Early indicators of immunodeficiency in adults and children: protocols for screening for primary immunological defects

A Tribute to Two Master Teachers of Immunology

A Special Issue dedicated in memory of Prof. Fernando Aiuti is a special tribute to a clinician who led the field of Clinical Immunology in Italy and introduced the entire Italian medical and academic scene to it. [...].

Diverse clinical features and diagnostic delay in monogenic inborn errors of immunity: A call for access to genetic testing

BACKGROUND

Inborn errors of immunity (IEIs) are a group of conditions affecting immune system development and function. Due to their clinical heterogeneity and lack of provider awareness, patients suffer from long diagnostic delays that increase morbidity and mortality. Next-generation sequencing facilitates earlier diagnosis and treatment of IEIs, but too often patients are unable to see the benefit of this technology due to gaps in providers' knowledge regarding which patients to test and barriers to accessing sequencing.

METHODS

Here, we provide detailed clinical phenotyping and describe the impact of genetic sequencing on a cohort of 43 patients with monogenic IEIs seen in a tertiary care center from 2014 to 2019. Data were abstracted from a chart review, and a panel of clinical immunologists were consulted on the impact of genetic sequencing on their patients.

RESULTS

We found that our patients had significant diagnostic delays, averaging 3.3 years; had diverse manifestations of immune system dysfunction; and had demonstrated highly complex medical needs, with on average 7.9 subspecialties involved in their care and 4.9 hospitalizations prior to definitive treatment. Our results also demonstrate the benefits of genetic testing, as it provided the majority of our patients with a diagnosis, and positively impacted their treatment, follow-up, and prognosis.

CONCLUSION

This paper expands the paucity of literature on genetically confirmed IEIs in North America and supports the expansion of access to genetic testing for patients with clinical features suggesting IEI, such as those presented in our cohort.

How effective are the 6 European Society of Immunodeficiency warning signs for primary immunodeficiency disease?

BACKGROUND

The European Society of Immunodeficiency (ESID) developed 6 warning signs to promote the awareness of adult primary immunodeficiency disease (PID).

OBJECTIVE

To screen adult patients for the presence of PID using these 6 warning signs to determine the effectiveness of this protocol.

METHODS

Questions related to the ESID warning signs for adult PID were added to the standard outpatient clinic file system and asked of 3,510 patients who were admitted to our clinic for any reason. Patients with signs and/or suspicion of PID based on their medical history underwent immunologic investigation.

RESULTS

In total, 24 patients were diagnosed as having a PID. The most common reason that patients with PID were admitted was frequent infection (n=18 [75%]), and the most common PID subgroup was common variable immunodeficiency (n=12 [50%]). Twenty patients with PID had at least one positive finding according to the ESID warning signs. Two patients with gastrointestinal concerns and 2 with dermatologic symptoms were also diagnosed as having a PID, although they did not have any of the ESID warning signs.

CONCLUSION

The ESID warning signs do not specify the need for symptoms to diagnose a PIDs and do not include a comprehensive list of all signs and symptoms of PIDs. As a result, more than infection-centric questions are needed to identify adult patients with immunodeficiencies.

T cell immunodeficiency

T cell immunodeficiency can occur as one of a group of primary disorders or develop secondary to chronic infection, illness or drug therapy. Primary T cell disorders are rare, accounting for approximately 11% of reported primary immunodeficiencies, and generally present in infancy or early childhood. Early recognition is very important as many of these patients will require bone marrow transplantation prior to the onset of severe infection or other complications. Because of their rarity, these infants usually present to clinicians who have little or no prior experience of these conditions, and therefore laboratory-based clinicians with knowledge of the key laboratory/pathological abnormalities and clinical features have a valuable role in identifying the possibility of immunodeficiency. Secondary T cell deficiency is a cardinal feature of HIV infection and the specific susceptibility to infectious micro-organisms is highlighted. The possibility of T cell immunodeficiency should be considered in any patient presenting with unusual or severe viral, fungal or protozoal infection.

The child with recalcitrant dermatitis: when to worry?

Dermatitis is a frequent cause for referral to the pediatric dermatologist. In this article, a brief overview is given of common childhood dermatoses as well as some rarer dermatoses that may give the clinician cause for concern. Widespread scaling and erythema, described as erythroderma, are a cause of frustration for patients, families, and their physician(s). Both unusual and common skin disorders can present in this fashion. Just as recognizing common dermatoses is important, it is also important to recognize when a dermatitis fails to fit the common pattern and may prompt further investigation.

Clinical predictors of primary immunodeficiency diseases in children

Purpose

To promote awareness of primary immunodeficiency (PID), the "10 warning signs" of PID and an immunodeficiency-related (IDR) score were developed. However, their efficiency in identifying PID cases was not sufficiently evaluated in clinical practice. The objective of this study was to test the validity of the 10 warning signs and IDR score in identifying PID among children with recurrent infections at a tertiary pediatric hospital in Egypt.

Methods

A retrospective analysis of the medical records of 204 patients was performed. Of these patients, 92 had defined PID diseases and 112 were considered non-PID cases because investigations were inconclusive.

Results

Demonstrating two warning signs and an IDR score of 6 led to sensitivities of 94 and 66%, respectively, and specificities of 64 and 75%, respectively, in identifying PID cases. The strongest predictor of PID was family history that, if combined with the need for intravenous antibiotics, recurrent deep-seated infections, and failure to thrive, could identify 81% of PID patients. A family history of PID, sibling death, and/or parental consanguinity would predict 92% of combined immunodeficiencies, 92% of phagocyte defects, 87% of well-identified immunodeficiency syndromes, and 84% of antibody deficiency if the need for intravenous antibiotics is considered in the latter.

Conclusions

The 10 warning signs and IDR score do not aid in an early diagnosis of severe PID. Educational campaigns should target pediatricians aiming to increase PID awareness and to address family history of PID, parental consanguinity, and previous sibling death as key predictors of PID in communities with a high prevalence of consanguineous marriages.

Advances in primary immunodeficiency diseases in Latin America: epidemiology, research, and perspectives

Primary immunodeficiencies (PIDs) are genetic disorders of the immune system comprising many different phenotypes. Although previously considered rare, recent advances in their clinical, epidemiological, and molecular definitions are revealing how much we still need to learn about them. For example, geographical and ethnic variations as well as the impact of certain practices influence their frequency and presentation, making it necessary to consider their study in terms of regions. The Latin American Society for Immunodeficiencies was established as an organization dedicated to provide scientific support for basic and clinical research and to develop tools and educational resources to promote awareness in the medical community. Initiatives such as these are positively influencing the way PIDs are tackled in these countries, as shown by recent reports and publications. This paper provides a historical compilation and a current view of the many issues faced by scientists studying these diseases in these countries, highlighting the diverse scientific contributions and offering a promising perspective for the further developments in this field in Latin America.

Children with frequent infections: a proposal for a stepwise assessment and investigation of the immune system

Although many children develop frequent infections, only a few have an underlying immune disorder. Children with dysfunction of the immune system develop frequent infections and/or recurrent, persistent, severe, and rare infections. The aim of this review is to provide to the clinician a valuable tool for recognizing any 'discords' of the 'immune-system symphonic orchestra'. By following a reverse route, it will be possible to brighten up the dark and winding road of immunodeficiencies and identify the exact point of immune dysfunction. This is fundamental and crucial to perceive etiologic management and subsequently achieve the best for these young patients and their families.

Common variable immunodeficiency: 20-yr experience at a single centre

Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency. It can present at any age in patients with a history of recurrent bacterial infections, with or without a family history of other primary immunodeficiencies (PID), and shows a wide range of clinical manifestations and immunological data. Diagnosis is based on low IgG, IgM and/or IgA levels. Delayed diagnosis and therapy can lead to bronchiectasis and malabsorption. The aim of this study was to describe a paediatric population diagnosed of CVID and its evolution in the population. Memory B-cell (MB) classification carried out in these patients was correlated with clinical manifestations and outcome. Clinical and immunological data of 22 CVID children under 18 yr treated at our centre between 1985 and 2005 are presented. Immunological studies included those for diagnosis and MB quantification. Differences in form of presentation, familial incidence and MB classification were reviewed. A statistical descriptive analysis was made. Infections were the commonest manifestation, affecting mainly respiratory (19/22) and gastrointestinal (10/22) tracts. Bronchiectasis was present in seven cases, and detected prior to CVID diagnosis in five. Replacement therapy led to a significant reduction in the number of infections. Severe complications appeared mostly in patients without MB. Patients of the same family share the same MB group. Family members had also been diagnosed of CVID in seven cases. Early diagnosis and therapy are essential to improve outcome in these patients. MB studies are useful in children to orient prognosis and further genetic studies.

Clinical immunology review series: an approach to the patient with recurrent superficial abscesses

Patients may be referred to the immunology clinic for investigation of recurrent superficial abscess formation. In the majority of adult patients this clinical presentation does not equate with an underlying primary immune deficiency. Nevertheless, recurrent mucocutaneous abscesses can be associated with significant morbidity and long-term complications, including scarring and fistula formation, and may be associated with underlying immune-mediated disease. This review sets out an approach to the patient with recurrent superficial abscesses, focusing on the differential diagnoses, investigation and management of both the common causes and those associated with specific immune deficiency.

Clinical immunology review series: an approach to the patient with recurrent infections in childhood

Recurrent or persistent infection is the major manifestation of primary immunodeficiency, which also results in atypical infection with opportunistic organisms. Young children are also vulnerable to infection and recurrent infection is common. While most children with recurrent infection have a normal immunity, it is important to recognize the child with an underlying primary immunodeficiency and investigate and treat appropriately and yet not over investigate normal children. Prompt, accurate diagnosis directs the most appropriate treatment, and early and judicious use of prophylactic antibiotics and replacement immunoglobulin can prevent significant end organ damage and improve long-term outlook and quality of life. This paper describes important presenting features of primary immunodeficiency and indicates when further investigation is warranted.

The European internet-based patient and research database for primary immunodeficiencies: results 2004-06

Because primary immunodeficiencies (PID) are rare diseases, transnational studies are essential to maximize the scientific outcome and lead to improved diagnosis and therapy. Immunologists in Europe have united to determine the prevalence of PID in Europe and to establish and evaluate harmonized guidelines for the diagnosis and treatment of PID as well as to improve the awareness of PID in Europe. In order to achieve this aim we have developed an internet-based database for clinical and research data on patients with PID. This database forms the platform for studies of demographics, the development of new diagnostic and therapeutic strategies and the identification of novel disease-associated genes. The database is completely secure, while providing access to researchers via a standard browser using password and encrypted log-in sessions and conforms to all European and national ethics and data protection guidelines. So far 2386 patients have been documented by 35 documenting centres in 20 countries. Common variable immunodeficiency (CVID) is the most common entity, accounting for almost 30% of all entries. First statistical analyses on the quality of life of patients show the advantages of immunoglobulin replacement therapy, at the same time revealing a mean diagnostic delay of over 4 years. First studies on specific questions on selected PID are now under way. The platform of this database can be used for any type of medical condition.