Adult-onset presentations of genetic immunodeficiencies: genes can throw slow curves

Developing a genetic testing panel for evaluation of morbidities in kidney transplant recipients

Cardiovascular disease, infection, malignancy, and thromboembolism are major causes of morbidity and mortality in kidney transplant recipients (KTR). Prospectively identifying monogenic conditions associated with post-transplant complications may enable personalized management. Therefore, we developed a transplant morbidity panel (355 genes) associated with major post-transplant complications including cardiometabolic disorders, immunodeficiency, malignancy, and thrombophilia. This gene panel was then evaluated using exome sequencing data from 1590 KTR. Additionally, genes associated with monogenic kidney and genitourinary disorders along with American College of Medical Genetics (ACMG) secondary findings v3.2 were annotated. Altogether, diagnostic variants in 37 genes associated with Mendelian kidney and genitourinary disorders were detected in 9.9% (158/1590) of KTR; 25.9% (41/158) had not been clinically diagnosed. Moreover, the transplant morbidity gene panel detected diagnostic variants for 56 monogenic disorders in 9.1% KTRs (144/1590). Cardiovascular disease, malignancy, immunodeficiency, and thrombophilia variants were detected in 5.1% (81), 2.1% (34), 1.8% (29) and 0.2% (3) among 1590 KTRs, respectively. Concordant phenotypes were present in half of these cases. Reviewing implications for transplant care, these genetic findings would have allowed physicians to set specific risk factor targets in 6.3% (9/144), arrange intensive surveillance in 97.2% (140/144), utilize preventive measures in 13.2% (19/144), guide disease-specific therapy in 63.9% (92/144), initiate specialty referral in 90.3% (130/144) and alter immunosuppression in 56.9% (82/144). Thus, beyond diagnostic testing for kidney disorders, sequence annotation identified monogenic disorders associated with common post-transplant complications in 9.1% of KTR, with important clinical implications. Incorporating genetic diagnostics for transplant morbidities would enable personalized management in pre- and post-transplant care.

Inborn errors of immunity in adulthood

Inborn errors of immunity (IEIs) are a group of conditions whereby parts of the immune system are missing or dysfunctional. Once thought to primarily be a pediatric disorder, it is now estimated that more than 50% of worldwide incident IEI cases are accounted for by adults. Delayed diagnosis, late symptom onset, and IEI phenocopies can all lead to adult-onset recognition of IEIs. Lack of awareness regarding the diversity of IEI manifestations in adults contributes to diagnostic and treatment delays. Prompt referral to immunology is critical so that patients can receive a precise molecular diagnosis and targeted therapy when available. This article serves as a primer on IEIs in adulthood, highlighting the pathophysiology, epidemiology and clinical features. We present clinical vignettes of three key IEIs to assist clinicians in building illness scripts on their presentations. We provide a framework for the laboratory evaluation of IEIs and their initial treatment, with the aim of improving recognition and management of these conditions.

Heterogeneity in combined immunodeficiencies with associated or syndromic features (Review)

Primary immunodeficiencies are genetic diseases, mainly monogenic, that affect various components of the immune system and stages of the immune response. The category of combined immunodeficiencies with associated or syndromic features comprises over 70 clinical entities, characterized by heterogeneity of clinical presentation, mode of transmission, molecular, biological, mutational and immunological aspects. The mutational spectrum is wide, ranging from structural chromosomal abnormalities to gene mutations. The impact on the function of the proteins encoded by the genes involved is different; loss of function is most common, but situations with gain of function are also described. Most proteins have multiple functions and are components of several protein interaction networks. The pathophysiological mechanisms mainly involve: Missing enzymes, absent or non-functional proteins, abnormal DNA repair pathways, altered signal transduction, developmental arrest in immune differentiation, impairment of cell-to-cell and intracellular communications. Allelic heterogeneity, reduced penetrance and variable expressivity are genetic phenomena that cause diagnostic difficulties, especially since most are rare/very rare diseases, which is equivalent to delaying proper case management. Most primary immunodeficiencies are Mendelian diseases with X-linked or recessive inheritance, and molecular diagnosis allows the identification of family members at risk and the application of appropriate primary and secondary prevention measures in addition to the specific curative ones. In conclusion, recognizing heterogeneity and its sources is extremely important for current medical practice, but also for the theoretical value of improving biological and biomedical applications.

Septische Granulomatose als seltene Differenzialdiagnose rezidivierender pulmonaler Infektionen bei Erwachsenen

Die septische Granulomatose (engl.: chronic granulomatous disease, CGD) ist bei Kindern und Jugendlichen mit häufigen Infektionen durch bestimmte Erreger differenzialdiagnostisch zu berücksichtigen.

In vorliegender Kasuistik berichten wir über eine 64-jährige Patientin mit über Jahre zunehmenden bronchopulmonalen Infektionen, teilweise durch seltene Erreger, Autoimmunphänomenen, Malignomen und im weiteren Verlauf rezidivierenden organisierenden Pneumonien (OP) mit Nachweis von Granulomen. Ursächlich wurde bei der Patientin eine septische Granulomatose, Unterform p47phox-Defizienz diagnostiziert. Ein Überleben von Patienten mit einem primären Immundefekt (PID) bis ins hohe Erwachsenenalter wird trotz wiederholter Komplikationen in Einzelfällen beobachtet, insbesondere wenn die defekte Zellstruktur eine Restaktivität aufweist. Bei rezidivierenden bronchopulmonalen Infektionen insbesondere durch bestimmte seltene Erreger und in Kombination mit organisierend-granulomatösen Lungenreaktionen sowie Autoimmunphänomenen ist auch bei älteren Erwachsenen an eine CGD zu denken. Durch eine Diagnoseverzögerung kommt es oft zu einem erheblichen Anstieg der Morbidität und Mortalität.

Acute primary purulent pericarditis in an adult patient with unknown X-linked agammaglobulinemia

X-linked agammaglobulinemia (XLA) is a rare form of inherited immunodeficiency due to an impairment in B-lymphocyte differentiation and maturation. In the majority of cases XLA is diagnosed in childhood, particularly among males affected by recurrent infections and with a family history of immunodeficiency. Infections of respiratory tract, gastrointestinal apparatus, eyes, nose and ears are frequent in XLA patients; on the contrary, infections of myocardium, cardiac valves and pericardium are rarely described in XLA. A 34-year-old man with unknown XLA was hospitalized because of syncope, due to pericardial tamponade, caused by acute primary purulent pericarditis. Immediate pericardiocentesis was effective in improving hemodynamics, and empiric antibiotic therapy was successful in controlling the infection. Purulent pericarditis is a rare disease with high mortality rate: it is usually caused by hematogenous bacterial propagation, direct infection of pericardial space by chest wounds or thoracic surgery, or extension of infection from adjacent tissues. However, this patient had no recent local or systemic infections. Because of unusual clinical picture during hospitalization he underwent further clinical and laboratory evaluations, that showed low immunoglobulin levels. After exclusion of acquired immunodeficiency, genetic tests were performed: they detected deletion of exons 8-9-10 of Bruton Tyrosine Kinase gene on X chromosome, leading to the diagnosis of XLA. Acute purulent primary pericarditis may also occur in adult XLA patients as first clinical manifestation. According to this case report, a primary immunodeficiency syndrome should be considered in patients with atypical cardiac infections and no predisposing conditions, regardless of age.

Munchausen syndrome mimicking refractory subcutaneous abscess with bacteremia, diagnosed by repetitive element sequence-based polymerase chain reaction: a case report

Background

Rapid diagnosis and appropriate treatment of Munchausen syndrome is important not only for the patient but also for health care workers because a delay in diagnosis can worsen patients’ clinical outcomes, and result in a substantial medical cost.

Case presentation

A young and previously healthy 24-year-old Japanese woman, a nurse, presented with complaints of refractory abscess on her left upper limb for 3 months. A physical examination on admission revealed low-grade fever and a subcutaneous abscess in her left forearm. Laboratory data suggested mild systemic inflammation and liver dysfunction, but no abnormalities of the immune system, including changes in the number of lymphocytes and neutrophils, neutrophil phagocytic capacity, and natural killer (NK) cell activity, were observed. A human immunodeficiency virus test was also negative. Multiple modalities, including positron emission tomography-computed tomography, failed to detect any cause and focus of infection except her left upper limb. Streptococcus mitis and Prevotella buccae were detected from the wound, but no microorganisms were detected in a blood culture. The cellulitis promptly resolved; however, exacerbation of the subcutaneous abscess with polymicrobial bacteremia repeatedly occurred unexpectedly. Because of this puzzling clinical course, the possibility of self-injury was finally suspected. Three syringes with needles, with a turbid liquid, were found in our patient’s bag. Enterobacter cloacae and Enterococcus faecalis were detected in the liquid, and an analysis via repetitive element sequence-based polymerase chain reaction determined that Enterococcus faecalis in the wound and syringe contents were genetically identical. She was diagnosed as having Munchausen syndrome and treated with the collaboration of a psychiatrist. She finally confessed that she had injected her own saliva and toilet water into the drip line and wound.

Conclusions

This case report is valuable in that it is the first case in which this syndrome was diagnosed by a genetic method. Munchausen syndrome should not be neglected as a possible cause of refractory and recurrent infection.

Primary Immune Deficiencies in the Adult: A Previously Underrecognized Common Condition

The large majority of classified primary immune deficiency (PID) diseases present in childhood. Yet, most patients with PID are adults, with a large proportion experiencing onset of symptoms beyond their childhood years. Most of these are diagnosed predominantly with antibody defects, but cellular and other disorders are increasingly being identified in older patients as well. Moreover, advances in clinical immunology are allowing pediatric patients, even those with severe disease, to reach adulthood. Because of differences in the physiology and pathophysiology of children and adults, the presentation, diagnosis, and management of a complex chronic disease could differ significantly between these patient populations and therefore require modifications in approach.

Adult Common Variable Immunodeficiency

BACKGROUND

Common variable immunodeficiency (CVID) is characterized by hypogammaglobulinemia, defective antibody production and recurrent upper and lower respiratory tract infections. The diagnosis in adult patients is often thought to be rare, and thus misdiagnosis often occurs. A limited number of cases of adult-onset CVID have been reported in China, and the features of the syndrome remain unclear. The objective of this study was to describe the main characteristics of CVID, and evaluate the treatment of adult patients who present with CVID.

MATERIALS AND METHODS

This was a retrospective analysis of 8 patients with CVID from different departments in 1 center in China. Patients were diagnosed according to the diagnostic criteria of the European Society for Immunodeficiency Diseases. Demographics, clinical and immunological data from each patient were collected and a statistical analysis was undertaken.

RESULTS

The mean age at diagnosis was 43 ± 13.7 years, whereas the mean duration of diagnostic delay was 10.5 years. The median total serum levels of immunoglobulin (Ig) G, IgA and IgM at diagnosis were 2.5 ± 0.59, 0.23 ± 0.05 and 0.17 ± 0.05g/L, respectively. A total of 7 patients also had a low CD4(+)/CD8(+) ratio. All patients presented with recurrent respiratory infections. Regular infusions of intravenous immunoglobulin every 3 weeks substantially reduced pneumonic episodes.

CONCLUSIONS

Diagnosis is often delayed in adult CVID. Pulmonary infections and diseases were the most frequent presentations at onset of the disease. Regular intravenous immunoglobulin infusions were beneficial in controlling recurrent infections.

Merkel cell carcinoma in a patient with GATA2 deficiency: a novel association with primary immunodeficiency

A 55-year-old woman with GATA2 deficiency and neurofibromatosis 1 was diagnosed with Merkel cell carcinoma (MCC). This polyomavirus-associated cutaneous malignancy has previously been associated with immunosuppression and acquired immunodeficiencies such as HIV/AIDS. However, MCC has not been previously reported in the setting of underlying primary or inherited immunodeficiency.

Patient-centred screening for primary immunodeficiency, a multi-stage diagnostic protocol designed for non-immunologists: 2011 update

Members of the European Society for Immunodeficiencies (ESID) and other colleagues have updated the multi-stage expert-opinion-based diagnostic protocol for non-immunologists incorporating newly defined primary immunodeficiency diseases (PIDs). The protocol presented here aims to increase the awareness of PIDs among doctors working in different fields. Prompt identification of PID is important for prognosis, but this may not be an easy task. The protocol therefore starts from the clinical presentation of the patient. Because PIDs may present at all ages, this protocol is aimed at both adult and paediatric physicians. The multi-stage design allows cost-effective screening for PID of the large number of potential cases in the early phases, with more expensive tests reserved for definitive classification in collaboration with a specialist in the field of immunodeficiency at a later stage.

[Are investigations for underlying causes needed for the management of an adult patient with bronchiectasis?]

Bronchiectasis may result from various causes. Recognition of these underlying causes may lead to specific management. Focal bronchiectasis are related to luminal blockage or extrinsic narrowing. The causative factors of diffuse bronchiectasis may be suggested by the predominant distribution of the disease and associated extrapulmonary manifestations. Primary immunodeficiencies cystic fibrosis, allergic bronchopulmonary aspergillosis, chronic Mycobacterium avium complex infection, and systemic diseases have to be looked for, even in patients with knowledge of a childhood respiratory infection.