Molecular Diagnosis in House Dust Mite-Allergic Patients Suggests That Der p 23 Is Clinically Relevant in Asthmatic Children

BACKGROUND

Patterns of sensitization to house dust mites depend on geographic area and are important in clinical practice. However, the role of molecular diagnosis is not currently defined. We sought to characterize a pediatric population by focusing on sensitization to different mite species and major mite components in order to assess the clinical relevance of sensitization to allergenic components in our practice.

METHODS

Consecutive children with respiratory allergy sensitized to house dust mites (determined by skin prick test [SPT]) were recruited. We determined specific IgE to nDer p 1, rDer p 2, and rDer p 23 using ImmunoCAP and sIgE using ImmunoCAP-ISAC microarray. Patients were followed up for 3 years.

RESULTS

A total of 276 children were recruited. The frequency of sensitization was 86.6% for nDer p 1, 79.3% for rDer p 2, and 75.8% for rDer p 23. Lepidoglyphus species was the most common storage mite detected by SPT. Twenty-six patients (9.4%) were not sensitized to Der p 1 or Der p 2. It is noteworthy that IgE binding to Der p 23 was positive in 14 (53.8%). Asthmatic patients, especially those with a persistent moderate-severe phenotype, more frequently recognized the 3 major allergens.

CONCLUSIONS

Most patients with mite allergy were sensitized to the major allergens Der p 1, Der p 2, and Der p 23. Of the allergens evaluated, 5% were sensitized to Der p 23 but not to Der p 1 or Der p 2. Sensitization to Der p 23 should be considered in the diagnosis and treatment of mite allergy, especially in patients with moderate-severe asthma, because it may worsen the clinical phenotype.

Dopamine and its receptors play a role in the modulation of CCR5 expression in innate immune cells following exposure to Methamphetamine: Implications to HIV infection

The Human Immunodeficiency Virus (HIV) infects cells in the Central Nervous System (CNS), where the access of antiretrovirals and antibodies that can kill the virus may be challenging. As a result of the early HIV entry in the brain, infected individuals develop inflammation and neurological deficits at various levels, which are aggravated by drugs of abuse. In the non-human primate model of HIV, we have previously shown that drugs of abuse such as Methamphetamine (Meth) increase brain viral load in correlation with a higher number of CCR5-expressing myeloid cells. CCR5 is a chemokine receptor that may be involved in increasing inflammation, but also, it is a co-receptor for viral entry into target cells. CCR5-expressing myeloid cells are the main targets of HIV in the CNS. Thus, the identification of factors and mechanisms that impact the expression of CCR5 in the brain is critical, as changes in CCR5 levels may affect the infection in the brain. Using a well-characterized in vitro system, with the THP1 human macrophage cell line, we have investigated the hypothesis that the expression of CCR5 is acutely affected by Meth, and examined pathways by which this effect could happen. We found that Meth plays a direct role by regulating the abundance and nuclear translocation of transcription factors with binding sites in the CCR5 promoter. However, we found that the main factor that modifies the CCR5 gene promoter at the epigenetic level towards transcription is Dopamine (DA), a neurotransmitter that is produced primarily in brain regions that are rich in dopaminergic neurons. In THP1 cells, the effect of DA on innate immune CCR5 transcription was mediated by DA receptors (DRDs), mainly DRD4. We also identified a role for DRD1 in suppressing CCR5 expression in this myeloid cell system, with potential implications for therapy. The effect of DA on innate immune CCR5 expression was also detectable on the cell surface during acute time-points, using low doses. In addition, HIV Tat acted by enhancing the surface expression of CCR5, in spite of its poor effect on transcription. Overall, our data suggests that the exposure of myeloid cells to Meth in the context of presence of HIV peptides such as Tat, may affect the number of HIV targets by modulating CCR5 expression, through a combination of DA-dependent and–independent mechanisms. Other drugs that increase DA may affect similar mechanisms. The implications of these epigenetic and translational mechanisms in enhancing HIV infection in the brain and elsewhere are demonstrated.

Human CD4+ CD25+ CD127hi cells and the Th1/Th2 phenotype

CD4⁺ T cells that co-express CD25 and CD127 (CD25⁺CD127⁺) make up around 20% of all circulating CD4⁺ memory T cells in healthy people. The clinical significance of these cells is that in children with type 1 diabetes their relative frequency at diagnosis is significantly and directly correlated with rate of disease progression. The purpose of this study was to further characterize the CD25⁺CD127^hi cells. We show that they are a mix of Th1 and Th2 cells however, they have a significantly higher relative frequency of pre-committed and committed Th2 cells, and secrete significantly higher levels of Th2-type cytokines than CD25^- memory T cells. Further, these cells are neither exhausted nor senescent and proliferate to the same extent as CD25^- memory cells. Thus, CD25⁺CD127^hi cells are a highly active subset of memory T cells that might play a role in controlling inflammation via anti-inflammatory Th2-type deviation.

A pilot study showing associations between frequency of CD4(+) memory cell subsets at diagnosis and duration of partial remission in type 1 diabetes

In some patients with type 1 diabetes the dose of insulin required to achieve euglycemia is substantially reduced soon after diagnosis. This partial remission is associated with β-cell function and good glucose control. The purpose of this study was to assess whether frequencies of CD4(+) T cell subsets in children newly diagnosed with type 1 diabetes are associated with length of partial remission. We found that the frequency of CD4(+) memory cells, activated Treg cells and CD25(+) cells that express a high density of the IL-7 receptor, CD127 (CD127(hi)) are strongly associated with length of partial remission. Prediction of length of remission via Cox regression is significantly enhanced when CD25(+) CD127(hi) cell frequency is combined with either Insulin Dependent Adjusted A1c (IDAA1c), or glycosylated hemoglobin (HbA1c), or C-peptide levels at diagnosis. CD25(+) CD127(hi) cells do not express Foxp3, LAG-3 and CD49b, indicating that they are neither Treg nor Tr1 cells.

The incidence of unexplained visual loss following removal of silicone oil

PURPOSE

To assess the incidence and clinical features of unexpected visual loss after removal of silicone oil (ROSO).

PATIENTS AND METHODS

A retrospective cross-sectional observational study of 421 consecutive eyes, which underwent silicone oil removal at one institution over a 2-year period.

RESULTS

Fourteen (3.3%) patients, (12 male, mean age of 53.1 years) suffered unexplained visual loss. In these eyes, the mean duration of silicone oil fill was 141 days (range 76-218). The mean loss of visual acuity was 3.7 (range 2-6) Snellen lines (SL) at 1 month, 3.5 (2-6) SL at 3 months and 2.91 (0-6) SL at 6 months. The change from preoperative visual acuity was statistically significant at all visits (P=0.02). Subgroup analysis of 20 fovea-sparing giant retinal tear (GRT) detachments, observed 10 (50%) cases of visual loss after ROSO. Electrodiagnostic testing suggested predominantly macular dysfunction, with optic nerve involvement in one case. Five of the 14 cases had variable recovery of vision.

CONCLUSION

There is a 3.3% overall incidence of visual loss following ROSO with a high rate (50%) observed in maculae on GRT detachments. Although recovery of visual acuity is seen in a minority of cases, visual loss after ROSO remains a serious and unexplained concern for vitreoretinal surgeons.

CD4(+) CD44(v.low) cells are unique peripheral precursors that are distinct from recent thymic emigrants and stem cell-like memory cells

CD4(+) CD44(v.low) cells are peripheral precursor T cells that inhibit lymphopenia by generating a large CD4(+) T cell pool containing balanced numbers of naïve, memory, and regulatory Foxp3(+) cells with a diverse TCR repertoire. Recent thymic emigrants (RTE) and stem cell-like memory T cells (T(SCM)) can also replenish a T cell pool. In this study we formally test whether CD44(v.low) cells are the same population as RTE and T(SCM). Our data show that, in contrast to RTE, CD44(v.low) cells express high levels of CD45RB and low levels of CD24. Moreover, CD44(v.low) cells isolated from mice devoid of RTE retain their capacity to repopulate lymphopenic mice with naïve and memory cells and Foxp3(+) Tregs. In addition, CD44(v.low) cells do not express IL-2Rβ, Sca-1, and CXCR3, the phenotypic hallmarks of T(SCM). Overall, these data demonstrate that CD44(v.low) cells are neither RTE nor T(SCM).

Tomato nsLTP as an "In Vivo" Diagnostic Tool: Sensitization in a Mediterranean Population

BACKGROUND

Tomato allergies have been extensively studied but component-resolved in vivo diagnosis with purified allergens has yet to be performed.

OBJECTIVES

To evaluate the prevalence of sensitization to Sola l 3 in a Mediterranean population, and to compare the resulting sensitization profile with that of individuals sensitized to tomato, peach, and/or purified lipid transfer protein (LTP).

METHODS

Sola l 3 was purified, characterized, and used to prepare skin prick tests (SPTs). Two groups of patients were selected. Group 1 consisted of patients with at least 1 positive SPT to tomato, peach, or LTP mixture (marker extracts) who were subsequently tested with Sola l 3 (n = 280). Group 2 (prevalence study) consisted of patients who underwent simultaneous SPT with the 3 marker extracts and Sola l 3 (n = 658). Patients from either group who were positive to any of the 4 extracts were studied in detail (study group, n = 1 23). ELISA and immunoblot assays were performed in individuals with a positive SPT to Sola l 3 to detect the presence of specific IgE antibodies to this allergen.

RESULTS

Prevalence of sensitization to Sola l 3 was 3.2% overall and 54.7% in tomato-positive patients. Most tomato-sensitized patients were asymptomatic. Symptoms were more common in Sola l 3-positive individuals. Sensitization to peach and the LTP mixture did not discriminate between Sola l 3-positive and Sola l 3-negative patients.

CONCLUSIONS

This study confirms that LTP, not only from peach but also from other fruit and vegetables, including tomato, is an important allergen in the Mediterranean area. Sensitization to Sola l 3 is associated with more symptoms in tomato-sensitized patients.

Epidemiology and clinical features of community-acquired, healthcare-associated and nosocomial bloodstream infections in tertiary-care and community hospitals

Classification of bloodstream infections (BSIs) as community-acquired (CA), healthcare-associated (HCA) and hospital-acquired (HA) has been proposed. The epidemiology and clinical features of BSI according to that classification in tertiary-care (TH) and community (CH) hospitals were investigated in a prospective cohort of 821 BSI episodes from 15 hospitals (ten TH and five CH hospitals) in Andalucía, Spain. Eighteen percent were CA, 24% were HCA and 58% were HA. The incidence of CA and HCA BSI was higher in CH than in TH (CA: 3.9 episodes per 1000 admissions vs. 2.2, p <0.01; HCA: 5.0 vs. 2.9, p <0.01), whereas the incidence of HA BSI was lower (7.7 vs. 8.7, p <0.01). In CA and HCA BSI, the respiratory tract was more frequently the source in CH than in TH (CA: 30% vs. 15%; HCA: 20% vs. 9%, p ≤0.03). In HCA BSI, chronic renal insufficiency and tunnelled catheters were less frequent in CH than in TH (11% vs. 26% and 7% vs. 19%, p ≤0.03), although chronic ulcers were more frequent (22% vs. 8%, p 0.008). BSIs as a result of methicillin-resistant Staphylococcus aureus or Pseudomonas aeruginosa were very rare in CA episodes, although extended-spectrum b-lactamase-producing Escherichia coli (ESBLEC) caused a similar proportion of all BSIs in CA, HCA and HA episodes. Multivariate analysis revealed no significant difference in mortality rates in CH and TH. HCA infections should be considered as a separate class of BSI in both TH and CH, although differences between hospitals must be considered. CA BSIs were not caused by multidrug-resistant pathogens, except for ESBLEC.

Oral health status and inequalities among ambulant older adults living in central Chile

OBJECTIVE

To assess the oral health status and treatment needs of older adults, living in the Valparaiso Region of Chile.

BASIC RESEARCH DESIGN

A random sample of 354 older adults, aged 60 years or older, living independently in the community were examined orally by calibrated examiners and underwent a structured oral health interview. Data collection extended from October 2006 to June 2007.

RESULTS

This was a largely dentate population (80%) with a mean DMFT score of 21.6 (s.d. 5.7). While about 28% of the dentate sample had all their restorative needs unmet, 30.8% had all of their restorative needs met. Regarding periodontal health, 3.3% had sound periodontum; complex periodontal therapy (CPI 3-4) was needed by 43.1% of the sample.

CONCLUSION

This study represents one of the largest data collections in oral health among older adults living in Chile. Participants seemed to have better oral health status than previously reported. Of particular relevance is the reduction of the decayed component and the increased number of sound teeth in the present sample. Participants also presented lower need for advance periodontal treatment. Yet, inequalities were apparent in the proportion of unmet restorative needs. Strategies to develop oral health care programmes focused on improving access to and use of preventive services for older adults are critical. Further research is indicated to get a more complete picture of the factors that shape the oral health of Chilean older adults.

Evaluation of readmissions in hematopoietic stem cell transplant recipients

BACKGROUND

There is a lack of information on health expenses caused by readmissions among hematopoietic stem cell transplant (HSCT) recipients. We analyzed the rate, causes, and evolution of hospitalization after HSCT.

METHODS

We retrospectively studied 140 consecutive patients who received an autologous HSCT (n = 107; 76.4%) or an allogeneic HSCT (n = 33; 23.6%) in our institution from May 2001 through September 2004.

RESULTS

There were 45 readmissions in 28 patients (20%): three (10%) in the autologous and 25 (90%), in the allogeneic HSCT cohorts. The overall median age was 35.3 +/- 13.5 years and 54% were women. Hematologic diseases were: multiple myeloma (n = 1, 4%), myelodysplastic syndrome (n = 2, 7%), acute lymphoblastic leukemia (n = 2, 7%), aplastic anemia (n = 2, 7%), chronic myeloid leukemia (n = 3, 11%), non-Hodgkin's lymphoma (n = 4, 14%), Hodgkin's disease (n = 4, 14%) and acute nonlymphoblastic leukemia (n = 10, 38%). The length of stay for each readmission was 25 +/- 21 days. The median day of readmission was +62.5 (range = +19 to +987); however, 75% occurred between days +30 and +70. The causes of hospitalization were: infections (n = 24, 54%), due to the graft (n = 14, 31%), graft failure (n = 4, 9%), coagulation disorders (n = 2, 4%), and second neoplasm (n = 1, 2%). Mortality due to the transplant was 10 patients (14%) including: graft-versus-host disease (n = 3), sepsis (n = 3), thrombotic thrombocytopenic purpura (n = 1), and relapse (n = 3).

CONCLUSIONS

Although there was a frequent use of hospital resources (20%) after HSCT with patients hospitalized for a median of 25 days, it was beneficial since there were 86% survivors at 36 months follow-up.

Questionnaire survey of California consumers' use and rating of sources of health care information including the Internet

OBJECTIVE

To understand how Californians use and rate various health information sources, including the Internet.

RESEARCH DESIGN

Computer-assisted telephone interviews through which surveys were conducted in English or Spanish.

SUBJECTS

A household sample generated by random digit dialing. The sample included 1007 adults (18+), 407 (40%) of whom had access to the Internet.

MAIN OUTCOME MEASURES

Past health information sources used, their usefulness and ease of use; future health information sources, which are trusted and distrusted; and concerns about integrating the Internet into future health information seeking and health care behaviors.

RESULTS

Physicians and health care providers are more trusted for information than any other source, including the Internet. Among those with Internet access, a minority use it to obtain health information, and a minority is "very likely" to use e-mail to communicate with medical professionals or their own doctors and nurses, to refill prescriptions, or to make doctor appointments. Also, most of those with Internet access are "unlikely" to make their medical records available via the Internet, even if securely protected.

CONCLUSIONS

The public, including frequent Internet users, has major concerns about the confidentiality of electronic medical records. Legislation may not assuage these fears and a long-term, open and collaborative process involving consumers and organizations from all the health care sectors may be needed for full public assurance.

Studies on the humoral immune response to a synthetic vaccine against Plasmodium falciparum malaria

A synthetic vaccine against the asexual blood stages of P. falciparum, the SPf 66 synthetic hybrid polymer, composed of peptides derived from three merozoite membrane proteins as well as one peptide from the sporozoite CS protein, has been developed by our group and tested in different protection assays in Aotus monkeys as well as in human volunteers. This study evaluates the humoral immune response induced by the SPf 66 protein vaccination in adult human volunteers from the Colombian Pacific coast as follows: determination of specific IgG antibody levels against SPf 66 by FAST-ELISA after each immunization; analysis of antibody reactivity with P. falciparum schizont lysates by immunoblots; and determination of the in vitro parasite growth inhibition. A clear boosting effect, dependent on time and dose, was observed in the antibody production kinetics. These antibodies also specifically recognize three proteins of the P. falciparum schizont lysate corresponding to the molecular weights of the proteins from which the amino acid sequence was derived. These sera were also capable of markedly inhibiting in vitro parasite growth.

[Phase contrast microscopy in the detection of bacteriuria]

Despite the recognized superiority of traditional culture methods to investigate bacteriuria their routine use in population studies is costly. We proposed to use Phase contrast microscopy (PCM) which allows clear visualization of bacteria with no centrifugation or staining. Urine samples from 214 patients were studied by PCM and results compared to those obtained by quantitative culture. MCF had 95% sensitivity and 96% specificity. Therefore, PCM may be used to screen urine samples for further bacteriologic study with the highest chance of obtaining positive cultures.