AIM™ platform: A new immunotherapy approach for viral diseases

In addition to complications of acute diseases, chronic viral infections are linked to both malignancies and autoimmune disorders. Lack of adequate treatment options for Epstein-Barr virus (EBV), Human T-lymphotropic virus type 1 (HTLV-1), and human papillomavirus (HPV) remains. The NexImmune Artificial Immune Modulation (AIM) nanoparticle platform can be used to direct T cell responses by mimicking the dendritic cell function. In one application, AIM nanoparticles are used ex vivo to enrich and expand (E+E) rare populations of multi-antigen-specific CD8⁺ T cells for use of these cells as an AIM adoptive cell therapy. This study has demonstrated using E+E CD8⁺ T cells, the functional relevance of targeting EBV, HTLV-1, and HPV. Expanded T cells consist primarily of effector memory, central memory, and self-renewing stem-like memory T cells directed at selected viral antigen peptides presented by the AIM nanoparticle. T cells expanded against either EBV- or HPV-antigens were highly polyfunctional and displayed substantial in vitro cytotoxic activity against cell lines expressing the respective antigens. Our initial work was in the context of exploring T cells expanded from healthy donors and restricted to human leukocyte antigen (HLA)-A*02:01 serotype. AIM Adoptive Cell Therapies (ACT) are also being developed for other HLA class I serotypes. AIM adoptive cell therapies of autologous or allogeneic T cells specific to antigens associated with acute myeloid leukemia and multiple myeloma are currently in the clinic. The utility and flexibility of the AIM nanoparticle platform will be expanded as we advance the second application, an AIM injectable off-the-shelf nanoparticle, which targets multiple antigen-specific T cell populations to either activate, tolerize, or destroy these targeted CD8⁺ T cells directly in vivo, leaving non-target cells alone. The AIM injectable platform offers the potential to develop new multi-antigen specific therapies for treating infectious diseases, cancer, and autoimmune diseases.

97 High throughput screening of HPV-antigen peptides and expansion of tumor-specific T cells for adoptive cell therapy of HPV-associated malignancies

Background

NexImmune is developing highly differentiated immunotherapies to target, activate and expand tumor antigen-specific T cells using the proprietary Artificial Immune Modulation (AIM™) nanotechnology platform. The AIM nanoparticle (AIM-np) technology functions as synthetic dendritic cells capable of directing a specific T cell-mediated immune response. By mimicking natural T cell biology, NexImmune’s cellular therapy product candidates (AIM ACT) are designed to combine the attributes of cellular precision, potency, and persistence with reduced potential for undesired toxicities. Human papilloma virus (HPV) is responsible for >45,000 cancers yearly in the United States, according to the CDC. From 2013–2017 an estimate 79% of cervical, vulva, penis, vaginal, anus, and oropharyngeal cancers were attributed to HPV and of these about 80% were associated with high-risk HPV types 16 and 18. Although multivalent vaccines against high-risk HPV infections exist, significant clinical challenges remain. A limited vaccination rate means many remain vulnerable and vaccination does not treat pre-existing HPV infections or malignancies.

Methods

Therefore, NexImmune is employing its AIM-np technology to generate an adoptive cell therapy (ACT) using its proprietary enrichment and expansion (E+E) ex vivo process to expand clinically relevant numbers of CD8+ T cells that recognize the HPV16 and HPV18 oncogenic antigens (i.e., E6 and E7) expressed by malignant cells of head and neck, cervical, and anal cancers. Using the Immune Epitope Database and Analysis Resource (IEDB), 44 HLA-A2 restricted peptides were identified as potential immunogenic targets for preclinical screening. Using PBMCs from healthy donor-derived apheresis material, different combinations of these peptides were used in the E+E process to expand HPV-cancer specific CD8+ T cells.

Results

After multiple E+E experiments were concluded, 5 peptides were identified that consistently elicited the strongest T cell responses. Furthermore, these CD8+ T cells were predominantly from the central memory (CD62L+CD45RA-) and effector memory (CD62L-CD45RA-) phenotype (sum total 82.18 ± 8.29 [Mean ± SEM]) suggesting their in vivo functionality and persistence will combine anti-tumor activity with long-term immunologic memory.

Conclusions

A similar E+E screening is being conducted with PBMCs isolated from HPV+ cancer patients. A comparison of the CD8+ T cell responses from healthy donor and cancer patient cells will provide critical preclinical data to support a planned FIH trial for HPV-associated malignancies. The current study demonstrates the ability for high-throughput peptide screening to identify clinically relevant peptide cocktails capable of expanding multi-antigen tumor-specific CD8+ T cell populations within 2 weeks.

202 In vivo and in vitro characterization of AIM ACT, a novel nanoparticle-based technology, expanded MART-1 specific T cells

Background

NexImmune is developing highly differentiated immunotherapies to target, activate and expand tumor antigen-specific T cells using the proprietary Artificial Immune Modulation (AIM™) nanotechnology platform. The AIM nanoparticle (AIM-np) technology functions as synthetic dendritic cells capable of directing a specific T cell-mediated immune response. By mimicking natural T cell biology, NexImmune’s non-genetically engineered cellular therapy product candidates (AIM ACT) are designed to combine the attributes of cellular precision, potency, and persistence with reduced potential for undesired toxicities.

Methods

Here we present an example of AIM ACT expanded MART-1 specific T cells and their phenotypic and functional characterization in vitro and in vivo. Leukopaks from healthy donors were used to produce AIM ACT T cell products with our proprietary AIM ACT enrichment and expansion (E+E) manufacturing process and antigen peptide-loaded AIM-nanoparticles.

Results

The final MART1 T cell products include up to 62.8% (20.8% in average) MART-1-specific CD8+ T cells as determined by MART1 peptide (ELAGIGILTV)-loaded multimer staining. MART1-specific T cells were tested in flow cytometry-based and live cell imaging-based cytotoxicity assays using HLA-A2 positive MART1 peptide-loaded target cells. The AIM ACT-generated T cells showed potent cytotoxicity to MART1 peptide-loaded target cells in vitro, while unloaded control cells were not killed. In over 30 independent AIM ACT E+E clinical scale runs, the expanded T cells consisted of a combined average of 91.7% T stem cell like, central and effector memory T cells, as determined by CD62L, CD45RA and CD95 staining. These phenotypes have been associated with long term in vivo persistence and anti-tumor efficacy. In a human melanoma PDX model, we confirmed that transfusion of AIM ACT T cells resulted in long term survival in vivo and significant reduction of tumor growth with complete tumor clearance in 6 out of 15 animals.

Conclusions

The results demonstrate that AIM ACT MART1 T cells have long term persistence and anti-tumor activity in solid tumors such as melanoma, and that the AIM ACT E+E approach is a reproducible clinical scale manufacturing process for non-genetically engineered antigen-specific T cells. The AIM ACT platform is currently being used for generating T cell products for our current clinical trials, NEXI-001 (NCT04284228) and NEXI-002 (NCT04505813), and our pre-clinical development for HPV-associated malignancies. The findings support initiating Phase I trials of adoptive T cell therapy in solid tumors.

Ethics Approval

The study was approved by the Institutional Animal Care and Use Committee (IACUC).

Preliminary analysis of a phase 1/2 study of NEXI-001 donor-derived multi-antigen-specific CD8+ T-cells for the treatment of relapsed acute myeloid leukemia (AML) after allogeneic hematopoietic cell transplantation (HCT)

2538

Background: Allogeneic HCT is a potentially curative therapy for many patients with AML that relies on a graft-versus-leukemia (GvL) effect. Patients who relapse after allogeneic HCT have a poor prognosis and few treatment options. Donor lymphocyte infusion (DLI) can achieve a GvL effect in some patients, however, efficacy is frequently associated with the development graft-versus-host disease (GVHD). There is a substantial need for treatment approaches that enhance the benefit of GVL while decoupling toxicities associated with GVHD. Methods: We report ongoing results from a first-in-human study (NCT04284228) of a non-genetically engineered, donor-derived adoptive cellular therapy product, NEXI-001, which contains multiple populations of CD8+ T cells that recognize different HLA 02.01-restricted peptides from the WT1, PRAME, and Cyclin A1 antigens. NEXI-001 contains T cell memory subtypes that combine anti-tumor potency with long-term persistence. Results: At the time of this analysis, 7 patients with relapsed AML after allogeneic HCT were enrolled. Five Patients were treated with single infusions of NEXI-001 at three different dose levels: 50, 100 and 200 million. Currently, the median follow-up is 5 months. Significantly, GVHD, cytokine release syndrome, neurotoxicity, or NEXI-001-related adverse events were not observed. NEXI-001 treatment resulted in reductions in red blood cell and platelet transfusions and increased donor chimerism. Decreases in myeloblasts in bone marrow and peripheral blood and reduction in the size of an extramedullary myeloid sarcoma were suggestive of an anti-leukemia effect (Table). Correlative studies indicate that NEXI-001 CD8+ cells undergo a rapid proliferation after infusion and are also associated with a robust hostlymphocyte recovery that occurs as quickly Day 3 after infusion. NEXI-001 infused CD8+T cells are detectable by multimer staining in peripheral blood of patients and proliferate over time. TCR sequencing analyses determined that infused NEXI-001 cells contain T cell clones that were undetectable in the peripheral blood of patients at baseline but were detected in blood and bone marrow and persist over time. Conclusions: NEXI-001 has the potential to enhance GvL effect without the associated toxicities of GVHD, cytokine release syndrome, and neurotoxicity. Due to these encouraging results, the trial will proceed with an evaluation of repeated NEXI-001 dosing Clinical trial information: NCT04284228. [Table: see text]

AIM Platform: A Novel Nano Artificial Antigen-Presenting Cell-Based Clinical System Designed to Consistently Produce Multi-Antigen-Specific T-Cell Products with Potent and Durable Anti-Tumor Properties

Over the last decade, tremendous progress has been made in the field of adoptive cell therapy. The two prevailing modalities include endogenous non-engineered approaches and genetically engineered T-cell approaches. Endogenous non-engineered approaches include dendritic cell-based systems and tumor-infiltrating lymphocytes (TIL) that are used to produce multi-antigen-specific T-cell products. Genetically engineered approaches, such as T-cell receptor engineered cells and chimeric antigen receptor T cells are used to produce single antigen-specific T-cell products. It is noted by the authors that there are alternative methods to sort for antigen-specific T cells such as peptide multimer sorting or cytokine secretion assay-based sorting, both of which are potentially challenging for broad development and commercialization. In this review, we are focusing on a novel nanoparticle technology that generates a non-engineered product from the endogenous T-cell repertoire. The most common approaches for ex vivo activation and expansion of endogenous, non-genetically engineered cell therapy products rely on dendritic cell-based systems or IL-2 expanded TIL. Hurdles remain in developing efficient, consistent, controlled processes; thus, these processes still have limited access to broad patient populations. Here, we describe a novel approach to produce cellular therapies at clinical scale, using proprietary nanoparticles combined with a proprietary manufacturing process to enrich and expand antigen-specific CD8⁺ T-cell products with consistent purity, identity, and composition required for effective and durable anti-tumor response.

Radiodermatitis: Clinical Summary of the ONS Guidelines™ for Cancer Treatment-Related Radiodermatitis

Approximately 50%-70% of patients with cancer will receive radiation therapy. Radiodermatitis is one of the most common side effects of radiation therapy, with as many as 95% of patients experiencing some degree of skin change. Radiodermatitis can cause pain, itching, and burning and potentially has a significant impact on a patient's quality of life. If radiodermatitis becomes severe, it can cause treatment interruption. The prevalence of radiodermatitis coupled with the effect this side effect can have on quality of life prompts the need for evidence-based recommendations for management.

Abstract 1423: AIM ACT, a novel nanoparticle-based technology that generates therapeutic numbers of functional tumor-specific CD8+ T cells with T stem cell, central and effector memory phenotype in 14 days

Background:

Efficient ex-vivo generation of functional tumor-specific T cells with an optimal memory phenotype remains a significant hurdle to the broad application of adoptive cell transfer (ACT) protocols for the treatment of cancer. Genetically engineered T cells represent a currently available option, but the genetic manipulation of T cells presents significant challenges in terms of manufacturing, cost and addressing tumor escape mechanisms. Here, we describe a novel nanoparticle-based approach for generating tumor-specific T cells at clinical grade and scale from the endogenous T cell repertoire using artificial antigen presenting cells (aAPC).

Methods:

aAPC consist of a paramagnetic nanoparticle to which humanized HLA-A2-Ig dimer-molecules and anti-CD28 antibodies are covalently linked. aAPC are loaded with multiple HLA-A2 restricted peptides and used to magnetically enrich and expand tumor-specific CD8+ T cells. Using peptide loaded aAPC, a fully enclosed and automated GMP T cell expansion platform has been developed that consistently generates clinically relevant numbers of tumor-specific, T stem cell, central and effector memory CD8+ T cells in 14 days, providing an alternative to genetically manipulated T cells.

Results:

Starting from a healthy donor leukopak, tumor-specific CD8+ T cells were generated using an aAPC cocktail loaded with 5 HLA-A2 epitopes from AML tumor antigens WT1, PRAME and Cyclin A1. On average, 1-2 x109 T cells were generated that were >90% of the memory phenotype that averaged 18% T stem cells, 40% central memory and 35% effector memory CD8+ T cells. AML-specific T cells were expanded 500 to >5000-fold from low frequency precursor populations. The system has also been used to generate MM specific T cells of the same quality from both from fresh leukopacks and cryopreserved PBL. All generated T cells were fully functional, as demonstrated by intra-cellular cytokine analysis and tumor cell killing.

Conclusion:

AIM ACT is a novel nanoparticle-based T cell platform developed for the rapid, streamlined generation of clinically-relevant numbers of tumor-specific, T stem cell, central and effector memory CD8+ T cells from donor PBMC in 14 days. The platform described here will be used to generate multi-antigen specific CD8+ T cell products that will be evaluated in multi-center P1/2 clinical trials. These trials will enroll r/r MM patients and r/r AML patients pre- and post-allogeneic hematopoietic stem cell transplant. The flexibility of the AIM ACT system, as shown has potential for clinical evaluation in other hematological tumors and can be used for targeting neo-epitopes.

Citation Format: Sojung Kim, Lauren Suarez, Emily Lu, Celine Walmacq, Daniel Dembrow, Juan Varela, Dan Bednárik, Kenneth Carter, Naimish Pandya, Kristi Jones, Mathias Oelke. AIM ACT, a novel nanoparticle-based technology that generates therapeutic numbers of functional tumor-specific CD8+ T cells with T stem cell, central and effector memory phenotype in 14 days [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1423.

Soluble MHC class I complexes for targeted immunotherapy

Major histocompatibility complexes (MHC) have been used for more than two decades in clinical and pre-clinical approaches of tumor immunotherapy. They have been proven efficient for detecting anti-tumor-specific T cells when utilized as soluble multimers, immobilized on cells or artificial structures such as artificial antigen-presenting cells (aAPC) and have been shown to generate effective anti-tumor responses. In this review we summarize the use of soluble MHC class I complexes in tumor vaccination studies, highlighting the different strategies and their contradicting results. In summary, we believe that soluble MHC class I molecules represent an exciting tool with great potential to impact the understanding and development of immunotherapeutic approaches on many levels from monitoring to treatment.

The MLL recombinome of acute leukemias in 2017

Chromosomal rearrangements of the human MLL/KMT2A gene are associated with infant, pediatric, adult and therapy-induced acute leukemias. Here we present the data obtained from 2345 acute leukemia patients. Genomic breakpoints within the MLL gene and the involved translocation partner genes (TPGs) were determined and 11 novel TPGs were identified. Thus, a total of 135 different MLL rearrangements have been identified so far, of which 94 TPGs are now characterized at the molecular level. In all, 35 out of these 94 TPGs occur recurrently, but only 9 specific gene fusions account for more than 90% of all illegitimate recombinations of the MLL gene. We observed an age-dependent breakpoint shift with breakpoints localizing within MLL intron 11 associated with acute lymphoblastic leukemia and younger patients, while breakpoints in MLL intron 9 predominate in AML or older patients. The molecular characterization of MLL breakpoints suggests different etiologies in the different age groups and allows the correlation of functional domains of the MLL gene with clinical outcome. This study provides a comprehensive analysis of the MLL recombinome in acute leukemia and demonstrates that the establishment of patient-specific chromosomal fusion sites allows the design of specific PCR primers for minimal residual disease analyses for all patients.

DNMT3A Haploinsufficiency Transforms FLT3ITD Myeloproliferative Disease into a Rapid, Spontaneous, and Fully Penetrant Acute Myeloid Leukemia

Cytogenetically normal acute myeloid leukemia (CN-AML) represents nearly 50% of human AML. Co-occurring mutations in the de novo DNA methyltransferase DNMT3A and the FMS related tyrosine kinase 3 (FLT3) are common in CN-AML and confer a poorer prognosis. We demonstrate that mice with Flt3-internal tandem duplication (Flt3(ITD)) and inducible deletion of Dnmt3a spontaneously develop a rapidly lethal, completely penetrant, and transplantable AML of normal karyotype. AML cells retain a single Dnmt3a floxed allele, revealing the oncogenic potential of Dnmt3a haploinsufficiency. FLT3(ITD)/DNMT3A-mutant primary human and murine AML exhibit a similar pattern of global DNA methylation associated with changes in the expression of nearby genes. In the murine model, rescuing Dnmt3a expression was accompanied by DNA remethylation and loss of clonogenic potential, suggesting that Dnmt3a-mutant oncogenic effects are reversible. Dissection of the cellular architecture of the AML model using single-cell assays, including single-cell RNA sequencing, identified clonogenic subpopulations that express genes sensitive to the methylation of nearby genomic loci and responsive to DNMT3A levels. Thus, Dnmt3a haploinsufficiency transforms Flt3(ITD) myeloproliferative disease by modulating methylation-sensitive gene expression within a clonogenic AML subpopulation.

SIGNIFICANCE

DNMT3A haploinsufficiency results in reversible epigenetic alterations that transform FLT3(ITD)-mutant myeloproliferative neoplasm into AML. Cancer Discov; 6(5); 501-15. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 461.

Characterization of visual pigments, oil droplets, lens and cornea in the whooping crane Grus americana

Vision has been investigated in many species of birds, but few studies have considered the visual systems of large birds and the particular implications of large eyes and long-life spans on visual system capabilities. To address these issues we investigated the visual system of the whooping crane Grus americana (Gruiformes, Gruidae), which is one of only two North American crane species. It is a large, long-lived bird in which UV sensitivity might be reduced by chromatic aberration and entrance of UV radiation into the eye could be detrimental to retinal tissues. To investigate the whooping crane visual system we used microspectrophotometry to determine the absorbance spectra of retinal oil droplets and to investigate whether the ocular media (i.e. the lens and cornea) absorb UV radiation. In vitro expression and reconstitution was used to determine the absorbance spectra of rod and cone visual pigments. The rod visual pigments had wavelengths of peak absorbance (λmax) at 500 nm, whereas the cone visual pigment λmax values were determined to be 404 nm (SWS1), 450 nm (SWS2), 499 nm (RH2) and 561 nm (LWS), similar to other characterized bird visual pigment absorbance values. The oil droplet cut-off wavelength (λcut) values similarly fell within ranges recorded in other avian species: 576 nm (R-type), 522 nm (Y-type), 506 nm (P-type) and 448 nm (C-type). We confirm that G. americana has a violet-sensitive visual system; however, as a consequence of the λmax of the SWS1 visual pigment (404 nm), it might also have some UV sensitivity.

Decitabine induces delayed reactive oxygen species (ROS) accumulation in leukemia cells and induces the expression of ROS generating enzymes

PURPOSE

Azanucleoside DNA methyltransferase (DNMT) inhibitors are currently approved by the U.S. Food and Drug Administration for treatment of myelodysplastic syndrome. The relative contributions of DNMT inhibition and other off-target effects to their clinical efficacy remain unclear. Data correlating DNA methylation reversal and clinical response have been conflicting. Consequently, it is necessary to investigate so-called off-target effects and their impact on cell survival and differentiation.

EXPERIMENTAL DESIGN

Flow cytometry was used for cell cycle, apoptosis, and reactive oxygen species (ROS) accumulation analysis. Gene expression analysis was performed using real-time PCR. DNA methylation was detected by methylation-specific PCR. Mitochondrial membrane potential was analyzed using JC-1 dye staining. Western blotting was used for quantitative protein expression analysis.

RESULTS

5-Aza-2'-deoxycytidine (DAC) induced cell-cycle arrest and apoptosis in leukemia cells. p53 expression was dispensable for DAC-induced apoptosis. DAC induced delayed ROS accumulation in leukemia cells but not in solid tumor cells and p53 expression was dispensable for ROS increase. ROS increase was deoxycytidine kinase dependent, indicating that incorporation of DAC into nuclear DNA is required for ROS generation. ROS accumulation by DAC was caspase-independent and mediated the dissipation of the mitochondrial membrane potential. Concordantly, ROS scavengers diminished DAC-induced apoptosis. DAC induced the expression of different NADPH oxidase isoforms and upregulated Nox4 protein expression in an ATM-dependent manner, indicating the involvement of DNA damage signaling in Nox4 upregulation.

CONCLUSION

These data highlight the importance of mechanisms other than DNA cytosine demethylation in modulating gene expression and suggest investigating the relevance of ROS accumulation to the clinical activity of DAC.

Non-operative management of acute cholecystitis in the elderly

BACKGROUND

Although cholecystectomy is the standard therapy for acute cholecystitis (AC), operative morbidity in the elderly may be high owing to medical co-morbidities and decreased physiological reserve. Outcomes of AC in the elderly have not been fully defined with regard to operative and long-term non-operative management.

METHODS

Patients aged 65 years or over admitted to a tertiary care centre with a diagnosis of AC between January 2000 and December 2009 were reviewed retrospectively. Patient data, operative and postoperative details were obtained. To determine cholecystectomy rates in the non-operative group, medical records were reviewed, and patients and families were interviewed.

RESULTS

A total of 290 patients underwent cholecystectomy during the index admission, of whom 59 (20·3 per cent) required conversion to open operation. Fifty-eight of these patients experienced 98 complications, including acute respiratory failure (27), pneumonia (18), myocardial infarction (16) and sepsis (15). Some 185 patients had non-operative treatment, of whom 67 underwent percutaneous cholecystostomy. Forty-four patients subsequently had elective cholecystectomy, with a complication rate of 23 per cent. One hundred and twenty-six patients were discharged without a plan for cholecystectomy; the rate of recurrent AC was 4 per cent among the two-thirds of patients followed to within 15 months of death. No deaths or major complications occurred among those with recurrent AC.

CONCLUSION

Despite selection of the best elderly candidates for cholecystectomy, postoperative morbidity was significant. Medical management, with interval cholecystectomy only for recurrent AC, may be appropriate in selected patients.

Preferences of owners of overweight dogs when buying commercial pet food

Most pet dogs in developed countries are fed commercial diets. The aim of this study was to evaluate the preferences of owners of overweight dogs when buying commercial pet food. The study was a descriptive observational multi-centre study on a group of 198 owners of urban household dogs. Personal interviews were conducted to examine the owners' opinions with questions rating the importance of certain qualities of prepared dog food. Bivariate analyses for comparisons of absolute means between groups of owners of dogs with excess weight (n = 137) and owners of normal weight dogs (n = 61) were made using the Mann-Whitney U-test. A low price (p < 0.001) and special offers (p = 0.008) of commercial dog food were more important for owners of dogs with excess weight than for owners of normal weight dogs. The quality of ingredients (p = 0.007) and the nutritional composition (p < 0.001) were more important for owners of normal weight dogs than for owners of dogs with excess weight. The veterinarian was the most important source of information on dog nutrition for both groups (83.6% for owners of normal weight dogs and 83.2% for owners of dogs with excess weight) (p = 0.88). The owners of dogs with excess weight had less interest in corrected dog nutrition than owners of normal weight dogs (p < 0.001).

The Sb14-3-3ζ recombinant protein protects against Schistosoma bovis in BALB/c mice

Schistosoma bovis is a trematode parasite mainly affecting cattle and sheep. Evidences about the arise of drug resistance and the high rates of re-infection of animals in endemic areas have pointed out the need of developing new control tools, e.g., effective vaccines. Schistosomes 14-3-3 proteins have been defined as vaccine candidates against respective infections. We have therefore investigated the protective capacity of the 14-3-3 protein from S. bovis - Sb14zeta - against S. bovis in mice. In addition, we have addressed the influence of the co-administration of four different immunomodulators with the 14-3-3 polypeptide. The values of protection against S. bovis were statistically significant when the Sb14zeta was combined in two independent experiments with the AA0029 (61.0% and 40.31%), AA2829 (49% and 36.3%) and PAL (49% and 40.075%) immunomodulatory molecules. Immune responses from vaccinated animals showed that the highest protection rates do not necessarily match with a dominant Th1-type response.

Seroprevalence of and risk factors for HIV-1 infection among female commercial sex workers in South America

OBJECTIVE

Assessment of HIV prevalence and associated risk behaviours among female commercial sex workers (FCSW) across major cities in South America.

METHODS

Seroepidemiological, cross sectional studies of 13 600 FCSW were conducted in nine countries of South America during the years 1999-2002. Participants were recruited in brothels, massage parlours, hotels, and streets where anonymous questionnaires and blood samples were collected. HIV infection was determined by enzyme linked immunosorbent assay (ELISA) screening and western blot confirmatory tests.

RESULTS

The overall HIV seroprevalence was 1.2% (range 0.0%-4.5%). The highest HIV seroprevalences were reported in Argentina (4.5%) and Paraguay (2.6%); no HIV infected FCSW were detected in Venezuela and Chile. Consistent predictors of HIV seropositivity were: (1) a previous history of sexually transmitted infections (STI, AORs = 3.8-8.3), and (2) 10 years or more in commercial sex work (AORs = 2.2-24.8). In addition, multiple (> or =3) sexual contacts (AOR = 5.0), sex with foreigners (AOR = 6.9), use of illegal drugs (AOR = 3.2), and marijuana use (AOR = 8.2) were associated with HIV seropositivity in Southern Cone countries.

CONCLUSIONS

Consistently low HIV seroprevalences were detected among FCSW in South America, particularly in the Andean region. Predictors of HIV infection across the continent were STI and length of commercial sex work; however, use of illegal drugs, especially marijuana, and sexual contacts with foreigners were also found to be associated risk factors in the Southern Cone region. Interventions for the control of HIV and other STI need to be region and country specific; drug use appears to have an ever increasing role in the spread of HIV among heterosexually active populations.

Predictive models in cirrhosis: correlation with the final results and costs of liver transplantation in Chile

Medical scores for predicting survival are essential to stratify patients with end-stage liver disease (ESLD) for prioritization for liver transplantation (OLT). Recently the UNOS has adopted the Mayo Model for End-stage Liver Disease (MELD) score as the basis for liver allocation in the United States. We retrospectively evaluated and assessed the prognostic impact, the length of stay (LOS), and hospital charges for OLT using two severity scores (Child-Turcotte-Pugh [CTP] versus MELD) to stratify cirrhotic patients before OLT. Twenty-six consecutive adult cirrhotic patients (11 women, mean age 46 years) underwent LT between 2000 and 2002. The main causes for transplantation were alcohol and primary biliary cirrhosis. The mean CTP and MELD scores at the moment of listing for OLT were 8.9 and 16.3 points, respectively. The best discriminative values with prognostic impact in terms of outcome and costs of OLT were a Child Pugh score >/=11 points or a MELD score >/=20 points. Patients in these strata showed a significant increase in LOS in the hospital (from a mean of 12 to 22 days) and intensive care stay (from a mean of 4 to 14 days) post-OLT when compared with patients with a lower CTP or MELD score (P <.05). There was also a trend toward higher hospital charges (P =.06). Organ allocation by MELD score will probably adversely affect the LOS and hospital charges of patients being transplanted due to ESLD.

Clinical characterization and survival of adult patients awaiting liver transplantation in Chile

Liver transplantation has become widely used for patients with decompensated disease. Because of the shortage of donors, each year more patients die on the waiting list. Our aim was to characterize and evaluate the final outcomes of all listed candidates for liver transplantation during a 34-month period. We retrospectively evaluated all adults listed between January 2000 and November 2002. Sixty-three patients (37 women, mean age 45.8 years) were listed: 48 due to chronic liver disease and 15 for a highly urgent transplantation due to acute liver failure. The main etiology of chronic disease was alcoholic (22%) or primary biliary cirrhosis (17%). Of 52 chronic patients, 26 (50%) were transplanted with a mean waiting time of 168 days. Among the others, 8 died (15%) while awaiting transplantation, 3 (5%) were removed from the list, and 15 patients still await transplantation (28%). Among acute liver failure patients, the main etiologies were autoimmune (25%) and medication induced (25%). Of 15 acute patients, 6 (37.5%) have been transplanted at a mean waiting time of 6.8 days with 100% survival posttransplantation. In this cohort, 6 patients (37.5%) died while awaiting liver transplantation, and 4 (25%) survived with medical support. In conclusion, the severity of liver disease and death rate among our waiting list was similar to that observed in developed countries. It seems reasonable to review our current allocation system based on waiting time on the list. We will have to decide whether to transplant sicker patients or those with hepatocarcinoma (as in the United States recently with the MELD system), thereby possibly decreasing the mortality rate on the waiting list at the expense of higher costs and more difficult postoperative care or to just keep our current policy.

Low-grade parasitaemias and cold agglutinins in patients with hyper-reactive malarious splenomegaly and acute haemolysis

A cluster of 16 cases of hyper-reactive malarious splenomegaly (HMS) with severe, acute haemolysis, from an isolated, Venezuelan, Yanomami population, was prospectively investigated. Nine (69%) of the 13 HMS sera investigated but only one (7%) of 14 control sera (P < 0.005) contained elevated titres (of at least 1:32) of complement-fixing IgM cold agglutinins (CA). The CA detected had specificity for both the I and i blood-group antigens (with a relative predominance of anti-I) and wide thermal stability. The mean reciprocal CA titre was much higher for the HMS sera than for the control samples (59.16 v. 2.28; P < 0.001). Indirect tests for antiglobulin were positive for two of the 13 HMS cases (but none of 14 controls) investigated; all of the direct tests for antiglobulin gave negative results. The seven HMS cases checked, using an assay based on a nested PCR which amplified species-specific ribosomal sequences from Plasmodium vivax or P. falciparum, each yielded the PCR product that indicated P. vivax infection. However, only six (25%) of the 24 control samples (collected, at the same time as the HMS samples, from asymptomatic adults from the same Yanomami population) were PCR-positive (P < 0.001). In some cases at least, the acute severe episodes of haemolysis occasionally seen in HMS appear to be associated with an auto-immune, cold-agglutinin-mediated response triggered by non-patent parasitaemias.

Effects of hyperinsulinemia and obesity on risk of neural tube defects among Mexican Americans

Although both maternal obesity and diabetes mellitus increase the risk for neural tube defects, it is unknown whether they are independent risk factors or manifestations of an underlying prediabetic state such as hyperinsulinemia. We investigated whether hyperinsulinemia was a risk factor for neural tube defects independent of obesity and hyperglycemia in Mexican-American women. We identified case and control women from residents delivering or terminating pregnancies in hospitals or birthing centers in any of the 14 Texas-Mexico border counties during 1995-2000. Case women had a pregnancy affected by anencephaly, spina bifida, or encephalocele; randomly selected control women had normal births, frequency matched by year and birth facility. Questionnaire and laboratory values obtained 5-6 weeks postpartum were available for 149 case and 178 control women. Both hyperinsulinemia and obesity were related to increased neural tube defect risk [odds ratio (OR) = 1.91, 95% confidence interval (CI) = 1.21-3.01 and OR = 1.73, 95% CI = 1.03-2.92, respectively]. Adjustment for obesity only slightly reduced the effect of hyperinsulinemia (OR = 1.75, 95% CI = 1.09-2.82). Alternatively, a modest effect remained for obesity after adjustment for hyperinsulinemia (OR = 1.45, 95% CI = 0.84-2.51). Hyperinsulinemia is a strong risk factor for neural tube defects and may be the driving force for the observed risk in obese women.

Cigarette smoking behavior among US Latino men and women from different countries of origin

OBJECTIVES

This study sought to compare smoking behavior among Latino men and women from different countries of origin.

METHODS

A telephone-administered survey was conducted in 8 cities with Latino men and women of different national origin living in census tracts with at least 70% Latino individuals.

RESULTS

A total of 8882 participants completed the survey; 53% were women. The average age of respondents was 44 years; 63% were foreign-born, and 59% preferred Spanish for the interview. Current smoking was more prevalent among men (25.0%, 95% confidence interval [CI] = 23.7, 26.3) than among women (12.1%, 95% CI = 11.1, 13.0). Smoking rates were not significantly different by national origin among men, but Puerto Rican women had higher rates of smoking than other women. Central American men and women had the lowest smoking rates. Foreign-born respondents were less likely to be smokers (odds ratio [OR] = 0.77, 95% CI = 0.66, 0.90) than US-born respondents, and respondents with 12 years or less of education had an increased odds of smoking (OR = 1.17, 95% CI = 1.01, 1.35). High ac culturation was associated with more smoking in women (OR = 1.12, 95% CI = 1.00-1.25) and less smoking in men (OR = 0.86, 95% CI = 0.78-0.95). Puerto Rican and Cuban respondents were more likely to be current smokers and to smoke more than 20 cigarettes per day.

CONCLUSIONS

Older, US-born, and more-educated respondents were less likely to be current smokers. Respondents of Puerto Rican and Cuban origin were more likely to smoke. Acculturation has divergent effects on smoking behavior by sex.

Neural tube defects among Mexican Americans living on the US-Mexico border: effects of folic acid and dietary folate

Populations of Mexican descent have high occurrences of neural tube defects (NTDs). A recent study suggested that folic acid supplements may not protect these populations from NTDs. In a case-control study, the authors investigated the role of folic acid and dietary folate intake in NTD risk among Mexican Americans living along the Texas-Mexico border. From January 1995 to February 1999, 148 Mexican-American women with NTD-affected pregnancies and 158 women with normal live births were interviewed in person about use of vitamin supplements and dietary intakes during a 6-month periconceptional period (from 3 months before conception to 3 months after conception). Daily preconceptional consumption of vitamin supplements containing folic acid was 2.5% in control women and 2.0% in case women (odds ratio = 0.77; 95% confidence interval (CI): 0.19, 3.22). With adjustment for maternal age, education, obesity, and previous stillbirth or miscarriage, the risk estimate was essentially null (odds ratio = 1.12; 95% CI: 0.22, 5.78). Combined folic acid intake from diet and supplements showed only a modest risk reduction for intakes of > or = 1.0 mg per day (adjusted odds ratio = 0.73; 95% CI: 0.31, 1.72). The fact that the primary folic acid exposure was in the form of dietary polyglutamates rather than the more easily absorbed supplemental monoglutamates may explain an apparent decreased effect in this population.

Breast cancer screening in regional Hispanic populations

Although Hispanics' use of breast cancer screening services has been investigated, to date there have been no published studies of distinct Hispanic populations in different areas of the country. Using the diverse populations and sites involved in the National Hispanic Leadership Initiative on Cancer 'En Acción', this study examines ethno-regional differences in breast cancer screening rates among these groups and explores the correlates of screening participation. Data collected through telephone surveys were analyzed for women 40 years of age and older (n = 2082). After controlling for demographic variables traditionally related to breast cancer screening rates, it was found that ethno-regional differences in breast cancer screening practices clearly persisted. In addition to traditional demographic factors, other variables evidently underlie differences in Hispanics' utilization of breast cancer screening services. These variables may be cultural and should be investigated in future research. Meanwhile, researchers should not refer to the 'Hispanic' population at large without identifying, addressing and clarifying the ethno-regional characteristics of their samples.

Social networks and cancer screening in four U.S. Hispanic groups

BACKGROUND

Evidence shows that social relationships play an important role in health and health behavior. We examined the relationship between social networks and cancer screening among four U.S. Hispanic groups.

METHODS

We used telephone surveys to collect data in eight U.S. regions that have concentrations of diverse Hispanic-origin populations. We interviewed 8903 Hispanic adults, for a response rate of 83%; analysis was restricted to the 2383 women aged > or =40. As a measure of social integration, we formed a social network index from items on the number of close relatives and friends, frequency of contact, and church membership. We used logistic regression to estimate the effects of social integration on screening, adjusting for sociodemographic factors.

RESULTS

Among Mexican, Cuban, and Central-American women, the effect of social integration on mammography screening was slight. The odds ratios (OR) per unit change in social integration category ranged from 1.16 to 1.22 with confidence intervals (CI) that overlapped with the null. For Pap smear screening, the effect was strongest among Mexican-American women (OR=1.44, 95% CI=1.21 to 1.72), but also evident among Central-American women (OR=1.22, 95% CI=0.72 to 2.06) and Cuban women (OR = 1.25, 95% CI = 0.81 to 1.93). Among Puerto Rican women, social integration had no effect on either mammography (OR=1.03) or Pap smear screening (OR=1.08).

CONCLUSIONS

Independent of socioeconomic factors, social integration appears to influence cancer screening participation of Hispanic women. The modest effect is not universal across Hispanic groups and was stronger for Pap smear than for mammography screening behavior. Researchers should recognize Hispanic group differences in social network characteristics and the potential of social networks to change screening behavior.

Texas physician immunization practices

INTRODUCTION

Immunization levels among young children could be improved if physicians administered immunizations at both well and urgent visits, provided simultaneous vaccinations, and knew the guidelines on valid contraindications, part of the Standards for Pediatric Immunization Practices (Standards). We report on a survey measuring the immunization knowledge and practice of Texas pediatricians, family practitioners, and general practitioners.

METHODS

A survey was mailed to a random sample of physicians. Questionnaire items covered 8 of the 18 Standards.

RESULTS

The response rate was 62% (608 of 976 eligible physicians). The mean summary adherence-to-Standards score was 4.1 for pediatricians, 3.6 for family practitioners, and 3.0 for general practitioners. Specialty and practice location were significant predictors of the summary score, whereas gender, managed-care participation, and graduation year were not.

DISCUSSION

Our study results suggest that in Texas, pediatricians and rural physicians most often adhere to the Standards. Improving the reimbursement level of administrative costs for immunization delivery, educating physicians on the Standards, and encouraging the use of patient immunization tracking systems are actions that could potentially improve immunization rates.

Investigation of folate pathway gene polymorphisms and the incidence of neural tube defects in a Texas hispanic population

Neural tube defects (NTDs) are multifactorial in their etiology, having both genetic and environmental factors contributing to their development. Recent evidence demonstrates that periconceptional supplementation of the maternal diet with a multivitamin containing folic acid significantly reduces the occurrence and recurrence risk for having a pregnancy complicated by NTDs. Unfortunately, the mechanism underlying the beneficial effects of folic acid remains unknown. NTD surveillance data from the Texas-Mexico border show that the high NTD rate (28/10,000 live births) noted during the 1990-1991 Cameron county NTD cluster was superimposed on a background Cameron county NTD rate (16/10,000 live births) which is considerably higher than that generally noted in the United States (8-10/10,000 live births). These data suggest that genetic factors as well as transient environmental factors may contribute to the etiology of the NTDs. Furthermore, clinical and experimental evidence imply that allelic forms of genes involved with folate metabolism and/or transport may explain some of the observed variation in the NTD rates found across different populations. Two folate pathway genes were selected for evaluation in this study. The loci investigated included two known alleles of the 5, 10-methylenetetrahydrofolate reductase (MTHFR) gene, as well as the promoter region of the folate receptor-alpha (FR-alpha) gene. Odds ratios (ORs) for the C677T polymorphism in the MTHFR gene were 1.8 (CI 0.47-6.8) for heterozygosity and 1.8 (CI 0.35-9.4) for homozygosity for the mutant 677T allele, relative to wildtype homozygotes. The odds ratio for the heterozygosity for the A1298C polymorphism in the same gene was 1.1 (CI 0.09-14). No individuals homozygous for the 1298C allele were observed. The OR for heterozygosity of FR-alpha gene polymorphisms detected at nucleotide 762 and at nucleotides 610/631 was 1.4 and 0.7, respectively. Neither of the FR-alpha polymorphisms was observed in the homozygous condition. No statistically significant associations were observed for any of the polymorphisms examined, as the 95% confidence intervals for all of the ORs included one. However, the frequency of the MTHFR 677T allele in the largely Hispanic control group from Texas was significantly different from other populations (P < 0.005), and among the highest reported for any control populations examined.

Hispanic women's breast and cervical cancer knowledge, attitudes, and screening behaviors

PURPOSE

This study examined breast and cervical cancer knowledge, attitudes, and screening behaviors among different Hispanic populations in the United States.

DESIGN

Data were collected from a random digit dial telephone survey of 8903 Hispanic adults from eight U.S. sites. Across sites, the average response rate was 83%.

SETTING

Data were collected as part of the baseline assessment in a national Hispanic cancer control and prevention intervention study.

SUBJECTS

Analysis was restricted to 2239 Hispanic women age 40 and older who were self-identified as either Central American (n = 174), Cuban (n = 279), Mexican American (n = 1550), or Puerto Rican (n = 236).

MEASURES

A bilingual survey instrument was used to solicit information on age, education, income, health insurance coverage, language use, U.S.-born status, knowledge of screening guidelines, attitudes toward cancer, and screening participation. Differences in knowledge and attitudes across Hispanic groups were assessed by either chi-square tests or analysis of variance. Logistic regression models assessed the influence of knowledge and attitudes on screening participation.

RESULTS

The level of knowledge of guidelines ranged from 58.3% (Mexican Americans) to 71.8% (Cubans) for mammography, and from 41.1% (Puerto Ricans) to 55.6% (Cubans) for Pap smear among the different Hispanic populations. Attitudes also varied, with Mexican Americans and Puerto Ricans having more negative or fatalistic views of cancer than Cuban or Central Americans. Knowledge was significantly related to age, education, income, language preference, and recent screening history. Overall, attitudes were not predictive of mammography and Pap smear behavior.

CONCLUSIONS

Factors related to mammography and Pap smear screening vary among the different Hispanic populations. Limitations include the cross-sectional nature of the study, self-reported measures of screening, and the limited assessment of attitudes. The data and diversity of Hispanic groups reinforce the position that ethno-regional characteristics should be clarified and addressed in cancer screening promotion efforts. The practical relationships among knowledge, attitudes, and cancer screening are not altogether clear and require further research.

Prevalence and risk factors of drug-resistant tuberculosis along the Mexico-Texas border

OBJECTIVES

This study determined factors associated with drug resistance among 3496 patients with tuberculosis who resided in Texas counties along the Mexican border.

METHODS

Univariate and logistic regression analyses were performed to identify risk factors associated with drug resistance.

RESULTS

Among patients with a history of previous tuberculosis, being 19 years or younger was the only factor associated with multiple drug resistance. Female sex, being 20 to 39 years of age, and foreign birth were risk factors for resistance among patients with no history of previous tuberculosis.

CONCLUSIONS

Factors contributing to drug resistance among Hispanic tuberculosis patients along the Texas-Mexico border may differ from those among other populations in the United States.

Epidemiology of drug-resistant tuberculosis in Texas

During 1987-1996, over 22,000 tuberculosis cases were reported in Texas, at an average annual incidence rate of 12.5 cases per 100,000 population. Counties with the highest rates were located along the Mexico-Texas border and in northwestern Texas. Nine percent of cases were resistant to at least one of the five first-line antituberculosis drugs used for treatment. Almost 5 percent (4.6%) were resistant to isoniazid, either alone or in combination with other antibiotics; 2.3% were resistant to rifampin; and only 1.3% were resistant to both isoniazid and rifampin. Being a recurrent case, being foreign-born, being 20-39 years of age, and residing in a Mexico-Texas border county were independent risk factors for isoniazid resistance and rifampin resistance. Tuberculosis patients with human immunodeficiency virus (HIV) infection were more likely to have rifampin resistance and less likely to have isoniazid resistance than patients without HIV infection. Factors associated with multi-drug-resistant tuberculosis included a history of previous tuberculosis (relative risk (RR) = 4.91, 95% confidence interval (CI) 3.5-6.8), non-US birth (RR = 2.69, 95% CI 2.1-3.5), age younger than 20 years (RR = 1.97, 95% CI 1.1-3.5), age 20-39 years (RR = 1.82, 95% CI 1.3-2.6), and residence in a Mexico-Texas border county (RR = 2.33, 95% CI 1.8-3.1).

Perceived family characteristic differences between depressed and anxious children and adolescents

BACKGROUND

The present study compared anxious vs. depressed children's and adolescents' perceptions about their family environment.

METHODS

One hundred inpatient youngsters were interviewed for the study. Of these participants, 21 who met criteria for a depressive disorder without an anxiety disorder and 18 who met criteria for an anxiety disorder without a depressive disorder were compared on several self-report family measures. These measures included the Family Adaptability and Cohesion Evaluation Scales-II (FACES-II), Family Strengths, and Social Support Questionnaire-Revised (SSQS-R).

RESULTS

Youngsters with depressive disorders reported having less pride in their families and perceived their families as being less adaptable to problems than did anxious children. Also, depressed children expressed lower levels of satisfaction with their social network than did anxious children.

LIMITATIONS

The fact that our study only included reports from inpatient youngsters, families of anxious and depressed children may differ in the way family members relate to one another and in the way they deal with everyday problems.

CONCLUSIONS

Based on the evidence obtained in this study, anxiety and depression may be two distinct internalizing disorders with specific family characteristics.

Advancing the role of participatory communication in the diffusion of cancer screening among Hispanics

Based on previously demonstrated methods, a cancer prevention program combining media and interpersonal communication was conducted in a Texas border city (Brownsville) in 1995-1996. To evaluate the program a quasi-experimental panel design study followed 107 women in a program site and 105 women in a comparison site from 1994 to 1996. Women in the program site reported an increase in levels of Pap screening adherence.

When acculturation hurts: the case of immunization

The study examined the relationship between the acculturation of Mexican American mothers in Texas and immunization status of their children between 3 and 24 months of age. Mothers' acculturation, demographic characteristics, and immunization status of their children were assessed in in-person interviews with a sample of Mexican American respondents representative for Texas (n = 2193). Acculturation was measured with ten scales assessing oral and written language use, proficiency, and preference, music and TV viewing preferences, ethnic identity, place where a person was reared, and contacts with Mexico. Immunization status, defined according to the recommendation of the CDC Advisory Committee on Immunization Practices, was determined from official shot records obtained directly from respondents or, for respondents without records, obtained from their health care providers. Regression analysis revealed that acculturation significantly contributed to inadequate immunization status, even when socioeconomic status and other demographic covariates of acculturation were statistically controlled. Mediational analysis revealed that acculturation contributed to inadequate immunization through less positive attitudes toward immunization, a diminished sense of parental responsibility for children's immunization, and more perceived barriers to immunization. It is concluded that culture-specific beliefs encouraging childhood immunization should be fostered among Mexican Americans.

Family characteristics and behavior problems of suicidal and non-suicidal children and adolescents

The present study examined familial and individual variables in youngsters at high risk for suicide and non-suicidal youngsters. One hundred inpatient children and adolescents completed a battery of questionnaires including, FACES II, Family Strengths, and Problem Behavior Scales, to assess family dysfunction and individual behavior problems. The results indicated that suicidal youngsters have lower pride in their families and perceived them as less adaptable than non-suicidal youngsters as indicated by scores on the Family Strengths and FACES II, respectively. Scores on the Problem Behavior Scales indicated that suicidal youngsters also exhibited self-inflicted behaviors, withdrawal from others, little interest in activities, poor concentration, and difficulties with sleeping. In addition, youths at risk for suicide were more likely to be diagnosed with a mood disorder, including major depressive disorder and dysthymia, as well as substance abuse and phobias. These findings suggest that suicidal youngsters' negative perceptions of their families and their maladaptive behaviors should be given special attention in designing appropriate interventions. In this way, treatment would likely be effective by providing appropriate coping skills and preventing future suicidal attempts in high risk youngsters.

Concerns and dilemmas of Hispanic AIDS information seekers: Spanish-speaking callers to the CDC National AIDS hotline

Hispanic communities suffer disproportionately from the impact of human immunodeficiency virus infection (HIV). Each year, thousands of Spanish-speaking Hispanics call the Centers for Disease Control and Prevention National AIDS Hotline to ask questions about HIV. During 1995 alone, Spanish line staff answered more than 29,000 calls. This article presents a profile of callers and their concerns based on a systematic sample of these calls (N = 6,933) and qualitative data. The authors triangulated quantitative and qualitative results to provide a deeper understanding of the issues and dilemmas discussed with callers. Males and females called in equal numbers, but significant gender differences were observed in both situational and content variables. Gender roles, cultural values, and anxiety strongly affect the way that callers approach information and prevention. Findings suggest that health educators need to carefully examine whether prevention programs will reinforce or challenge traditional gender roles, sexual norms, and cultural values.