Lily E. Leiva

Attending to Warning Signs of Primary Immunodeficiency Diseases Across the Range of Clinical Practice

PurposePatients with primary immunodeficiency diseases (PIDD) may present with recurrent infections affecting different organs, organ-specific inflammation/autoimmunity, and also increased cancer risk, particularly hematopoietic malignancies. The diversity of PIDD and the wide age range over which these clinical occurrences become apparent often make the identification of patients difficult for physicians other than immunologists. The aim of this report is to develop a tool for educative programs targeted to specialists and applied by clinical immunologists.MethodsConsidering the data from national surveys and clinical reports of experiences with specific PIDD patients, an evidence-based list of symptoms, signs, and corresponding laboratory tests were elaborated to help physicians other than immunologists look for PIDD.ResultsTables including main clinical manifestations, restricted immunological evaluation, and possible related diagnosis were organized for general practitioners and 5 specialties. Tables include information on specific warning signs of PIDD for pulmonologists, gastroenterologists, dermatologists, hematologists, and infectious disease specialists.ConclusionsThis report provides clinical immunologists with an instrument they can use to introduce specialists in other areas of medicine to the warning signs of PIDD and increase early diagnosis. Educational programs should be developed attending the needs of each specialty.

Immunological evaluation of allergic respiratory children with recurrent sinusitis.

The objective of this study was to evaluate humoral immunity of allergic respiratory children with chronic/recurrent sinusitis. Twenty‐seven allergic respiratory (persistent mild/moderate asthma and persistent allergic rhinitis) children (7–15‐year old) with chronic or recurrent sinusitis were evaluated. Patients had symptoms and abnormal computer tomography scan even after two adequate treatments (long‐lasting antibiotics, decongestants, and short‐term oral corticosteroids). clinical examination, sweat test, total blood cell count, measurement of serum levels of: total and specific IgE, immunoglobulins (G, M, A), IgG subclasses, antibodies to Haemophilus influenza type b (IgG anti‐Ps Hib) and pneumococcal serotypes (IgG anti‐Ps 1, 3, 5, 6B, 9V, and 14) before and after active immunization (Act‐Hib® and Pneumo23®, Aventis Pasteur SA, Lyon, France), Rubella neutralizing antibody titers and human immunodeficiency virus antibodies. Specific IgE to inhalant allergens higher than class III were observed in 24/27 patients. One patient had IgA plus IgG2 deficiency and other an IgG3 deficiency. Eight and 12 of 27 patients had IgG2 and IgG3 serum levels below 2.5th percentile, respectively. Immunological responses to protein and polysaccharide antigens were normal in all patients. Although our patients have been appropriately treated of their allergic diseases, they persisted with chronic/recurrent sinusitis and 60% of them had a documented osteomeatal complex blockade. In spite of the diagnosis of IgA plus IgG2 deficiency and an isolated IgG3 deficiency, in all patients an adequate response to Ps antigens was observed. Primary and/or secondary humoral immunodeficiency seems not to be the main cause of chronic/recurrent sinusitis in patients with respiratory allergic disease.

Recurrent Respiratory Infections, Specific Antibody Deficiencies, and Memory B Cells

ObjectivesTo investigate the immunological phenotypes detected in children with recurrent upper and lower respiratory infections that have normal total immunoglobulin concentrations.MethodsA cohort of over 60 children with recurrent respiration infections was evaluated for specific antibody deficiencies (SAD) and for memory B-cell abnormalities. A control group of children without recurrent infections was also evaluated. Evaluation included a detailed history of immunizations with pneumococcal vaccines; determination of IgM, IgG, IgA, and IgE concentrations; measurement of anti-pneumococcal polysaccharide antibody levels by ELISA and expression of CD27, IgD, and IgM on peripheral CD19+B cells by flow cytometry to determine the proportions of naive, IgM-memory B cells, and class-switched memory B cells.ResultsPatients were classified as having a SAD to either pure polysaccharides (PPV-SAD) or to conjugate polysaccharides (PCV-SAD) based on the number of polysaccharides to which they developed an adequate antibody response. A normal response to only 2 or fewer of 7 PCV or PPV serotypes was considered as evidence of SAD. Forty-one patients without SAD and 26 with SAD were identified. IgM-memory B cells were low in 3 of 41 patients without SAD; in 3 of 5 PPV-SAD patients; and in 10 of 21 PCV-SAD patients. Class-switched memory B cells were low in 19 of 41 patients without SAD; in all 5 patients with PPV-SAD; and in 11 of 21PCV-SAD patients.ConclusionsPatients with recurrent infection with or without SAD may have low IgM- and/or class-switched memory B cells. Ongoing research aims to determine the prognostic implications of these differences in patients with SAD.

Advancing the management of primary immunodeficiency diseases in Latin America, Latin American Society for Immunodeficiencies (LASID) Initiatives

Primary immunodeficiency diseases (PIDD) are associated with significant morbidity and mortality and result in a significant public health burden. This is in part due to the lack of appropriate diagnosis and treatment of these patients. It is critical that governments become aware of this problem and provide necessary resources to reduce this impact on health care systems. Leading physicians in their respective countries must be supported by their own governments in order to implement tools and provide education and thus improve the diagnosis and treatment of PIDD. The Latin American Society of Primary Immunodeficiencies (LASID) has initiated a large number of activities aimed at achieving these goals, including the establishment of a PIDD registry, development of educational programmes and guidelines, and the introduction of a PIDD fellowship programme. These initiatives are positively impacting the identification and appropriate treatment of patients with PIDD in Latin America. Nevertheless, much remains to be done to ensure that every person with PIDD receives proper therapy.

Reduced thymocyte proliferation but not increased apoptosis as a possible cause of thymus atrophy in iron-deficient mice.

Iron deficiency induces thymus atrophy in laboratory animals and very likely in humans by unknown mechanisms. The atrophy is associated with impaired cell-mediated immunity. In this study, we tested the hypothesis that thymus atrophy is a result of increased apoptosis and reduced thymocyte proliferation. Thymocytes were obtained from twenty-seven control, twenty-seven pairfed, twenty-seven iron-deficient (ID) mice; twelve and fourteen ID mice that received the control diet (0.9 mmol/kg versus 0.09 mmol/kg for the ID diet) for 1 d (repletion, R1) and 3 d (R3), respectively. Cell cycle analysis and apoptosis were studied by flow cytometry using propidium iodide staining and terminal deoxyuridine nick end labeling of DNA breaks assay respectively. When mice were killed, haemoglobin, haematocrit, and liver iron stores of ID, R1, and R3 mice were 25-40 % of those of control and pairfed mice Absolute and relative thymus weights and thymocyte numbers were 19 to 68 % lower in ID, R1, and R3 than in control and pairfed groups We found no significant difference among groups in the percentage of cells undergoing apoptosis. A higher percentage of thymocytes from ID and R1 mice than those of control, pairfed, and R3 mice were in the resting phase of the normal cell cycle Conversely, a lower percentage of thymocytes from ID and R1 mice than those from control, pairfed, and R3 mice were in the DNA synthesis phase and late phase of DNA synthesis and onset of mitosis (G2-M) Indicators of iron status positively correlated (r 0.3 to 0.56) with the percentage of thymocytes in the G2-M phase Results suggest that reduced cell proliferation but not increased apoptosis is the cause of thymus atrophy associated with iron deficiency.

Elevated Levels of Soluble HLA Class I (sHLA-1) in Children with Severe Atopic Dermatitis

BACKGROUND Atopic dermatitis is characterized by increased production of IgE and interleukin-4, immediate skin test reactivity to allergens, increased expression of CD23 on mononuclear cells, and decreased production of interferon-gamma. Soluble HLA-I molecule levels are elevated in conditions where T cells are activated such as viral infections, autoimmune diseases, and organ transplantation. OBJECTIVE We wished to determine if sHLA-I heterodimers were also elevated in patients with atopic dermatitis and if sHLA-I elevations correlated with disease activity. METHODS Fourteen children with atopic dermatitis resistant to conventional treatment were followed over an 8-week period during an ongoing trial of treatment with topical sodium cromoglycate. Extent of skin involvement, disease severity, absolute eosinophil counts, IgE and HLA-I levels were determined at the time of enrollment into the study. Additional sHLA-I levels were measured after 4 and 8 weeks of therapy. RESULTS Mean sHLA-I levels were significantly elevated in atopic dermatitis patients, 2.07 +/- 1.14 versus 1.00 +/- 0.22 microg/mL in controls (P < .0001). Nine of 14 patients (64%) had elevated sHLA-I antigens. Soluble HLA-I levels did not correlate with the extent of disease, disease severity score, eosinophil count, or IgE levels. There was a remarkable consistency in sHLA-I levels at baseline and after 4 and 8 weeks of therapy, even with significant clinical improvement. CONCLUSION We conclude that sHLA-I heterodimers are elevated in 64% of our patients with atopic dermatitis and that elevations persist after clinically effective therapy. This conclusion supports recommendations for prolonged preventative and treatment measures in this atopic disease.

Measurement of Pneumococcal Polysaccharide Antibodies

Janssen et al in this journal published their paper “Measurement of pneumococcal polysaccharide vaccine responses for immunodeficiency diagnostics: combined IgG responses compared to serotype specific IgG responses”. It is important to note that the message of this study is the observation that measuring antibodies against a mixture of all 23 pneumococcal serotype polysaccharides by ELISA does not reliably identify patients with a deficient response to pneumococcal polysaccharides. This holds true for patients with CVID, Specific Antibody Deficiency (SAD) or any other immunodeficiency affecting antibody production. Therefore, this study confirms a finding that is well established and beyond question; the only way to properly assess the ability of producing IgG anti-pneumococcal antibodies is to measure antibodies to each serotype individually. This is particularly important in the diagnosis of SAD since this deficiency is defined as an abnormal response to pure pneumococcal polysacchrides, as in the 23-valent poneumococcal vaccine [1]. Now that most young patients are already vaccinated with a pneumococcal conjugate vaccine and may have developed antibodies to serotypes present in these vaccines, the global ELISA test would not be able to identify the lack of response to serotypes that are only in the 23-valent polysaccharide and not in the conjugate vaccines. The study by Janssen et al does lend further clarification about the value of the Luminex method for the diagnosis of SAD. The Luminex method is now used by most commercial laboratories in the USA because it offers significant logistic advantages over the well-standardized but more cumbersome WHO ELISA method. Luminex allows the simultaneous quantitation of multiple serotype-specific antibodies. Both the third generation WHO ELISA and Luminex based tests offered in the USA incorporate double absorption of samples with cell wall polysaccharide (CPS) and serotype 22F. The WHO ELISA test results have been shown to correlate closely with opsonophagocytosis (OPA) measurements [2, 3]. Although the Luminex method has been approved for the measurement of specific anti-pneumococcal serotype IgG antibodies, the correlation of this test with the standard ELISA test is poor and its use as s a diagnostic tool for SAD still needs further study. Recent studies designed to validate the Luminex assay for anti-pneumococcal IgG antibodies have shown different degrees of variability when compared to the ELISA method [4]. Results obtained in a recent comprehensive com-

Effect of L-arginine supplementation on immune responsiveness in patients with sickle cell disease.

L‐arginine (L‐Arg) is deficient in sickle cell disease (SSD) during vasoocclusion. We investigated possible causal relationship between L‐Arg deficiency and immune dysfunction in SSD in steady‐state.

Specific Antibody Deficiency with Normal Immunoglobulins

Specific antibody deficiency (SAD) is a common antibody immunodeficiency defined as a poor antibody response to unconjugated pneumococcal polysccharides present in the 23-valent pneumococcal vaccine (PPV23). All immunoglobulin concentrations, including IgG subclasses, are normal, and antibody responses to protein antigens (e.g., tetanus toxoid, diphtheria toxoid) are also normal in most patients. In some patients with SAD, the response to the pneumococcal conjugate vaccines is also normal. The clinical manifestations of specific antibody deficiency include recurrent otitis media; sinopulmonary infections such as sinusitis; bronchitis; and pneumonia. In SAD patients these infections are more frequent or severe than infections observed in normal children or adults. There is not a single pathogenic mechanism for specific anti-polysaccharide antibody deficiencies. The variable conditions in which an inability to respond to polysaccharides is found suggest that many different immunologic phenotypes may lead to the same clinical phenotypic antibody deficiency. The interpretation of anti-pneumococcal antibody concentration results is based on increased post-immunization antibody concentrations over pre-immunization concentrations (immune response) and on the final post-immunization antibody concentrations, regardless of increase from pre-immunization concentrations (antibody concentration). The management of SAD, including prevention and treatment of recurrent infections, can be classified into the following broad categories: additional immunization, antibiotic prophylaxis and treatment, and immune serum globulin therapy. The immunologic phenotypes of SAD may be transient or permanent. Even in permanent phenotypes, the natural history of SAD is usually benign with proper management of these patients. Further insights into the pathogenesis of this immunodeficiency will allow further understanding of the correlation between immunologic and clinical phenotypes of SAD.

862 Transplacental transmission of serotype-specific pneumococcal antibodies in a Brazilian population

The highest incidence of severe pneumococcal infections in children occurs in the first 6 months of life; however, immunization of infants with the existing polysaccharide vaccines is ineffective. We wished to determine the prevalence of immunoglobulin G (IgG) pneumococcal antibodies in unimmunized Brazilian mothers and their transplacental transmission to term and preterm infants. Total IgG, IgG1 and -2 subclass levels, and IgG antibodies against Streptococcus pneumoniae serotypes 1, 3, 6B, 9V, and 14 were determined in 15 pairs of mothers and term newborns (gestational age, >/=37 weeks) and in 18 pairs of mothers and preterm newborns (gestational age, 32 to 36 weeks). Serotype-specific anti-pneumococcal antibodies were detected by a recently standardized enzyme-linked immunosorbent assay calibrated with the 89-SF reference serum. Varying percentages of the mothers had antibody concentrations below arbitrarily defined protective levels: 33% for serotype 1, 67% for serotype 3, 30% for serotype 6B, 52% for serotype 9V, and 22% for serotype 14. In term newborns, IgG1 concentrations were slightly higher than maternal concentrations; in preterm newborns, the concentrations were much lower. Concentrations of IgG2 in term and preterm infants were significantly lower than in the mothers. Transplacental transmission of antibodies to serotypes 3 and 14 was clearly different from that of antibodies to serotypes 1, 6B, and 9V. Concentrations of IgG antibodies against serotypes 3 and 14 were similar to or higher than those of the mothers; against serotypes 1, 6B, and 9V they ranged from 77 to 83% of maternal concentrations in term newborns and also in preterm infants, although transplacental transmission of antibodies was proportionally lower for each specific serotype in preterm than in term infants. These data are relevant for developing strategies to protect infants against pneumococcal infections in the first months of life. Our findings and a review of existing information stress the importance of understanding the relationships among pneumococcal immunization, IgG subclass antibodies to individual serotypes, transplacental transport, half-life, and antibody function and their protective values against infection.