Increased IL6 plasma levels in indolent systemic mastocytosis patients are associated with high risk of disease progression.

Systemic mastocytosis (SM) is a heterogeneous disease with altered interleukin (IL)-6 and IL13 plasma levels. However, no study has simultaneously investigated the plasma levels of IL1ß, IL6, IL13, CCL23 and clusterin in SM at diagnosis and correlated them with disease outcome. Here we investigated IL1ß, IL6, IL13, CCL23 and clusterin plasma levels in 75 SM patients--66 indolent SM (ISM) and 9 aggressive SM--and analyzed their prognostic impact among ISM cases grouped according to the extent of hematopoietic involvement of the bone marrow cells by the KIT D816V mutation. Although increased IL1ß, IL6 and CCL23 levels were detected in SM patients versus healthy controls, only IL6 and CCL23 levels gradually increased with disease severity. Moreover, increased IL6 plasma levels were associated with ISM progression to more aggressive disease, in particular among ISM patients with multilineal KIT mutation (ISM-ML), these patients also showing a higher frequency of organomegalies, versus other ISM-ML patients. Of note, all ISM patients who progressed had increased IL6 plasma levels already at diagnosis. Our results indicate that SM patients display an altered plasma cytokine profile already at diagnosis, increased IL6 plasma levels emerging as an early marker for disease progression among ISM cases, in particular among high-risk ISM patients who carry multilineage KIT mutation.

Anaphylaxis as a clinical manifestation of clonal mast cell disorders.

Clonal mast cell disorders comprise a heterogeneous group of disorders characterized by the presence of gain of function KIT mutations and a constitutively altered activation-associated mast cell immunophenotype frequently associated with clinical manifestations related to the release of mast cells mediators. These disorders do not always fulfil the World Health Organization (WHO)-proposed criteria for mastocytosis, particularly when low-sensitive diagnostic approaches are performed. Anaphylaxis is a frequent presentation of clonal mast cell disorders, particularly in mastocytosis patients without typical skin lesions. The presence of cardiovascular symptoms, e.g., hypotension, occurring after a hymenoptera sting or spontaneously in the absence of cutaneous manifestations such as urticaria is characteristic and differs from the presentation of anaphylaxis in the general population without mastocytosis.

Current state of biology and diagnosis of clonal mast cell diseases in adults.

Mastocytosis comprises a heterogeneous group of disorders characterized by the presence of clonal mast cells (MC) in organs such as skin, bone marrow (BM), and gastrointestinal tract, among other tissues. The clonal nature of the disease can be established in most adult patients by the demonstration of activating KIT mutations in their BM MC. When highly sensitive techniques capable of identifying cells present at very low frequencies in a sample are applied, BM MC from virtually all systemic mastocytosis patients display unique immunophenotypical features, particularly the aberrant expression of CD25. By contrast, large, multifocal BM MC aggregates (the only World Health Organization major criterion for systemic mastocytosis) are absent in a significant proportion of patients fulfilling at least three minor criteria for systemic mastocytosis, particularly in subjects studied at early stages of the disease with very low MC burden. Moreover, recent molecular and immunophenotypical investigations of BM MC from patients with indolent systemic mastocytosis have revealed a close association of some biological features (e.g., multilineage involvement of hematopoiesis by the KIT mutation and an immature mast cell immunophenotype) with an increased risk for disease progression. These observations support the fact that, although the current consensus diagnostic criteria for systemic mastocytosis have been a major advance for the diagnosis and classification of the disease, rationale usage of the most sensitive diagnostic techniques available nowadays is needed to improve the diagnosis, refine the classification, and reach objective prognostic stratification of adult mastocytosis.

Increased serum baseline tryptase levels and extensive skin involvement are predictors for the severity of mast cell activation episodes in children with mastocytosis.

BACKGROUND: Despite the good prognosis of pediatric mastocytosis, some patients suffer from severe mast cell (MC) mediator-associated symptoms. The aim of this study was to identify predictors for severe MC mediator release symptoms in children with mastocytosis in the skin (MIS). METHODS: Serum baseline total tryptase (sbT) levels in 111 children with MIS - 80 maculopapular cutaneous mastocytosis/plaque mastocytosis, 22 nodular mastocytosis, and nine diffuse cutaneous mastocytosis - were investigated as a predictive biomarker for the occurrence of MC mediator-related signs and symptoms within the first 18 months after disease onset. RESULTS: Twelve children (11%) who showed extensive cutaneous disease involving >90% of body surface area (BSA) suffered from severe symptoms requiring hospitalization, with (n = 5) or without (n = 6) management in the intensive care unit (ICU) owing to life-threatening complications. The median sbT was significantly (P < 0.001) higher in patients with extensive cutaneous disease vs those with <90% of BSA involved (45.5 vs 5.2 µg/l, respectively), as well as in children with grade 4 (severe mastocytosis-related symptoms requiring emergency therapy and hospitalization) vs those with grade <4 (46.2 vs 5.2 µg/l, respectively). Receiver operating characteristics curve analyses showed that the optimal cutoff s for sbT to predict the need for daily antimediator therapy, hospitalization, and the management in an ICU were 6.6, 15.5, and 30.8 µg/l, respectively (sensitivity and specificity of 77% and 79%, 100% and 95%, and 100% and 96%, respectively). CONCLUSIONS: Increased sbT in association with extensive cutaneous involvement identifies patients at risk for severe MC activation events in pediatric mastocytosis.

Validation of the REMA score for predicting mast cell clonality and systemic mastocytosis in patients with systemic mast cell activation symptoms.

BACKGROUND: A variable percentage of patients with systemic mast cell (MC) activation symptoms meet criteria for systemic mastocytosis (SM). We prospectively evaluated the clinical utility of the REMA score versus serum baseline tryptase (sBt) levels for predicting MC clonality and SM in 158 patients with systemic MC activation symptoms in the absence of mastocytosis in the skin (MIS). METHODS: World Health Organization criteria for SM were applied in all cases. MC clonality was defined as the presence of KIT-mutated MC or by a clonal HUMARA test. The REMA score consisted of the assignment of positive or negative points as follows: male (+1), female (-1), sBt <15 µg/l (-1) or >25 µg/l (+2), presence (-2) or absence (+1) of pruritus, hives or angioedema and presence (+3) of presyncope or syncope. Efficiency of the REMA score for predicting MC clonality and SM was assessed by receiver operating characteristic (ROC) curve analyses and compared to those obtained by means of sBt levels alone. RESULTS: Molecular studies revealed the presence of clonal MC in 68/80 SM cases and in 11/78 patients who did not meet the criteria for SM. ROC curve analyses confirmed the greater sensitivity and a similar specificity of the REMA score versus sBt levels (84 vs. 59% and 74 vs. 70% for MC clonality and 87 vs. 62% and 73 vs. 71% for SM, respectively). CONCLUSIONS: Our results confirm the clinical utility of the REMA score to predict MC clonality and SM in patients suffering from systemic MC activation symptoms without MIS.

An immature immunophenotype of bone marrow mast cells predicts for multilineage D816V KIT mutation in systemic mastocytosis.

D816V KIT mutation of bone marrow (BM) mast cells (MC) is a common feature to systemic mastocytosis (SM) patients. Nevertheless, occurrence of the KIT mutation in BM cell compartments other than MC is associated with progression to more aggressive forms of the disease and poor outcome in indolent SM (ISM). Here, we assessed the potential association between the immunophenotype of MC and multilineage KIT mutation in the BM of SM patients through the investigation of the flow cytometric protein expression profile (PEP) of bone marrow mast cells (BMMC) from 70 control individuals and 206 SM patients, classified according to the WHO (World Health Organization), and the degree of involvement of BM hematopoiesis by the D816V KIT mutation; additionally, we developed a score-based class prediction algorithm for the detection of SM cases with multilineage mutation. Our results show that aberrant expression of CD25 with a FcɛRI(lo), FSC(lo), SSC(lo) and CD45(lo) immature phenotype of BMMC, in the absence of coexisting normal MC in the BM, was associated with multilineage involvement by the D816V KIT mutation, regardless of the diagnostic subtype of the disease (for example, indolent vs aggressive SM), which supports the utility of the immunophenotype of BMMC as a surrogate marker to screen for multilineage KIT mutation in ISM.

Dermoscopic features of skin lesions in patients with mastocytosis.

OBJECTIVES: To evaluate dermoscopic features in a group of 127 patients with mastocytosis in the skin and to investigate the relationship between different dermoscopic patterns and other clinical and biological characteristics of the disease. DESIGN: Clinical and laboratory data were compared among patients with mastocytosis grouped according to the different dermoscopic patterns. SETTING: Patients were selected from the Instituto de Estudios de Mastocitosis de Castilla La Mancha and the Department of Dermatology of Hospital Universitario Ramón y Cajal from April 1 through September 30, 2009. Patients Overall, 127 consecutive patients (70 females [55.1%] and 57 males [44.9%]; median age, 17 years; range, 0-81 years) with mastocytosis in the skin were included in the study. MAIN OUTCOME MEASURES: Evaluation of dermoscopic patterns and investigation of potential predictive factors for more symptomatic forms of the disease according to the need for daily antimediator therapy. RESULTS: Four distinct dermoscopic patterns were observed: yellow-orange blot, pigment network, reticular vascular pattern, and (most frequently) light-brown blot. A reticular vascular pattern was identified in all telangiectasia macular eruptiva and some maculopapular mastocytosis. In turn, all patients with mastocytoma displayed the yellow-orange blot pattern. The reticular vascular dermoscopic pattern was associated with the need for daily antimediator therapy; this pattern, together with serum tryptase levels and plaque-type mastocytosis, represented the best combination of independent factors to predict the need for maintained antimediator therapy. CONCLUSIONS: Dermoscopy is a feasible method for the subclassification of mastocytosis. Of note, a reticular vascular pattern is more frequently associated with the need for antimediator therapy.

Evaluation of basophil activation in mastocytosis with Hymenoptera venom anaphylaxis.

BACKGROUND: Basophil activation tests (BATs) have been demonstrated to be useful in detecting IgE-mediated sensitization by measuring basophil activation surface markers (CD63 and CD203c). Hymenoptera venom is one of the best known mediators-release trigger in patients with systemic mastocytosis (SM). The aim of this study was to investigate the use of BATs as an additional diagnostic tool in patients with mastocytosis suffering from hymenoptera venom anaphylaxis (HVA). METHODS: A total of 22 patients with history of HVA and SM, together with a group of 11 patients with HVA in whom SM was ruled out after a complete bone marrow study, were analyzed. RESULTS: Among 11 SM patients who had specific serum IgE (sIgE) against hymenoptera venom and an evaluable BAT, a positive BAT was found in nine. Additionally, a positive BAT was detected in three of seven patients who had no sIgE. These three patients had low levels of total IgE compared with control population (mean of 20 vs. 78 IU/mL); one had discontinued immunotherapy after 5 years, when sIgE levels had turned negative, and, in the other two patients, BAT identified the culprit insect. CONCLUSIONS: BAT is a useful complementary diagnostic tool to sIgE in mastocytosis patients with HVA, and it may contribute to predict or confirm these nearly fatal reactions, especially before discontinuing venom immunotherapy in patients who are negative for skin tests or sIgE or display low total IgE levels; in such cases, it also provides evidence on the culprit insect prompting HVA.

Clinical impact of pregnancy in mastocytosis: a study of the Spanish Network on Mastocytosis (REMA) in 45 cases.

BACKGROUND: The impact of pregnancy on mast cell (MC)-related symptoms and newborn outcome in women with mastocytosis is not well described. We report a series of 30 women who had 45 pregnancies. METHODS: Patients completed a specific questionnaire concerning MC mediator release symptoms graded according to their frequency to detect clinical changes occurring during pregestation and pregnancy as well as postpartum. Information about the medications received during pregnancy and labor and about newborn medical complications was also recorded. RESULTS: Worsening of MC-related symptoms during pregnancy was observed in 10 cases (22%); additionally, 1 woman developed skin lesions as a manifestation of indolent systemic mastocytosis (ISM) within the third trimester of pregnancy. Conversely, 15 cases (33%) experienced clinical improvement during pregnancy, with a complete resolution of pregestational symptoms in 7 cases. MC mediator release symptoms intrapartum were observed in 5 cases (11%) without any fatal outcome. Newborn medical complications (e.g. prematurity, low birth weight, and respiratory distress) were detected in 7 infants (16%) who were all successfully managed with conservative measures. One infant developed cutaneous mastocytosis several years after birth. CONCLUSIONS: Mastocytosis has a heterogeneous clinical behavior during pregnancy: the profile of MC-related symptoms remained unchanged in half of the cases, while in the other half pregnant women experienced either an improvement or an exacerbation of the symptoms, with the manifestation of ISM during pregnancy in 1 case. To prevent potential life-threatening MC-related symptoms, adequate prophylactic antimediator therapy intrapartum should be systematically administered. The absence of both maternal and infant severe complications suggests that patients with nonaggressive categories of mastocytosis should not be advised against pregnancy.

Quantification and immunophenotypic characterization of bone marrow and umbilical cord blood mesenchymal stem cells by multicolor flow cytometry.

In recent years, mesenchymal stem cells (MSC) have been attracting the greatest interest in the regeneration of injured tissues, autoimmune diseases, and transplantation of hematopoietic progenitor cells. Bone marrow (BM) represents the major source of MSC; however, umbilical cord blood (UCB) MSC has some advantages over BM, such as the higher differentiation capability and noninvasive collection methods. We sought to establish a 7-color, single-tube flow cytometric assay to quantify MSC in fresh tissues, namely BM and UCB, based on phenotypic markers of these cells. Moreover, we evaluated the differential expression of these markers in BM and UCB MSC. We used 5 UCB samples and 5 BM samples obtained from individuals without hematologic disease. To characterize MSC we used the following combination of monoclonal antibodies: CD71-FITC; CD105-PE; CD184-PE-Cy5; CD34-PE-Cy7; CD133-APC; CD45-APC-H7; CD44-Pacific blue, acquiring at least 1 million nucleated cells. We observed a greater number of BM MSC when compared with UCB MSC as well as some differences in the expression of some MSC antigens, particularly CD105 and CD44. Based on our preliminary results, phenotypic identification of MSC by flow cytometry is possible using a 7-color, single-tube assay. However, culture assays after sorting of cells characterized in this study are required to prove that they correspond to MSC.

Contact sensitizers downregulate the expression of the chemokine receptors CCR6 and CXCR4 in a skin dendritic cell line.

Chemokines are involved in the control of dendritic cell (DC) trafficking, which is critical for the immune response, namely in allergic contact dermatitis (ACD). In this work, we investigated by flow cytometry the effect of the contact sensitizers 2,4-dinitrofluorobenzene (DNFB), 1,4-phenylenediamine (PPD) and nickel sulfate (NiSO(4)), on the surface expression of the chemokine receptors CCR6 and CXCR4 in DC. As an experimental model of a DC we used a fetal skin-derived dendritic cell line (FSDC), which has morphological, phenotypical and functional characteristics of skin DC. Our results show that all the skin sensitizers studied decreased the membrane expression of the chemokine receptors CCR6 and CXCR4. In contrast, 2,4-dichloronitrobenzene (DCNB), the inactive analogue of DNFB without contact sensitizing properties, was without effect on the surface expression of these receptors. Lipopolysaccharide (LPS), which induces the maturation of DC, also reduced surface CCR6 and CXCR4 expression.

Influence of pro- and anti-inflammatory cytokines in Th1 polarization after allogeneic stimulation.

The exogenous cytokine milieu can influence Th1/Th2 polarization. Besides the differential functional properties, T lymphocytes also acquire distinct profiles of chemokine receptors. Human Th1 lymphocytes preferentially express CCR5 and CXCR3 while Th2 lymphocytes express CCR3, CCR4 and CCR8. After their polarization into Th1 cells, grafted T lymphocytes mediate the development of graft-vs-host-disease, the major complication after bone marrow transplantation. We performed mixed lymphocyte cultures for ten days, with and without addition of IL-2, IL-4, IL-10, IL-12 and IL-18 at the third and sixth day of cultures. The expression of CXCR3 and CCR5, in CD4(+) and CD8(+) T lymphocytes was evaluated by flow cytometry, before and after ten days of culture. The exogenous addition of IL-2 or IL-12 favoured the Th1/Tc1 phenotype and IL-4 was also capable of inducing Th1 polarization. In opposition to IL-12, IL-18 didn't induce a significant polarization into Th1 phenotype, an effect more similar to that induced by IL-10. This action could explain, at least in part, its possible protective effect in the incidence of acute and chronic graft-versus-host disease after allogeneic stem cell transplantation.

Development of batch injection analysis for electrochemical measurements of trace metal ions in ecotoxicological test media.

Batch injection analysis with square-wave anodic stripping voltammetry has been developed as a powerful and rapid technique for obtaining data on the concentration of the fraction of labile metal ions present in media used in ecotoxicological tests. Microlitre samples of solution, without pretreatment, are injected directly over a detector electrode, the surface of which is protected by a thin Nafion polymer coating against irreversible adsorption by organic components. Examples are given showing the effect of adding vitamins and organic extract, singly and together, to the ASTM medium employed for tests using Daphnia magna and with lead and cadmium test ions. Such a methodology can be extended to other electroactive species present in these and similar media.

Targeted recombination demonstrates that the spike gene of transmissible gastroenteritis coronavirus is a determinant of its enteric tropism and virulence.

Targeted recombination within the S (spike) gene of transmissible gastroenteritis coronavirus (TGEV) was promoted by passage of helper respiratory virus isolates in cells transfected with a TGEV-derived defective minigenome carrying the S gene from an enteric isolate. The minigenome was efficiently replicated in trans and packaged by the helper virus, leading to the formation of true recombinant and pseudorecombinant viruses containing the S proteins of both enteric and respiratory TGEV strains in their envelopes. The recombinants acquired an enteric tropism, and their analysis showed that they were generated by homologous recombination that implied a double crossover in the S gene resulting in replacement of most of the respiratory, attenuated strain S gene (nucleotides 96 to 3700) by the S gene of the enteric, virulent isolate. The recombinant virus was virulent and rapidly evolved in swine testis cells by the introduction of point mutations and in-phase codon deletions in a domain of the S gene (nucleotides 217 to 665) previously implicated in the tropism of TGEV. The helper virus, with an original respiratory tropism, was also found in the enteric tract, probably because pseudorecombinant viruses carrying the spike proteins from the respiratory strain and the enteric virus in their envelopes were formed. These results demonstrated that a change in the tropism and virulence of TGEV can be engineered by sequence changes in the S gene.

Interference with virus and bacteria replication by the tissue specific expression of antibodies and interfering molecules.

Historically, protection against virus infections has relied on the use of vaccines, but the induction of an immune response requires several days and in certain situations, like in newborn animals that may be infected at birth and die in a few days, there is not sufficient time to elicit a protective immune response. Immediate protection in new born could be provided either by vectors that express virus-interfering molecules in a tissue specific form, or by the production of animals expressing resistance to virus replication. The mucosal surface is the largest body surface susceptible to virus infection that can serve for virus entry. Then, it is of high interest to develop strategies to prevent infections of these areas. Virus growth can be interfered intracellularly, extracellularly or both. The antibodies neutralize virus intra- and extracellularly and their molecular biology is well known. In addition, antibodies efficiently neutralize viruses in the mucosal areas. The autonomy of antibody molecules in virus neutralization makes them functional in cells different from those that produce the antibodies and in the extracellular medium. These properties have identified antibodies as very useful molecules to be expressed by vectors or in transgenic animals to provide resistance to virus infection. A similar role could be played by antimicrobial peptides in the case of bacteria. Intracellular interference with virus growth (intracellular immunity) can be mediated by molecules of very different nature: (i) full length or single chain antibodies; (ii) mutant viral proteins that strongly interfere with the replication of the wild type virus (dominant-negative mutants); (iii) antisense RNA and ribozyme sequences; and (iv) the product of antiviral genes such as the Mx proteins. All these molecules inhibiting virus replication may be used to obtain transgenic animals with resistance to viral infection built in their genomes. We have developed two strategies to target into mucosal areas either antibodies to provide immediate protection, or antigens to elicit immune responses in the enteric or respiratory surfaces in order to prevent virus infection. One strategy is based on the development of expression vectors using coronavirus derived defective RNA minigenomes, and the other relies on the development of transgenic animals providing virus neutralizing antibodies in the milk during lactation. Two types of expression vectors are being engineered based on transmissible gastroenteritis coronavirus (TGEV) defective minigenomes. The first one is a helper virus dependent expression system and the second is based on self-replicating RNAs including the information required to encode the TGEV replicase. The minigenomes expressing the heterologous gene have been improved by using a two-step amplification system based on cytomegalovirus (CMV) and viral promoters. Expression levels around 5 micrograms per 10(6) cells were obtained. The engineered minigenomes will be useful to understand the mechanism of coronavirus replication and for the tissue specific expression of antigen, antibody or virus interfering molecules. To protect from viral infections of the enteric tract, transgenic animals secreting virus neutralizing recombinant antibodies in the milk during lactation have been developed. Neutralizing antibodies with isotypes IgG1 or IgA were produced in the milk with titers of 10(6) in RIA that reduced virus infectivity by one million-fold. The recombinant antibodies recognized a conserved epitope apparently essential for virus replication. Antibody expression levels were transgene transgene copy number independent and were related to the transgene integration site. This strategy may be of general use since it could be applied to protect newborn animals against infections of the enteric tract by viruses or bacteria for which a protective MAb has been identified. Alternatively, the same strategy could be used to target the expression of antibio

Lactogenic immunity in transgenic mice producing recombinant antibodies neutralizing coronavirus.

Protection against coronavirus infections can be provided by the oral administration of virus neutralizing antibodies. To provide lactogenic immunity, eighteen lines of transgenic mice secreting a recombinant IgG1 monoclonal antibody (rIgG1) and ten lines of transgenic mice secreting recombinant IgA monoclonal antibodies (rIgA) neutralizing transmissible gastroenteritis coronavirus (TGEV) into the milk were generated. Genes encoding the light and heavy chains of monoclonal antibody (MAb) 6A.C3 were expressed under the control of regulatory sequences derived from the mouse genomic DNA encoding the whey acidic protein (WAP) and beta-lactoglobulin (BLG), which are highly abundant milk proteins. The MAb 6A.C3 binds to a highly conserved epitope present in coronaviruses of several species. This MAb does not allow the selection of neutralization escaping virus mutants. The antibody was expressed in the milk of transgenic mice with titers of one million as determined by RIA, and neutralized TGEV infectivity by one million fold corresponding to immunoglobulin concentrations of 5 to 6 mg per ml. Matrix attachment regions (MAR) sequences were not essential for rIgG1 transgene expression, but co-microinjection of MAR and antibody genes led to a twenty to ten thousand-fold increase in the antibody titer in 50% of the rIgG1 transgenic animals generated. Co-microinjection of the genomic BLG gene with rIgA light and heavy chain genes led to the generation of transgenic mice carrying the three transgenes. The highest antibody titers were produced by transgenic mice that had integrated the antibody and BLG genes, although the number of transgenic animals generated does not allow a definitive conclusion on the enhancing effect of BLG co-integration. Antibody expression levels were transgene copy number independent and integration site dependent. The generation of transgenic animals producing virus neutralizing antibodies in the milk could be a general approach to provide protection against neonatal infections of the enteric tract.