Clinical picture and treatment of 2212 patients with common variable immunodeficiency

Indolent cytotoxic T cell lymphoproliferation associated with nodular regenerative hyperplasia: a common liver lesion in the context of common variable immunodeficiency disorder

Patients with common variable immunodeficiency disorder (CVID) are subject to lymphoproliferative disorders and predisposed to lymphoma. Some patients may also develop liver lesions. The purpose of this study was to define clinical and histopathological features of patients with CVID presenting with liver lesions suspicious of lymphoma. Four CVID cases corresponding to these criteria were retrieved from our files. Liver biopsy specimens were subjected to morphologic, immunophenotypic and molecular analysis. All patients presented with hepatosplenomegaly and two furthermore with lymphadenopathy. The clinical working diagnosis in the four cases was lymphoma. All liver biopsies revealed nodular regenerative hyperplasia (NRH), associated with mild to marked sinusoid lymphocytic infiltrate consisting of "activated" cytotoxic T cells (CD8+, Tia1+, granzyme B+, TCRβF1+, CD56-). EBER was negative in all cases. T cell clonality was found in one of the two interpretable cases. All patients had an indolent course and clinical symptoms regressed with immunoglobulin replacement. This study suggests that indolent proliferation in the liver sinusoid of cytotoxic T cell associated with NRH is a specific liver lesion in the context of CVID. In CVID patients clinically suspected of lymphoma, pathologists should avoid a misdiagnosis of aggressive T cell lymphoma with a risk of over treatment.

The Incidence and Prevalence of Common Variable Immunodeficiency Disease in Taiwan, A Population-Based Study

Common variable immunodeficiency (CVID) is one of the primary immunodeficiency diseases that occur in both children and adults. We present here a nationwide, population-based epidemiological study of CVID across all ages in Taiwan during 2002–2011. Using the International Classification of Diseases, Ninth Revision code 279.06, cases of CVID were identified from Taiwan's National Health Insurance Research Database from January 2002 to December 2011. Age- and sex-specific incidence and prevalence rates were calculated. A total of 47 new cases of CVID during 2002–2011 were identified. Total prevalence rose from 0.13 per 100,000 in 2002 to 0.28 per 100,000 in 2011. The annual incidence rate during 2002–2011 was 0.019 per 100,000. Cases were equally distributed between males and females and males mostly occurred in younger patients. This nationwide population-based study showed that the incidence and prevalence of CVID in Taiwan were lower than that in Western countries.

Immune deficiency: changing spectrum of pathogens

Current UK national standards recommend routine bacteriology surveillance in severe antibody-deficient patients, but less guidance exists on virology screening and viral infections in these patients. In this retrospective audit, we assessed the proportion of positive virology or bacteriology respiratory and stool samples from patients with severe, partial or no immune deficiency during a 2-year period. Medical notes were reviewed to identify symptomatic viral infections and to describe the course of persistent viral infections. During the 2-year period, 31 of 78 (39·7%) severe immune-deficient patients tested had a positive virology result and 89 of 160 (55.6%) had a positive bacteriology result. The most commonly detected pathogens were rhinovirus (12 patients), norovirus (6), Haemophilus influenzae (24), Pseudomonas spp. (22) and Staphylococcus aureus (21). Ninety-seven per cent of positive viral detection samples were from patients who were symptomatic. Low serum immunoglobulin IgA levels were more prevalent in patients with a positive virology sample compared to the total cohort (P = 0·0078). Three patients had persistent norovirus infection with sequential positive isolates for 9, 30 and 16 months. Virology screening of symptomatic antibody-deficient patients may be useful as a guide to anti-microbial treatment. A proportion of these patients may experience persistent viral infections with significant morbidity.

Health-related quality of life in patients with primary immunodeficiency disease

Primary immunodeficiency disease (PIDD) with hypogammaglobulinemia is characterized by recurrent and severe bacterial infections and IgG replacement is the standard of care in many of these patients. Health-related quality of life (HRQOL) is becoming increasingly recognized as a factor that affects patient well-being and treatment preferences. In an effort to better understand what factors affect HRQOL in patients with PIDD, we reviewed the published literature that used standardized instruments for the measurement of HRQOL. We investigated HRQOL in PIDD patients compared with normal controls and patients with other chronic diseases; we also investigated the impact of treatment administration on patient satisfaction. The most commonly encountered health-related quality of life instruments were the child heath questionnaire parental form 50, short form 36, PedsQL 4.0, Lansky's play performance scale, and Life Quality Index. Patients with PIDD scored significantly lower on many of the instruments compared with normal controls. Also, while it appears that many patients appreciate home-based and subcutaneous IgG replacement therapy, patient satisfaction ultimately involves various clinical factors and individual patient preferences. By further analyzing what factors impact HRQOL, therapy adjustments can be made to maximize patient well-being and minimize disease impact on daily functioning.

Antigen-specific IgA titres after 23-valent pneumococcal vaccine indicate transient antibody deficiency disease in children

Paediatric patients with antibody deficiency may either be delayed in development of humoral immunity or may be persistently deficient in antibody production. To differentiate between these entities, we examined the 23-valent pneumococcal polysaccharide (PnPS) vaccine-induced IgM-, IgG- and IgA antibody responses in a cohort of 66 children with recurrent respiratory tract infections. Individual serum titres against 11 pneumococcal serotypes were measured by Luminex. The cohort contained 33 antibody deficiency patients, 17 transient antibody deficiency patients and 16 patients without antibody deficiency diagnosis (control group). Transient antibody deficiency patients produced consistently higher levels of PnPS-specific IgA responses than antibody deficiency patients. Decreased IgA responses to serotypes 1, 5, 7F and 18C were most discriminative to stratify transient antibody deficiency patients from antibody deficiency patients with persistent disease. We conclude that measuring PnPS-specific IgA responses may predict the disease course in young children diagnosed with antibody deficiency and suggest confirmation of these data in a prospective setting.

Practice parameter for the diagnosis and management of primary immunodeficiency

The American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology (ACAAI) have jointly accepted responsibility for establishing the "Practice parameter for the diagnosis and management of primary immunodeficiency." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Common Variable Immunodeficiency: Diagnosis, Management, and Treatment

Common variable immunodeficiency (CVID) refers to a grouping of antibody deficiencies that lack a more specific genetic or phenotypic classification. It is the immunodeficiency classification with the greatest number of constituents, likely because of the numerous ways in which antibody production can be impaired and the frequency in which antibody production becomes impaired in human beings. CVID comprises a heterogeneous group of rare diseases. Consequently, CVID presents a significant challenge for researchers and clinicians. Despite these difficulties, both our understanding of and ability to manage this grouping of complex immune diseases has advanced significantly over the past 60 years.

Bryant V, Frede N, Slade C, Woon ST, Lehnert K, Winzer S, Bulashevska A, Scerri T, Leung E, Jordan A, Keller B, de Vries E, Cao H, Yang F, Schäffer A, Warnatz K, Browett P, Douglass J, Ameratunga R, van der Meer J, Grimbacher B. Haploinsufficiency of the NF-κB1 Subunit p50 in Common Variable Immunodeficiency

Common variable immunodeficiency (CVID), characterized by recurrent infections, is the most prevalent symptomatic antibody deficiency. In ∼90% of CVID-affected individuals, no genetic cause of the disease has been identified. In a Dutch-Australian CVID-affected family, we identified a NFKB1 heterozygous splice-donor-site mutation (c.730+4A>G), causing in-frame skipping of exon 8. NFKB1 encodes the transcription-factor precursor p105, which is processed to p50 (canonical NF-κB pathway). The altered protein bearing an internal deletion (p.Asp191_Lys244delinsGlu; p105ΔEx8) is degraded, but is not processed to p50ΔEx8. Altered NF-κB1 proteins were also undetectable in a German CVID-affected family with a heterozygous in-frame exon 9 skipping mutation (c.835+2T>G) and in a CVID-affected family from New Zealand with a heterozygous frameshift mutation (c.465dupA) in exon 7. Given that residual p105 and p50—translated from the non-mutated alleles—were normal, and altered p50 proteins were absent, we conclude that the CVID phenotype in these families is caused by NF-κB1 p50 haploinsufficiency.

CVID Associated with Systemic Amyloidosis

Common variable immunodeficiency (CVID) is a frequent primary immune deficiency (PID), which consists of a heterogeneous group of disorders and can present with recurrent infections, chronic diarrhea, autoimmunity, chronic pulmonary and gastrointestinal diseases, and malignancy. Secondary amyloidosis is an uncommon complication of CVID. We report an unusual case of a 27-year-old male patient who presented with recurrent sinopulmonary infections, chronic diarrhea, and hypogammaglobulinemia and was diagnosed with CVID. The patient was treated with intravenous immunoglobulin (IVIg) therapy once every 21 days and daily trimethoprim-sulfamethoxazole for prophylaxis. Two years after initial diagnosis, the patient was found to have progressive decline in IgG levels (as low as 200–300 mg/dL) despite regular Ig infusions. The laboratory tests revealed massive proteinuria and his kidney biopsy showed accumulation of AA type amyloid. We believe that the delay in the diagnosis of CVID and initiation of Ig replacement therapy caused chronic inflammation due to recurrent infections in our patient and this led to an uncommon and life-threatening complication, amyloidosis. Patients with CVID require regular follow-up for the control of infections and assessment of adequacy of Ig replacement therapy. Amyloidosis should be kept in the differential diagnosis when managing patients with CVID.

Advances in basic and clinical immunology in 2014

Genetic identification of immunodeficiency syndromes has become more efficient with the availability of whole-exome sequencing, expediting the identification of relevant genes and complementing traditional linkage analysis and homozygosity mapping. New genes defects causing immunodeficiency include phophoglucomutase 3 (PGM3), cytidine 5' triphosphate synthase 1 (CTPS1), nuclear factor κB-inducing kinase (NIK), cytotoxic T lymphocyte-associated antigen 4 (CTLA4), B-cell chronic lymphocytic leukemia/lymphoma 10 (BCL10), phosphoinositide-3 kinase regulatory subunit 1 (PIK3R1), IL21, and Jagunal homolog 1 (JAGN1). New case reports expanded the clinical spectrum of gene defects. For example, a specific recombination-activating gene 1 variant protein with partial recombinant activity might produce Omenn syndrome or a common variable immunodeficiency phenotype. Central and peripheral B-cell tolerance was investigated in patients with several primary immunodeficiencies, including common variable immunodeficiency and Wiskott-Aldrich syndrome, to explain the occurrence of autoimmunity and inflammatory disorders. The role of IL-12 and IL-15 in the enhancement of natural killer cell activity was reported. Newborn screening for T-cell deficiency is being implemented in more states and is achieving its goal of defining the true incidence of severe combined immunodeficiency and providing early treatment that offers the highest survival for these patients. Definitive treatment of severe immunodeficiency with both hematopoietic stem cell transplantation and gene therapy was reported to be successful, with increasing definition of conditions needed for optimal outcomes. Progress in HIV infection is directed toward the development of an effective vaccine and the eradication of hidden latent virus reservoirs.

Lung disease in primary antibody deficiency

This Review summarises current knowledge on the pulmonary manifestations of primary antibody deficiency (PAD) syndromes in adults. We describe the major PAD syndromes, with a particular focus on common variable immunodeficiency (CVID). Respiratory infection is a common presenting feature of PAD syndromes. Respiratory complications are frequent and responsible for much of the morbidity and mortality associated with these syndromes. Respiratory complications include acute infections, the sequelae of infection (eg, bronchiectasis), non-infectious immune-mediated manifestations (notably the development of granulomatous-lymphocytic interstitial lung disease in CVID), and an increased risk of lymphoma. Although minor abnormalities are detectable in the lungs of most patients with CVID by CT scanning, not all patients develop lung complications. Mechanisms associated with the maintenance of lung health versus lung disease, and the development of bronchiectasis versus immune-mediated complications, are now being dissected. We review the investigation, treatment, and management strategies for PAD syndromes, and include key research questions relating to both infectious and non-infectious complications of PAD in the lung.

Accelerated atherosclerosis in patients with common variable immunodeficiency: Is it overlooked or absent?

Common variable immunodeficiency (CVID) is a heterogeneous primary deficiency characterized by hypogammaglobulinemia, recurrent infections, and an increased risk of autoimmune disease and malignancy, and so chronic inflammation. Cardiovascular disease is the leading cause of mortality in the general population. Recent studies have suggested that chronic inflammation is an important player in the pathogenesis of CVID. Accelerated atherosclerosis due to ongoing inflammation from recurrent infections and autoimmunity is an expected clinical entity in patients with CVID. However, cardiovascular mortality as a cause of death in CVID series is either absent or minor. We hypothesized that accelerated atherosclerosis and cardiovascular disease are overlooked by clinicians, or atherosclerosis is really lower than that in the general population that may be prevented by some factors such as life-long immunoglobulin replacement treatment.

The use of databases in primary immunodeficiencies

PURPOSE OF REVIEW

We provide an overview on the latest developments in primary immunodeficiency registries worldwide, on the basis of the recent literature amended by some older references to achieve completeness.

RECENT FINDINGS

New primary immunodeficiency registries are emerging worldwide, although existing databases continue to thrive and provide valuable insights for clinicians and researchers.

SUMMARY

In the area of rare disease research, data on a meaningful number of patients can only be achieved via collaboration. Registries for primary immunodeficiency are organized on different geographic levels and appear in various technical forms. Some registries are operated within single departments or hospitals, whereas others collect data from a country in the form of a national registry. With modern information technology and networks, it has become feasible to easily extend documentation to the transnational level. Most patient registries cover similar but not identical sets of data, whereas some have a special focus on, for example, genetics or incorporate only data from patients who have undergone a specific form of treatment. This review shows the usefulness and power of international immunodeficiency registries, as well as possible hurdles and limitations.

Monozygotic twins discordant for common variable immunodeficiency reveal impaired DNA demethylation during naïve-to-memory B-cell transition

Common variable immunodeficiency (CVID), the most frequent primary immunodeficiency characterized by loss of B-cell function, depends partly on genetic defects, and epigenetic changes are thought to contribute to its aetiology. Here we perform a high-throughput DNA methylation analysis of this disorder using a pair of CVID-discordant MZ twins and show predominant gain of DNA methylation in CVID B cells with respect to those from the healthy sibling in critical B lymphocyte genes, such as PIK3CD, BCL2L1, RPS6KB2, TCF3 and KCNN4. Individual analysis confirms hypermethylation of these genes. Analysis in naive, unswitched and switched memory B cells in a CVID patient cohort shows impaired ability to demethylate and upregulate these genes in transitioning from naive to memory cells in CVID. Our results not only indicate a role for epigenetic alterations in CVID but also identify relevant DNA methylation changes in B cells that could explain the clinical manifestations of CVID individuals.

Thrombocytopenia in common variable immunodeficiency patients - clinical course, management, and effect of immunoglobulins

Common variable immunodeficiency (CVID) is a primary immunodeficiency of humoral immunity with heterogeneous clinical features. Diagnosis of CVID is based on hypogammaglobulinaemia, low production of specific antibodies, and disorders of cellular immunity. The standard therapy includes replacement of specific antibodies with human immunoglobulin, prophylaxis, and symptomatic therapy of infections. High prevalence of autoimmunity is characteristic for CVID, most commonly: thrombocytopaenia and neutropaenia, celiac disease, and systemic autoimmune diseases.

The study included seven children diagnosed with CVID and treated with immunoglobulin substitution from 2 to 12 years. Thrombocytopenia was diagnosed prior to CVID in four children, developed during immunoglobulin substitution in three children. In one boy with CVID and thrombocytopaenia, haemolytic anaemia occurred, so a diagnosis of Evans syndrome was established. Therapy of thrombocytopaenia previous to CVID included steroids and/or immunoglobulins in high dose, and azathioprine. In children with CVID on regular immunoglobulin substitution, episodes of acute thrombocytopaenia were associated with infections and were treated with high doses of immunoglobulins and steroids. In two patients only chronic thrombocytopaenia was noted. Splenectomy was necessary in one patient because of severe course of thrombocytopaenia.

The results of the study indicated a supportive role of regular immunoglobulin substitution in patients with CVID and chronic thrombocytopaenia. However, regular substitution of immunoglobulins in CVID patients did not prevent the occurrence of autoimmune thrombocytopaenia episodes or exacerbations of chronic form. In episodes of acute thrombocytopaenia or exacerbations of chronic thrombocytopaenia, infusions of immunoglobulins in high dose are effective, despite previous regular substitution in the replacing dose.

Immunodeficiency in Chronic Sinusitis: Recognition and Treatment

Chronic rhinosinusitis (CRS) is estimated to affect over 35 million people. However, not all patients with the diagnosis respond to standard medical and surgical treatments. Although there are a variety of reasons a patient may be refractory to therapy, one possible etiology is the presence of an underlying immunodeficiency. This review will focus on the description, recognition, and treatment of several antibody deficiencies associated with CRS, including common variable immunodeficiency (CVID), selective IgA deficiency, IgG subclass deficiency, and specific antibody deficiency (SAD). The diagnosis of antibody deficiency in patients with CRS is important because of the large clinical implications it can have on sinus disease management. CVID is treated with immunoglobulin replacement, whereas SAD may be managed symptomatically and sometimes with prophylactic antibiotics and/or immunoglobulin replacement.

Familial hepatopulmonary syndrome in common variable immunodeficiency

Common Variable Immunodeficiency (CVID) comprises a heterogeneous group of primary antibody deficiencies which lead to a range of complications, including infectious, neoplastic and inflammatory disorders. This report describes monozygotic twin brothers with CVID who developed cryptogenic liver disease and subsequently hepatopulmonary syndrome (HPS). This is the second report of the association of HPS and CVID. Its occurrence in two identical twins implicates a genetic basis.

Low ficolin-2 levels in common variable immunodeficiency patients with bronchiectasis

Common variable immunodeficiency (CVID) encompasses a heterogeneous group of antibody deficiencies characterized by susceptibility to recurrent infections and sequelae, including bronchiectasis. We investigated the relevance of the lectin complement pathway in CVID patients by analysing ficolin-2 and ficolin-3 serum levels and genotyping single nucleotide polymorphisms (SNPs) in the FCN2 and FCN3 genes. Our results show that ficolin-2 levels in CVID patients are significantly lower (P < 0.0001) than in controls. The lowest ficolin-2 levels are found in CVID patients with bronchiectasis (P = 0.0004) and autoimmunity (P = 0.04). Although serum levels of ficolin-3 were similar in CVID patients and controls, CVID patients with bronchiectasis again showed lower levels when compared to controls (P = 0.0001). Analysis of single nucleotide polymorphisms in the FCN2 gene confirmed known influences on ficolin-2 serum levels, but did not support a genetic basis for the observed ficolin-2 deficiency in CVID. We found that CVID patients with bronchiectasis have very low levels of ficolin-2. The reason for the deficiency of ficolin-2 in CVID and any possible causal relationship is currently unknown. However, as bronchiectasis is a very important factor for morbidity and mortality in CVID, ficolin-2 could also serve as biomarker for monitoring disease complications such as bronchiectasis.

Mechanisms of action of Ig preparations: immunomodulatory and anti-inflammatory effects

Primary immunodeficiency (PID) disorders that predispose patients to recurrent infections require immunoglobulin (Ig) replacement therapy. Ig replacement therapy has been stated as beneficial, although the optimal IgG trough level to be maintained over time in order to minimize infectious risk has not been established. The most common route of administration of Ig has been intravenously, although there are different options, one of them being the subcutaneous route. Ig replacement therapy has been a life-saving treatment for patients suffering from primary and secondary antibody immunodeficiency. The key role of regular Ig replacement in patients with antibody deficiencies is related to the ability to provide specific antibodies that could not be produced by these patients as demonstrated by the reduction of severe infections such as meningitis and pneumonia. The therapeutic benefits of Ig may also be due to an active role in various anti-inflammatory and immunomodulatory activities, which may complicate the clinical picture of PID. Anti-inflammatory activities are seen more generally when intravenous Ig is administered at high dose. The immunomodulatory and anti-inflammatory activities are important not only in the treatment of autoimmune diseases but also in patients suffering from immunodeficiency.

Identification of patients with RAG mutations previously diagnosed with common variable immunodeficiency disorders

PURPOSE

Combined immunodeficiency (CID) presents a unique challenge to clinicians. Two patients presented with the prior clinical diagnosis of common variable immunodeficiency (CVID) disorder marked by an early age of presentation, opportunistic infections, and persistent lymphopenia. Due to the presence of atypical clinical features, next generation sequencing was applied documenting RAG deficiency in both patients.

METHODS

Two different genetic analysis techniques were applied in these patients including whole exome sequencing in one patient and the use of a gene panel designed to target genes known to cause primary immunodeficiency disorders (PIDD) in a second patient. Sanger dideoxy sequencing was used to confirm RAG1 mutations in both patients.

RESULTS

Two young adults with a history of recurrent bacterial sinopulmonary infections, viral infections, and autoimmune disease as well as progressive hypogammaglobulinemia, abnormal antibody responses, lymphopenia and a prior diagnosis of CVID disorder were evaluated. Compound heterozygous mutations in RAG1 (1) c256_257delAA, p86VfsX32 and (2) c1835A>G, pH612R were documented in one patient. Compound heterozygous mutations in RAG1 (1) c.1566G>T, p.W522C and (2) c.2689C>T, p. R897X) were documented in a second patient post-mortem following a fatal opportunistic infection.

CONCLUSION

Astute clinical judgment in the evaluation of patients with PIDD is necessary. Atypical clinical findings such as early onset, granulomatous disease, or opportunistic infections should support the consideration of atypical forms of late onset CID secondary to RAG deficiency. Next generation sequencing approaches provide powerful tools in the investigation of these patients and may expedite definitive treatments.

Is dosing of therapeutic immunoglobulins optimal? A review of a three-decade long debate in europe

The consumption of immunoglobulins (Ig) is increasing due to better recognition of antibody deficiencies, an aging population, and new indications. This review aims to examine the various dosing regimens and research developments in the established and in some of the relevant off-label indications in Europe. The background to the current regulatory settings in Europe is provided as a backdrop for the latest developments in primary and secondary immunodeficiencies and in immunomodulatory indications. In these heterogeneous areas, clinical trials encompassing different routes of administration, varying intervals, and infusion rates are paving the way toward more individualized therapy regimens. In primary antibody deficiencies, adjustments in dosing and intervals will depend on the clinical presentation, effective IgG trough levels and IgG metabolism. Ideally, individual pharmacokinetic profiles in conjunction with the clinical phenotype could lead to highly tailored treatment. In practice, incremental dosage increases are necessary to titrate the optimal dose for more severely ill patients. Higher intravenous doses in these patients also have beneficial immunomodulatory effects beyond mere IgG replacement. Better understanding of the pharmacokinetics of Ig therapy is leading to a move away from simplistic "per kg" dosing. Defective antibody production is common in many secondary immunodeficiencies irrespective of whether the causative factor was lymphoid malignancies (established indications), certain autoimmune disorders, immunosuppressive agents, or biologics. This antibody failure, as shown by test immunization, may be amenable to treatment with replacement Ig therapy. In certain immunomodulatory settings [e.g., idiopathic thrombocytopenic purpura (ITP)], selection of patients for Ig therapy may be enhanced by relevant biomarkers in order to exclude non-responders and thus obtain higher response rates. In this review, the developments in dosing of therapeutic immunoglobulins have been limited to high and some medium priority indications such as ITP, Kawasaki' disease, Guillain-Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy, myasthenia gravis, multifocal motor neuropathy, fetal alloimmune thrombocytopenia, fetal hemolytic anemia, and dermatological diseases.

Autosomal dominant immune dysregulation syndrome in humans with CTLA4 mutations

The protein cytotoxic T lymphocyte antigen-4 (CTLA-4) is an essential negative regulator of immune responses, and its loss causes fatal autoimmunity in mice. We studied a large family in which five individuals presented with a complex, autosomal dominant immune dysregulation syndrome characterized by hypogammaglobulinemia, recurrent infections and multiple autoimmune clinical features. We identified a heterozygous nonsense mutation in exon 1 of CTLA4. Screening of 71 unrelated patients with comparable clinical phenotypes identified five additional families (nine individuals) with previously undescribed splice site and missense mutations in CTLA4. Clinical penetrance was incomplete (eight adults of a total of 19 genetically proven CTLA4 mutation carriers were considered unaffected). However, CTLA-4 protein expression was decreased in regulatory T cells (Treg cells) in both patients and carriers with CTLA4 mutations. Whereas Treg cells were generally present at elevated numbers in these individuals, their suppressive function, CTLA-4 ligand binding and transendocytosis of CD80 were impaired. Mutations in CTLA4 were also associated with decreased circulating B cell numbers. Taken together, mutations in CTLA4 resulting in CTLA-4 haploinsufficiency or impaired ligand binding result in disrupted T and B cell homeostasis and a complex immune dysregulation syndrome.

Immunodeficiency in adults a practical guide for the allergist

Knowing the clinical warning signs of immunodeficiency (ID) in adulthood is crucial for early detection of the over 200 forms of primary ID known to date. Many of these congenital diseases with a genetic background already manifest in childhood. Antibody deficiency diseases represent an important exception, with common variable immunodeficiency (CVID) being the most common form of ID. The median age of onset of CVID is 24 years. Unfortunately, the delay in diagnosis is still in excess of 4 years. General practitioners as well as allergists play a particularly important role in early detection. ID patients who present primarily with signs of immune dysregulation pose an even greater diagnostic challenge. Thus, autoimmune cytopenia, inflammatory bowel diseases, or sarcoid-like granulomatous inflammation can be the first manifestation in up to 20 % of ID patients. Secondary forms of ID [e. g., due to long-term corticosteroid treatment, HIV-infection, leukemia, lymphoma, nephrotic syndrome, malabsorption syndrome] need to be differentiated from primary antibody deficiency. Considering the overlap with allergic symptoms [ID accompanied by a susceptibility to eczema, elevated total IgE, blood eosinophilia], the present article discusses, the clinical warning signs of ID, the first diagnostic steps required and the option of further diagnostic work up at specialist centers for complex cases, as well as the treatment options for such cases.

Primary immunodeficiencies in the Netherlands: national patient data demonstrate the increased risk of malignancy

PURPOSE

To analyze the data of the national registry of all Dutch primary immune deficiency (PID) patients, according to the European Society for Immunodeficiencies (ESID) definitions.

RESULTS

In the Netherlands, 745 patients had been registered between 2009 and 2012. An overall prevalence of 4.0 per 100,000 inhabitants was calculated. The most prevalent PID was 'predominantly antibody disorder (PAD)' (60.4%). In total, 118 transplantations were reported, mostly hematopoietic stem cell transplantations (HSCT). Almost 10% of the PID patients suffered from a malignancy, in particular 'lymphoma' and 'skin cancer'. Compared to the general Dutch population, the relative risk of developing any malignancy was 2.3-fold increased, with a >10-fold increase for some solid tumors (thymus, endocrine organs) and hematological disease (lymphoma, leukemia), varying per disease category.

CONCLUSIONS

The incidence rate and characteristics of PID in the Netherlands are similar to those in other European countries. Compared to the general population, PID patients carry an increased risk to develop a malignancy.

IRAK-4 and MyD88 deficiencies impair IgM responses against T-independent bacterial antigens

IRAK-4 and MyD88 deficiencies impair interleukin 1 receptor and Toll-like receptor (TLR) signaling and lead to heightened susceptibility to invasive bacterial infections. Individuals with these primary immunodeficiencies have fewer immunoglobulin M (IgM)(+)IgD(+)CD27(+) B cells, a population that resembles murine splenic marginal zone B cells that mount T-independent antibody responses against bacterial antigens. However, the significance of this B-cell subset in humans is poorly understood. Using both a 610 carbohydrate array and enzyme-linked immunosorbent assay, we found that patients with IRAK-4 and MyD88 deficiencies have reduced serum IgM, but not IgG antibody, recognizing T-independent bacterial antigens. Moreover, the quantity of specific IgM correlated with IgM(+)IgD(+)CD27(+) B-cell frequencies. As with mouse marginal zone B cells, human IgM(+)CD27(+) B cells activated by TLR7 or TLR9 agonists produced phosphorylcholine-specific IgM. Further linking splenic IgM(+)IgD(+)CD27(+) B cells with production of T-independent IgM, serum from splenectomized subjects, who also have few IgM(+)IgD(+)CD27(+) B cells, had reduced antibacterial IgM. IRAK-4 and MyD88 deficiencies impaired TLR-induced proliferation of this B-cell subset, suggesting a means by which loss of this activation pathway leads to reduced cell numbers. Thus, by bolstering the IgM(+)IgD(+)CD27(+) B-cell subset, IRAK-4 and MyD88 promote optimal T-independent IgM antibody responses against bacteria in humans.

Utility of next generation sequencing in clinical primary immunodeficiencies

Primary immunodeficiencies (PIDs) are a group of genetically heterogeneous disorders that present with very similar symptoms, complicating definitive diagnosis. More than 240 genes have hitherto been associated with PIDs, of which more than 30 have been identified in the last 3 years. Next generation sequencing (NGS) of genomes or exomes of informative families has played a central role in the discovery of novel PID genes. Furthermore, NGS has the potential to transform clinical molecular testing for established PIDs, allowing all PID differential diagnoses to be tested at once, leading to increased diagnostic yield, while decreasing both the time and cost of obtaining a molecular diagnosis. Given that treatment of PID varies by disease gene, early achievement of a molecular diagnosis is likely to enhance treatment decisions and improve patient outcomes.

Comparison of diagnostic criteria for common variable immunodeficiency disorder

Common variable immunodeficiency disorders (CVIDs) are the most frequent symptomatic primary immune deficiency condition in adults. The genetic basis for the condition is not known and no single clinical feature or laboratory test can establish the diagnosis; it has been a diagnosis of exclusion. In areas of uncertainty, diagnostic criteria can provide valuable clinical information. Here, we compare the revised European society of immune deficiencies (ESID) registry (2014) criteria with the diagnostic criteria of Ameratunga et al. (2013) and the original ESID/pan American group for immune deficiency (ESID/PAGID 1999) criteria. The ESID/PAGID (1999) criteria either require absent isohemagglutinins or impaired vaccine responses to establish the diagnosis in patients with primary hypogammaglobulinemia. Although commonly encountered, infective and autoimmune sequelae of CVID were not part of the original ESID/PAGID (1999) criteria. Also excluded were a series of characteristic laboratory and histological abnormalities, which are useful when making the diagnosis. The diagnostic criteria of Ameratunga et al. (2013) for CVID are based on these markers. The revised ESID registry (2014) criteria for CVID require the presence of symptoms as well as laboratory abnormalities to establish the diagnosis. Once validated, criteria for CVID will improve diagnostic precision and will result in more equitable and judicious use of intravenous or subcutaneous immunoglobulin therapy.

Comparisons of CVID and IgGSD: referring physicians, autoimmune conditions, pneumovax reactivity, immunoglobulin levels, blood lymphocyte subsets, and HLA-A and -B typing in 432 adult index patients

Common variable immunodeficiency (CVID) and immunoglobulin (Ig) G subclass deficiency (IgGSD) are heterogeneous disorders characterized by respiratory tract infections, selective Ig isotype deficiencies, and impaired antibody responses to polysaccharide antigens. Using univariable analyses, we compared observations in 34 CVID and 398 IgGSD adult index patients (81.9% women) referred to a hematology/oncology practice. Similarities included specialties of referring physicians, mean ages, proportions of women, reactivity to Pneumovax, median serum IgG3 and IgG4 levels, median blood CD56+/CD16+ lymphocyte levels, positivity for HLA-A and -B types, and frequencies of selected HLA-A, -B haplotypes. Dissimilarities included greater prevalence of autoimmune conditions, lower median IgG, IgA, and IgM, and lower median CD19+, CD3+/CD4+, and CD3+/CD8+ blood lymphocytes in CVID patients. Prevalence of Sjögren's syndrome and hypothyroidism was significantly greater in CVID patients. Combined subnormal IgG1/IgG3 occurred in 59% and 29% of CVID and IgGSD patients, respectively. Isolated subnormal IgG3 occurred in 121 IgGSD patients (88% women). Logistic regression on CVID (versus IgGSD) revealed a significant positive association with autoimmune conditions and significant negative associations with IgG1, IgG3, and IgA and CD56+/CD16+ lymphocyte levels, but the odds ratio was increased for autoimmune conditions alone (6.9 (95% CI 1.3, 35.5)).

Primary immunodeficiency in infection-prone children in southern Sweden: occurrence, clinical characteristics and immunological findings

Background

Primary immunodeficiency diseases (PIDs) comprise a heterogeneous group of disorders mainly characterized by increased susceptibility to infections. The aims of this study were to estimate the occurrence rate of PID in the paediatric (age ≤ 18 years) population of southern Sweden (approx. 265,000 children) and to describe their demographic, clinical and immunological characteristics. During a period of 4 years, in four paediatric speciality clinics in Skåne County in southern Sweden, children being seen for infections and fulfilling specific criteria were evaluated according to a predefined examination schedule. The initial analysis consisted of complete blood counts with analysis of lymphocyte subpopulations (T, B, NK cells), measurement of immunoglobulins (IgG, IgA, IgM, IgE and IgG subclasses), and assessment of the complement system (classical, alternative and lectin pathways). In addition, results of these immunological analyses in other children from the same area and time period were evaluated.

Results

In total, 259 children (53.6% males) met the criteria and were included. The most common infection was recurrent otitis media. Immunological analyses results for about two thirds of the patients were outside age-related reference intervals. Further examination in this latter group identified 15 children with PID (9 males); 7 (2.7%) had genetically defined PID, representing 4 different diagnoses, and another 8 (3.1%) had a clinically defined PID - common variable immunodeficiency. No additional PID patient was identified from the evaluation of laboratory results in children not included in the study. The median age at diagnosis was 3.5 years (range 1–12 years).

Conclusions

The occurrence rate of PID was about 4 new cases per year in this population. Several different PID diagnoses were found, and the application of specified criteria to identify PID patients was useful. In children who are prone to infection, the use of a predefined set of immunological laboratory analyses at their first examination was beneficial for early identification of patients with PID.

Primary vs. secondary antibody deficiency: clinical features and infection outcomes of immunoglobulin replacement

Secondary antibody deficiency can occur as a result of haematological malignancies or certain medications, but not much is known about the clinical and immunological features of this group of patients as a whole. Here we describe a cohort of 167 patients with primary or secondary antibody deficiencies on immunoglobulin (Ig)-replacement treatment. The demographics, causes of immunodeficiency, diagnostic delay, clinical and laboratory features, and infection frequency were analysed retrospectively. Chemotherapy for B cell lymphoma and the use of Rituximab, corticosteroids or immunosuppressive medications were the most common causes of secondary antibody deficiency in this cohort. There was no difference in diagnostic delay or bronchiectasis between primary and secondary antibody deficiency patients, and both groups experienced disorders associated with immune dysregulation. Secondary antibody deficiency patients had similar baseline levels of serum IgG, but higher IgM and IgA, and a higher frequency of switched memory B cells than primary antibody deficiency patients. Serious and non-serious infections before and after Ig-replacement were also compared in both groups. Although secondary antibody deficiency patients had more serious infections before initiation of Ig-replacement, treatment resulted in a significant reduction of serious and non-serious infections in both primary and secondary antibody deficiency patients. Patients with secondary antibody deficiency experience similar delays in diagnosis as primary antibody deficiency patients and can also benefit from immunoglobulin-replacement treatment.

Pulmonary radiologic findings in common variable immunodeficiency: clinical and immunological correlations

BACKGROUND

It remains unclear whether interstitial lung disease (ILD) in common variable immunodeficiency (CVID) is a consequence of chronic infection or a manifestation of dysregulated lymphoid proliferation found in those with this condition.

OBJECTIVE

To increase understanding of CVID-associated lung disease by comparing clinical and immunologic associations in those with bronchiectasis, ILD, or no lung disease observed on chest computerized tomography (CT).

METHODS

Retrospective review of electronic medical records of 61 patients with CVID was used to identify clinical and laboratory correlates of bronchiectasis, ground glass opacity, and pulmonary nodules on CT scan.

RESULTS

Significant clinical and immunologic associations were identified for common CT scan findings in CVID. Bronchiectasis was strongly correlated with a CD4+ T-cell count lower than 700 cells/μL and was associated with a history of pneumonia and older age. Pulmonary nodular disease was correlated with increased CD4+:CD8+ T-cell ratios, a history of autoimmune hemolytic anemia or immune thrombocytopenic purpura, elevated IgM, and younger age. Ground glass opacity had similar clinical and laboratory characteristics as those for nodular lung disease but was associated with elevated monocyte counts and the presence of liver disease.

CONCLUSION

CT findings of bronchiectasis or ILD, including ground glass opacity and extensive pulmonary nodules, were correlated with selected clinical and laboratory characteristics. These results suggest divergent processes of CVID lung disease, with bronchiectasis more strongly associated with infection and T-cell lymphopenia and ILD more strongly linked with autoimmunity and lymphoproliferation.

Pulmonary manifestations of primary immunodeficiency disorders in children

Primary immunodeficiencies (PIDs) are inherited disorders in which one or several components of immune system are decreased, missing, or of non-appropriate function. These diseases affect the development, function, or morphology of the immune system. The group of PID comprises more than 200 different disorders and syndromes and the number of newly recognized and revealed deficiencies is still increasing. Their clinical presentation and complications depend on the type of defects and there is a great variability in the relationship between genotypes and phenotypes. A variation of clinical presentation across various age categories is also presented and children could widely differ from adult patients with PID. Respiratory symptoms and complications present a significant cause of morbidity and also mortality among patients suffering from different forms of PIDs and they are observed both in children and adults. They can affect primarily either upper airways (e.g., sinusitis and otitis media) or lower respiratory tract [e.g., pneumonia, bronchitis, bronchiectasis, and interstitial lung diseases (ILDs)]. The complications from lower respiratory tract are usually considered to be more important and also more specific for PIDs and they determinate patients' prognosis. The spectrum of the causal pathogens usually demonstrates typical pattern characteristic for each PID category. The respiratory signs of PIDs can be divided into infectious (upper and lower respiratory tract infections and complications) and non-infectious (ILDs, bronchial abnormalities - especially bronchiectasis, malignancies, and benign lymphoproliferation). Early diagnosis and appropriate therapy can prevent or at least slow down the development and course of respiratory complications of PIDs.