Sensorineural hearing loss in primary antibody deficiency disorders

Mammalian Inner Ear-Resident Immune Cells-A Scoping Review

BACKGROUND

Several studies have demonstrated the presence of resident immune cells in the healthy inner ear.

AIM

This scoping review aimed to systematize this knowledge by collecting the data on resident immune cells in the inner ear of different species under steady-state conditions.

METHODS

The databases PubMed, MEDLINE (Ovid), CINAHL (EBSCO), and LIVIVO were used to identify articles. Systematic reviews, experimental studies, and clinical data in English and German were included without time limitations.

RESULTS

The search yielded 49 eligible articles published between 1979 and 2022. Resident immune cells, including macrophages, lymphocytes, leukocytes, and mast cells, have been observed in various mammalian inner ear structures under steady-state conditions. However, the physiological function of these cells in the healthy cochlea remains unclear, providing an opportunity for basic research in inner ear biology.

CONCLUSIONS

This review highlights the need for further investigation into the role of these cells, which is crucial for advancing the development of therapeutic methods for treating inner ear disorders, potentially transforming the field of otolaryngology and immunology.

Autoimmune Inner Ear Disease among Patients with Selective IgA Deficiency

OBJECTIVES

Autoimmune inner ear disease (AIED) is a distinct clinical entity from sudden sensorineural hearing loss. The purpose of this study was to investigate the clinical characteristics of AIED in patients with selective IgA deficiency (sIgAD).

MATERIALS AND METHODS

This retrospective observational study was based on data from the Leumit Healthcare Services database in Israel. We searched all subjects aged ≥12 years who had undergone serum total IgA measurements during 2004-2014 for any reason. The sIgAD patients included all subjects with serum IgA of ≤7 mg/dL (0.07 g/L). A control group was randomly sampled from the full study population (n ≈ 730,000) with a case-control ratio of 10 controls for each case (1:10).

RESULTS

Among 347 subjects with sIgAD, we identified 9 patients with concomitant AIED (sIgAD + AIED group). This group was characterized by a higher prevalence of allergic diseases (8 patients; 88.9%) than sIgAD patients without AEID (sIgAD + AIED group; 153 patients; 45.2%; p = 0.014). Both systemic diseases (3 patients; 33.3%) and organ-specific autoimmune diseases (7 patients; 77.8%) were more prevalent in the sIgAD + AIED group (sIgAD + AIED group: 19 patients 5.5%, p = 0.015; sIgAD - AEID group: 76 patients, 21.9%, p < 0.001), with an OR of 8.39 (1.94-36.19; p = 0.004). sIgAD patients with and without AIED were characterized by a higher prevalence of documented episodes of acute otitis media, allergic diseases, and autoimmune diseases than the control group.

CONCLUSION

The study exposes a significant association between AIED and sIgAD. We believe that sIgAD has to be excluded in AIED patients.

Otitis Media and Inborn Errors of Immunity

PURPOSE OF REVIEW

The aim of this review is as follows: (1) to present the role of otitis as a warning sign for inborn errors of immunity (IEI), (2) to establish which patients presenting otitis should be investigated for IEI, (3) to review data about main IEI associated with otitis-prone patients.

RECENT FINDINGS

Otitis media is a very common infection in general population. The concept of otitis-prone children established a certain frequency of the infections in order to look for conditions leading to them. The confirmation of middle ear impairment by specialists has demonstrated better confiability. The hallmarks for immunologic evaluation are the presence of complications as mastoiditis and membrane perforation, failure to thrive, and additional respiratory symptoms. Humoral immunodeficiencies have been more frequently described in association with otitis-prone patients, for example, hypogammaglobulinemia, MBL deficiency, and IEI associated with major syndromes. Most of the patients with confirmed IEI present otitis as one of the recurrent infections. It is suggested the investigation of immune defects in patients with otitis, and the following warning signs are suggested: Otitis evolving with mastoiditis, abscesses, or systemic infections; no response to appropriate antibiotic therapy; otitis media associated with other infections; recurrent otitis leading to failure to thrive and general developmental delay; and family history of primary immunodeficiency and/or consanguinity.

Sensorineural Hearing Loss in Selective Immunglobulin A Deficiency

Objective

To assess hearing functions in pediatric patients with selective immunoglobulin A (IgA) deficiency (SIGAD).

Methods

Pure-tone audiometry, acoustic impedance, otoacoustic emission, and brainstem audiometric measurements were taken during a non-infectious period in 28 patients with SIGAD and 28 healthy children with normal otoscopic examination. The results of the hearing tests were compared between the two groups.

Results

Two male patients and one female patient in the SIGAD group were found to have sensorineural hearing loss (SNHL). However, a comparison of the average pure tone cut-off values at 0.5, 1, 2, and 4 kHz did not reveal any statistically significant difference between the groups (p>0.05).

Conclusion

Pediatric patients with SIGAD may exhibit SNHL at certain frequencies and require follow-up for the potential development of hearing loss.

Primary immunodeficiency for the primary care provider

Primary immunodeficiencies are a group of heterogeneous disorders resulting from defects affecting the function of ≥1 parts of the immune system. Current estimates of the prevalence of primary immunodeficiency disease are one in 1200 patients. In Ontario, where the average general practitioner follows 1300 to 2000 patients, an estimated two patients will have primary immunodeficiency. With new primary immunodeficiencies being described at an exponential rate, and those previously described becoming better understood, it is challenging for health care providers to stay up to date. Knowledge gaps delay diagnosis and treatment, leading to increased morbidity and mortality. The present review aims to provide the primary care provider with the tools necessary to recognize primary immunodeficiency and assist in establishing diagnoses.

Primary immunodeficiency in the neonate: Early diagnosis and management

Many primary immunodeficiencies (PIDs) manifest in the neonatal period but can be challenging to diagnose and manage optimally. In part, the difficulty stems from the natural immaturity of the neonatal immune system that may mask immune deficits and/or complicate interpretation of clinical findings and laboratory assays. The great diversity of PIDs--from innate immune system defects to those that impact the humoral and/or cellular components of the adaptive immune system--and the rapid rate at which new PIDs are being discovered makes it challenging for practitioners to stay current. Moreover, recent appreciation for immune deficiencies that lead to autoinflammation and autoimmunity have broadened the spectrum of neonatal PID, adding additional complexity to an already intricate field. This article serves to highlight the deficiencies in the neonatal immune system, while providing a review of the more common PIDs that present in the neonate and guidelines for diagnosis and supportive care.

Debilitating progressive encephalitis in a patient with BTK deficiency

X-linked agammaglobulinemia (XLA), also known as Bruton's tyrosine kinase (BTK) deficiency, is a primary antibody deficiency, characterized by low number of B cells, agammaglobulinemia and increased susceptibility to a variety of infections. Herein, we report a case of XLA with confirmed BTK mutation that developed neurological deficits. While we could not detect any responsible microorganism in spite of comprehensive workup, brain magnetic resonance imaging revealed moderate brain atrophy. The diagnosis of progressive encephalitis was made for this patient. Patients with XLA have a higher chance of encephalitis compared with other primary antibody deficiencies. Given the violent nature of encephalitis, it is a concern among XLA patients.

Placental transfer of maternally-derived IgA precludes the use of guthrie card eluates as a screening tool for primary immunodeficiency diseases

There is a need for neonatal screening tools to improve the long-term clinical outcome of patients with primary immunodeficiency diseases (PID). Recently, a PCR-based screening method for both TRECs and KRECs using Guthrie card samples has been developed. However, the applicability of these excision circle assays is limited to patients with severe T or B cell lymphopenia (SCID, XLA and A-T), whereas the most common forms of PID are not detected. Absence of serum IgA is seen in a major fraction of patients with immunological defects. As serum IgA in newborns is considered to be of fetal origin, eluates from routinely collected dried blood spot samples might thus be suitable for identification of children with PID. To assess the applicability of such screening assays, stored Guthrie card samples were obtained from 47 patients with various forms of primary immunodeficiency diseases (SCID, XLA, A-T, HIGM and IgAD), 20 individuals with normal serum IgA levels born to IgA-deficient mothers and 51 matched healthy newborns. Surprisingly, normal serum IgA levels were found in all SCID, XLA, A-T and HIGM patients and, additionally, in all those IgAD patients born to IgA-sufficient mothers. Conversely, no serum IgA was found in any of the 16 IgAD patients born by IgA-deficient mothers. Moreover, half of the IgA-sufficient individuals born by IgA-deficient mothers also lacked IgA at birth whereas no IgA-deficient individuals were found among the controls. IgA in neonatal dried blood samples thus appears to be of both maternal and fetal origin and precludes its use as a reliable marker for neonatal screening of primary immunodeficiency diseases.

Pathogenesis, diagnosis, and management of primary antibody deficiencies and infections

Primary antibody deficiencies are the most common primary immunodeficiency diseases. They are a heterogeneous group of disorders with various degrees of dysfunctional antibody production resulting from a disruption of B-cell differentiation at different stages. While there has been tremendous recent progress in the understanding of some of these disorders, the etiology remains unknown for the majority of patients. As there is a large spectrum of underlying defects, the age at presentation varies widely, and the clinical manifestations range from an almost complete absence of B cells and serum immunoglobulins to selectively impaired antibody responses to specific antigens with normal total serum immunoglobulin concentrations. However, all of these disorders share an increased susceptibility to infections, affecting predominantly the respiratory tract. A delay of appropriate treatment for some diseases can result in serious complications related to infections, while timely diagnosis and adequate therapy can significantly decrease morbidity and increase life expectancy and quality of life.