Bevacizumab mitigates codon-specific effects of trifluridine/tipiracil on efficacy outcome parameters in metastatic colorectal cancer

BACKGROUND

Molecular informed therapy changed treatment patterns of metastatic colorectal cancer (mCRC). Recently KRAS G12, the most prevalent RAS mutation in mCRC, was investigated to be a negative predictive marker for the efficacy of trifluridine/tipiracil (FTD/TPI). Whether this proposed selectivity remains when FTD/TPI is combined with bevacizumab remains elusive. We aimed to describe the efficacy of FTD/TPI + bevacizumab depending on the RAS mutational status in a real-world population.

PATIENTS AND METHODS

Patients from five different cancer centers in Austria who received FTD/TPI + bevacizumab in any treatment line having available information on their molecular profile were eligible. Data were retrospectively collected by chart review. Survival data were compared using log-rank test. Multivariate Cox regression models included several established covariates.

RESULTS

One hundred and twenty-three patients with mCRC were included in this study. Median overall survival (OS) was highly similar in the RAS wild type (WT) [9.63 months (95% confidence interval [CI] 8.055-13.775 months)] and the RAS mutant cohorts [8.78 months (95% CI 8.055-11.014 months)], which was confirmed in a multivariable model adjusting for potential confounders; hazard ratio (HR): 1.05 (95% CI 0.618-1.785; P = 0.857). In addition, no effect of KRAS G12 status on patient outcome was observed. In detail, OS was 8.88 months (95% CI 7.332-12.921 months) in patients with KRAS G12 mutation, compared to 9.47 months (95% CI 8.088-11.375 months) in patients with RAS WT/no-KRAS G12 disease [HR: 0.822 (95% CI 0.527-1.282; P = 0.387)].

CONCLUSION

This real-world study indicates that the efficacy of FTD/TPI + bevacizumab is independent of RAS mutational status and that bevacizumab may therefore mitigate the potentially limited efficacy of FTD/TPI monotherapy in the KRAS G12-mutated population.

Prognostic value of metastatic pattern in colorectal cancer: a multicenter retrospective analysis in a real-life cohort

BACKGROUND

Metastatic patterns have been linked with prognosis in colorectal cancer. We aim to determine the distribution of metastases, their dynamics during disease and their prognostic impact for specific clinical treatment scenarios (resection of metastasis and/or systemic treatment, best supportive care).

MATERIAL AND METHODS

978 patients diagnosed with metastatic colorectal adenocarcinoma treated at three oncological centers from 2006 to 2018 were included. Overall survival was assessed depending on tumor load, distribution of metastases and treatment of the patients.

RESULTS

Most patients had single site metastasis (n = 684; 69.9%): 398 patients had liver (n = 398; 40.7%) and 103 patients had lung only metastasis (10.6%). The number of organs involved in metastases at diagnosis was highly prognostic (HR 0.77; CI 0.65, 0.90), whereas the additional gain of metastases during progression of the disease was not. The majority of patients (62.9-74.2%) with initial lung, liver or both metastases retained their initial metastatic status. In the overall population, lung only metastases were associated with the most favorable outcome (HR 0.64; CI 0.50, 0.81). This was also observed in patients receiving best supportive care (HR 0.45; CI 0.27, 0.75). Resection of lung only metastases resulted in longer median survival (102.2 months). A relevant survival difference in patients treated by systemic therapy alone was not observed. Lung only metastasis was associated with rectal cancer (p < .001) and RAS-mutation (p = .01); both, lung and liver metastasis were associated with time from diagnosis to first metastasis (p < .001).

CONCLUSION

The number of organs involved in metastasis at diagnosis but not the total cumulative number of involved organs is of prognostic relevance in colorectal adenocarcinoma. This prognostic relevant initial metastasis distribution remains unchanged in the majority of patients during the disease. However, the prognostic impact of the metastatic pattern is potentially altered by treatment modality.

Abstract OT3-07-01: Ixazomib in combination with carboplatin in pretreated women with advanced triple negative breast cancer, an ongoing phase I/II trial (AGMT MBC-10 trial)

Background:Triple-negative breast cancer (TNBC) comprises a heterogeneous group of diseases which are generally associated with poor prognosis. Recently, the PARP inhibitor olaparib was approved as first targeted treatment beyond antiVEGF therapy for the BRCA1/2 mutated subgroup of TNBC. However, cytotoxic agents still remain the mainstay of treatment for this breast cancer subtype. Ixazomib is a selective and reversible inhibitor of the proteasome, which has been mainly investigated as treatment of multiple myeloma. In a preclinical cell line model for TNBC the first-generation proteasome inhibitor bortezomib showed synergistic efficacy with cisplatin. Clinical data are available for carboplatin plus bortezomib in metastatic ovarian and lung cancers showing remarkable antitumor activity (47% and 38% response rate, respectively) and good tolerability. In solid tumors cytotoxic effect of proteasome inhibitors is thought to be mediated through different mechanisms: (1) Inhibition of the Fanconi Anemia and BRCA1 DNA repair mechanism (2) Inhibition of p53 degradation (3) Inhibition of NF-kappa B signaling cascade. Based on this evidence, the phase I/II MBC-10 trial will evaluate the toxicity profile and efficacy of the oral second-generation proteasome inhibitor ixazomib in combination with carboplatin in patients with advanced TNBC. Trial Design: Patients with metastatic TNBC pretreated with at least one prior line of chemotherapy for advanced disease with a confirmed disease progression and measurable disease are eligible for this study.Patients will receive ixazomib in combination with carboplatin on days 1, 8, and 15 in a 28-day cycle. The phase I part of this study uses an alternate dose escalation accelerated titration design. After establishing the maximum tolerated dose (MTD), accrual continues to evaluate the efficacy and safety of the combination (phase II, including 41 evaluable patients). All patients will continue on study drugs until disease progression, unacceptable toxicity or discontinuation for any other reason. Primary endpoint of the phase II is overall response rate, secondary endpoints include safety profile, progression-free survival and quality of life. The MBC-10 trial is accompanied by a broad biomarker program investigating predictive biomarkers for treatment response and potential resistance mechanisms to the investigational drug combination. This trial is open for patient enrollment since November 2016 in six Austrian cancer centers. Accrual is planned to be completed within two years. ClinicalTrials.gov Identifier: NCT02993094

Citation Format: Rinnerthaler G, Gampenrieder SP, Petzer A, Burgstaller S, Voskova D, Rossmann D, Balic M, Egle D, Rumpold H, Singer CF, Petru E, Melchardt T, Ulmer H, Mlineritsch B, Greil R. Ixazomib in combination with carboplatin in pretreated women with advanced triple negative breast cancer, an ongoing phase I/II trial (AGMT MBC-10 trial) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT3-07-01.

Abstract OT2-07-11: Ixazomib in combination with carboplatin in pretreated women with advanced triple negative breast cancer, a phase I/II trial (AGMT MBC-10 trial)

Background: Triple-negative breast cancer (TNBC) comprises a heterogeneous group of diseases which are generally associated with a poor prognosis. Up to now, no targeted treatment beyond anti-VEGF therapy is approved for TNBC so far and cytotoxic agents are the mainstay for the treatment of advanced tumor stages. Ixazomib is a selective, and reversible inhibitor of the proteasome, which has been mainly investigated in the treatment of multiple myeloma. In a preclinical study triple-negative breast cancer cells were treated with bortezomib, a first generation proteaseome inhibitor, alone and in combination with cisplatin, which had a synergistic effect. Clinical data are available for carboplatin plus bortezomib in metastatic ovarian and lung cancers showing remarkable antitumor activity and good tolerability. Based on this rational, the MBC-10 trial will evaluate the toxicity profile and efficacy of ixazomib in combination with carboplatin in patients with advanced TNBC.

Trial Design: Patients with metastatic TNBC pretreated with at least one prior line of chemotherapy for advanced disease with a confirmed disease progression and measurable disease are eligible for this study. Patients will receive ixazomib in combination with carboplatin on days 1, 8, and 15 in a 28-day cycle. The phase I part of this study uses an alternate dose escalation accelerated titration design. After establishing the maximum tolerated dose (MTD), accrual continues to evaluate the efficacy and safety of the combination (phase II, including 41 evaluable patients). All patients will continue on study drugs until disease progression, unacceptable toxicity or discontinuation for any other reason. Primary endpoint of the phase II is overall response rate, secondary endpoints include safety profile, progression-free survival and quality of life. This trial is open for patient enrollment since November 2016 in six Austrian cancer centers. Accrual is planned to be completed within two years. ClinicalTrials.gov Identifier: NCT02993094

Citation Format: Rinnerthaler G, Gampenrieder SP, Petzer A, Pusch R, Fridrik M, Rossmann D, Balic M, Egle D, Rumpold H, Singer C, Bartsch R, Melchardt T, Ulmer H, Mlineritsch B, Greil R. Ixazomib in combination with carboplatin in pretreated women with advanced triple negative breast cancer, a phase I/II trial (AGMT MBC-10 trial) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-07-11.

The liver graft as Trojan horse-multilineage donor-derived hematopoiesis after liver transplantation: case report

Hematopoietic macrochimerism, which is rarely seen after orthotopic liver transplantation (OLT), has been linked to the development of graft versus host disease (GvHD). We report on a patient with GvHD after OLT in whom full engraftment of donor-derived, multilineage hematopoiesis occurred, indicating that the liver contains pluripotent hematopoietic progenitor cells (HPC) capable to restore hematopoiesis in recipients. Although preventing graft rejection, standard immunosuppressive therapy may be under certain immunological conditions not sufficient to prevent GvHD. Age-, disease-, and treatment-related variables might be critical determinants for the development of an effective alloreactive T-cell response leading to the establishment of full hematopoietic chimerism.

Ovarian cancer stem cells

Because of its semi-solid character in dissemination and growth, advanced ovarian cancer with its hundreds of peritoneal tumor nodules and plaques appears to be an excellent in vivo model for studying the cancer stem cell hypothesis. The most important obstacle, however, is to adequately define and isolate these tumor-initiating cells endowed with the properties of anoikis-resistance and unlimited self-renewal. Until now, no universal single marker or marker constellation has been found to faithfully isolate (ovarian) cancer stem cells. As these multipotent cells are known to possess highly elaborated efflux systems for cytotoxic agents, these pump systems have been exploited to outline putative stem cells as a side-population (SP) via dye exclusion analysis. Furthermore, the cells in question have been isolated via flow cytometry on the basis of cell surface markers thought to be characteristic for stem cells.In the Vienna variant of the ovarian cancer cell line A2780 a proof-of-principle model with both a stable SP and a stable ALDH1A1+ cell population was established. Double staining clearly revealed that both cell fractions were not identical. Of note, A2780V cells were negative for expression of surface markers CD44 and CD117 (c-kit). When cultured on monolayers of healthy human mesothelial cells, green-fluorescence-protein (GFP)-transfected SP of A2780V exhibited spheroid-formation, whereas non-side-population (NSP) developed a spare monolayer growing over the healthy mesothelium. Furthermore, A2780V SP was found to be partially resistant to platinum. However, this resistance could not be explained by over-expression of the "excision repair cross-complementation group 1" (ERCC1) gene, which is essentially involved in the repair of platinated DNA damage. ERCC1 was, nonetheless, over-expressed in A2780V cells grown as spheres under stem cell-selective conditions as compared to adherent monolayers cultured under differentiating conditions. The same was true for the primary ovarian cancer cells B-57.In summary our investigations indicate that even in multi-passaged cancer cell lines hierarchic government of growth and differentiation is conserved and that the key cancer stem cell population may be composed of small overlapping cell fractions defined by various arbitrary markers.

Patients suffering from non-IgE-mediated cow's milk protein intolerance cannot be diagnosed based on IgG subclass or IgA responses to milk allergens

BACKGROUND

Cow's milk is one of the most common causes of food allergy. In two-thirds of patients, adverse symptoms following milk ingestion are caused by IgE-mediated allergic reactions, whereas for one-third, the mechanisms are unknown. Aim of this study was to investigate whether patients suffering from non-IgE-mediated cow's milk protein intolerance can be distinguished from persons without cow's milk protein intolerance based on serological measurement of IgG and IgA specific for purified cow's milk antigens.

METHODS

We determined IgG(1-4) subclass and IgA antibody levels to purified recombinant αS1-casein, αS2-casein, β-casein, κ-casein, α-lactalbumin, and β-lactoglobulin in four patient groups by ELISA: Patients with IgE-mediated cow's milk allergy (CMA, n=25), patients with non-IgE-mediated cow's milk protein intolerance (CMPI, n=19), patients with gastrointestinal symptoms not associated with cow's milk ingestion (GI, n=15) and control persons without gastrointestinal problems (C, n=26). Cow's milk-specific IgE levels were determined by ImmunoCAP.

RESULTS

Only CMA patients had IgE antibodies to cow's milk. Cow's milk allergic patients mounted the highest IgG(1) and IgG(4) antibody levels to αS1-casein, αS2-casein, β-casein, κ-casein, and α-lactalbumin. No elevated levels of IgG(4) , IgA, and complement-binding IgG subclasses (IgG(1) , IgG(2) , IgG(3) ) to purified cow's milk allergens were found within the CMPI patients compared to persons without cow's milk protein intolerance (GI and C groups).

CONCLUSION

Cow's milk protein intolerant patients cannot be distinguished from persons without cow's milk protein intolerance on the basis of IgG subclass or IgA reactivity to cow's milk allergens.

Elevated tryptase levels selectively cluster in myeloid neoplasms: a novel diagnostic approach and screen marker in clinical haematology

BACKGROUND

Recent data suggest that tryptase, a mast cell enzyme, is expressed in neoplastic cells in myeloid leukaemias. In several of these patients, increased serum tryptase levels are detectable.

MATERIALS AND METHODS

We have determined serum tryptase levels in 914 patients with haematological malignancies, including myeloproliferative disorders (n = 156), myelodysplastic syndromes (MDS, n = 241), acute myeloid leukaemia (AML, n = 317), systemic mastocytosis (SM, n = 81), non-Hodgkin's lymphoma (n = 59) and acute lymphoblastic leukaemia (n = 26). Moreover, tryptase was measured in 136 patients with non-neoplastic haematological disorders, 102 with non-haematological disorders and 164 healthy subjects.

RESULTS

In healthy subjects, the median serum tryptase was 5.2 ng mL(-1). Elevated serum tryptase levels were found to cluster in myeloid neoplasm, whereas almost all patients with lymphoid neoplasms exhibited normal tryptase. Among myeloid neoplasms, elevated tryptase levels (> 15 ng mL(-1)) were recorded in > 90% of patients with SM, 38% with AML, 34% with CML and 25% with MDS. The highest tryptase levels, often > 1000 ng mL(-1), were found in advanced SM and core-binding-factor leukaemias. In most patients with non-neoplastic haematological disorders and non-haematological disorders analysed in our study, tryptase levels were normal, the exception being a few patients with end-stage kidney disease and helminth infections, in whom a slightly elevated tryptase was found.

CONCLUSIONS

In summary, tryptase is a new diagnostic marker of myeloid neoplasms and a useful test in clinical haematology.

Cerebrospinal fluid neuron‐specific enolase in non‐selected patients

The degree to which cerebrospinal fluid (CSF) neuron-specific enolase (NSE) contributes to the diagnosis and prognosis of disorders of the central nervous system (CNS) or peripheral nervous system (PNS) is still under debate. The aim of the study was thus to assess the validity of CSF-NSE levels in the diagnostic work-up of these conditions. The study consecutively included 106 adult patients who had undergone a diagnostic spinal tap or myelography during the diagnostic work-up for various CNS or PNS disorders. Thirty-five of these patients (16 F, 19 M, aged 24-88 years) without indication of a CNS disorder and with normal routine CSF investigations served as controls. The remaining 71 patients (31 F, 40 M, aged 28-87 years) constituted the disease group. CSF-NSE was independent of sex and age. The upper reference limit of CSF-NSE was 0.01536 ng/L. CSF-NSE was elevated in 13 of the 71 patients (18%): 6 with metabolic myopathy, 4 with polyneuropathy and 3 with hepatic encephalopathy, multiple sclerosis and paraspasticity, respectively. Only 6 of the 13 patients (46%) showed CNS involvement. The study shows that CSF-NSE is elevated in only one-fifth of unselected patients who consecutively undergo a spinal tap. CSF-NSE is elevated most frequently in patients with metabolic myopathy and polyneuropathy, even in cases without CNS abnormalities.

Detection of an allergen in dog dander that cross-reacts with the major cat allergen, Fel d 1

BACKGROUND

A considerable proportion of animal-allergic patients are sensitized to both cat and dog allergens but knowledge about cross-reactive allergens in cat and dog dander is limited.

OBJECTIVE

To investigate whether dog dander contains an allergen that cross-reacts with the major cat allergen, Fel d 1.

METHODS

Recombinant Fel d 1 with the same immunological properties as natural Fel d 1 was used for quantitative (CAP) IgE competition experiments performed with sera obtained from cat-allergic patients (n=36). A Fel d 1 cross-reactive dog allergen was characterized by one- and two-dimensional immunoblotting using rFel d 1 for IgE inhibition experiments and with monospecific, polyclonal rabbit anti-recombinant Fel d 1 antibodies.

RESULTS

In 25% of Fel d 1-reactive cat-allergic patients, more than 50% inhibition of IgE reactivity to dog allergens was achieved with recombinant Fel d 1. An Fel d 1 cross-reactive 20 kDa allergen with a pI of approximately 3.4 was detected in dander extracts of several different dog breeds.

CONCLUSION

This is the first report demonstrating the presence of an Fel d 1-like allergen in dog dander extracts, which may be responsible for double positivity to cat and dog in serology. However, the clinical relevance of this cross-sensitization needs to be confirmed. These results are important for the diagnostic and therapeutic use of dog dander allergen extracts.

The Kinase Inhibitor Imatinib - An Immunosuppressive Drug?

The phenylaminopyrimidine-derivate Imatinib mesylate has been developed for targeted inhibition of the Abelson kinase (c-ABL), which is constitutively activated when translocated to the genetic locus of the breakpoint cluster region (leading to the BCR/ABL fusion gene), thereby forming the causative pathogenetic event for the development of chronic myeloid leukemia (CML). Of note, due to its physico-chemical properties, kinase specificity of Imatinib is limited. Despite of its well documented clinical efficacy mediated by inhibition of constitutively activated tyrosine kinases such as BCR/ABL in CML, PDGF-RA in HES and mutated c-kit in GIST patients, other tyrosine kinases such as Flt-3, Lck and mitogen-activated kinases (MAPK) are affected as well. Accordingly, it has recently been shown that therapeutic doses of Imatinib also target a variety of immune cells, e.g. by modulating the differentiation of dendritic cells (DC) as well as by impeding proper T-cell and macrophage function. In contrast, combining Imatinib with Interleukin 2 (IL-2) potently activates NK-cells and led to the description of a new subclass of DC, so-called IK-DC. The latter mediate Imatinib/IL-2-induced regression of tumors in pre-clinical animal models via production of high amounts of IFN-gamma and the death receptor ligand TRAIL. Thus, Imatinib exerts potent immuno-modulatory effects in vitro and in vivo, which will be discussed together with their clinical relevance in detail throughout this review.

Association of low-grade inflammation with nephropathy in type 2 diabetic patients: role of elevated CRP-levels and 2 different gene-polymorphisms of proinflammatory cytokines

BACKGROUND

Chronic inflammatory processes are thought to play a key role in the development of micro- and macrovascular complications in type 2 diabetes mellitus. An association between low -grade inflammation and type 2 diabetes has been described in some studies. We assayed the association of two frequent polymorphisms in proinflammatory cytokines: the interleukin 6 G(-174)C promoter polymorphism [IL-6G(-174)C], the exon 2 interleukin receptor antagonist insertion deletion polymorphism [IL1RA]) and serum CRP levels with the prevalence of diabetic nephropathy in patients suffering from type 2 diabetes mellitus.

SUBJECTS AND METHODS

A total of 141 patients with type 2 diabetes mellitus, with and without diabetic nephropathy was genotyped for the above mentioned polymorphisms: 66 with normoalbuminuria, 31 with microalbuminuria and 44 with macroalbuminuria. CRP levels were analysed by a high sensitivity - immunnephelometric assay.

RESULTS

While a significant association be-tween macroalbuminuria and CRP could be observed (p<0,015), no associations were found between IL-6G(-174)C or IL1RA genotype and any stage of nephropathy. CRP-levels were similar in the 3 different IL-6G(-174)C genotypes as well as in the 2 IL1RA genotypes.

CONCLUSIONS

In type 2 diabetic subjects elevated CRP levels are associated with an increased prevalence of albuminuria. The two investigated proinflammatory polymorphisms do not seem to contribute to initiation of nephropathy in type 2 diabetic patients but we cannot exclude effects of these polymorphisms on course of nephropathy.

Skin cholesterol: test performance, evaluation of potential determinants and correlation analysis with cardiovascular risk factors and circulating markers of inflammation

BACKGROUND

Skin cholesterol (SkC) has been suggested to be an additional risk predictor, so we evaluated the test performance, potential determinants of this marker as well as a potential correlation of SkC with markers of inflammation and the history of cardiovascular events.

PATIENTS AND METHODS

SkC, determined by the non-invasive PREVU POC Skin Sterol test, as well as serum lipids, the body fat status, high-sensitive CRP (hs-CRP) and serum amyloid A (SAA) were evaluated in consecutive patients with and without documented atherosclerotic disease.

RESULTS

SkC was assessed in 201 patients. The within-day precision (CV) was 3.8%, the day-to-day CV of the right hand was 8.6% and 4.3% for the left hand, respectively. Neither univariate analysis nor multiple regressions identified a significant influence of age, sex, serum lipids, body fat status, smoking or diabetes mellitus on SkC, corresponding results were observed in a further analysis including 174 of these patients concerning hs-CRP and SAA (all p > 0.05). T-test analyses detected no significant differences between patients with and without a history of coronary, peripheral vascular and cerebrovascular events (all p > 0.05).

CONCLUSIONS

The PREVU POC Skin Sterol test for the assessment of SkC proved an acceptable test performance. SkC is independent from serum lipids, traditional cardiovascular risk factors, two sensitive markers of systemic inflammation as well as the history of cardiovascular events indicating that the perception of this parameter as an established marker of vascular disease is premature.

The antiapoptotic effect of IL-6 autocrine loop in a cellular model of advanced prostate cancer is mediated by Mcl-1

Levels of the proinflammatory cytokine interleukin-6 (IL-6) are increased in therapy-resistant prostate cancer. IL-6 has been considered a positive growth factor in late-stage prostate cancer cells and a potential target for therapeutic interference. Effects of inhibition of IL-6 on cell survival were studied in LNCaP-IL6+ cells, a model system for advanced prostate cancer, which produce IL-6. We show that the autocrine IL-6 loop is responsible for resistance to apoptosis and increased cellular levels of myeloid cell leukemia-1 (Mcl-1) protein, an antiapoptotic member of the Bcl-2 family. Treatment of cells with a chimeric anti-IL-6 antibody (CNTO 328) led to the induction of apoptosis and downregulation of Mcl-1 protein levels. Specific knockdown of Mcl-1 gene expression by small interfering RNA also yielded an increase in apoptosis of LNCaP-IL-6+ cells. Vice versa, inactivation of IL-6 autocrine loop had no influence on apoptosis levels in the absence of Mcl-1, thus suggesting this molecule as a mediator of the survival action of IL-6. Mcl-1 protein regulation by the endogenous cytokine directly involved the extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase pathway. Our data support the concept of anti-IL-6 targeted therapy in therapy-resistant prostate cancer.

The presence of IgG antibodies against beta2-glycoprotein I predicts the risk of thrombosis in patients with the lupus anticoagulant

BACKGROUND

Lupus anticoagulant (LA) is a strong risk factor of thrombosis. However, a subgroup of patients positive for LA is unaffected by thrombosis and currently no predictive markers are available to identify patients positive for LA at increased risk for thrombosis.

OBJECTIVE

The aim of the study was to investigate whether anti-beta-2-glycoprotein I (anti-beta2GPI) or anticardiolipin antibodies (ACA) are associated with an increased risk of thrombosis in patients persistently positive for LA.

PATIENTS AND METHODS

A cohort of 87 consecutive patients persistently positive for LA was investigated, 55 with and 32 without a history of thrombosis. Immunoglobulin G (IgG) and M (IgM) antibodies against beta2GPI and cardiolipin were determined by enzyme-linked immunoassay.

RESULTS

Patients positive for LA with thrombosis had significantly higher levels of anti-beta2GPI IgG (median 16.7 standard units, interquartile range 3.0-75.2, P = 0.002) and of ACA IgG (41.1 IgG phospholipid units per mL, 8.9-109.0, P = 0.002) than those without thrombosis (2.6, 1.4-7.9 and 9.7, 4.6-22.1, respectively). Levels of anti-beta2GPI IgM and ACA IgM did not differ significantly between LA patients with and without thrombosis (P = 0.25 and 0.12, respectively). Elevated anti-beta2GPI IgG was associated with an increased risk for thrombosis (OR = 4.0, 95% CI 1.2-13.1), especially for venous thromboembolism (OR = 5.2, 95% CI 1.5-18.0).

CONCLUSIONS

Increased levels of anti-beta2GPI IgG were associated with thrombosis. We conclude that anti-beta2GPI IgG levels above normal predict an increased risk of thrombosis in patients persistently positive for LA.

[Complete remission of an idiopathic hypereosinophilic syndrome while using imatinib]

HISTORY AND ADMISSION FINDINGS

A 47-year-old man with a hypereosinophilic syndrome (HES), which has been known for 20 years, was admitted to our department due to insufficient therapeutic response to hydroxyurea. In general, the patient felt well, but reported increasing neurological problems, such as ataxia, memory deficits and dysarthria.

INVESTIGATIONS

Bone marrow assessments corroborated the diagnosis of a HES. However, we were not able to detect the insertional deletion 4q12 with concomitant fusion of the FIP1L1 to the PDGFRA locus. Magnetic resonance imaging (MRI) indicated a granulomatous vasculitis, which was most likely due to the hematologic malignancy.

TREATMENT AND COURSE

: Despite negativity for the FIP1L1-PDGFRA fusion gene, therapy was started with the tyrosine kinase inhibitor Imatinib. This led to a rapid normalization of eosinophilic granulocytes in the peripheral blood as well as in the bone marrow. In addition, the neurologic symptoms substantially improved.

CONCLUSION

Imatinib provides a potent therapeutic option in FIP1L1-PDGFRA negative patients suffering from HES.

Characterization of recombinant cat albumin

BACKGROUND

Indoor allergens derived from animals and mites often contribute to exacerbation of skin manifestations in atopic dermatitis (AD) patients.

OBJECTIVE

To produce and characterize recombinant cat albumin, a cross-reactive animal allergen.

METHODS

A complete cDNA coding for cat albumin was obtained by RT-PCR amplification from cat liver RNA. Recombinant cat albumin was expressed in Escherichia coli as hexahistidine-tagged protein, purified by nickel affinity chromatography and studied for IgE reactivity with sera from cat-allergic patients by ELISA and immunoblotting. Furthermore, CD203c expression of basophils from cat-allergic patients upon exposure to recombinant cat albumin was analysed.

RESULTS

Recombinant cat albumin, a cross-reactive animal allergen sharing most IgE epitopes with its natural counterpart, was produced in E. coli. It was recognized preferentially by IgE from AD patients and elicited IgE-dependent basophil activation in sensitized patients.

CONCLUSIONS

Recombinant cat albumin may be used as a paradigmatic tool to analyse mechanisms of allergen-triggered exacerbation of AD, for diagnostic and, perhaps for therapeutic purposes.

TGF-β cytokines increase senescence-associated beta-galactosidase activity in human prostate basal cells by supporting differentiation processes, but not cellular senescence

The family of transforming growth factors betas (TGF-betas) comprises molecules involved in growth inhibition, stress-induced premature senescence, epithelial mesenchymal transition and differentiation processes. The aim of this study was to clarify the effect of long term exposure of human prostate basal cells to TGF-betas, which are found in high concentrations in prostatic fluid and areas of benign prostatic hyperplasia (BPH). Basal cell cultures established from prostate explants (n=3) were either grown into cellular senescence, or stimulated with TGF-beta1, beta2 and beta3. Similar to cellular senescence, TGF-beta stimulation resulted in an increase of SA-beta galactosidase (SA-beta-gal) activity, flattened and enlarged cell morphology, and down-regulation of the inhibitor of differentiation Id-1. TGF-beta-treated prostate epithelial cells neither showed terminal growth arrest nor induction of important senescence-relevant genes, such as p16(INK4A), IFI-6-16, IGFBP-3 or Dkk-3. Cells stained positive for cytokeratins 8/18, but did not express other lumenal markers, such as prostate-specific antigen and androgen-receptors. TGF-betas increased also the expression of the mesenchymal marker vimentin, indicating that basal epithelial cells underwent differentiation with lumenal and mesenchymal features. In contrast, in vitro-differentiated neuroendocrine-like cells from prostate organoide cultures, expressing chromogranin A and cytokeratin 18, strongly stained positive for SA-beta-gal. Thus, SA-beta-gal activity is not only a marker for senescence, but also for differentiation of human prostate epithelial cells. With regard to the in vivo situation, in addition to cellular senescence, TGF-beta could contribute to the increased number of SA-beta-gal positive epithelial cells in BPH.

Possible modes of allergen-specific sensitization and boosting in an atopic child

Several studies document that allergen-specific IgE levels are boosted by allergen contact via the respiratory tract in allergic patients. Only few data are available on whether other routes of allergen contact have an influence on systemic IgE responses. We report the case of a boy who developed egg allergy after heavy consumption of eggs by the mother during pregnancy and breast feeding. In contrast to other children who outgrow egg allergy during the first years of life, the boy experienced further dramatic increases in hen egg-specific IgE antibodies after prolonged consumption of ostrich eggs containing cross-reactive allergens. IgE antibodies to most of the important respiratory allergens remained either low or not detectable. The dramatic increases in hen egg-specific IgE antibody levels after oral intake of allergens demonstrate that systemic IgE responses in allergic patients can be strongly boosted by allergen contact via routes other than the respiratory tract.

Seminal plasma factors induce in vitro PRL secretion in smooth muscle cells of the human prostate

Next to the sex steroid hormone T, PRL has been shown to influence prostatic function and development. Transgenic mice overexpressing the rat PRL gene develop dramatic enlargements of the prostate gland. Proliferation and secretory activities of epithelial cells are stimulated by PRL in rodents and men. Low concentrations of human PRL (hPRL) and hPRL receptors have been observed in human prostatic epithelial cells (ECs). The aim of this study was to compare regulation of the in vitro hPRL secretion in prostatic ECs and stromal smooth muscle cells (SMCs) after stimulation with seminal plasma (SMP), containing a variety of prostatic factors. SMCs released up to 1 ng hPRL/ml (i.e., approximately 500-fold more than unstimulated SMCs and ECs). Quantification of PRL mRNA by highly sensitive quantitative RT-PCR revealed that hPRL gene expression increased 5-fold within 24 h of SMP incubation. Sex steroids (dihydrotestosterone, progesterone, 17beta-estradiol), prostaglandins (PGE-1, PGE-2), and cAMP-stimulating substances (forskolin) were not responsible for induction of hPRL. Compared with endometrial SMCs, regulation of prostatic hPRL secretion was independent of progesterone and cAMP. HPLC analysis of human SMP revealed that the common action of at least two different proteins and a low molecular cofactor is required. We concluded that prostatic ECs secrete proteins acting synergistically with low-molecular-weight cofactors to induce differentiation and hPRL release in SMCs. Age-related increases in SMC-derived hPRL might contribute to the development of benign hyperplasia of the prostate.

A low-molecular-weight fraction of human seminal plasma activates adenylyl cyclase and induces caspase 3-independent apoptosis in prostatic epithelial cells by decreasing mitochondrial potential and Bcl-2/Bax ratio

The majority of elderly men are affected by benign and malign diseases of the prostate that are governed by endocrine factors and local stromal/epithelial and luminal/epithelial interactions. Prostate epithelial cells secrete numerous factors into the seminal plasma (SMP) that are thought to be responsible for nutrition, accurate pH, and ionic environment of sperm. Our hypothesis assumes that prostatic factors responsible for optimal fertility might have retrograde influences on epithelial cell growth, differentiation, and function. SMP was analyzed for proteins and other biologically active substances by size exclusion high-performance liquid chromatography. Each fraction was investigated for its effect on cell growth and death. A low molecular mass fraction (2-4 kDa) was responsible for inducing apoptosis in proliferating prostate epithelial cells. Signal transduction was mediated by the production of cAMP; no significant changes in tyrosine phosphorylation of membrane receptors were observed. Mechanisms of apoptosis, i.e., caspase- and mitochondria-dependent pathways, were investigated in prostate epithelial cells by caspase activity assays, annexin/propidium iodide staining, changes in mitochondrial potential, p53, Par-4, Bax, and Bcl-2 protein levels. SMP induced p53- and Bcl-2-dependent apoptosis without activation of caspase-3. Obviously, SMP contains protective factors that help eliminate degenerated cells and control epithelial renewal. Age-related changes in the composition of SMP or the susceptibility of epithelial cells might, therefore, contribute to proliferative prostatic diseases

Urinary excretion of apolipoprotein(a): relation to other plasma proteins

The atherogenic lipoprotein Lp(a) consists of an LDL-like core and apo(a), linked to apoB via a thiol bridge. Apo(a) fragments ranging in size from 60 to 220 kDa are excreted into urine and the excretion rate correlates significantly with the plasma levels of Lp(a). In order to study the interrelationship of apo(a) secretion with that of other plasma proteins, urinary apo(a) and protein secretion of five probands were followed for 24 h at different urinary densities. The excretion rate of apo(a) fragments, despite their high molecular weight, was highest, followed by apoD, orosomucoid, albumin and beta(2)-glycoprotein-I (beta2-GI) and plasminogen (1.58, 0.87, 0.095, 0.027, 0.013 and <0.001%/day, respectively). There was a highly significant correlation between apo(a), apoD and beta2-GI concentrations but not with albumin and orosomucoid concentrations in urine. The only protein that was fragmented in urine was apo(a) while the other proteins had molecular weights comparable to those in plasma. We conclude that a previously suggested fragmentation of apo(a) by the kidney is not a rate-limiting step in its excretion. Since plasminogen, another kringle-IV-containing plasma compound, and fragments thereof, are undetectable in urine under identical experimental conditions, it is very unlikely that the characteristic kringle structure is responsible for the high excretion rate of apo(a).

High levels of zinc ions induce loss of mitochondrial potential and degradation of antiapoptotic Bcl-2 protein in in vitro cultivated human prostate epithelial cells

Prostate epithelial cells contain the highest levels of zinc among all organs and tissues in the human body. Zinc is accumulated primarily in the mitochondria, where it is responsible for inhibition of mitochondrial aconitase activity, thereby increasing citrate production. The present study was designed to clarify the role of zinc for human prostate epithelial cell growth and apoptosis. Apoptosis of in vitro cultivated human prostate epithelial cells exposed to ZnCl(2) was analyzed by determination of phospholipid membrane asymmetry, nuclear fragmentation, DNA strand breaks, changes of mitochondrial potential and cellular pro/antiapoptotic proteins. Zinc induced apoptosis without involvement of p53 by decreasing mitochondrial transmembrane potential (DeltaPsi(m)) and Bcl-2 protein levels in proliferating epithelial cells. Thus, the high local concentrations of zinc ions in the prostatic lumen seem to be necessary to regulate proliferative activities and to enforce epithelial differentiation processes.

Aging of the male reproductive system

Reproductive and sexual physiology, changes in body composition and mental performance in the aging male cannot simply be reduced to presumptive hypogonadism defined by low androgen serum levels or by decreasing levels of growth hormone (GH) and melatonin. Morphological changes in organs at different regulatory levels of hormonal networks governing, for example reproduction, such as diminished hypothalamic pulse generator mass, focal degeneration and loss of Leydig cells in testicular tissue, lead to diminished reserve capacities in production and to loss of coordinated pulsatile release of hypothalamic neuropeptides (e.g. gonadotropin releasing hormone, GnRH) and consequently diminished release of pituitary protein and glycoprotein hormones and testicular steroid hormones. Owing to presumptive alterations in feedback sensitivity, decreased testosterone levels do not necessarily upregulate pituitary LH secretion. Alternatively, increased serum levels of LH and FSH can be observed in old men either because of primary hypogonadism or to decreased hypothalamic opioid tone. In general, endocrine functions are sufficient to maintain fertility in elderly men because, except for sperm motility, quantitative and qualitative functional semen parameters are apparently not affected by age. Nevertheless, reduced endocrine and organic functions might become critical at different levels, with high inter-individual variability, of the hypothalamo/pituitary/gonadal-axis. One of the most intriguing organic manifestations of male aging is benign prostatic hyperplasia (BPH), the pathologic prevalence of which closely matches age. Age-associated changes in the endocrine system and in local networks of epithelial, stromal and luminal factors may play important roles in BPH development.

An unusual member of the human growth hormone/placental lactogen (GH/PL) family, the testicular alternative splicing variant hPL-A2: recombinant expression revealed a membrane-associated growth factor molecule

The human growth hormone/placental lactogen (GH/PL) gene cluster consists of five highly-related genes (GH-N, GH-V, PL-L, PL-A, PL-B). This evolutionarily young gene cluster codes for an array of mRNAs and proteins, such as the major 22 k forms (hGH-N/V, identical PL-A and B), 20 k and 17.5 k hGH-N and the recently described 25 k hGH-Delta4, a presumably chimeric molecule. In addition, two longer alternatively spliced, (intron D retaining) mRNAs isoforms, termed PL-A2 and GH-V2, have been described in placenta and testis. To elucidate the role of hPL-A2 in male reproduction and pregnancy, testicular PL-A2 cDNA was cloned in a complementary overlapping 2-way RT-PCR approach to analyze translation, localization and structure/function of this unusual member of the GH/PL growth factor family. Analysis of insect mRNA revealed that intron D-retaining PL-A2 cDNA was expressed without splicing in the baculovirus expression system. Thus, PL-A2 mRNA does not represent a nuclear intermediate splicing product simply co-isolated with the mature RNA, but is a stable mRNA isoform generated by placental/testis-specific splicing factors. Recombinant protein was present in whole cell extracts, and no secreted protein was detected in the supernatant. Immunologically, the N-terminus of the 230 amino acid protein is similar to 22 k hPL-A/B, as determined by hPL-specific monoclonal antibodies. In contrast, the C-terminus shares a hydrophobic region presumably responsible for membrane insertion. By the use of confocal microscopy recombinant hPL-A2 was localized in the cell membrane. Thus, hPL-A2 might exert its function by modulating GH/PL actions or act as an independent growth-regulatory molecule itself and its functions in male reproduction and embryonic development remain to be investigated.

Purification, biochemical, and immunological characterisation of a major food allergen: different immunoglobulin E recognition of the apo- and calcium-bound forms of carp parvalbumin

BACKGROUND

Almost 4% of the population suffer from food allergy which is an adverse reaction to food with an underlying immunological mechanism.

AIMS

To characterise one of the most frequent IgE defined food allergens, fish parvalbumin.

METHODS

Tissue and subcellular distribution of carp parvalbumin was analysed by immunogold electron microscopy and cell fractionation. Parvalbumin was purified to homogeneity, analysed by mass spectrometry and circular dichroism (CD) spectroscopy, and its allergenic activity was analysed by IgE binding and basophil histamine release tests.

RESULTS

The isoelectric point (pI) 4.7 form of carp parvalbumin, a three EF-hand calcium-binding protein, was purified to homogeneity. CD analysis revealed a remarkable stability and refolding capacity of calcium-bound parvalbumin. This may explain why parvalbumin, despite cooking and exposure to the gastrointestinal tract, can sensitise patients. Purified parvalbumin reacted with IgE of more than 95% of individuals allergic to fish, induced dose-dependent basophil histamine release and contained, on average, 83% of the IgE epitopes present in other fish species. Calcium depletion reduced the IgE binding capacity of parvalbumin which, according to CD analysis, may be due to conformation-dependent IgE recognition.

CONCLUSIONS

Purified carp parvalbumin represents an important cross reactive food allergen. It can be used for in vitro and in vivo diagnosis of fish-induced food allergy. Our finding that the apo-form of parvalbumin had a greatly reduced IgE binding capacity indicates that this form may be a candidate for safe immunotherapy of fish-related food allergy.

Escherichia coli expression and purification of recombinant dog albumin, a cross-reactive animal allergen

BACKGROUND

Animal hair-dander represents an important source of indoor allergens. Diagnosis and therapy of animal allergy would benefit from the availability of defined recombinant allergens. They may be preferred to animal-derived proteins, particularly for in vivo application in patients.

OBJECTIVE

The purpose of this study was to express and purify recombinant dog albumin, an important cross-reactive animal allergen.

METHODS

Complementary (c)DNA sequences coding for dog albumin were obtained by reverse transcription and subsequent PCR amplification from dog liver RNA. Dog albumin-encoding cDNA sequences were inserted into phage lambdagt11, and IgE-reactive phage clones were isolated by immunoscreening with serum IgE from a patient with dog allergy. Dog albumin was expressed as IgE-reactive recombinant protein in Escherichia coli and purified by inclusion body preparation, resolubilization, and diethylaminoethyl cellulose chromatography. Cross-reactivity of dog albumin with cat and human albumin was examined by immunoblot, as well as ELISA inhibition experiments.

RESULTS

A cDNA sequence coding for complete dog albumin was obtained by reverse transcription and subsequent PCR amplification from dog liver. The cDNA and deduced amino acid sequence of dog albumin was highly homologous to the sequences of albumins from animals to human subjects, thus explaining the extensive cross-reactivities among albumins. Recombinant dog albumin was expressed in E coli and purified. It reacted with serum IgE from patients allergic to dog albumin and a monoclonal anti-human albumin antibody. Immunologic competition experiments performed with serum IgE from patients allergic to dog albumin and a mouse monoclonal antihuman albumin antibody indicated the presence of similar epitopes on dog, cat, and human albumin.

CONCLUSION

Recombinant dog albumin may be used for diagnostic purposes to identify patients who are cross-sensitized to many animal species and perhaps for specific immunotherapy of sensitized individuals.

pET-prof, a plasmid for high-level expression of recombinant peptides fused to a birch profilin-derived hexadecapeptide tag: a system for the detection and presentation of recombinant antigens

We have previously identified a birch pollen profilin hexadecapeptide (Bp36/51), which was recognized by a monoclonal antibody (moAb 4A6) with high affinity. Here, we report the construction of a T7 RNA polymerase-driven high-level plasmid expression system, pET-prof, capable of producing proteins and peptides containing the Bp36/51 birch profilin-derived peptide fused to their N-terminus. As examples, the cDNAs coding for two major timothy grass (Phleum pratense) pollen allergens, Phl p 2 and Phl p 6, as well as for an alder (Alnus glutinosa) pollen allergen, Aln g 4, were overexpressed in Escherichia coli as BP36/51-tagged proteins. All three recombinant allergens were readily detected in nitrocellulose-blotted E. coli extracts by the Bp36/51-specific moAb 4A6. We demonstrate comparable IgE recognition of Bp36/51-tagged and untagged recombinant allergens by immunoblotting. A sandwich ELISA was developed using plate-bound moAb 4A6 to immobilize and present Bp36/51-tagged recombinant allergens to IgE antibodies of allergic patients. Using immunoelectronmicroscopy, we demonstrate that even under harsh fixation conditions, tagged allergens can be localized simultaneously in situ by moAb 4A6 and allergen-specific antisera. We suggest the use of the pET-prof system for the high-level expression of Bp36/51-tagged polypeptides that can be rapidly detected in total protein extracts, immunolocalized in situ, immobilized and presented to other antigen-specific antibodies (e.g. IgE), even when they occur in minute concentrations.

Calcium-dependent immunoglobulin E recognition of the apo- and calcium-bound form of a cross-reactive two EF-hand timothy grass pollen allergen, Phl p 7

Type I allergy, an immunodisorder that affects almost 20% of the population worldwide, is based on the immunoglobulin E (IgE) recognition of per se innocuous antigens (allergens). Pollen from wind-pollinated plants belong to the most potent allergen sources. We report the isolation of a cDNA coding for a 8.6 kDa two EF-hand calcium binding allergen, Phl p 7, from a timothy grass (Phleum pratense) pollen expression cDNA library, using serum IgE from a grass pollen allergic patient. Sequence analysis identified Phl p 7 as a member of a recently discovered subfamily of pollen-specific calcium binding proteins. Recombinant Phl p 7 was expressed in Escherichia coli and purified to homogeneity as determined by mass spectroscopy. Approximately 10% of pollen allergic patients displayed IgE reactivity to rPhl p 7 and Phl p 7-homologous allergens present in pollens of monocotyledonic and dicotyledonic plants. Circular dichroism analysis of the calcium-bound and apo-rPhl p 7 indicated that differences in IgE recognition may be due to calcium-induced changes in the protein conformation. The fact that patients mount IgE antibodies against different protein conformations is interpreted as a footprint of a preferential sensitization against either form. The biological activity of rPhl p 7 was demonstrated by its ability to induce basophil histamine release and immediate type skin reactions in sensitized individuals. In conclusion, IgE binding to Phl p 7 represents an example for the conformation-dependent IgE recognition of an allergen. Recombinant Phl p 7 may be used for diagnosis and perhaps treatment of a group of patients who suffer from allergy to pollens of many unrelated plant species.

Proliferative disorders of the aging human prostate: involvement of protein hormones and their receptors

The majority of elderly men is affected by benign and malignant diseases of the prostate. Both proliferative disorders, i.e., benign hyperplasia of the prostate (BPH) and prostate cancer (PCa)-which has recently emerged as the most common male malignancy in industrialized countries-seem to be governed by endocrine factors such as sex steroid hormones, but auto/paracrine factors are involved as well. Age-related changes in levels and ratios of endocrine factors as androgens, estrogens, gonadotropins, and prolactin (PRL) and changes in the balance between auto/paracrine growth-stimulatory and growth-inhibitory factors such as insulin-like growth factors (IGFs), epidermal growth factor (EGF), nerve growth factor (NGF), IGF-binding proteins (IGFBPs), and transforming growth factor beta (TGFbeta) are meant to be responsible for abnormal prostatic growth. We investigated the existence of putative local regulatory circuits involving the protein hormones, human growth hormone (hGH), human placental lactogen (hPL), and hPRL, and their corresponding receptors in prostatic tissue specimens (transurethral resections of the prostate, TURP; n = 11), in the prostatic cancer cell lines PC3, Du145, LnCap, a virus-transformed BPH cell line (BPH-1), and in a normal healthy prostate by RT-PCRs and highly specific and sensitive immunofluorometric assays (IFMA). Neither hPRL nor hGH was detected at the mRNA or protein levels in prostatic tissue and cell lines, with the exception of 2 of 11 prostatic TURP-samples, which showed weak expression of the PL-A/B genes. PRL- and GH-receptors were expressed in all normal and pathological prostatic specimens. Surprisingly, PRL-receptor expression was not detectable in prostatic cancer cell lines. The trophic effects of exogenous hGH, hPL, and hPRL were investigated by cell proliferation assays (WST-I) in prostatic primary cell cultures and PCa cell lines. hGH significantly (p < 0.005) increased cell proliferation up to 138+/-3.2% (1 nM hGH), while hPL and hPRL revealed only moderate effects. Our data suggest that local auto/paracrine networks of protein hormone actions are not involved in the pathology of BPH or prostatic cancer. On the other hand, systemic pituitary-derived hGH can increase the proliferative response of BPH and PCa, acting directly on the target organ prostate, via the hGH-R. In this case, envisaged GH substitution in elderly people must be viewed at with caution because age-related declines in GH/IGF-I could act as a protective mechanism against abnormal cell growth.

Plasma levels of the interleukin-6 cytokine family in persons with severe Plasmodium falciparum malaria

Plasma levels of interleukin (IL)-6, soluble IL-6 receptor, soluble gp130, leukemia inhibitory factor (LIF), and ciliary neutrophic factor (CNTF) were analyzed in 32 patients with severe malaria. Ten had renal failure, 8 had cerebral malaria, and 14 had other causes of severity. Before treatment, the IL-6 and soluble IL-6 receptor plasma levels were significantly higher in persons with cerebral malaria or renal failure than in other groups (P<.01 for both). After initiation of therapy, IL-6 levels dropped within 24 h, but soluble IL-6 receptor levels increased. CNTF levels were significantly reduced in persons with cerebral malaria or renal failure but normalized within 24 h. Plasma concentrations of gp130 and LIF did not differ between the malaria groups or normal controls. Excessive levels of IL-6 could be controlled by a subsequent shedding of the soluble IL-6 receptor, and low-level CNTF expression could contribute to or even result from cerebral malaria or renal failure.