HPS Patients Research Articles

Increased colorectal cancer risk in first-degree relatives of patients with hyperplastic polyposis syndrome

IntroductionHyperplastic polyposis syndrome (HPS) is characterised by the presence of multiple colorectal hyperplastic polyps and is associated with an increased colorectal cancer (CRC) risk. For first-degree relatives of HPS patients...

748 ErbB4 Transactivation by TNF Mediates Colon Epithelial Cell Survival by TNF Alpha Converting Enzyme-Dependent Ligand Release

cases occurred among FDRs at a median age of 62 years (interquartile range: 57-78) compared to 5 expected CRC cases (p<0.001). The relative risk of CRC in FDRs compared to the general population was 5.4 (95%-CI: 3.7-7.8). No significant difference was seen between the relative risk for male and female FDRs regarding the CRC incidence. In 4 FDRs from 4 different pedigrees multiple histologically confirmed hyperplastic polyps were reported, satisfying the criteria for HPS. Based on the estimated HPS prevalence of 1:3000 in the general population the projected relative risk of HPS in FDRs would be 39 (95%-CI: 13121). In most FDRs endoscopy was not performed (281/347: 81%) suggesting that the true prevalence of CRC and HPS in FDRs may be underestimated. Conclusions: Our results showed that FDRs of HPS patients have an increased relative risk for both CRC and HPS. Hence, as long as no genetic substrate has been identified, screening colonoscopies for FDRs seem justified but needs to be prospectively evaluated.

Prevention of Hemophagocytosis by TNF-α and IL-6 Blockade in TLR9- and Nod1- Ligand Induced Hemophagocytic Syndrome.

Abstract 1351Poster Board I-373 IntroductionHemophagocytic syndrome (HPS, also referred as hemophagocytic lymphohistiocytosis; HLH) is a life-threatening condition caused by hyperinflammatory response. It can be classified into familial and acquired forms. Familial HPS is a disorder inherited in an autosomal recessive or X-linked manner. Several loci and genes have been implicated in the familial HPS, including perforin, or cytotoxic granule exocytosis genes. While, acquired (secondary) HPS is a sporadic syndrome occurring in association with systemic infection (virus, bacteria, protozoa, and fungi), underlying malignancy, or immunodeficient disorder. The central pathophysiologic abnormality in HPS is cytokine dysfunction, resulting in uncontrolled accumulation of activated T-lymphocytes and activated histiocytes (macrophages) in many organs. Several cytokines including interferon-γ, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-10, IL-12, and soluble IL-2 receptor (sCD25), found at extremely high levels in the plasma of HPS patients. Treatment of hemophagocytic lymphohistiocytosis is based on epipodophyllotoxin derivatives, etoposide, corticosteroids, cyclosporin A, antithymocyte globulin (ATG), and, in selected patients, intrathecal methotrexate. Recently, anti-TNF-α therapy has been reported to prove patients with refractory HPS, however, there is not enough evidence. In this study, we established murine HPS model by intravenous injection of CpG oligodeoxynucleotide (ODN)-1668, a ligand for Toll-like receptor 9 (TLR9) and combination of CpG and iE-DAP, which is a ligand for Nod1, and investigated the role of TNF-α and other cytokine in HPS model. MethodsC57BL/6J mice were injected intravenously with 200 μg of CpG or combination of CpG and 100 μg of iE-DAP. The treated mice were assayed for temperature, spleen weight, and complete blood count. The serum cytokines levels (TNF-α and IL-6) and triglycerides were determined by ELISA and auto-analyzer, resectively. Hemophagocytosis was determined by flow cytometric (FCM) analysis in the peripheral blood and spleen. The spleen was subjected into immunohistochemistry staining and histological examination.For TNF-α and IL-6 blockade, the mice were treated with TNF receptor (TNFR)-Fc (etanercept) or combination of TNFR-Fc and anti-mouse IL-6 receptor (IL-6R) monoclonal antibody (MR16-1) by intravenous injection. ResultsCpG injected mouse displayed the typical HPS clinical criteria, such as, fever, cytopenia, splenomegaly, hemophagocytosis in the peripheral blood and spleen. Furthermore, elevations of inflammatory cytokines (TNF-α and IL-6) and triglyceride were detected in the serum of these mice. These clinical symptoms were not observed in CpG-injected TLR2−/−4−/−9−/− mice and LPS-injected wild type mice. Interestingly, combination challenge of CpG and iE-DAP led to synergistic induction of hemophagocytosis and enhanced production of TNF-α and IL-6 in the serum, however, single iE-DAP challenge did not induce HPS. FCM analysis revealed that monocyte-derived dendritic cells, which were CD11b, Ly6c, and F4/80, were mobilized and engulfed TER119+ erythrocyte in the peripheral blood and spleen after these challenge. Treatment of mice with TNFR-Fc partially prevented, and combination of TNFR-Fc and anti IL-6R mAb markedly suppressed hemophagocytosis in the peripheral blood and spleen.Conclusions: Based on these results, CpG or CpG + iE-DAP-induced mouse HPS model is valuable to study for cellular and molecular mechanism of HPS development, and potential system to apply preclinical research. Furthermore, prevention of both TNF-α and IL-6 might represent a novel therapy for HPS. DisclosuresNo relevant conflicts of interest to declare.

Hyperplastic Polyposis Syndrome

Purpose: A 52 year old male with no family history of colon cancer presented for an initial average risk screening colonoscopy. He had no past medical history of chronic diseases and did not take prescription medication. He had a 30 pack year history of smoking. He worked as a foreman and was asymptomatic. At screening colonoscopy more than 50 polyps were seen throughout the colon, most of which were <5 mm. These polyps were predominantly seen in the descending and transverse colon but both the right and left colon were involved (see Figure 1). The largest polyp was a 1 cm polyp in the cecum and this was removed by snare cautery. The other polyps were extensively sampled (N=10). The histopathology of the 1 cm polyp was that of a serrated adenoma while the rest of the polyps were hyperplastic in nature. This patient satisfies the criteria for hyperplastic polyposis syndrome, a syndrome different from familial adenomatous polyposis (FAP). This syndrome is defined by the presence of >30 hyperplastic polyps which are pan colonic in distribution or ≥5 hyperplastic polyps proximal to the rectosigmoid of which at least 2 polyps are greater than 1 cm. HPS is the manifestation of the unique serrated adenoma pathway which is different from the other traditional colon cancer pathways. Although HPS patients are at an increased risk for right sided colon cancer, precious little is known about this syndrome. The present guidelines for management of HPS recommend removal of all polyps >5 either in a single or multiple setting. Screening colonoscopy must be done every 1-2 years in such patients. In selected patients with high polyp lode, colectomy with ileorectal anastomosis may be an option. All first degree relatives should be screened for HPS. In addition, smoking cessation and regular exercise are recommended. In our patient all polyps >5 mm were removed in 2 settings and yearly surveillance colonoscopy is planned. First degree relatives were screened but none met criteria for HPS.Figure 1: Transverse colon with at least 13 polyps.

Utility of Pulse Oximetry Screening for Hepatopulmonary Syndrome

Hepatopulmonary syndrome is characterized by oxygenation abnormalities caused by intrapulmonary vasodilatation in the setting of liver disease and/or portal hypertension. This syndrome occurs in approximately 15%-30% of cirrhotic patients and influences mortality and transplant candidacy. However, no specific screening guidelines are established. We evaluated pulse oximetry with contrast echocardiography in detecting hepatopulmonary syndrome in a cohort of patients undergoing evaluation for liver transplantation. One hundred twenty-seven consecutive patients referred for liver transplantation evaluation were prospectively enrolled and underwent pulse oximetry, contrast echocardiography, and arterial blood gas measurements on room air. Demographic, clinical, and laboratory data were recorded and analyzed. Forty-one (32%) patients were found to have hepatopulmonary syndrome. There were no significant differences in demographic or clinical features compared with patients without hepatopulmonary syndrome, with the exception of pulse oximetry and oxygenation abnormalities. With a threshold value of <96%, pulse oximetry had a sensitivity and specificity of 100% and 88%, respectively, for detecting patients with a partial pressure of oxygen <60 mm Hg. Receiver operator characteristic analysis revealed that a pulse oximetry value of < or =94% detected all patients with a partial pressure of oxygen <60 mm Hg with an increased specificity of 93%. In addition, higher pulse oximetry thresholds reliably identified HPS patients with less severe hypoxemia, albeit with lower specificity. Pulse oximetry is a simple, low cost, and widely available technique that reliably predicts the presence and severity of hypoxemia in patients with hepatopulmonary syndrome. Institution of pulse oximetry screening might enhance detection and improve management of hepatopulmonary syndrome in cirrhosis.

Andes and Prospect Hill Hantaviruses Differ in Early Induction of Interferon although Both Can Downregulate Interferon Signaling

Hantavirus pulmonary syndrome (HPS) is a severe respiratory disease which is thought to result from a dysregulated immune response to infection with pathogenic hantaviruses, such as Sin Nombre virus or Andes virus (ANDV). Other New World hantaviruses, such as Prospect Hill virus (PHV), have not been associated with human disease. Activation of an antiviral state and cell signaling in response to hantavirus infection were examined using human primary lung endothelial cells, the main target cell infected in HPS patients. PHV, but not ANDV, was found to induce a robust beta interferon (IFN-beta) response early after infection of primary lung endothelial cells. The level of IFN induction correlated with IFN regulatory factor 3 (IRF-3) activation, in that IRF-3 dimerization and nuclear translocation were detected in PHV but not ANDV infection. In addition, phosphorylated Stat-1/2 levels were significantly lower in the ANDV-infected cells relative to PHV. Presumably, this reflects the lower level of IRF-3 activation and initial IFN induced by ANDV relative to PHV. To determine whether, in addition, ANDV interference with IFN signaling also contributed to the low Stat-1/2 activation seen in ANDV infection, the levels of exogenous IFN-beta-induced Stat-1/2 activation detectable in uninfected versus ANDV- or PHV-infected Vero-E6 cells were examined. Surprisingly, both viruses were found to downregulate IFN-induced Stat-1/2 activation. Analysis of cells transiently expressing only ANDV or PHV glycoproteins implicated these proteins in this downregulation. In conclusion, while both viruses can interfere with IFN signaling, there is a major difference in the initial interferon induction via IRF-3 activation between ANDV and PHV in infected primary endothelial cells, and this correlates with the reported differences in pathogenicity of these viruses.

Circulating IgA from acute stage of childhood Henoch-Schönlein purpura can enhance endothelial interleukin (IL)-8 production through MEK/ERK signalling pathway

Recently, sera from children with active Henoch-Schönlein purpura (HSP) have been found to enhance interleukin (IL)-8 production by human umbilical venous endothelial cells (HUVEC). To further determine the possible factor with the ability to enhance endothelial IL-8 production in sera from acute stage of HSP, 10 children with HSP at the acute stage and 10 healthy controls were enrolled. IgA antiendothelial cell antibodies (AECA) were detected by cell-based ELISA. Active sera with or without pretreatment with anti-human IgA antibody, sera of controls, and immunoglobulin A (IgA) derived from sera were used to stimulate the HUVEC. The ability of these factors to enhance endothelial IL-8 production was evaluated. Furthermore, signalling pathways were also assayed by different inhibitors, and confirmed by immunoblotting. Serum levels of IgA AECA in HPS patients at the acute stage were significantly higher than in controls (P < 0.001). The active sera could enhance endothelial IL-8 production (P = 0.004, compared with control sera), and the ability of these sera was mostly abolished when pretreated with fixed anti-human IgA antibody. The supernatant IL-8 levels of endothelial cells stimulated by IgA derived from acute stage of HSP were statistically higher than controls (P < 0.001). PD98059, an inhibitor of ERK phosphorylation, significantly reduced IgA AECA-stimulated endothelial IL-8. IgA AECA also enhanced the phosphorylation of ERK1 with a time-dependent manner. Together with these findings, it is concluded that IgA AECA derived from acute stage of HSP may bind to endothelial and enhance endothelial cells to produce IL-8 via MEK/REK signalling pathway.

RFVIIa Treatment and Efficacy Prediction in a Patient with Hermansky-Pudlak Syndrome Type 1 (HPS-1) Using Global Clotting Tests and Flow Cytometry.

The use of hemostatic agents for patients with platelet function related disorders causing impaired clotting is predominantly monitored via clinical parameters to date. For HPS patients, which suffer from a platelet storage pool disease, up to now mainly desmopressin and/or platelet concentrates have been administered as therapeutic agent in case of bleeding or surgery, with variable success. A more recent option is rFVIIa (NovoSeven®, N7), but there are few reports of its use in HPS patients. Before administering, it would be of therapeutical interest to know the maximum efficacy and the patient's individual response. We investigated the hemostatic efficacy of rFVIIa in a patient with HPS-1 (63 y; 2 mutations: 972delC, T322N), who was undergoing tooth extraction. rFVIIa (90 U/kg body weight bolus) was administered 30 minutes before the procedure. Citrated blood samples were taken before, 15 minutes after rFVIIa administration and after the dental treatment was completed. Platelet rich plasma was generated by centrifugation (750g, 5 min) and the samples assayed using a fluorometric thrombin generation test (TGT), thrombelastography (RoTEG) and flow cytometry (FACS). The TGT was started adding Ca 16,7 mM and fluorogenic substrate. RoTEG was used with Ca, N7, tissue factor separately and combined. From the pre-substitution samples a reference value with rFVIIa, 80 U/ml added in vitro, and a dose-response curve from 0 to 400 U/ml were measured. N7 recovery was evaluated from pre-, post-substitution and the reference values. The TGT showed a presubstitutional residual activity of 50 % of the maximum ETP value, and 100% after substitution. TGT response to N7 was dose-dependent and entered a plateau at 90 % of the value after substitution, from 80 U/ml N7 on. The effect of subsituted rFVIIa persisted 2h after the extraction. Other TGT parameters (peak, time to peak, lag time) changed concordantly. RoTEG changes were most pronounced for Ca 12 mM alone as a trigger, which showed a transient reduction of clotting time and clot formation time after N7 substitution. FACS showed a 2.2fold CD62P increase indicating platelet activation after administration. Altogether, the TGT parameter changes corresponded best to the clinical outcome, as no bleeding events were observed during and 2h after the dental procedure. Thrombin generation may thus be useful to evaluate and predict N7 therapeutic efficacy in HPS patients. More HPS patients have to be treated to confirm these findings.

Severe imbalance of IL-18/IL-18BP in patients with secondary hemophagocytic syndrome

AbstractHemophagocytic syndrome (HPS) is characterized by an uncontrolled and poorly understood activation of T-helper 1 (Th-1) lymphocytes and macrophages. We studied 20 patients with HPS secondary to infections, autoimmune disease, lymphoma, or cancer and observed that the concentrations of serum interleukin 18 (IL-18), a strong inducer of Th-1 responses, interferon γ (IFN-γ) production, and stimulation of macrophages and natural killer (NK) cells were highly increased in HPS but not in control patients. In contrast, concentrations of its natural inhibitor, the IL-18 binding protein (IL-18BP), were only moderately elevated, resulting in a high level of biologically active free IL-18 in HPS (4.6-fold increase compared with controls; P < .001). Free IL-18 but not IL-12 concentrations significantly correlated with clinical status and the biologic markers of HPS such as anemia (P < .001), hypertriglyceridemia, and hyperferritinemia (P < .01) and also with markers of Th-1 lymphocyte or macrophage activation, such as elevated concentrations of IFN-γ and soluble IL-2 and tumor necrosis factor α (TNF-α) receptor concentrations. Despite high IL-18 elevation, in vitro NK-cell cytotoxicity was severely impaired in HPS patients, in part due to NK-cell lymphopenia that was observed in a majority of patients but also secondary to an intrinsic NK-cell functional deficiency. We concluded that a severe IL-18/IL-18BP imbalance results in Th-1 lymphocyte and macrophage activation, which escapes control by NK-cell cytotoxicity and may allow for secondary HPS in patients with underlying diseases.

Hantaviruses in Central South America: Phylogenetic analysis of the S segment from HPS cases in Paraná, Brazil

We sequenced the complete S segments of hantaviruses detected from 12 HPS patients living in southern of Brazil. Samples were obtained from patients diagnosed in different years, in distinct areas, and with a broad spectrum of clinical signs. Despite these differences, all the S proteins of hantavirus from Paraná were identical, except for one amino acid substitution. Phylogenetic analyses of the complete S segment nucleotide and amino acid sequences indicated that hantaviruses from Paraná form a distinct clade from those circulating in South and North America. Other hantaviruses from Brazil were not placed in the same clade. The Oligoryzomys nigripes-associated strains ITA37 and ITA38 from Paraguay were found to belong to the same clade as the hantaviruses from Paraná. Paraguay and Paraná state are located at the same latitude and some ecosystems are similar in both places. The geographic position and common rodent hosts could explain this phylogenetic relationship.

Normal Lytic Granule Secretion by Cytotoxic T Lymphocytes Deficient in BLOC‐1, ‐2 and ‐3 and Myosins Va, VIIa and XV

Melanocytes and cells of the immune system share an unusual secretory mechanism which uses the lysosome as a regulated secretory organelle. Recently, a number of the proteins required for these 'secretory lysosomes' to undergo exocytosis have been identified. These include Rab27a, Lyst, Rab geranyl geranyl transferase and the adapter protein complex AP-3. Patients lacking any of these proteins are characterized by the rare combination of albinism and immunodeficiency, revealing roles for these proteins in both melanocyte and immune cell secretion. In order to ask how far the link between albinism and immunodeficiency extends we have examined cytotoxic T-lymphocyte (CTL) secretion from two BLOC-3-deficient patients and seven different mouse models of Hermansky-Pudlak syndrome, all of which display defects in pigmentation and platelet function. We find that CTL function is normal in HPS patients and pale-ear mice deficient in BLOC-3, pallid, muted and sandy mice deficient in BLOC-1, ruby-eye mice deficient in BLOC-2 and buff mice deficient in Vps33a. Similarly, the unconventional myosins, Va, VIIa and XV, which can act as effectors for Rab27a in some cell types, are not required in CTL. These results reveal differences in the protein machinery required for biogenesis and/or secretion of lysosome-related organelles in CTL and melanocytes.

Platelet granule disorders

The present review has cataloged the inherited and acquired disorders of platelet granules. Unfortunately, a mere listing of different conditions in which dense bodies, alpha granules, or both are decreased, absent, or fused does little to define their importance in human platelet physiology or as a causative factor in hemorrhagic disease. The inherited disorders serve as the best index of granule involvement in platelet hemostatic function. Our experience with storage pool deficiency in patients with Hermansky-Pudlak syndrome has suggested that in many individuals virtual absence of dense bodies and their contents does not present a serious threat to hemostasis. Placing HPS patients on aspirin did not cause spontaneous hemorrhage, suggesting that secretion of dense body contents and synthesis of endoperoxides and thromboxane A2 are not absolutely essential for platelet function. However, the literature strongly suggests that many patients with HPS and SPD face a serious risk from bleeding, and hemorrhage may cause death. We can only conclude that some patients with HPS have platelet defects or other hemostatic problems that render SPD a far more serious threat than in other patients who appear to have the same disease. Dense bodies of and by themselves do not appear absolutely required for platelet function. Isolated deficiency of alpha granules presents the same enigma. Only a few patients with this rare inherited disease have been reported. They are generally considered to have mild to severe hemorrhagic problems. However, the past medical history of our two patients with GPS has recently been reviewed and platelet function studies repeated. Despite the mild thrombocytopenia, they are free of any significant bleeding episodes and their platelet function appears virtually normal. Our findings do not support the concept that alpha granules are essential for platelet function. The only condition that seems to support a critical role for storage organelles in hemostasis is the combined alpha-granule, dense body deficiency in one patient reported by Weiss. This patient does have bleeding problems. However, it is difficult to draw conclusions based on a single patient, and the discovery of other patients will help to clarify the hemostatic problem of patients with dual storage organelle deficiencies. In the meantime, we have prepared platelets from normal individuals free of storage granules by sedimentation through gradients containing cytochalasin B. The function of the normal agranular platelets is compromised, but they do respond to some aggregating agents.(ABSTRACT TRUNCATED AT 400 WORDS)