Retinal phakomatosis and Von Hippel-Lindau peripheral capillary hemangioblastoma: proposal for staged surgery

PURPOSE

Retinal capillary hemangioblastoma (RCH) is present in about half of the carriers of the VHL (von Hippel-Lindau) gene mutation and can lead to the evolution of blindness. Herewith is a proposal for surgical intraretinal feeder vessel ligature to induce ischemia the phakoma and to resolve the exudative secondary retinal detachment, with satisfying results at the 6 months follow-up end point.

METHODS

The patient underwent a chandelier-assisted 23 G pars plana vitrectomy with valved trocars. A bimanual transretinal ligature of the hemangioblastoma's feeder vessel was performed, followed by localized endolaser to ablate the surrounding retina and capillaries, and a Polydimethylsiloxane 1000 (PDMS 1000) final tamponade. After 3 months, exchange PDMS/air/balanced salt solution (BSS), phacoemulsification, and in-the-bag intraocular lens (IOL) implantation were performed.

RESULTS

At sixth month, fundus fluorescein angiography (FFA) showed a significant reduction of blood flow in the phakoma. Final best-corrected visual acuity (BCVA) was 6/6 (9 lines gain obtained compared to the baseline time).

CONCLUSIONS

This surgical technique seems to be effective and promising for the treatment of VHL retinal capillary hemangioblastomas and their related retinal complications.

Living with food allergies: the experiences of adult patients and caregivers

Background

Few studies have addressed how food allergy may impact differently on the daily lives of adults with food allergies and caregivers for food-allergic dependents.

Objective

To explore similarities and differences in life experiences and unmet needs between individuals caring for a child with food allergy and adults with food allergy world-wide.

Methods

Two multinational, virtual, interactive, moderated discussions of specific questions between respectively people with food allergies and caregivers for people with food allergies, with experienced clinicians participating.

Results

Sixteen individuals living with food allergies and nine caregivers took part in the two roundtables. Food avoidance and antihistamines were the most common treatments for food-allergic reactions in both groups. Caregivers reported greater burden of disease on affected individuals and families than did adult patients. Adult panelists considered autoinjectors easy to use but caregivers reported additional emotional stress thinking about autoinjector use. Caregivers described an ever-present fear of inattention and of overlooking a risk factor for a severe reaction, whereas adult panelists showed a determination not to let their food allergies interfere with living their lives. Both groups had safety-conscious attitudes to treatments, but adult patients emphasized convenience while caregivers prioritized reduced severity of reactions and eliminated fear. Both groups confirmed the need for improved, trusted sources of information, and for resources and training programs for any new therapies.

Conclusion

The interactive exchange provided insights into differences between adult patients and caregivers, notably in fear and confidence in daily life, severity of disease impact, and unmet needs for treatments.

Omalizumab in IgE-Mediated Food Allergy: A Systematic Review and Meta-Analysis

BACKGROUND

A growing number of studies have shown encouraging results with omalizumab (OMA) as monotherapy and as an adjunct to oral immunotherapy (OMA+OIT) in patients with single/multiple food allergies.

OBJECTIVES

To evaluate the efficacy and safety of OMA or OMA+OIT in patients with immunoglobulin E (IgE)-mediated food allergy.

METHODS

An extensive literature search (inception to December 31, 2020) was performed to identify randomized, controlled, and observational studies that assessed OMA as monotherapy or OMA+OIT in patients with IgE-mediated food allergy. The outcomes were an increase in tolerated dose of foods, successful desensitization, sustained unresponsiveness, immunological biomarkers, severity of allergic reactions to food, quality of life (QoL), and safety. A P less than .05 was considered significant.

RESULTS

In total, 36 studies were included. The OMA monotherapy (vs pre-OMA) significantly increased the tolerated dose of multiple foods; increased the threshold of tolerated dose for milk, egg, wheat, and baked milk; improved QoL; and reduced food-induced allergic reactions (all P < .01). The OMA+OIT significantly increased the tolerated dose of multiple foods (vs placebo and pre-OMA), desensitization (vs placebo+OIT and pre-OMA) (all P ≤ .01), and improved QoL (vs pre-OMA) and immunoglobulin G4 levels (both P < .01). No major safety concerns were identified.

CONCLUSIONS

In IgE-mediated food allergy, OMA can help patients consume multiple foods and allow for food dose escalation. As an adjunct to OIT, OMA can also support high-dose desensitization and higher maintenance doses. Further studies are warranted to empirically evaluate the effect of OMA and confirm these findings.

Regulatory T cells and immunoglobulin E: A new therapeutic link for autoimmunity?

Autoimmune diseases have a prevalence of approximately 7 to 9% and are classified as either organ-specific diseases, including type I diabetes, multiple sclerosis, inflammatory bowel disease and myasthenia gravis, or systemic diseases, including systemic lupus erythematosus, rheumatoid arthritis and Sjögren's syndrome. While many advancements have been made in understanding of the mechanisms of autoimmune disease, including the nature of self-tolerance and its breakdown, there remain unmet needs in terms of effective and highly targeted treatments. T regulatory cells (Tregs) are key mediators of peripheral tolerance and are implicated in many autoimmune diseases, either as a result of reduced numbers or altered function. Tregs may be broadly divided into those generated in the thymus (tTregs) and those generated in the periphery (pTregs). Tregs target many different immune cell subsets and tissues to suppress excessive inflammation and to support tissue repair and homeostasis: there is a fine balance between Treg cell stability and the plasticity that is required to adjust Tregs' regulatory purposes to particular immune responses. The central role of immunoglobulin E (IgE) in allergic disease is well recognized, and it is becoming increasingly apparent that this immunoglobulin also has a wider role encompassing other diseases including autoimmune disease. Anti-IgE treatment restores the capacity of plasmacytoid dendritic cells (pDCs) impaired by IgE- high-affinity IgE receptor (FcεR1) cross-linking to induce Tregs in vitro in atopic patients. The finding that anti-IgE therapy restores Treg cell homeostasis, and that this mechanism is associated with clinical improvement in asthma and chronic spontaneous urticaria suggests that anti-IgE therapy may also have a potential role in the treatment of autoimmune diseases in which Tregs are involved.

The rationale for development of ligelizumab in food allergy

Food allergy (FA) is a growing healthcare problem worldwide and the rising prevalence in many countries can be attributed to lifestyle, environmental, and nutritional changes. Immunoglobulin E (IgE)-mediated FA is the most common form of FA affecting approximately 3%-10% of adults and 8% of children across the globe. Food allergen-induced immediate hypersensitivity reactions mediated by IgE and high-affinity IgE receptor (FcεRI) complexes on mast cells and basophils are a major hallmark of the disease. FA can affect several aspects of health-related quality of life and impose a substantial financial burden on patients and healthcare systems. Although currently there is one United States Food and Drug Administration (FDA) and European Medicines Agency (EMA)-approved treatment for peanut allergy (Palforzia), the main treatment approaches are based on allergen avoidance and symptom management. Thus, there is an urgent need for more effective and ideally disease-modifying strategies. Given the crucial role of IgE in FA, anti-IgE monoclonal antibodies are considered promising therapeutic agents. Talizumab was the first humanized anti-IgE antibody to demonstrate substantial protection against allergic reactions from accidental peanut exposure by substantially increasing the peanut reactivity threshold on oral food challenge. However, development of talizumab was discontinued and further trials were performed using omalizumab. In double-blind, Phase 2, placebo-controlled trials in patients with multi-FAs, sustained dosing with omalizumab, or omalizumab in combination with oral immunotherapy, enabled rapid desensitization to multiple trigger foods. In this review, we describe the development of ligelizumab (a derivative of talizumab), a next generation, humanized monoclonal anti-IgE antibody, its existing clinical evidence, and its potential in the management of FA. When compared with omalizumab, ligelizumab binds with ∼88-fold higher affinity for human IgE and recognizes a different epitope that substantially overlaps with the binding site of FcεRI. These properties translate into a high potency to block IgE/FcεRI signaling in both in vitro and in vivo studies. Given its efficient suppression of IgE levels, good safety and pharmacokinetic/pharmacodynamic profile, ligelizumab clearly warrants further studies for the potential management of FA.

Real-life Effectiveness of Omalizumab in Patients with Severe Allergic Asthma: RELIEF Study

Introduction:

Patients with severe allergic asthma (SAA) are at risk of severe exacerbations. Omalizumab is recommended as an add-on treatment for patients with uncontrolled SAA, despite high-dose inhaled corticosteroids and long acting β2-agonist combination therapy (standard therapy).

RELIEF was a prospective, open label, multicenter study conducted to assess the real-life effectiveness of omalizumab co-administered with standard therapy in patients with SAA for 24 months.

Methods:

A total of 347 patients aged ≥ 6 years with SAA were enrolled, 285 of whom (8 pediatrics and 277 adolescents and adults) completed this 24-month study. Compared with the 12 months prior to baseline, the mean number of exacerbations was reduced in the overall population at any time interval during the study. Proportion of patients with no exacerbations increased to 77.7% at 24 months from 32.6% at 12 months prior to baseline. A reduction in healthcare resource utilization was also observed. The mean number of specialist visits reduced from baseline (5.8 visits) to 2.4 visits at Month 24.

Results:

The mean asthma control test score was >19 at every time-point during the study. The rate of Global Evaluation of Treatment Effectiveness (GETE) for asthma response significantly increased at Months 18 and 24 (P <0.05) compared to baseline. Pulmonary function remained relatively stable for the overall study population. There were no new or unexpected safety findings in the study.

Conclusion:

RELIEF study showed that add-on therapy with omalizumab is effective in reducing exacerbations, healthcare utilization, and improving GETE score in patients with SAA uncontrolled by standard therapy.

Genetic Basis and Molecular Mechanisms of Uveal Melanoma Metastasis: A Focus on Prognosis

Uveal melanoma (UM) is the most frequently found primary intraocular tumor, although it accounts for only 5% of all melanomas. Despite novel systemic therapies, patient survival has remained poor. Indeed, almost half of UM patients develop metastases from micro-metastases which were undetectable at diagnosis. Genetic analysis is crucial for metastatic risk prediction, as well as for patient management and follow-up. Several prognostic parameters have been explored, including tumor location, basal dimension and thickness, histopathologic cell type, vascular mimicry patterns, and infiltrating lymphocytes. Herein, the Authors review the available literature concerning cytogenetic prognostic markers and biochemical pathways correlated to UM metastasis development.

Molecular Mechanisms Related to Oxidative Stress in Retinitis Pigmentosa

Retinitis pigmentosa (RP) is an inherited retinopathy. Nevertheless, non-genetic biological factors play a central role in its pathogenesis and progression, including inflammation, autophagy and oxidative stress. The retina is particularly affected by oxidative stress due to its high metabolic rate and oxygen consumption as well as photosensitizer molecules inside the photoreceptors being constantly subjected to light/oxidative stress, which induces accumulation of ROS in RPE, caused by damaged photoreceptor’s daily recycling. Oxidative DNA damage is a key regulator of microglial activation and photoreceptor degeneration in RP, as well as mutations in endogenous antioxidant pathways involved in DNA repair, oxidative stress protection and activation of antioxidant enzymes (MUTYH, CERKL and GLO1 genes, respectively). Moreover, exposure to oxidative stress alters the expression of micro-RNA (miRNAs) and of long non-codingRNA (lncRNAs), which might be implicated in RP etiopathogenesis and progression, modifying gene expression and cellular response to oxidative stress. The upregulation of the P2X7 receptor (P2X7R) also seems to be involved, causing pro-inflammatory cytokines and ROS release by macrophages and microglia, contributing to neuroinflammatory and neurodegenerative progression in RP. The multiple pathways analysed demonstrate that oxidative microglial activation may trigger the vicious cycle of non-resolved neuroinflammation and degeneration, suggesting that microglia may be a key therapy target of oxidative stress in RP.

Chronic urticaria treatment patterns and changes in quality of life: AWARE study 2-year results

Background

A Worldwide Antihistamine-Refractory Chronic Urticaria (CU) patient Evaluation (AWARE) is a non-interventional, multicenter study including patients from Europe, Central and Latin America, Asia-Pacific, and the Middle East. AWARE describes real-world evidence for CU, including clinical characteristics, treatment patterns and the impact on quality of life.

Methods

Over the 2-year study, therapy changes, angioedema occurrence, and patient-reported outcomes (PROs) were recorded over 9 visits, including dermatology life quality index (DLQI) and 7-day urticaria activity score (UAS7). Data were stratified into subgroups: chronic spontaneous urticaria (CSU), chronic inducible urticaria (CIndU), or CSU + CIndU.

Results

Out of 4838 patients analyzed, 9.9% were receiving no treatment for their CU symptoms at baseline, and 20.4% were receiving first-line non-sedating H₁-antihistamine at approved doses. The predominant baseline therapy was up-dosed non-sedating H₁-antihistamines (25.5%). By Visit 2, omalizumab was the overall most commonly used therapy (29.6%), increasing to 30.1% by the end of the study. Baseline DLQI scores for patients with CSU, CIndU and CSU + CIndU were 8.3, 7.6 and 9.1, respectively; scores decreased over the study for CSU and CSU + CIndU patients, but fluctuated for CIndU patients. Baseline angioedema occurrence was higher in CSU and CSU + CIndU patients, reported in 45.4% and 45.5% of patients, respectively, compared to 17.0% in CIndU patients. By the final visit, angioedema had decreased to 11.9% and 11.2% for CSU and CSU + CIndU, respectively, and 9.6% for CIndU.

Conclusion

CU patients are undertreated at baseline; after entering the AWARE study, more patients received appropriate treatment. However, over two thirds are not escalated to third-line treatments.

An international collaborative evaluation of central serous chorioretinopathy: different therapeutic approaches and review of literature. The European Vitreoretinal Society central serous chorioretinopathy study

PURPOSE

To study and compare the efficacy of different therapeutic options for the treatment of central serous chorioretinopathy (CSCR).

METHODS

This is a nonrandomized, international multicentre study on 1719 patients (1861 eyes) diagnosed with CSCR, from 63 centres (24 countries). Reported data included different methods of treatment and both results of diagnostic examinations [fluorescein angiography and/or optical coherent tomography (OCT)] and best-corrected visual acuity (BCVA) before and after therapy. The duration of observation had a mean of 11 months but was extended in a minority of cases up to 7 years. The aim of this study is to evaluate the efficacy of the different therapeutic options of CSCR in terms of both visual (BCVA) and anatomic (OCT) improvement.

RESULTS

One thousand seven hundred nineteen patients (1861 eyes) diagnosed with CSCR were included. Treatments performed were nonsteroidal anti-inflammatory eye drops, laser photocoagulation, micropulse diode laser photocoagulation, photodynamic therapy (PDT; Standard PDT, Reduced-dose PDT, Reduced-fluence PDT), intravitreal (IVT) antivascular endothelial growth factor injection (VEGF), observation and other treatments. The list of the OTHERS included both combinations of the main proposed treatments or a variety of other treatments such as eplerenone, spironolactone, acetazolamide, beta-blockers, anti-anxiety drugs, aspirin, folic acid, methotrexate, statins, vitis vinifera extract medication and pars plana vitrectomy. The majority of the patients were men with a prevalence of 77%. The odds ratio (OR) showed a partial or complete resolution of fluid on OCT with any treatment as compared with observation. In univariate analysis, the anatomical result (improvement in subretinal fluid using OCT at 1 month) was favoured by age <60 years (p < 0.005), no previous observation (p < 0.0002), duration less than 3 months (p < 0.0001), absence of CSCR in the fellow eye (p = 0.04), leakage outside of the arcade (p = 0.05) and fluid height >500 μm (p = 0.03). The OR for obtaining partial or complete resolution showed that anti-VEGF and eyedrops were not statistically significant; whereas PDT (8.5), thermal laser (11.3) and micropulse laser (8.9) lead to better anatomical results with less variability. In univariate analysis, the functional result at 1 month was favoured by first episode (p = 0.04), height of subretinal fluid >500 μm (p < 0.0001) and short duration of observation (p = 0.02). Finally, there was no statistically significant difference among the treatments at 12 months.

CONCLUSION

Spontaneous resolution has been described in a high percentage of patients. Laser (micropulse and thermal) and PDT seem to lead to significant early anatomical improvement; however, there is little change beyond the first month of treatment. The real visual benefit needs further clarification.

Diagnosis and treatment of urticaria and angioedema: a worldwide perspective

: Urticaria and angioedema are common clinical conditions representing a major concern for physicians and patients alike. The World Allergy Organization (WAO), recognizing the importance of these diseases, has contributed to previous guidelines for the diagnosis and management of urticaria. The Scientific and Clinical Issues Council of WAO proposed the development of this global Position Paper to further enhance the clinical management of these disorders through the participation of renowned experts from all WAO regions of the world. Sections on definition and classification, prevalence, etiology and pathogenesis, diagnosis, treatment, and prognosis are based on the best scientific evidence presently available. Additional sections devoted to urticaria and angioedema in children and pregnant women, quality of life and patient-reported outcomes, and physical urticarias have been incorporated into this document. It is expected that this article will supplement recent international guidelines with the contribution of an expert panel designated by the WAO, increasing awareness of the importance of urticaria and angioedema in medical practice and will become a useful source of information for optimum patient management worldwide.

Maintenance of skills, competencies, and performance in allergy and clinical immunology: time to lay the foundation for a universal approach

Allergist/clinical immunologist maintenance of certification and training program reaccreditation are mandatory in some countries. The World Allergy Organization conducted surveys in 2009 and 2011 to assess where such programs were available and to promote the establishment of such programs on a global level. This was done with the presumption that after such an "inventory," World Allergy Organization could offer guidance to its Member Societies on the promotion of such programs to assure the highest standards of practice in the field of allergy and clinical immunology. This review draws on the experience of countries where successful programs are in place and makes recommendations for those wishing to implement such programs for the specialty.

Distribution of killer cell immunoglobulin-like receptor genes in the mestizo population from Venezuela

This study represents the first report on the distribution of KIR genes in 205 unrelated healthy mestizo Venezuelan individuals. Genotyping analysis showed that all KIR genes are present in this population. Frequency of inhibitory killer cell immunoglobulin-like receptors (KIRs) exceeded 0.69, except for KIR2DL2 (0.29) and 2DL5 (0.37). Activating KIRs showed low frequencies (0.11-0.29), except for KIR2DS4 (0.68). Forty-five different KIR genotypes were identified, with a predominance of three genotypes found in 50.7% of the population of which 25.9% were individuals homozygous for haplotype A. The frequencies of KIR genes reflect the ethnic admixture existing in the mestizo Venezuelan population.

Genetic contribution of major histocompatibility complex class II region to type 1 autoimmune hepatitis susceptibility in Venezuela

AIMS

Autoimmune hepatitis (AIH) is a progressive liver disease characterized by the presence of circulating autoantibodies, hypergammaglobulinaemia and a favourable response to immunosuppressive treatment. Although the pathogenesis of type 1 AIH is unknown, disease susceptibility is partially determined by genes linked to the class II region of the major histocompatibility complex. Type 1 AIH has been associated with DRB1*03, DRB1*04 and DRB3 alleles in European and North American Caucasians, with DRB1*0405 in Japanese, with DRB1*0404 in Mexican, and with DRB1*1301 in Argentinean populations.

METHODS

To analyse the molecular basis of these associations in Venezuela (mestizo population), we examined the frequency of human leucocyte antigens (HLA)-A -B -C, HLA-DQ and HLA-DR genes by low- and high-resolution oligonucleotide typing in a population of 41 type 1 AIH patients and 111 ethnic- and aged-matched healthy subjects.

RESULTS

The frequencies of both DRB1(*)1301 (P<0.0001) and DRB1*0301 (P<0.005) were significantly higher in patients than in controls. In addition, patients showed a strong association with the DRB3 allele (P<0.01). In contrast, the DQB1*04 allele was significantly decreased in the patient group (P<0.01). The frequencies of haplotypes A*01-B*08-DQB1*02-DRB1*03-DRB3, DQB1*05-DRB1*1301, DQB1*06-DRB1*1301 and A*02-DRB1*1301, B*45-DRB3 were significantly increased in type 1 AIH patients compared with the controls (P<0.01).

CONCLUSIONS

In conclusion, our data indicate that type 1 AIH predisposition in a Venezuelan mestizo population of different ethnic backgrounds is associated with DRB1*1301 and DRB1*0301 alleles. In addition, our findings suggest that protection against disease might be conferred by the DQB1*04 allele, with distinct ethnic differences from other populations.

Respiratory allergies in Venezuela: are fungi responsible?

Exposure to fungi in the indoor environment may trigger hypersensitivity to a variety of fungi and is known to be an influencing factor in allergic rhinitis and asthma. A wide list of airborne fungal spores and dust containing fungi have been described for different environments; however, their clinical relevance is seldom clear. In this survey we measure levels of fungi indoor and outdoor of domestic dwellings of 10 patients with known chronic allergic respiratory disease to fungi. To measure hypersensitivity to fungi, Prick (sensitivity to fungi), RAST (specific serum IgE levels) and PAR (persistent allergic rhinitis) severity are assessed in relation to fungal load in the environment. Only association of PAR and indoor fungal load were found to be significant (P = 0.1648). No direct causality with sensitivity to the amount of exposure, or a hypersensitivity to a specific fungal genus could be established. There is still no consensus on the most relevant methods for measuring personal exposure and 'no safe levels' have been established yet.

Activation of human eosinophils through leukocyte immunoglobulin-like receptor 7

Eosinophils are implicated prominently in allergic diseases and the host response to parasitic infections. Eosinophils may be activated in vitro by diverse classes of agonists such as immunoglobulins, lipid mediators, and cytokines. The leukocyte Ig-like receptors (LIRs) comprise a family of inhibitory and activating cell-surface receptors. Inhibitory LIRs down-regulate cellular responses through cytoplasmic immunoreceptor tyrosine-based inhibitory motifs. There are limited data on the action of the activating LIRs, which are thought to signal through the Fc receptor gamma chain, which contains an immunoreceptor tyrosine-based activation motif. We now demonstrate the expression of LIR1 (inhibitory), LIR2 (inhibitory), LIR3 (inhibitory), and LIR7 (activating) on eosinophils from 4, 4, 12, and 11, respectively, of 12 healthy donors. Cross-linking of LIR7 with plate-bound antibody elicited the dose- and time-dependent release of eosinophil-derived neurotoxin and leukotriene C(4). Eosinophils activated with antibodies to LIR7 embedded in gel-phase EliCell preparations showed leukotriene C(4) generation at the nuclear envelope and the release of IL-12 but not IL-4 by vesicular transport. Thus, LIR7 is an activating receptor for eosinophils that elicited the release of cytotoxic granule proteins, de novo lipid mediator generation, and cytokine release through vesicular transport.

Interleukin-2 induces peroxide production by primed normodense eosinophils of patients with asthma

In this study we assessed, by flow cytometry, the effect of interleukin 2 (IL-2) on the oxidative burst of normodense eosinophils (Eos's) isolated from 15 patients with moderately severe extrinsic asthma and 17 controls. We found that IL-2 significantly induced peroxide (H2O2) production in normodense Eos's from patients with asthma on a time kinetics study. This rise was higher in patients with immunoglobulin E levels > 180 IU/mL versus normal immunoglobulin E values. The effect of IL-2 was partially blocked by using anti-Tac antibody. In contrast, IL-2 decreased H2O2 production in normodense Eos's from controls. Cell surface expression of CD25, CD122, CD132, and CD69 were also determined and no statistical differences were found between both groups. In conclusion, IL-2 is able to increase H2O2 production by normodense Eos's isolated from patients with asthma and it may contribute to bronchial epithelium damage and chronic inflammation.

Hypodense eosinophils: characterization of surface molecule expression

Distinct eosinophil populations have been characterized on the basis of discontinuous Percoll density gradients. In peripheral blood, normal individuals show a low number of normodense and hypodense eosinophils, contrasting with the high amount of hypodense cells in patients who have allergies. To characterize these two eosinophil populations, we analyzed membrane expression of several antigens and cytokine receptors in normodense and hypodense eosinophils from patients who have allergies and controls. Hypodense eosinophils expressed higher levels of CD122, CD69, and CD4 in both patients with allergies and control individuals when compared to normodense eosinophils. The expression of CD125, CD124, CD25, CD132, and CD23 were similar in both cell types.

Lymphocyte subset diversity in idiopathic CD4+ T lymphocytopenia

The clinical and public health importance of CD4+ T lymphocytopenia without human immunodeficiency virus infection is still unclear. We describe herein two new human immunodeficiency virus-negative patients with low numbers of peripheral CD4+ T cells and opportunistic infections (cerebral toxoplasmosis and tuberculosis plus extrapulmonary histoplasmosis). The low numbers of CD4+ CD29+ memory cells, the high percentage of gamma delta T-cell receptor cells, and the recovery of CD4+ cells after treatment were remarkable.

Decreased T-cell proliferative response to common environmental antigens could be an indicator of early human immunodeficiency virus-mediated lymphocyte lesions

To evaluate CD4+/CD29+ cells and their responses to different antigens in polar stages of human immunodeficiency virus (HIV) infection, we studied 26 HIV-seropositive carriers (SPCs) and 15 patients with AIDS simultaneously with 20 healthy volunteers (HVs) and 10 seronegative homosexual and bisexual men (SNH). CD3, CD4, CD29, and CD45RA phenotypes were analyzed by two-color flow cytometry. Significant depletion of CD4+ T cells and both memory (CD4+/CD29+) and naive (CD4+/CD45RA+) T-cell subsets was found among SPCs and AIDS patients compared with the numbers of such cells in the HV and SNH groups. Responses to optimal doses of Candida albicans, streptokinase, and tetanus toxoid were explored in peripheral blood mononuclear cells and CD4(+)- and CD4+/CD29(+)-enriched cell populations. In SPCs, the response to C. albicans in peripheral blood mononuclear cells showed a statistically significant diminution compared with the response of HVs (15,308 versus 35,951 cpm). In addition, a significantly reduced response to streptokinase was evident only when cell preparations were CD4+/CD29+ enriched (3,048 versus 10,367 cpm). Furthermore, the SPC group comprised seven responders to at least one antigen and seven nonresponders to any of the selected specific antigens. Absence of a response in these latter patients was independent of the absolute counts of memory and naive T-cell populations. The response to tetanus toxoid, although diminished in SPCs, was not significantly different from that in controls. Our results suggest that defective responses to common environmental antigens, unrelated to the absolute number of CD4+/CD29+ cells, is probably an early indicator of an HIV-induced lymphocyte lesion.

A double-blind, cross-over study using salbutamol, beclomethasone, and a combination of both in bronchial asthma

A double-blind, cross-over protocol was applied to 22 asthmatic patients who were previously subjected to provocation tests with methacholine. The baseline FEV1 for mild asthma was 89.6 +/- 13.6% while for moderate asthma it was 73 +/- 6%. The initial provocation tests with methacholine revealed that the mild asthma group needed a greater accumulated dose of methacholine than that required by the moderate asthma group to lower the FEV1 by 20%, stressing the enhanced bronchial hyperreactivity present in the latter group. Significant differences in the PD20 values were obtained in both groups of patients using the combination of salbutamol plus beclomethasone. Salbutamol alone was ineffective to change the PD20 values in mild asthma while beclomethasone alone was able to change significantly the PD20 values in these patients, stressing the importance of the inflammatory component in the pathogenesis of stable asthma. Furthermore, the combination of both drugs was also more effective in the moderate asthma group than either medication alone, confirming the pharmacological control of the obstructive and inflammatory changes that are already established in patients with moderate asthma.

[Immunoclinical, molecular and immunopathologic approach to chronic viral hepatitis. Therapeutic considerations]

Through a pilot study which includes a clinical, molecular and immunopathological approach to the chronic Hepatitis induced by HBV or by HCV, we determined that 66% of HBsAg carriers are in the "non viremic" phase. The positive HBeAg "viremic" carriers showed HBV-DNA quantitation which varies between > 50 pg to > 100 pg. Both types of carries are infected with the "wild" type HBV. Each subgroup of positive surface antigemia carriers demonstrated a differential immunopathological response. So far, 96% of the HCV carriers investigated, showed HCV-RNA associated to repeatedly positive anti-HCV antibodies. Those patients with increased ALT values uniformly expressed liver histopathological signs of inflammation caused by HCV; demonstrating also the presence of peripheral blood mononuclear cells infected with HCV. At the present, the genotypes investigation indicates a predominance of HCV genotype II (1b). Autoimmune phenomenons associated to HCV have been detected only in 3 patients. The therapeutic approach with interferon alpha applied to the HCV infection preliminary showed similar results to those reported worldwide. Currently, a comprehensive approach to the chronic HBV and chronic HCV infections requires the application of Immunochemistry, Molecular Biology and Cellular Immunology combined technologies.