Introduction to immunodeficiency reviews

Diagnostic assay to assist clinical decisions for unclassified severe combined immune deficiency

3D organoid T-cell differentiation from a few hundred peripheral blood CD34+ cells was successfully achieved. 3D organoid T-cell differentiation could help physicians distinguish intrinsic from extrinsic defects underlying a clinical SCID phenotype.

Inborn errors of metabolism underlying primary immunodeficiencies

A number of inborn errors of metabolism (IEM) have been shown to result in predominantly immunologic phenotypes, manifesting in part as inborn errors of immunity. These phenotypes are mostly caused by defects that affect the (i) quality or quantity of essential structural building blocks (e.g., nucleic acids, and amino acids), (ii) cellular energy economy (e.g., glucose metabolism), (iii) post-translational protein modification (e.g., glycosylation) or (iv) mitochondrial function. Presenting as multisystemic defects, they also affect innate or adaptive immunity, or both, and display various types of immune dysregulation. Specific and potentially curative therapies are available for some of these diseases, whereas targeted treatments capable of inducing clinical remission are available for others. We will herein review the pathogenesis, diagnosis, and treatment of primary immunodeficiencies (PIDs) due to underlying metabolic disorders.

Current treatment options for chronic granulomatous disease

Chronic granulomatous disease is a rare inherited disorder of phagocytic cells which results in a susceptibility to infections of catalase-positive bacteria and fungi (especially Aspergillus species), as well as granuloma formation. The mainstay of therapy is antibacterial and antifungal prophylaxis. Trimethoprim sulfamethoxazole is the drug of choice for the prevention of bacterial infection, while itraconazole is most widely used for the prevention of fungal infection. Immunomodulatory agents, such as IFN-phi, have a role in the prevention and treatment of intractable infection. New antifungal agents provide the promise of improved cure rates for invasive Aspergillus, while bone marrow transplants and gene therapy may offer the promise of complete cure.

Myositis in children

Idiopathic inflammatory myositis in children includes multiple disease entities, but is primarily made up of juvenile dermatomyositis and, to a lesser degree, juvenile polymyositis. Much new information has been published in the last few years about these diseases, including the epidemiology, pathogenesis, clinical diagnosis, and outcomes and treatment. This includes information on onset of symptoms, potential inciting agents, and regional differences. Exciting data have emerged in our understanding of the immune response gene associations and the description of chimerism in children with these disorders. Finally, new advances in clinical evaluations and outcomes have been described as well as new treatment protocols to provide a more effective therapy with less toxicity. Continued investigation is needed to further understand these diseases, but great strides are being made in our understanding and ability to care for children with idiopathic inflammatory myositis.

Detection of mRNA for the terminal complement components C5, C6, C8 and C9 in human umbilical vein endothelial cells in vitro

Human umbilical vein endothelial cells (HUVEC) have previously been shown to synthesize the functional terminal pathway of complement based on the detection by radioimmunoassay of the terminal complement complex (TCC) on coincubated agarose beads. In addition, C7 secretion by these cells in amounts comparable to C3, as well as C7 mRNA, has recently been demonstrated. However, it has not been possible to detect C5-6 and C8 in the fluid phase, and only trace amounts of soluble C9. Against this background we examined whether mRNA for the remaining terminal complement factors was present in HUVEC. By the use of reverse transcription (RT)-polymerase chain reaction (PCR) and Northern blot the presence of mRNA for complement factors C5, C6, C8 and C9 was demonstrated.

Update on the genetics of the idiopathic inflammatory myopathies

A number of lines of investigation suggest that, as is likely the case for other autoimmune diseases, the idiopathic inflammatory myopathies (IIM) develop as a result of specific environmental exposures in genetically susceptible individuals. Current data imply that multiple genes are involved in the etiology of these complex disorders. Targeted gene studies and whole genome approaches have begun to identify several genetic risk factors for autoimmune diseases, but the rarity and heterogeneity of the IIM have limited our knowledge of their associated genes. Current findings suggest that human leukocyte antigen (HLA) genes on chromosome 6, particularly HLA DRB1*0301 and the linked allele DQA1*0501, have the strongest associations with all clinical forms of IIM in white patients. Different HLA alleles, however, may confer risk or protection for myositis in distinct ethnic, serologic, and environmental exposure groups. Non-HLA genetic risk factors, which have been documented for other autoimmune diseases, are now being identified for the IIM. These include polymorphic genes encoding immunoglobulin heavy chains (defined by serologic markers known as Gm allotypes), cytokines and their receptors, and certain proteins that accumulate in the myocyte vacuoles of inclusion body myositis patients. Selected allelic polymorphisms of interleukin-1 receptor antagonist variable number tandem repeats and genes for tumor necrosis factor alpha and interleukin-1 alpha also have recently been associated with IIM. The pathogenic bases for the differences among the many clinically, pathologically and immunologically defined syndromes known as the IIM will be elucidated through a better understanding of the multiple genes that define risks for their development, as well as through investigations of gene-gene and gene-environment interactions.