The role of complement-fixing donor-specific antibodies identified by a C1q assay after heart transplantation.

BACKGROUND: The development of donor-specific antibodies (DSA) to human leukocyte antigens (HLA) has been associated with acute rejection and allograft failure after heart transplantation. Not all DSA, however, can fix complement. METHODS: To determine the association between complement-fixing DSA and heart transplant outcomes, we retrospectively analyzed results obtained using the C1q solid-phase assay that specifically detects complement-fixing DSA in parallel with the standard IgG assay in 121 adult heart transplant recipients. RESULTS: The 52 recipients who developed post-transplant DSA had a higher incidence of acute cellular rejection (58% vs 19%, P < .001) and antibody-mediated rejection (29% vs 7%, P < .001) than the 69 recipients without DSA. The 24 recipients with C1q+ DSA had more antibody-mediated rejection than the 28 recipients with C1q- DSA (46% vs 14%, P = .012), but there was no difference in the incidence of acute cellular rejection between these two groups. Patients with post-transplant DSA had higher mortality than patients with no DSA (29% vs 13%, P = .031), mainly due to increased incidence of acute rejection. No differences in survival were found between recipients with C1q+ DSA and C1q- DSA. CONCLUSIONS: Routine monitoring of DSA post-transplant, and their characterization using the C1q assay, may provide prognostic information for acute rejection after heart transplantation.

The killer immunoglobulin-like receptor KIR3DL1 in combination with HLA-Bw4 is protective against multiple sclerosis in African Americans.

We investigated the role of the KIR loci and their HLA class I ligands in a large cohort of African American multiple sclerosis (MS) patients (N=907) and controls (N=1456). No significant differences in carrier frequencies for any KIR locus or haplotype were observed between cases and controls. However, examination of KIR in the context of their cognate HLA ligands revealed a strong protective effect for KIR3DL1 in combination with HLA-A and -B alleles bearing the Bw4 motif (P=10(-8); odds ratio (OR)=0.60, confidence interval (CI)=0.50-0.71) and the Bw4 ligand alone (P<10(-6); OR=0.63, CI=0.53-0.75). The observed effect cannot be explained by either a specific HLA-B allele or by linkage disequilibrium with HLA-DRB1 or HLA-A. The protective effect was observed only in individuals who were not positive for the MS risk allele HLA-DRB1*15:01 (P<10(-6); OR=0.61, CI=0.51-0.74). Our study, the first investigation of KIR and MS in African Americans, confirms and refines previous findings in a European cohort.

Improved strategies for HIV diagnosis among men who have sex with men (MSM) in Buenos Aires, Argentina, a population with a high prevalence and incidence of HIV infection.

BACKGROUND: In Argentina, HIV diagnosis in adults is made using one or two enzyme immunoassay tests and a confirmatory test. These strategies may fail to identify infected individuals during early primary infection, which represents an important public health problem among groups with a high HIV incidence, such as men who have sex with men (MSM) (6.3% persons/year). The general objective of this study was to contribute to reducing HIV transmission among MSM through the identification of antibody-negative, nucleic acid-positive individuals. FINDINGS: A total of 1549 MSM were recruited for an HIV seroprevalence study. A total of 161 (10.4%) MSM were HIV-positive and 14 (0.9%) were indeterminate. Among the 1374 negative individuals, 16 (1.2%) exhibited reactive results in the screening assay. Indeterminate Western blot (WB) samples and negative WB samples (with discordant results in the screening) were analysed to detect HIV nucleic acid by viral load testing. Up to 23.1% of HIV-indeterminate WB samples and 7.1% of HIV-negative WB samples with discordant results in the screening assays had detectable nucleic acid. Overall, 14.8% of the samples with discordant or indeterminate results were identified as HIV-positive using direct diagnosis. With the identification of four new cases using the nucleic acid detection test, the HIV prevalence in MSM increased by 0.3% (from 10.4 to 10.7%). CONCLUSIONS: The results of this study suggest the importance of including nucleic acid detection in the HIV algorithm for MSM with HIV-indeterminate WB results and those with HIV-negative WB results and discordant results in screening assays, in order to decrease HIV transmission among this population with a high HIV prevalence and incidence.

A multi-site study using high-resolution HLA genotyping by next generation sequencing.

The high degree of polymorphism at human leukocyte antigen (HLA) class I and class II loci makes high-resolution HLA typing challenging. Current typing methods, including Sanger sequencing, yield ambiguous typing results because of incomplete genomic coverage and inability to set phase for HLA allele determination. The 454 Life Sciences Genome Sequencer (GS FLX) next generation sequencing system coupled with conexio atf software can provide very high-resolution HLA genotyping. High-throughput genotyping can be achieved by use of primers with multiplex identifier (MID) tags to allow pooling of the amplicons generated from different individuals prior to sequencing. We have conducted a double-blind study in which eight laboratory sites performed amplicon sequencing using GS FLX standard chemistry and genotyped the same 20 samples for HLA-A, -B, -C, DPB1, DQA1, DQB1, DRB1, DRB3, DRB4, and DRB5 (DRB3/4/5) in a single sequencing run. The average sequence read length was 250 base pairs and the average number of sequence reads per amplicon was 672, providing confidence in the allele assignments. Of the 1280 genotypes considered, assignment was possible in 95% of the cases. Failure to assign genotypes was the result of researcher procedural error or the presence of a novel allele rather than a failure of sequencing technology. Concordance with known genotypes, in cases where assignment was possible, ranged from 95.3% to 99.4% for the eight sites, with overall concordance of 97.2%. We conclude that clonal pyrosequencing using the GS FLX platform and CONEXIO ATF software allows reliable identification of HLA genotypes at high resolution.

BoLA-DRB3 exon2 polymorphisms among tuberculous cattle: Nucleotide and functional variability and their association with bovine tuberculosis pathology.

Bovine tuberculosis (bTB) is caused by Mycobacterium bovis and disseminated worldwide. In Argentina, the highest prevalence occurs in dairy areas. BoLA DRB3.2 is related to the adaptive immunity in mycobacterial infections. Genetic polymorphisms of this marker have been associated with resistance or susceptibility to bovine diseases. We evaluated the association between BoLA DRB3.2 polymorphisms and bTB pathology scores in dairy and beef cattle breeds of Argentina. Most bovines exhibited visible lesions compatible with tuberculosis and, furthermore, 150 (85.7%) were also positive by bacteriology. A pathology index showed a variable degree of disease, from 3 to 76 (median pathology score = 9 (IQR: 7-15)). Thirty-five BoLA DRB3.2 alleles were identified with an associated frequency from 16% to 0.3%, distributed 73% (n = 128) in heterozygosis and 27% (n = 47) in homozygosis, with 12 BoLA DRB3.2 alleles (*0101, *1101, *1501, *0201, *2707 *1001, *1002, *1201, *14011, *0501 *0902 and *0701) representing the 74.7% of the population variability. A functional analysis grouped them in 4 out of 5 clusters (A-D), suggesting a functional overlapping. Among the 90 identified genotypes, *1101/*1101, *1101/*1501 and *0101/*0101 were the most frequent (10%, 8.9% and 8.9%, respectively). No association was detected between the pathology scores and a specific DRB3.2 allele (p > .05). Animals infected with M. bovis spoligotype SB0153 showed a significantly higher pathology score than those affected by the spoligotype SB0145 (p = .018). Furthermore, the Aberdeen Angus breed exhibited highest pathological scores (p < .0001), which were associated with disseminated lesion, thus suggesting that the host component could be important to the disease progression.

Reciprocal role of ERK and NF-kappaB pathways in survival and activation of osteoclasts.

To examine the role of mitogen-activated protein kinase and nuclear factor kappa B (NF-kappaB) pathways on osteoclast survival and activation, we constructed adenovirus vectors carrying various mutants of signaling molecules: dominant negative Ras (Ras(DN)), constitutively active MEK1 (MEK(CA)), dominant negative IkappaB kinase 2 (IKK(DN)), and constitutively active IKK2 (IKK(CA)). Inhibiting ERK activity by Ras(DN) overexpression rapidly induced the apoptosis of osteoclast-like cells (OCLs) formed in vitro, whereas ERK activation after the introduction of MEK(CA) remarkably lengthened their survival by preventing spontaneous apoptosis. Neither inhibition nor activation of ERK affected the bone-resorbing activity of OCLs. Inhibition of NF-kappaB pathway with IKK(DN) virus suppressed the pit-forming activity of OCLs and NF-kappaB activation by IKK(CA) expression upregulated it without affecting their survival. Interleukin 1alpha (IL-1alpha) strongly induced ERK activation as well as NF-kappaB activation. Ras(DN) virus partially inhibited ERK activation, and OCL survival promoted by IL-1alpha. Inhibiting NF-kappaB activation by IKK(DN) virus significantly suppressed the pit-forming activity enhanced by IL-1alpha. These results indicate that ERK and NF-kappaB regulate different aspects of osteoclast activation: ERK is responsible for osteoclast survival, whereas NF-kappaB regulates osteoclast activation for bone resorption.

Microtubule proteins and their post-translational forms in the cerebrospinal fluid of patients with paraparesis associated with HTLV-I infection and in SH-SY5Y cells: an in vitro model of HTLV-I-induced disease.

HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is characterized by axonal degeneration of the corticospinal tracts. The specific requirements for transport of proteins and organelles to the distal part of the long axon are crucial in the corticospinal tracts. Microtubule dysfunction could be involved in this disease, configuring an axonal transport disease. We measured tubulin and its post-translational modified forms (acetylated and tyrosinated) in CSF of patients and controls, as well as tau and its phosphorylated forms. There were no significant differences in the contents of tubulin and acetyl-tubulin between patients and controls; tyrosyl-tubulin was not detected. In HAM/TSP, tau levels were significantly reduced, while the ratio of pT181/total tau was higher in patients than in controls, this being completely different from what is reported in other neurodegenerative diseases. Phosphorylation at T181 was also confirmed by Mass Spectrometry analysis. Western Blotting with monospecific polyclonal antibodies against pS199, pT205, pT231, pS262, pS356, pS396, pS404 and pS422 did not show differences in phosphorylation in these residues between patients and controls. Treating human SH-SY5Y neuroblastoma cells, a well-known in vitro neurite retraction model, with culture supernatant of MT-2 cells (HTLV-I infected cell line that secretes the viral Tax protein) we observed neurite retraction and an increase in tau phosphorylation at T181. A disruption of normal phosphorylation of tau protein in T181 could result in its dysfunction, contributing to axonal damage.

[Prevalence of human immunodeficiency virus (HIV)-Trypanosoma cruzi co-infection and injectable-drugs abuse in a Buenos Aires health center]. / Prevalencia de la coinfección virus de la inmunodeficiencia humana (VIH)-Trypanosoma cruzi e impacto del abuso de drogas inyectables en un centro de salud de la ciudad de buenos aires.

The aim of this study was to evaluate the prevalence of human immunodeficiency virus (HIV)-Trypanosoma cruzi co-infection in a Buenos Aires health center. A retrospective analysis of the clinical charts of 602 HIV-infected patients was performed. Only 51.3% of the patients were evaluated against T. cruzi. The global co-infection prevalence was 4.2%, being more frequent among injectable drug users (IDU) (8.9% vs. 2.6%, < 0.05). The indication of T. cruzi testing should be stressed for HIV-infected patients, especially in those centers where IDU are assisted.

Signaling to the mammalian circadian clocks: in pursuit of the primary mammalian circadian photoreceptor.

The mammalian circadian system is critical for the proper regulation of behavioral and physiological rhythms. The central oscillator, or master clock, is located in the hypothalamic suprachiasmatic nucleus (SCN). Additional circadian clocks are dispersed throughout most organs and tissues of an animal. The most prominent stimuli capable of synchronizing circadian oscillations to the environment is light. This occurs through daily photic signaling to the SCN, which ultimately results in the appropriate phasing of the various biological rhythms. Two critical aspects of circadian biology that will be discussed here are photic signaling and the communication between central and peripheral clocks. After 10 years of investigation, the primary mammalian circadian photoreceptor remains elusive. Recent findings suggest that multiple photoreceptive molecules may contribute to the perception of environmental light cycles. In addition, the relatively recent identification of cell-autonomous peripheral clocks has opened up an entirely new area of investigation. Deciphering the communication networks responsible for harmonious central and peripheral clock function is a critical step toward the development of effective therapies for circadian-related disorders.

Diverse BF recombinants have spread widely since the introduction of HIV-1 into South America.

OBJECTIVE: To describe the genetic diversity of HIV-1 in South America by full genome sequencing and analysis. METHODS: Purified peripheral blood mononuclear cell DNA from HIV-infected individuals in Argentina, Uruguay and Bolivia was used to amplify full HIV-1 genomes. These were sequenced using the ABI 3100 automated sequencer and phylogenetically analysed. RESULTS: Twenty-one HIV-1 strains from three South American countries, 17 of which were pre-screened by envelope heteroduplex mobility assay (HMA), were studied. Ten out of 10 HMA subtype F and four out of seven HMA subtype B strains were actually BF recombinants upon full genome analysis. Two BF recombinants from Argentina and two from Uruguay had the same structure, representing a new circulating recombinant form termed CRF12_BF(ARMA159). Twelve other BF recombinants had structures related to CRF12 but with additional segments of subtype B; each was unique. BF recombinants were temporally and geographically widespread, found as early as 1986-1987 in vertically infected Argentinian children and in Argentina, Uruguay, and Bolivia.

Chronic active autoimmune hepatitis in children. Strong association with a particular HLA-DR6 (DRB1*1301) haplotype.

The association of HLA antigens and type I or "lupoid" CAH-C was investigated in a population of 52 Argentinian Caucasoid patients. When compared with a population of normal individuals of the same ethnic group (n = 197), a significant increase of HLA-DR6 was observed (68.6% in patients vs 17.3% in controls; RR = 12.3, chi 2 = 52.4, pc = 0.00001). DNA typing showed that the HLA-DRB1*1301 allele was present in 32 out of 33 HLA-DR6 patients (66.6% of all the C-CAH patients vs 10.5% in controls; RR = 16.2, chi 2 = 111.3, pc = 0.00001). Analysis of HLA-DQB1 alleles also showed a significant increase of DQB1*0603 (RR = 15.4, chi 2 = 106.5, pc = 0.00001), an allele found in strong linkage disequilibrium with DRB1*1301. The association of CAH-C with this particular HLA-DR6 haplotype has not been previously described for the adult onset CAH. This different HLA predisposition, together with the fact that extrahepatic autoimmune diseases occur frequently only in the adult form of the disease, suggest that the immunopathogenic mechanisms involved in the development of these diseases may be different.

Mother-to-child HIV type 1 transmission in Argentina: BF recombinants have predominated in infected children since the mid-1980s.

The molecular epidemiology of HIV-1 in Argentina is more complex than was previously appreciated. One circulating recombinant form, CRF12_BF, and many related BF recombinant forms predominate in the capital city, Buenos Aires. This study of HIV-1 subtypes acquired perinatally between 1984 and 2000 has permitted, for the first time, a reconstruction of the history of BF recombination in Argentina. Sequencing of a partial genome region from the beginning of vpu to the beginning of env(gp120), which spans a breakpoint common in most contemporary Argentine BF recombinants, enabled samples to be rapidly screened. Among 23 children born between 1984 and 2000, 15 including 1 child born in 1986, harbored a BF recombinant. Thirteen of the 15 recombinants shared a common breakpoint at the 5' end of env(gp120). Full genome sequencing of two viruses, from 1986 and 1987, respectively, revealed them to be genetically related but not identical to CRF12_BF. Both contained more subtype B sequence than did CRF12_BF. BF recombinants related to CRF12_BF have been in circulation in Buenos Aires since 1986 and continue to predominate in perinatal transmissions.

Documentation of subtype C HIV Type 1 strains in Argentina, Paraguay, and Uruguay.

HIV subtypes B, F, and BF recombinants have been previously reported in South America. This report describes the presence of HIV-1 subtype C infection in the countries of Argentina, Uruguay, and Paraguay dating back to at least 1999. Surveillance for uncommon non-B/non-F subtype viruses circulating in South America has been conducted in samples obtained from nine countries. Peripheral blood mononuclear cells (PBMC), dried filter paper (FP), and fresh blood (FB) samples were collected from HIV-positive patients from Ecuador, Colombia, Venezuela, Peru, Chile, Bolivia, Argentina, Uruguay, and Paraguay. From a total of 2962 HIV seropositive samples examined during a 9-year period (1995-2003), only 11 (0.4%) were found to be infected with non-B/non-F HIV variants. Eight of these 11 strains were determined to be subtype C by heteroduplex mobility assay (HMA). Five of these 8 strains were further characterized by sequencing and phylogenetic analysis of the protease (Pro) and reverse transcriptase (RT) region of the genome and two were sequenced full length. One of the strains was found to be a unique BC recombinant. The spread of a third subtype of HIV, subtype C, should raise the question of its potential future role in the HIV epidemic in this region.

[Distribution of subtypes and recombinant of HIV. Situation in Argentina]. / Distribución de subtipos y recombinantes del HIV. Situación en la Argentina.

Soon after HIV (Human Immunodeficiency Virus) was discovered, its characteristics level of diversity and variability was established. So far, within HIV-1 it is known that there exist 3 main groups, 9 subtypes and at least 12 recombinant forms. Not only does this diversity affect taxonomy, but also prophylaxis and therapy for HIV infection. Numerous studies worldwide have demonstrated the influence this variability has on both diagnosis and monitoring assays as well as on the pathogenesis of HIV infection. In Argentina, from the molecular point of view, the epidemic shows a complex pattern. HIV-1 subtypes B and F have been described as well as a recombinant B/F form. Epidemiology and molecular data suggest high percentage levels and a great diversity of these recombinant forms in the heterosexual population.

[Prevalence of ankyloglossia in newborns in Asturias (Spain)]. / Prevalencia de anquiloglosia en recién nacidos en el Principado de Asturias.

INTRODUCTION: The prevalence of ankyloglossia has been estimated at around 4% of live births. Its prevalence at national level is unknown. MATERIAL AND METHODS: Multicenter, prospective observational study. Six hospitals in Asturias took part. All newborns were examined on Sundays, Tuesdays and Thursdays for 3 months. Coryllos and Hazelbaker criteria were used to diagnose ankyloglossia. RESULTS: The prevalence in the 667 newborns examined was 12.11% (95% CI: 9.58 to 14.64), of whom 62% were male. One in 4 children with ankyloglossia had a family history. According to Coryllos' classification, type II was the most common (54%). CONCLUSIONS: The prevalence of ankyloglossia in Asturias was 2 to t3 times higher than expected. The diagnostic criteria for ankyloglossia needs to be unified, and further studies are required to determine the association with breastfeeding difficulties and other health problems.

Pregnancy-related human leukocyte antigen sensitization leading to cardiac allograft vasculopathy and graft failure in a heart transplant recipient: a case report.

In this report, we present a heart transplant recipient who developed cross-reactive paternal and donor-specific human leukocyte antigen (HLA) class II antibodies during pregnancy, leading to accelerated cardiac allograft vasculopathy and severe allograft dysfunction 17 years after transplantation. This resulted in acute heart failure and ventricular arrhythmias requiring repeat heart transplantation.

Desensitization combined with paired exchange leads to successful transplantation in highly sensitized kidney transplant recipients: strategy and report of five cases.

Sensitization remains a major barrier to kidney transplantation. Sensitized patients comprise 30% of the kidney transplant waiting list but fewer than 15% of highly sensitized patients are transplanted each year. Options for highly sensitized patients with an immunologically incompatible living donor include desensitization or kidney paired donation (KPD). However, these options when used alone may still not be sufficient to allow a compatible transplant for recipients who are broadly sensitized with cumulative calculated panel-reactive antibody (cPRA) > 95%. We describe in this report the combined use of both desensitization and KPD to maximize the likelihood of finding a compatible match with a more immunologically favorable donor through a kidney exchange program. This combined approach was used in five very highly sensitized patients, all with cPRA 100%, who ultimately received compatible living and deceased donor kidney transplants. We conclude that early enrollment in paired kidney donor exchange and tailored desensitization protocols are key strategies to improve care and rates of kidney transplantation in highly sensitized patients.

EHT0202 in Alzheimer's disease: a 3-month, randomized, placebo-controlled, double-blind study.

BACKGROUND: EHT0202 (etazolate hydrochloride) is a new compound exhibiting both potential disease-modifying and symptomatic treatment properties in Alzheimer's Disease increasing alpha-secretase activity and sAPP alpha secretion, as well as acting as a GABA-A receptor modulator and as a PDE-4 inhibitor. METHODS: This pilot, randomized, double-blind, placebo-controlled, parallel group, multicentre, Phase IIA study was conducted in 159 randomized patients suffering from mild to moderate Alzheimer's Disease. EHT0202 (40 or 80 mg bid) or placebo was administered as adjunctive therapy to one acetylcholinesterase inhibitor over a 3-month period. This study was designed to assess the clinical safety and tolerability of EHT0202 as a primary objective, with secondary endpoints (cognitive function, daily living activities, behaviour, caregiver burden and global functioning) included to explore clinical efficacy of EHT0202 versus placebo. RESULTS: EHT0202 was shown to be safe and generally well tolerated. Dose-dependent numbers of early withdrawal and central nervous system related adverse events were observed. As expected, since the study was not powered and not designed to show drug efficacy, and except for ratings on the ADCS-ADL scale, no significant differences were seen between treatment groups. CONCLUSIONS: These first encouraging safety results do support further development of EHT0202 in order to assess its clinical efficacy and to confirm its tolerability in a larger cohort of Alzheimer patients and for a longer period.

Incidence of HIV type 1 infection, antiretroviral drug resistance, and molecular characterization in newly diagnosed individuals in Argentina: A Global Fund Project.

An HIV incidence estimation was performed among men who have sex with men (MSM), drug users (DUs), sex workers (SWs), and pregnant women (PW) from Argentina. Volunteers older than 18 years old without a previous HIV-positive diagnosis were included. HIV-positive samples were analyzed by the Serological Testing Algorithm for Recent HIV Seroconversion (STARHS) to estimate incidence. By partial RT-PCR and sequencing of the HIV pol gene, an HIV subtype and resistance profile were determined. A total of 12,192 volunteers were recruited from October 2006 to September 2008. A higher HIV prevalence was detected among trans SWs (33.9%, 38/112), male SWs (10.8%, 12/111), and MSM 10.4% (161/1549). HIV incidence estimates by STARHS was also higher on trans SWs (11.31 per 100 person-years), male SWs (6.06 per 100 person-years), and MSM (6.36 per 100 person-years). Antiretroviral primary resistant mutations were detected in 8.4% of the study group, with a higher frequency in female DUs (33.3%). Phylogenetic analysis showed that 124 (57.9%) samples were subtype B, 84 (39.3%) intersubtype BF recombinants, 5 (2.3%) subtype C, and 1 (0.5%) subtype F in the pol region. Subtype B was most commonly found in MSM and male SWs whereas the intersubtype BF recombinant was more prevalent in female DUs, female SWs, and PW. Given the high HIV prevalence and incidence found in most of these groups, monitoring the continuing spread of the HIV epidemic is essential for determining public health priorities, assessing the impact of interventions, and estimating current and future health care needs.

Etazolate improves performance in a foraging and homing task in aged rats.

Etazolate is a phosphodiesterase 4 (PDE4) inhibitor and GABAA receptor modulator that also stimulates alpha-secretase activity and neurotrophic soluble amyloid precursor protein (sAPPalpha) production, currently developed as a possible Alzheimer's disease therapeutic. In this study two doses of etazolate were tested for cognitive effects in normally aged rats, using a complex spatial learning and memory task that emphasized two naturally occurring behaviors in rodents, foraging for food and returning large pieces of found food to a safe home location. Both etazolate doses completely prevented both (1) a foraging deficit that developed in untreated aged rats over the course of the test, as well as (2) a trial-specific deficit in memory for previously visited food locations that also developed over the course of the test in untreated aged rats. Both doses also significantly reduced a separate memory deficit for changing locations of the animals' home box, plus completely prevented a significant tendency for untreated aged animals to attempt entry into similar-appearing but incorrect home boxes. The combined behavioral data demonstrate positive effects of etazolate on separate age-related cognitive deficits, using a complex task based on naturally occurring rodent behaviors.