope mapping with neutralising monoclonal antibodies indicates that the internal variable region of VP2 (aa 200-350) folds into an immunodominant structure including both serotype specific and conserved neutralisation epitopes that can renaturate spontaneously from E. coli-expressed recombinant VP2 (rVP2). Analysis with an IPNV group-A specific neutralising monoclonal antibody indicates that immunisation with recombinant protein containing the segment (aa 86-210) might induce protection against all IPNV serotypes. Subunit vaccines based on E. coli-expressed IPNV proteins have been tested in rainbow trout and Atlantic salmon. Vaccination by immersion in rainbow trout fry with bacterial lysate from E. coli expressing the IPNV Sp strain gene segment A induced protection against challenge with the IPNV Buhl strain. By injection of Atlantic salmon parr with partly purified E. coli-expressed rVP2 (N1 strain), increased resistance against IPN infection was demonstrated by challenge. In field trials it is shown that vaccination of pre-smolt with rVP2 included in a commercial oil/glucan adjuvanted multivalent bacterial vaccine gives protection against IPN in natural outbreaks, compared to fish vaccinated with the same vaccine without the IPNV component.