[Pheochromocytoma can be an insidious disease]. / Feokromosytooma voi olla salakavala tauti.

Pheochromocytoma is a tumor of the chromaffin tissue, originating from the suprarenal medulla and secreting cathecolamines, adrenalin and noradrenalin. Because the symptoms of this rare disease may deceptively resemble those of other diseases, its diagnosis may be delayed. Episodic symptoms are characteristic of pheochromocytoma. In most cases the tumor is curable with surgery, but untreated may lead to sudden death of the patient, or have time to spread. Alpha-blockade is started before the operation. The operations should be concentrated to units specialized in endocrine surgery.

Dietary intervention in infancy and later signs of beta-cell autoimmunity.

BACKGROUND: Early exposure to complex dietary proteins may increase the risk of beta-cell autoimmunity and type 1 diabetes in children with genetic susceptibility. We tested the hypothesis that supplementing breast milk with highly hydrolyzed milk formula would decrease the cumulative incidence of diabetes-associated autoantibodies in such children. METHODS: In this double-blind, randomized trial, we assigned 230 infants with HLA-conferred susceptibility to type 1 diabetes and at least one family member with type 1 diabetes to receive either a casein hydrolysate formula or a conventional, cow's-milk-based formula (control) whenever breast milk was not available during the first 6 to 8 months of life. Autoantibodies to insulin, glutamic acid decarboxylase (GAD), the insulinoma-associated 2 molecule (IA-2), and zinc transporter 8 were analyzed with the use of radiobinding assays, and islet-cell antibodies were analyzed with the use of immunofluorescence, during a median observation period of 10 years (mean, 7.5). The children were monitored for incident type 1 diabetes until they were 10 years of age. RESULTS: The unadjusted hazard ratio for positivity for one or more autoantibodies in the casein hydrolysate group, as compared with the control group, was 0.54 (95% confidence interval [CI], 0.29 to 0.95), and the hazard ratio adjusted for an observed difference in the duration of exposure to the study formula was 0.51 (95% CI, 0.28 to 0.91). The unadjusted hazard ratio for positivity for two or more autoantibodies was 0.52 (95% CI, 0.21 to 1.17), and the adjusted hazard ratio was 0.47 (95% CI, 0.19 to 1.07). The rate of reported adverse events was similar in the two groups. CONCLUSIONS: Dietary intervention during infancy appears to have a long-lasting effect on markers of beta-cell autoimmunity--markers that may reflect an autoimmune process leading to type 1 diabetes. (ClinicalTrials.gov number, NCT00570102.).

Dietary insulin as an immunogen and tolerogen.

We have shown that exposure to bovine insulin (BI) in cow's milk (CM) formula induces an insulin-specific immune response in infants. Here we studied the role of human insulin (HI) in breast milk as a modulator of the immune response to insulin. In a group of 128 children participating in the TRIGR pilot study, maternal breast milk samples were collected 3-7 days and/or 3 months after delivery. After exclusive breast-feeding, the children received either CM formula or casein hydrolysate during the first 6-8 months of life. Insulin concentration in breast milk and immunoglobulin G (IgG) antibodies to BI in plasma samples were measured by EIA. The levels of insulin in breast milk samples were higher in mothers affected by type 1 diabetes than in non-diabetic mothers (p = 0.007 and p < 0.001). The concentration of insulin in breast milk correlated inversely with the plasma levels of IgG antibodies to BI at 6 months of age in children who received CM formula (r = -0.39, p = 0.013), and at 12 months of age in all children (r = -0.25, p = 0.029). The levels of breast milk insulin were higher in the mothers of nine children who developed beta-cell autoimmunity when compared with autoantibody-negative children (p = 0.030); this holds true also when only children of diabetic mothers were included (p = 0.045). BI in CM induces higher levels of IgG to insulin in infants than does HI in breast-fed children. Instead, HI in breast milk seems to be tolerogenic and may downregulate the IgG response to dietary BI. However, our results in infants who developed beta-cell autoimmunity suggest that in this subgroup of children breast milk insulin does not promote tolerance.

Interferon-alpha as a mediator of polyinosinic:polycytidylic acid-induced type 1 diabetes.

A number of studies and clinical case reports have implicated interferon (IFN)-alpha as a potential mediator of type 1 diabetes pathogenesis. Administration of polyinosinic:polycytidylic acid (poly I:C), a mimic of viral double-stranded RNA, induces diabetes in C57BL/6 mice expressing the B7.1 costimulatory molecule in islets. We investigated the potential role of IFN-alpha in this disease model. The quantitative correlation between IFN-alpha levels and time to diabetes, diabetes prevention with anti-IFN-alpha antibody, and ability of IFN-alpha itself to induce diabetes are consistent with the hypothesis that poly I:C in this model acts by induction of IFN-alpha in a genetically susceptible host. Numerous recent studies highlight the importance of the innate immune system and toll receptors in determining adaptive immune responses, and we speculate that for type 1 diabetes, viral and other environmental factors may act through induction of IFNs.

Preventing peptide-induced anaphylaxis: addition of C-terminal amino acids to produce a neutral isoelectric point.

BACKGROUND: Progress in peptide immunotherapy for the treatment of autoimmune diseases has been hampered by reports of anaphylactic reactions in both mice and human subjects. Fatal anaphylaxis in nonobese diabetic (NOD) mice has been described after repeated subcutaneous insulin peptide B:9-23 immunizations. On the basis of observations that rapid systemic delivery of peptide to a sensitized mouse (eg, intravenous delivery) increases the anaphylactic response, it was hypothesized that slowing down the absorption of the peptide would prevent anaphylaxis. OBJECTIVES: We sought to prevent anaphylaxis from B:9-23 peptide by altering the isoelectric point (pI) to neutral, thereby decreasing solubility and rate of absorption after subcutaneous injection. METHODS: B:9-23 peptide was modified by the addition of 2 arginine (RR) amino acids to the C-terminus to create B:9-23RR, thereby increasing the pI from 5.4 to 7.0. Both native and modified B:9-23 peptide were tested for the ability to induce anaphylaxis in a NOD mouse model of self-peptide anaphylaxis. RESULTS: This modification resulted in a peptide vaccine with decreased solubility when administered subcutaneously at a neutral pH. B:9-23RR significantly protected NOD mice from peptide-induced anaphylaxis compared with B:9-23 peptide. Furthermore, B:9-23RR peptide retains its ability to induce insulin autoantibodies and prevent diabetes in NOD mice. CONCLUSION: The modification of the pI of a peptide vaccine might be a generalizable method to prevent anaphylaxis without changing the immunologic properties.

Genetic differentiation of poly I:C from B:9-23 peptide induced experimental autoimmune diabetes.

Type 1 diabetes is an immune-mediated disease, in which T cells of the adaptive immune system mediate beta cell destruction. Recently the innate immune system has been linked to etiopathogenesis of several autoimmune diseases including type 1 diabetes, as innate effector cells (e.g. dendritic cells, monocytes/macrophages and NK cells) can prime and promote or regulate (auto)immune responses. We have previously developed an experimental autoimmune diabetes (EAD) model with insulin peptide B:9-23 immunization in transgenic H-2(d)mice expressing the costimulatory molecule B7.1 in their islets (under the Rat Insulin Promotor, RIP). We compared the induction of diabetes with polyinosinic-polycytidylic acid (Poly I:C), a mimic of double stranded viral RNA versus insulin B:9-23 peptide in mice following backcrossing of the B7.1 transgene on to BALB/c mice from original B7.1 C57Bl/6 mice. We find that diabetes induction by Poly I:C is C57Bl/6 associated, whereas B:9-23 peptide induced diabetes and induction of insulin autoantibodies (IAA) are dependent on BALB/c genes. This B:9-23 peptide induced diabetes is consistent with MHC class II H-2(d)being necessary for the response to this peptide. Of note Poly I:C induction of diabetes was lost while B:9-23 induction was retained with backcrossing to BALB/c mice. Interaction of genes and environment (antigenic epitope and viral mimic) can be important in the pathogenesis of immune mediated diabetes and activation of the innate immune system (e.g. Poly I:C) may be one key determinant.

Differential immune induction with subcutaneous versus oral administration of a diabetogenic insulin peptide in the NOD mouse.

The B chain insulin peptide 9 to 23 (B:9-23) is a dominant T cell epitope of the NOD mouse. Given in oral form with multiple different vehicles, it did not alter expression of insulin autoantibodies in contrast to subcutaneous administration.

Comparative study of oral versus subcutaneous B:9-23 insulin peptide in Balb/c mice as an experimental model for autoimmune diabetes.

Insulin peptide B:9-23 (amino acids 9 to 23 of the B chain) can induce immune targeting of insulin and islets in normal Balb/c mice. The insulin autoantibodies induced react with insulin and not the immunizing peptide. Oral administration of insulin as well as subcutaneous insulin can sensitize to insulin.

Establishing insulin 1 and insulin 2 knockout congenic strains on NOD genetic background.

As insulin is a major autoantigen in autoimmune diabetes and because the insulin gene region locus in humans has been linked to diabetes risk, we have bred insulin gene knockouts onto the NOD mouse. Mice differ from humans in terms that they express two nonallelic genes of insulin. Insulin 2 is the murine homologue of the human insulin gene and is located on mouse chromosome 7. Insulin 1 is thought to have evolved by a gene duplication event, lacks the second intron of the insulin 2 gene, and is located on mouse chromosome 19. The differential thymic expression of the insulin gene may be important for central tolerance induction. Here, we present the initial establishment of congenic knockouts and characterization of the congenic intervals corresponding to insulin 1 and insulin 2 knockout genes on mouse chromosome 19 and 7, respectively.

Nondepleting anti-CD4 monoclonal antibody prevents diabetes and blocks induction of insulin autoantibodies following insulin peptide B:9-23 immunization in the NOD mouse.

INTRODUCTION: Insulin peptide B:9-23 is a major autoantigen in type 1 diabetes that induces insulin autoantibodies and prevents diabetes in the NOD. However, immunization with peptide without adjuvant may be insufficient to reverse disease or induce long-term tolerance. Furthermore, recent experience has demonstrated the potential dangers of disease exacerbation or anaphylaxis with peptide immunotherapy. METHODS: Combination therapy of B:9-23 with a nondepleting anti-CD4 monoclonal antibody (YTS 177.9) was studied in female NOD mice from 4 through 6 weeks of age. Injections of either B:9-23 in saline, YTS 177.9 antibody, or both peptide and antibody were given to mice. RESULTS: By 52 weeks follow-up, 40% of B:9-23-treated, 100% of YTS177.9-treated, and 70% of B:9-23 and YTS177.9 combination-treated mice remained diabetes-free. IAA, both spontaneous and induced by B:9-23, was almost completely suppressed in mice receiving YTS 177.9. In addition to suppression of IAA expression, anti-B:9-23 peptide antibodies are also suppressed in mice receiving B:9-23 with YTS 177.9, compared to B:9-23 alone. CONCLUSION: A brief course of the nondepleting anti-CD4 monoclonal antibody (YTS 177.9) in NOD mice confers long-term protection from diabetes and insulitis and profoundly blocks spontaneous and B:9-23 peptide-induced insulin autoantibodies.

Evidence for a primary islet autoantigen (preproinsulin 1) for insulitis and diabetes in the nonobese diabetic mouse.

It has been reported that an insulin 2 gene knockout, when bred onto nonobese diabetic (NOD) mice, accelerates diabetes. We produced insulin 1 gene knockout congenic NOD mice. In contrast to insulin 2, diabetes and insulitis were markedly reduced in insulin 1 knockout mice, with decreased and delayed diabetes in heterozygous females and no insulitis and diabetes in most homozygous female mice. Lack of insulitis was found for insulin 1 female homozygous knockout mice at 8, 12, and 37 weeks of age. Despite a lack of insulitis, insulin 1 homozygous knockout mice spontaneously expressed insulin autoantibodies. Administration of insulin peptide B:9-23 of both insulin 1 and 2 to NOD mice induced insulin autoantibodies. Insulin 1 is not the only lymphocytic target of NOD mice. Insulin 1 homozygous knockout islets, when transplanted into recently diabetic wild-type NOD mice, became infiltrated with lymphocytes and only transiently reversed diabetes. These observations indicate that loss of either insulin gene can influence progression to diabetes of NOD mice and suggest that the preproinsulin 1 gene is crucial for the spontaneous development of NOD insulitis and diabetes.