Clinical assessment and management of abnormal IgA levels

Causes of chronic productive cough: An approach to management

A chronic 'productive' or 'wet' cough is a common presenting complaint for patients attending the adult respiratory clinic. Most reviews and guidelines suggest that the causes of a productive cough are the same as those of a non-productive cough and as such the same diagnostic pathway should be followed. We suggest a different diagnostic approach for patients with a productive cough, focussing on the conditions that are the most likely causes of this problem. This review is intended to briefly summarise the epidemiology, clinical features, pathophysiology and treatment of a number of conditions which are often associated with chronic productive cough to aid decision making when encountering a patient with this often distressing symptom. The conditions discussed include bronchiectasis, chronic bronchitis, asthma, eosinophilic bronchitis and immunodeficiency. We also propose an adult version of the paediatric diagnosis of protracted bacterial bronchitis (PBB) in patients with idiopathic chronic productive cough who appear to respond well to low dose macrolide therapy.

IgA deficiency and autoimmunity

IgA is the most abundant immunoglobulin in the human body, and performs a very specialized role which involves mucosal immunity, development of tolerance and protection against infection. IgA is the key immunoglobulin in the respiratory and gastrointestinal tracts, which provide the most intimate interface between the environment and self. Normal levels of IgA are based on early studies consisting of only small numbers of patients. The international consensus definition of IgA deficiency is a level of 0.07g/l after the age of four years in the absence of IgG and IgM deficiencies. The epidemiology of IgA deficiency reveals interesting variances between geographical regions - the incidence in Caucasians being much higher than that in Asians. IgA deficiency has also been found to co-exist with autoimmune diseases, allergies and malignancies. The association with autoimmunity is particularly interesting because it suggests a common genetic linkage that could potentially also explain the diversity in geoepidemiology. Both MHC and non-MHC associations have been described and the 8.1 haplotype has been significantly associated with autoimmunity in IgA deficiency patients over controls. Non-MHC genetic associations include IFIH1 and CLEC16A. The mutations leading to IgA deficiency have not been defined, but in some cases of IgA deficiency it has been suggested that the pathogenesis involves a failure in switched memory B cells that can lead to this cohort experiencing an increased incidence of recurrent bacterial infections or autoimmune diseases. Attempts to investigate the role of cytokines that can induce IgA synthesis in cells of patients with IgA deficiency, such as IL21 or the combination of CD40L/anti-CD40, IL-4 and IL10, are underway.

Children with partial IgA deficiency: clinical characteristics observed in the pediatric rheumatology clinic

Literature is lacking on partial IgA deficiency. In this study, the authors propose to describe the clinical manifestations of patients with partial IgA deficiency. Methods. The authors conducted a retrospective chart review of 13 patients with partial IgA deficiency followed at the pediatric rheumatology clinic at Robert Wood Johnson Medical School. They looked for the presence of rashes, joint pain, joint swelling, and morning stiffness. The authors also examined charts for a history of frequent infections, allergies, and the presence of elevated antinuclear antibody. Results. Eleven out of the 13 patients complained of joint pain, joint swelling, or morning stiffness. Six patients carried a diagnosis of a definitive rheumatic disease. Four patients suffered from frequent infections and 2 patients reported allergies. Conclusion. Partial IgA deficiency appears to be associated with rheumatic diseases and complaints of joint pain, joint swelling, and morning stiffness. A larger study is needed to confirm these results.

B-lymphocyte stimulator and a proliferation-inducing ligand serum levels in IgA-deficient patients with and without celiac disease

IgA deficiency (IgAD) is the most common form of immunodeficiency and frequently associates with autoimmunity, especially with celiac disease (CD). The mechanisms underlying IgAD and the development of autoimmunity are still relatively unknown. Elevated B-lymphocyte stimulator (BLyS) and APRIL (a proliferation-inducing ligand) serum levels characterize several autoimmune diseases. We herein investigated BLyS and APRIL serum levels in IgAD patients with and without CD and compared these patients to CD patients with normal IgA and control patients (HBDs). Compared to HBDs, IgAD patients demonstrated a significant increase of BLyS (P < 0.0001) and APRIL (P = 0.003) levels, and no differences were seen between patients with or without CD. While BLyS appeared similarly overexpressed in IgAD and CD patients, APRIL was significantly increased only in IgAD patients. Because APRIL promotes IgA production, its overexpression may represent a physiological mechanism of compensation. BLyS upregulation may be involved in the increased risk of autoimmune disease development characterizing people carrying IgAD.

Common variable immunodeficiency (CVID): case report and review of the literature

Common variable immunodeficiency (CVID) is an immunodeficiency disease characterized by diminished ability to produce immunoglobulins. CVID has an estimated incidence of 1:10,000 to 1:200,000 (male:female 1:1) and usually presents in the second and third decade, although it also has a peak of incidence in childhood. The exact pathophysiology remains unclear. CVID can be associated with autoimmune, granulomatous and gastrointestinal diseases and patients have a predisposition to malignancies (especially non-Hodgkin lymphoma). Since different organ systems can be affected, all clinicians need to be aware of this entity, especially when confronted with patients with recurrent infections and/or multiple autoimmune diseases.

Otitis media as a presenting complaint in childhood immunodeficiency diseases

Otitis media is one of the most common childhood infections and may result from a variety of underlying problems. Suspicion of immunodeficiency should increase when ear infections are frequent; suppurative; unresponsive to antibiotics; caused by unusual organisms; or seen in the context of other frequent infections, severe eczema, or failure to thrive. Humoral immune deficiencies, particularly with an inability to make antibody to encapsulated organisms, are the immunodeficiencies most likely to cause increased otitis media. Immune system evaluation should concentrate on humoral immunodeficiency disorders, but the presenting history and physical findings also should be considered when designing the work-up. Treating the underlying immune deficiency is usually necessary to adequately control the ear infections.