Pablo Javier Patiño

Primary Immunodeficiency Diseases in Latin America: The Second Report of the LAGID Registry

This is the second report on the continuing efforts of LAGID to increase the recognition and registration of patients with primary immunodeficiency diseases in 12 Latin American countries: Argentina, Brazil, Chile, Colombia, Costa Rica, Honduras, Mexico, Panama, Paraguay, Peru, Uruguay, and Venezuela. This report reveals that from a total of 3321 patients registered, the most common form of primary immunodeficiency disease was predominantly antibody deficiency (53.2%) with IgA deficiency reported as the most frequent phenotype. This category was followed by 22.6% other well-defined ID syndromes, 9.5% combined T- and B-cell inmunodeficiency, 8.6% phagocytic disorders, 3.3% diseases of immune dysregulation, and 2.8% complement deficiencies. All countries that participated in the first publication in 1998 reported an increase in registered primary immunodeficiency cases, ranging between 10 and 80%. A comparison of the estimated minimal incidence of X-linked agammaglobulinemia, chronic granulomatous disease, and severe combined immunodeficiency between the first report and the present one shows an increase in the reporting of these diseases in all countries. In this report, the estimated minimal incidence of chronic granulomatous disease was between 0.72 and 1.26 cases per 100,000 births in Argentina, Chile, Costa Rica, and Uruguay and the incidence of severe combined immunodeficiency was 1.28 and 3.79 per 100,000 births in Chile and Costa Rica, respectively. However, these diseases are underreported in other participating countries. In addition to a better diagnosis of primary immunodeficiency diseases, more work on improving the registration of patients by each participating country and by countries that have not yet joined LAGID is still needed.

Activation of Plasmacytoid Dendritic Cells with TLR9 Agonists Initiates Invariant NKT Cell-Mediated Cross-Talk with Myeloid Dendritic Cells

CD1d-restricted invariant NK T (iNKT) cells and dendritic cells (DCs) have been shown to play crucial roles in various types of immune responses, including TLR9-dependent antiviral responses initiated by plasmacytoid DCs (pDCs). However, the mechanism by which this occurs is enigmatic because TLRs are absent in iNKT cells and human pDCs do not express CD1d. To explore this process, pDCs were activated with CpG oligodeoxyribonucleotides, which stimulated the secretion of several cytokines such as type I and TNF-α. These cytokines and other soluble factors potently induced the expression of activation markers on iNKT cells, selectively enhanced double-negative iNKT cell survival, but did not induce their expansion or production of cytokines. Notably, pDC-derived factors licensed iNKT cells to respond to myeloid DCs: an important downstream cellular target of iNKT cell effector function and a critical contributor to the initiation of adaptive immune responses. This interaction supports the notion that iNKT cells can mediate cross-talk between DC subsets known to express mutually exclusive TLR and cytokine profiles.

Diagnostic Accuracy of HMGB‐1, sTREM‐1, and CD64 as Markers of Sepsis in Patients Recently Admitted to the Emergency Department

OBJECTIVES The objectives were to evaluate the diagnostic accuracy for sepsis in an emergency department (ED) population of the cluster of differentiation-64 (CD64) glycoprotein expression on the surface of neutrophils (nCD64), serum levels of soluble triggering receptor expressed on myeloid cells-1 (s-TREM-1), and high-mobility group box-1 protein (HMGB-1). METHODS Patients with any of the following as admission diagnosis were enrolled: 1) suspected infection, 2) fever, 3) delirium, or 4) acute hypotension of unexplained origin within 24 hours of ED presentation. Levels of nCD64, HMGB-1, and s-TREM-1 were measured within the first 24 hours of the first ED evaluation. Baseline clinical data, Sepsis-related Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation (APACHE II) score, daily clinical and microbiologic information, and 28-day mortality rate were collected. Because there is not a definitive criterion standard for sepsis, the authors used expert consensus based on clinical, microbiologic, laboratory, and radiologic data collected for each patient during the first 7 days of hospitalization. This expert consensus defined the primary outcome of sepsis, and the primary data analysis was based in the comparison of sepsis versus nonsepsis patients. The cut points to define sensitivity and specificity values, as well as positive and negative likelihood ratios (LRs) for the markers related to sepsis diagnosis, were determined using receiver operative characteristics (ROC) curves. The patients in this study were a prespecified nested subsample population of a larger study. RESULTS Of 631 patients included in the study, 66% (95% confidence interval [CI] = 62% to 67%, n = 416) had sepsis according with the expert consensus diagnosis. Among these sepsis patients, SOFA score defined 67% (95% CI = 62% to 71%, n = 277) in severe sepsis and 1% (95% CI = 0.3% to 3%, n = 6) in septic shock. The sensitivities for sepsis diagnosis were CD64, 65.8% (95% CI = 61.1% to 70.3%); HMGB-1, 57.5% (95% CI = 52.7% to 62.3%); and s-TREM-1, 60% (95% CI = 55.2% to 64.7%). The specificities were CD64, 64.6% (95% CI = 57.8% to 70.8%), HMGB-1, 57.8% (95% CI = 51.1% to 64.3%), and s-TREM-1, 59.2% (95% CI = 52.5% to 65.6%). The positive LR (LR+) for CD64 was 1.85 (95% CI = 1.52 to 2.26) and the negative LR (LR-) was 0.52 (95% CI = 0.44 to 0.62]; for HMGB-1 the LR+ was 1.36 (95% CI = 1.14 to 1.63) and LR- was 0.73 (95% CI = 0.62 to 0.86); and for s-TREM-1 the LR+ was 1.47 (95% CI = 1.22 to 1.76) and the LR- was 0.67 (95% CI = 0.57 to 0.79). CONCLUSIONS In this cohort of patients suspected of having any infection in the ED, the accuracy of nCD64, s-TREM-1, and HMGB-1 was not significantly sensitive or specific for diagnosis of sepsis.

Dexamethasone inhibits apoptosis of human neutrophils induced by reactive oxygen species

Neutrophils are completely differentiated cells that die in tissues a few days after they migrate from the vascular compartment as a consequence of a rigouous apoptotic program. Many of the mediators produced during an inflammatory response delay neutrophil apoptosis allowing a more efficient removal of microorganisms but also favoring the tissue damage by reactive oxygen species (ROS) and lysosomal proteins released by neutrophils. Glucocorticoids delay the apoptosis of neutrophils but the mechanisms are not completely understood. To investigate the inhibition of glucocorticoids on neutrophil apoptosis we have used the glucose/glucose oxidase (G/GO) system as a constant source of hydrogen peroxide. When neutrophils are incubated in the presence of the G/GO system, a significant acceleration of their apoptotic response is observed. Preincubation with 10−6 M, 10−7 M, 10−8 M or 10−9 M of dexamethasone, negatively modulated the spontaneous and G/GO induced apoptosis of neutrophils. Then the G/GO system is a useful model to simulate the oxidative stress of neutrophils, and that the effect of DXM on neutrophil apoptosis depends, at least in part, on blocking the proapoptotic effect of ROS.

Frequency of CCR5 Delta-32 Mutation in Human Immunodeficiency Virus (HIV)-seropositive and HIV-exposed Seronegative Individuals and in General Population of Medellin, Colombia

Repeated exposure to human immunodeficiency virus (HIV) does not always result in seroconversion. Modifications in coreceptors for HIV entrance to target cells are one of the factors that block the infection. We studied the frequency of Delta-32 mutation in ccr5 gene in Medellin, Colombia. Two hundred and eighteen individuals distributed in three different groups were analyzed for Delta-32 mutation in ccr5 gene by polymerase chain reaction (PCR): 29 HIV seropositive (SP), 39 exposed seronegative (ESN) and 150 individuals as a general population sample (GPS). The frequency of the Delta-32 mutant allele was 3.8% for ESN, 2.7% for GPS and 1.7% for SP. Only one homozygous mutant genotype (Delta-32/Delta-32) was found among the ESN (2.6%). The heterozygous genotype (ccr5/Delta-32) was found in eight GPS (5.3%), in one SP (3.4%) and in one ESN (2.6%). The differences in the allelic and genotypic frequencies among the three groups were not statistically significant. A comparison between the expected and the observed genotypic frequencies showed that these frequencies were significantly different for the ESN group, which indirectly suggests a protective effect of the mutant genotype (Delta-32/Delta-32). Since this mutant genotype explained the resistance of infection in only one of our ESN persons, different mechanisms of protection must be playing a more important role in this population.

Broad histopathologic patterns of non-glabrous skin and glabrous skin from patients with a new variant of endemic pemphigus foliaceus-part 1

A prospective, controlled epidemiologic survey performed in El Bagre, Colombia revealed a new variant of endemic pemphigus disease, occurring in a gold mining region. The disease resembled Senear‐Usher syndrome, and occurred in an endemic fashion. The aim of this study is to describe the most frequent histopathologic patterns in non‐glabrous skin and in glabrous skin observed in these patients, and their clinical correlation. The study was performed on non‐glabrous skin biopsies of 30 patients from the dominantly clinical affected areas (either on the chest, arms or face). Simultaneously, biopsies from the palms were obtained in 10 randomly chosen patients of the 30 total patients. The specimens were examined following hematoxylin and eosin (H&E) staining. The most common blisters observed were subcorneal, although in some cases intraspinous and subepidermal blisters were visualized. Our results showed a very heterogeneous pattern of histopathologic patterns in non‐glabrous skin, which seemed to correlate with the clinical features. The most common pattern was typical pemphigus foliaceus‐like, with some lupus erythematosus‐like features. A non‐specific, chronic dermatitis pattern prevailed in the clinically controlled patients taking daily corticosteroids. In the patients who have had the most severe and relapsing pemphigus, early sclerodermatous changes and scleredermoid alterations prevailed in their reticular dermis. In addition to the scleredermoid alterations, the reticular dermis showed a paucity of appendageal structures. On the contrary, in the palms, a similar pattern was seen in all cases, including thickening of the stratum corneum, hypergranulosis, edema in the papillary and reticular dermis and a dermal perivascular lymphocytic infiltrate. The direct immunofluorescence of the glabrous vs. the non‐glabrous skin also showed some differences. We conclude that the histopathologic features of this new variant of endemic pemphigus are complex, therefore, classical histopathologic features previously described for superficial, endemic pemphigus cannot be used alone to diagnose this disease.

Interleukin 4 and Interferon-Gamma Secretion by Antigen and Mitogen-Stimulated Mononuclear Cells in the Hyper-IgE Syndrome: No TH-2 Cytokine Pattern

BACKGROUND Enhanced production of TH-2 cytokines plays a key role in increased IgE production in allergic diseases. Reports about the cytokine profile secreted by peripheral blood mononuclear cells of patients with hyper-IgE syndrome, however, are controversial, suggesting alternative causes for increased IgE production in this syndrome. OBJECTIVE We wished to determine whether mononuclear cells from patients with hyper-IgE syndrome have a pattern of interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) production characteristic of a predominance of TH-2 cells and whether the cytokine production pattern is constant over time. METHODS IL-4 and IFN-gamma secretion by peripheral blood mononuclear cells stimulated with phytohemagglutinin and D. pteronyssinus was measured by ELISA in culture supernatants. Patients with the hyper-IgE syndrome were evaluated 3 times at 4-week intervals and compared with asthmatic patients and normal subjects. RESULTS In PHA-stimulated cultures, patients with hyper-IgE syndrome had an IL-4 and IFN-gamma secretion similar to that of controls, while asthmatic patients had increased IL-4 and decreased IFN-gamma production. Cultures stimulated with D. pteronyssinus showed a variable pattern of secretion for both cytokines. CONCLUSIONS In allergic diseases, increased serum IgE level is the result of a TH-2 pattern of cytokine production, with high IL-4 and decreased IFN-gamma protein secretion. The increased serum IgE concentration typical of the hyper-IgE syndrome is likely the result of a different immunoregulatory process.

A Study of Granulocyte Respiratory Burst in Patients with Allergic Bronchial Asthma

The respiratory burst of phagocytes plays an important role in the tissue damage that accompanies the inflammatory response. One of these conditions is allergic bronchial asthma, therefore, to evaluate the activation state of peripheral granulocytes the generation of reactive oxygen metabolites was evaluated using Luminol-enhanced chemiluminescence (LCL) and reduction of cytochrome C by superoxide. The resting granulocytes of the asthmatic patients under crisis showed a higher LCL compared to the noncrisis patients and control subjects. The granulocytes stimulated with PMA presented a significant increase in the respiratory burst in both groups of asthmatics. The granulocytes of noncrisis asthmatics challenged with Ops-Zym and with fMLP+Ops-Zym showed a higher metabolic activity, whereas the asthmatics under crisis presented no difference between reactive oxygen generation and that of the control group. The quantitative analysis of superoxide generation by granulocytes of the same patients did not show differences among the groups. Our findings suggest that the granulocytes of crisis and noncrisis asthmatics seem to be in a hyperreactive state and with a higher metabolic response when compared to the control group. However, the patients present a different behavior depending on stimulus used to activate cells. This could indicate that in peripheral blood exist different granulocyte populations depending on the inflammatory response taking place in the respiratory tract.

Increase in granulocyte-macrophage-colony-stimulating factor secretion and the respiratory burst with decreased l-selectin expression in hyper-IgE syndrome patients

BACKGROUND The hyper-IgE syndrome is a primary immunodeficiency characterized by severe recurrent abscesses, pneumonia with pneumatocele formation, and elevated serum IgE. Eosinophilia, neutrophil chemotactic defects, and marked tissue damage are frequently present in this syndrome. OBJECTIVE To study whether functional changes in cytokines, adhesion molecules, and neutrophils might help explain these clinical observations. METHODS The following functions were analyzed in patients with the hyper-IgE syndrome and in controls: (1) production of granulocyte-macrophage-colony-stimulating factor by peripheral blood mononuclear cells by ELISA; (2) respiratory burst and reactive oxygen intermediates production by peripheral neutrophils using the luminol-enhanced chemiluminescense technique; and (3) expression of L-selectin on granulocytes and lymphocytes by flow cytometry. RESULTS Patients with hyper-IgE syndrome had significantly increased production of granulocyte-macrophage-colony-stimulating factor by resting or stimulated mononuclear cells, increased generation of reactive oxygen intermediates by neutrophils treated with opsonized zymosan, and reduced L-selectin expression on quiescent and activated granulocytes and lymphocytes. CONCLUSIONS Our results suggest that an important feature of the hyper-IgE syndrome is the increased production of granulocyte-macrophage-colony-stimulating factor, which may explain the reduced L-selectin expression, decreased chemotaxis, and increased oxygen radical production and tissue damage in this disease.

Molecular characterization of the CCR 5 gene in seronegative individuals exposed to human immunodeficiency virus (HIV)

BACKGROUND Both clinical and laboratory evidence in exposed seronegative (ESN) individuals to human HIV-1 has suggested the existence of mechanisms of natural resistance to the infection. A 32 base-pair deletion in the gene that codes for the CCR5, which is the main coreceptor for HIV-1, confers a high degree of resistance to HIV-1 infection. However, the genotype Delta32/Delta32 is present only in 2-4% of Caucasoid ESN individuals suggesting the existence of other mechanisms of protection. Mutations different from Delta32 have also been proposed as playing a role in resistance/susceptibility to this infection. OBJECTIVE To screen for different mutations along the entire coding region of the ccr5 gene that can potentially explain the persistent seronegativity in a group of ESN individuals. STUDY DESIGN Of a total of 86 individuals analyzed for Delta32 mutation by the PCR technique, 36 scored HIV seropositive (SP) and 50 were ESN. The entire group of ESN individuals was screened for other mutations in the ccr5 gene by single strand conformational polymorphism (SSCP) and DNA sequencing. RESULTS The frequency of the mutant allele Delta32 was 4% (4/100) for ESN individuals and 4.2% (3/72) for SP individuals. The homozygous mutant genotype (Delta32/Delta32) was found in only 2% (1/50) of ESN individuals, but in no SP individuals. The heterozygous genotype was found in 8.3% (3/36) of SP individuals and in 4% (2/50) of ESN individuals. The differences in the allelic and genotypic frequencies among the groups were not statistically significant. A comparison between the observed and the expected genotypic frequencies showed that they were significantly different for the ESN group, suggesting a protective, yet indirect effect of the mutant genotype. CONCLUSIONS The screening of the entire coding region of the ccr5 gene in all ESN did not revealed no other mutations that could account for resistance to HIV-1 infection. Although the CCR5 molecule is the most important coreceptor for HIV-1, mutations in this gene do not account for most of the cases of natural resistance to this virus that have so far been reported.