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

Lower serum AMH concentration is correlated with serum IgG1 decreased in the infertile woman: A real-world retrospective study

OBJECTIVES

In this real-world approach, we examined the serum Anti-Mullerian Hormone (AMH) level and the relationship with serum IgG subclass in the infertile women.

METHODS

A total of 574 female participants were recruited for this study. The serum AMH, IgG subclass(IgG1, IgG2, IgG3, IgG4) and immunoglobulin (Ig) G、IgM、IgA、IgE as well as complement C3, C4 were analyzed. The difference in serum AMH level was assessed according categorized as above or below the median of the ratio of serum IgG subclass(IgG1, IgG2, IgG3, IgG4) to total IgG (RIgG subclass/IgG).

RESULTS

The serum AMH level of the low RIgG1/IgG group is significantly decreased than that high RIgG1/IgG group (p < 0.05). The Spearman correlation analysis showed that the serum AMH level was significantly negatively correlated with age and significantly positively correlated with serum IgG1 levels respectively (p < 0.05). GLMMs multivariate model showed that after adjusting the covariate and possible mixed factors including age, serum immunoglobulin, complement C3 and C4, the serum AMH level was significantly positively correlated with IgG1 level (p < 0.01).

CONCLUSIONS

Decreased serum IgG1 may significantly affect the ovarian reserve function of women. Confirmation of this association and elucidation of its underlying mechanisms are needed to place these results in a clinical perspective.

Current Issues in the Management of IgG Subclass Deficiencies in Adults With Chronic Respiratory Diseases

Primary immunodeficiency diseases (PIDs) are uncommon in adults; however, immunoglobulin G subclass deficiency (IGGSCD) is often found in a subset of adult patients with chronic respiratory diseases. As quantitative laboratory tests are used to diagnose IGGSCD, the clinical significance of IGGSCD remains controversial. However, respiratory infection is a common presenting feature of IGGSCD, and respiratory complications are responsible for subsequent morbidities, such as severe asthma, bronchiectasis, chronic obstructive airway diseases, and mortality. This review summarizes the current epidemiological data for PIDs, focusing on IGGSCD in the adult population. In addition, the investigation, treatment, and management strategies are detailed, including distinct issues faced by patients with chronic airway disease and their physicians in the proper diagnosis and treatment of IGGSCD.

Hydroxychloroquine Therapy and Serum Immunoglobulin Levels in Women with IgG Subclass Deficiency and Systemic Lupus Erythematosus, Sjögren Syndrome, and Rheumatoid Arthritis: A Retrospective Study

Hydroxychloroquine (HCQ) therapy decreased immunoglobulin (Ig) levels in patients with Sjögren syndrome (SS) and rheumatoid arthritis (RA) in previous studies. We found no report of Ig levels of women with IgG subclass deficiency (IgGSD) and systemic lupus erythematosus (SLE), SS, or RA treated with HCQ. We retrospectively evaluated IgG, IgG subclass, IgA, and IgM levels and other characteristics of women at IgGSD diagnosis who did and did not take HCQ for SLE, SS, or RA. There were 132 women (48 subnormal IgG1 only, 49 combined subnormal IgG1/IgG3, and 35 subnormal IgG3 only). Mean age was 49 ± 13 years. Twenty-two women with SLE, SS, RA, or combination thereof reported HCQ ≥ 200 mg/day ≥ 6 months. In each IgGSD subtype, median Ig levels of women who took HCQ were not significantly lower than those of women who did not take HCQ. Women with combined subnormal IgG1/IgG3 who took HCQ had greater median IgG2 than women who did not take HCQ (4.89 g/L (range 4.43, 4.94) vs. 2.57 g/L (1.21, 6.44), respectively; p = 0.0123). Regressions on IgG1, IgG2, and IgG3 revealed positive associations with HCQ therapy (p = 0.0043, 0.0037, and 0.0139, respectively). There were no significant Ig associations with age, SLE, SS, or RA as independent variables. HCQ therapy of SLE, SS, or RA in women with IgGSD was not associated with significantly lower IgG, IgG subclass, IgA, or IgM levels. IgG1, IgG2, and IgG3 were positively associated with HCQ therapy, after adjustment for other variables.

Spectrum of Disease Manifestations in Patients with Selective Immunoglobulin E Deficiency

BACKGROUND

Selective IgE deficiency (SIgED) has been previously evaluated in selected patients from allergy units. This study investigates the effects of SIgED on the entire population in a hospital setting and sought to delineate in detail the clinical aspects of SIgED.

METHODS

A retrospective study of the data obtained from electronic medical records of 52 adult patients (56% female) with a mean age of 43 years and IgE levels of <2.0 kU/L with normal immunoglobulin (Ig) IgG, IgA, and IgM levels, seen at our hospital, without selection bias, from 2010 to 2019.

RESULTS

Recurrent upper respiratory infections were recorded in 18 (34.6%) patients, pneumonia was recorded in 16 (30.7%) patients, bronchiectasis was recorded in 16 (30.7%) patients, and asthma was recorded in 10 (19.2%) patients. Eighteen patients (34.6%) suffered autoimmune clinical manifestations either isolated (19%) or combining two or more diseases (15%), Hashimoto's thyroiditis being the most frequent (19%), which was followed by arthritis (10%) and thrombocytopenia and/or neutropenia (5.7%). Other less frequent associations were Graves' disease, primary sclerosing cholangitis, Sjögren's syndrome, and autoimmune hepatitis. Eczematous dermatitis (15.3%), chronic spontaneous urticaria (17.3%), and symptoms of enteropathy (21%) were also highly prevalent. Thirty percent of patients developed malignancies, with non-Hodgkin lymphomas (13.4%) being the most prevalent.

CONCLUSIONS

The clinical manifestations of SIgED encompass a variety of infectious, non-infectious complications, and malignancy. Since it cannot be ruled out that some type of selection bias occurred in the routine assessment of IgE serum Ievels, prospective studies are required to better characterize SIgED and to determine whether it should be added to the list of antibody deficiencies.

Factors associated with IgG levels in adults with IgG subclass deficiency

Background

Factors associated with IgG levels in adults with IgG subclass deficiency (IgGSD) are incompletely understood. We studied adults with IgGSD with subnormal IgG1 only, subnormal IgG1/IgG3, or subnormal IgG3 only without other subnormal IgG subclasses, IgA, or IgM. We compiled: age; sex; autoimmune condition(s) (AC); atopy; IgG, IgG subclasses, IgA, IgM; IgGsum (IgG1 + IgG2 + IgG3 + IgG4); and D (percentage difference between IgGsum and IgG). We compared attributes of patients with/without subnormal IgG (< 7.00 g/L; subnormal IgG1 subclass groups only) and analyzed IgGsum and IgG relationships. We performed backward stepwise regressions on IgG using independent variables IgG subclasses, age, and sex and on D using independent variables age and sex.

Results

There were 39 patients with subnormal IgG1 only (89.7% women), 53 with subnormal IgG1/IgG3 (88.7% women), and 115 with subnormal IgG3 only (91.3% women). Fifteen patients (38.5%) and 32 patients (60.4%) in the respective subnormal IgG1 subclass groups had subnormal IgG. Attributes of patients with/without IgG < 7.00 g/L were similar, except that AC prevalence was lower in patients with subnormal IgG1 only and IgG < 7.00 g/L than ≥ 7.00 g/L (p = 0.0484). Mean/median IgG1 and IgG2 were significantly lower in patients with IgG < 7.00 g/L in both subnormal IgG1 subclass groups (p < 0.0001, all comparisons). Regressions on IgG in three subclass groups revealed positive associations with IgG1 and IgG2 (p < 0.0001 each association). Regressions on D revealed no significant association. IgG1 percentages of IgGsum were lower and IgG2 percentages were higher in patients with subnormal IgG1 subclass levels than subnormal IgG3 only (p < 0.0001 all comparisons).

Conclusions

We conclude that both IgG1 and IgG2 are major determinants of IgG in patients with subnormal IgG1, combined subnormal IgG1/IgG3, or subnormal IgG3 and that in patients with subnormal IgG1 or combined subnormal IgG1/IgG3, median IgG2 levels are significantly lower in those with IgG < 7.00 g/L than those with IgG ≥ 7.00 g/L.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-021-00447-3.

Lessons Learned From the Clinical Presentation of Common Variable Immunodeficiency Disorders: A Systematic Review and Meta-Analysis

Background

Diagnostic delay in common variable immunodeficiency disorders (CVID) is considerable. There is no generally accepted symptom-recognition framework for its early detection.

Objective

To systematically review all existing data on the clinical presentation of CVID.

Methods

PubMed, EMBASE and Cochrane were searched for cohort studies, published January/1999-December/2019, detailing the clinical manifestations before, at and after the CVID-diagnosis.

Results

In 51 studies (n=8521 patients) 134 presenting and 270 total clinical manifestations were identified. Recurrent upper and/or lower respiratory infections were present at diagnosis in 75%. Many patients had suffered severe bacterial infections (osteomyelitis 4%, meningitis 6%, septicemia 8%, mastoiditis 8%). Bronchiectasis (28%), lymphadenopathy (27%), splenomegaly (13%), inflammatory bowel disease (11%), autoimmune cytopenia (10%) and idiopathic thrombocytopenia (6%) were also frequently reported. A bimodal sex distribution was found, with male predominance in children (62%) and female predominance in adults (58%). 25% of CVID-patients developed other manifestations besides infections in childhood, this percentage was much higher in adults (62%). Immune-dysregulation features, such as granulomatous-lymphocytic interstitial lung disease and inflammatory bowel disease, were more prominent in adults.

Conclusions

The shift from male predominance in childhood to female predominance in adults suggests differences in genetic and environmental etiology in CVID and has consequences for pathophysiologic studies. We confirm the high frequency of respiratory infections at presentation, but also show a high incidence of severe bacterial infections such as sepsis and meningitis, and immune dysregulation features including lymphoproliferative, gastrointestinal and autoimmune manifestations. Early detection of CVID may be improved by screening for antibody deficiency in patients with these manifestations.

Reconstitution of IgG Subclasses Following Immunoglobulin Administration in Adult Patients with Common Variable Immune Deficiency

BACKGROUND

Immunoglobulin (Ig) therapy reduces the frequency and severity of infection among patients with antibody deficiency disorders. However, a subset of patients lacks adequate clinical response.

OBJECTIVE

The purpose of this study was to determine in adult common variable immune deficiency (CVID) patients (A) if lack of clinical response to Ig therapy correlates with lack of reconstitution of IgG subclass (es), (B) correlation between Ig dosing and/or IgG trough levels and IgG subclass reconstitution, (C) and most common impaired Streptococcus pneumoniae (S. pneumoniae) serotype antibody response.

METHODS

Single-institution, retrospective chart review for CVID patients at immunology clinics from 2015 to 2019. Patients were monitored every 3-6 months for IgG dosage, IgG trough levels, IgG subclass reconstitution, infectious episodes (chronic sinusitis, bronchitis, upper respiratory, and lower respiratory tract infections), urinary tract infections, and antibiotic use. Follow-up was calculated in patient years.

RESULTS

Twenty-five of 41 patients achieved complete reconstitution of all IgG subclasses, and 16/41 demonstrated intermittent or lack of reconstitution. There were significantly less (p < 0.001) infections among fully reconstituted patients (0.66 ± 0.19 infections per patient year) as compared to those with intermittent or lack of reconstitution (1.26 ± 0.13 infections per patient year). There was a significant correlation between IgG trough levels and IgG subclass reconstitution. Most common impaired S. pneumoniae serotype included 3, 4, 9n, 10a, 11a, 12f, and 15b.

CONCLUSIONS

Incomplete IgG subclass reconstitution was associated with increased frequency of infections. IgG trough levels correlate with IgG subclass reconstitution. A limited number of S. pneumoniae serotype antibodies are commonly impaired in CVID.

Characterization of adult patients with IgG subclass deficiency and subnormal IgG2

Background

Adults with IgG subclass deficiency (IgGSD) with subnormal IgG2 are inadequately characterized.

Methods

We retrospectively analyzed observations in unrelated adults with IgGSD evaluated in a single hematology clinic (1991–2019) and selected those with subnormal serum IgG2 (<117 mg/dL (<1.2 g/L)) without corticosteroid therapy to describe: age; prevalence of women; upper/lower respiratory infection; autoimmune condition(s); atopy; other allergy; frequent or severe respiratory tract infection in first-degree relatives; IgG, IgG subclasses, IgA, and IgM; blood lymphocyte subpopulations; human leukocyte antigen (HLA)-A and -B types and haplotypes; and 23-valent pneumococcal polysaccharide vaccination (PPSV23) responses. We determined the prevalence of subnormal IgG2 among unrelated adults with IgGSD without corticosteroid therapy and compared general characteristics of those with and without subnormal IgG2.

Results

There were 18 patients (94.4% women) with subnormal IgG2. Mean age was 52 ± 11 y. Upper/lower respiratory infection occurred in 94.4%/74.8%, respectively. Autoimmune condition(s), atopy, other allergy, and frequent or severe respiratory infection in first-degree relatives occurred in 44.4%, 44.4%, 61.1%, and 22.2%, respectively. Median IgG2 was 105 mg/dL (83, 116). Subnormal IgG, IgG1, IgG3, IgG4, IgA, and IgM was observed in 66.7%, 50.0%, 100.0%, 5.6%, 33.3%, and 0%, respectively. Lymphocyte subpopulations were normal in most patients. HLA frequencies were similar in patients and controls. Three of 4 patients had no protective S. pneumoniae serotype-specific IgG levels before or after PPSV23. These 18 patients represent 7.6% of 236 adults with IgGSD. Prevalence of subnormal IgG, subnormal IgG3, and subnormal IgA was significantly greater in 18 adults with subnormal IgG2 than 218 adults without subnormal IgG2. Prevalence of subnormal IgM was significantly lower in patients with subnormal IgG2.

Conclusions

Characteristics of adults with IgGSD with subnormal IgG2 include female predominance, other immunologic abnormalities, subnormal IgG3 and/or IgG1, lack of HLA-A and -B association, and suboptimal PPSV23 response.

HLA-A and -B Type and Haplotype Frequencies in IgG Subclass Deficiency Subgroups

We sought to determine whether HLA-A and -B type and haplotype frequencies differ between subgroups of adults with IgG subclass deficiency (IgGSD). We retrospectively compared type and haplotype frequencies of three subgroups of 269 unrelated adult IgGSD patients (70 subnormal IgG1; 121 subnormal IgG3; 78 subnormal IgG1/IgG3) and controls (1,321 for types; 751 for haplotypes). We selected types and haplotypes because their uncorrected frequencies differed significantly from controls in a previous adult IgGSD/common variable immunodeficiency cohort: A*24; B*14; B*35; B*40; B*49; B*50; B*58; B*62; A*01,B*08; A*02,B*44; A*02,B*60; A*03,B*07; A*03,B*14; A*03,B*44; A*31,B*40; and A*32,B*14. We used χ² analysis (2 × 4 tables) to identify frequency differences across three subgroups and controls. If the null hypothesis was rejected (p < 0.05), we computed 2 × 2 χ² tables to compare six combinations of subgroup and control frequencies [Bonferroni p < 0.0083 (< 0.05/6)]. Mean age was 48 ± 13 years; 82.2% were women. B*35 and B*40 frequencies were higher in subnormal IgG1 than subnormal IgG3 patients (0.1000 vs. 0.0248 and 0.0571 vs. 0.0083, respectively; p ≤ 0.0061). B*62 frequencies were lower in three IgGSD subgroups than controls (p < 0.0001, respectively). A*02, B*44 frequency was higher in subnormal IgG1/IgG3 patients than controls (0.1282 vs. 0.0632, respectively; p = 0.0024). A*02, B*60 frequency was lower in subnormal IgG3 patients than controls (0.0 vs. 0.0233, respectively; p = 0.0051). HLA-B*35 and -B*40 frequencies differ significantly between some IgGSD subgroups. B*62, A*02, B*44, and A*02, B*60 frequencies differ significantly between some IgGSD subgroups and controls.

Histocompatibility Complex Status and Mendelian Randomization Analysis in Unsolved Antibody Deficiency

The pathogenesis in the majority of patients with common variable immunodeficiency (CVID), the most common symptomatic primary immunodeficiency, remains unknown. We aimed to compare the minor and major histocompatibility complex (MHC) markers as well as polygenic scores of common genetic variants between patients with monogenic CVID and without known genetic mutation detected. Monogenic patients were identified in a CVID cohort using whole exome sequencing. Computational full-resolution MHC typing and confirmatory PCR amplicon-based high-resolution typing were performed. Exome-wide polygenic scores were developed using significantly different variants and multi-variant Mendelian randomization (MR) analyses were used to test the causality of significant genetic variants on antibody levels and susceptibility to infectious diseases. Among 83 CVID patients (44.5% females), monogenic defects were found in 40 individuals. Evaluation of the remaining CVID patients without known genetic mutation detected showed 13 and 27 significantly associated MHC-class I and II alleles, respectively. The most significant partial haplotype linked with the unsolved CVID was W^*01:01:01-DMA^*01:01:01-DMB^*01:03:01:02-TAP1^*01:01:01 (P < 0.001), where carriers had a late onset of the disease, only infection clinical phenotype, a non-familial form of CVID, post-germinal center defects and a non-progressive form of their disease. Exclusion of monogenic diseases allowed MR analyses to identify significant genetic variants associated with bacterial infections and improved discrepancies observed in MR analyses of previous GWAS studies with low pleiotropy mainly for a lower respiratory infection, bacterial infection and Streptococcal infection. This is the first study on the full-resolution of minor and major MHC typing and polygenic scores on CVID patients and showed that exclusion of monogenic forms of the disease unraveled an independent role of MHC genes and common genetic variants in the pathogenesis of CVID.

Pneumococcal vaccination responses in adults with subnormal IgG subclass concentrations

BACKGROUND

We sought to compare Pneumovax®23 responses in adults with subnormal IgG subclass concentrations. We studied adults with normal total IgG, frequent/severe respiratory infection, and subnormal IgG1, IgG3, or IgG1 + IgG3 before and after Pneumovax®23. We defined response as serotype-specific IgG > 1.3 μg/mL and aggregate response as IgG > 1.3 μg/mL for ≥70% of all serotypes tested. We compared patients with and without serotype-specific responses and performed logistic regression on aggregate responses using: age; male sex; body mass index; autoimmune condition(s); atopy; other allergies; subnormal IgGSc immunophenotypes; IgA; and IgM.

RESULTS

There were 59 patients (mean age 44 ± 13 (SD) years; 83.1% women). Median days between pre- and post-Pneumovax®23 testing was 33 (range 19-158). The median post-vaccination summated concentration of serotype-specific IgG was higher in patients with subnormal IgG1 than subnormal IgG3 (responders and non-responders). All subnormal IgG1 + IgG3 non-responders responded to serotypes 8, 9 and 26, unlike other non-responders. Subnormal IgG3 responders had lower responses to serotypes 1, 4, 12, 23, 26, and 51. Subnormal IgG3 non-responders had higher responses to serotypes 1, 3, 8, 9, 12, 14, 19, 51, and 56. Response rates decreased with increasing age. Aggregate responders were: subnormal IgG1, 54%; IgG3, 46%; and IgG1 + IgG3, 46%. Regression on aggregate response revealed lower response with male sex (odds ratio 0.09 [95% CI 0.01, 0.77]) and atopy (0.17 [0.03, 0.83]).

CONCLUSIONS

Serotype-specific IgG responses to Pneumovax®23 were greater in patients with subnormal IgG1 than subnormal IgG3. Male sex and atopy were associated with lower aggregate responses.

Clinical and laboratory associations of mannose-binding lectin in 219 adults with IgG subclass deficiency

Background

Mannose-binding lectin (MBL) deficiency may increase risk of respiratory tract infection in adults unselected for IgG or IgG subclass levels. In a retrospective study, we sought to determine associations of serum MBL levels with clinical and laboratory characteristics of unrelated non-Hispanic white adults at diagnosis of IgG subclass deficiency (IgGSD). We computed the correlation of first and second MBL levels expressed as natural logarithms (ln) in a patient subgroup. We compared these characteristics of all adults with and without MBL ≤50 ng/mL: age; sex; body mass index; upper/lower respiratory tract infection; diabetes; autoimmune condition(s); atopy; other allergy; corticosteroid therapy; and subnormal serum IgG subclasses, IgA, and IgM. We performed logistic regression on MBL ≤50 ng/mL (dichotomous) using the three independent variables with the lowest values of p in univariate comparisons.

Results

There were 219 patients (mean age 51 ± 13 y; 82.5% women). Thirty-six patients (16.4%) had MBL ≤50 ng/mL. Two MBL measurements were available in 14 patients. The median interval between the first and second measurements was 125 d (range 18–1031). For ln-transformed data, we observed adjusted r² = 0.9675; Pearson correlation coefficient 0.9849; and p < 0.0001. Characteristics of patients with and without MBL ≤50 ng/mL did not differ significantly in univariate comparisons. We performed a regression on MBL ≤50 ng/mL using: subnormal IgM (p = 0.0565); upper respiratory tract infection (p = 0.1094); and body mass index (p = 0.1865). This regression revealed no significant associations. Conclusions: We conclude that the proportion of the present IgGSD patients with serum MBL ≤50 ng/mL is similar to that of healthy European adults. MBL ≤50 ng/mL was not significantly associated with independent variables we studied.

Duration of frequent or severe respiratory tract infection in adults before diagnosis of IgG subclass deficiency

Many adults with IgG subclass deficiency (IgGSD) experience long intervals of frequent/severe respiratory tract infection before IgGSD diagnosis, but reasons for delays in IgGSD diagnoses are incompletely understood. We performed a retrospective study of 300 white adults (ages ≥18 y) with IgGSD including frequency analyses of age at IgGSD diagnosis, duration of frequent/severe respiratory tract infection before IgGSD diagnosis, and age at onset of frequent/severe infection (calculated). We performed multivariable regressions on age at diagnosis, infection duration, and age at infection onset using these variables, as appropriate: sex; age at diagnosis; diabetes; autoimmune condition(s); atopy; allergy; corticosteroid use; body mass index; serum immunoglobulin isotype levels; blood lymphocyte subsets; three IgGSD-associated human leukocyte antigen-A and -B haplotypes; and referring physician specialties. Mean age at diagnosis was 50 ± 12 (standard deviation) y (median 50 y (range 19–79)). There were 247 women (82.3%). Mean infection duration at IgGSD diagnosis was 12 ± 13 y (median 7 y (range 1–66)). Mean age at infection onset was 38 ± 16 y (median 38 y (range 4, 76)). Age at infection onset was ≥18 y in 95.7% of subjects. Regressions on age at diagnosis and infection duration revealed no significant associations. Regression on age at infection onset revealed one positive association: age at diagnosis (p <0.0001). We conclude that the median duration of frequent/severe respiratory tract infection in adults before IgGSD diagnosis was 7 y. Older adults may be diagnosed to have IgGSD after longer intervals of infection than younger adults. Duration of frequent/severe respiratory tract infection before IgGSD diagnosis was not significantly associated with routine clinical and laboratory variables, including referring physician specialties.

Delayed Diagnosis and Complications of Predominantly Antibody Deficiencies in a Cohort of Australian Adults

Background

Predominantly antibody deficiencies (PADs) are the most common type of primary immunodeficiency in adults. PADs frequently pass undetected leading to delayed diagnosis, delayed treatment, and the potential for end-organ damage including bronchiectasis. In addition, PADs are frequently accompanied by comorbid autoimmune disease, and an increased risk of malignancy.

Objectives

To characterize the diagnostic and clinical features of adult PAD patients in Victoria, Australia.

Methods

We identified adult patients receiving, or having previously received immunoglobulin replacement therapy for a PAD at four hospitals in metropolitan Melbourne, and retrospectively characterized their clinical and diagnostic features.

Results

179 patients from The Royal Melbourne, Alfred and Austin Hospitals, and Monash Medical Centre were included in the study with a median age of 49.7 years (range: 16–87 years), of whom 98 (54.7%) were female. The majority of patients (116; 64.8%) met diagnostic criteria for common variable immunodeficiency (CVID), and 21 (11.7%) were diagnosed with X-linked agammaglobulinemia (XLA). Unclassified hypogammaglobulinemia (HGG) was described in 22 patients (12.3%), IgG subclass deficiency (IGSCD) in 12 (6.7%), and specific antibody deficiency (SpAD) in 4 individuals (2.2%). The remaining four patients had a diagnosis of Good syndrome (thymoma with immunodeficiency). There was no significant difference between the age at diagnosis of the disorders, with the exception of XLA, with a median age at diagnosis of less than 1 year. The median age of reported symptom onset was 20 years for those with a diagnosis of CVID, with a median age at diagnosis of 35 years. CVID patients experienced significantly more non-infectious complications, such as autoimmune cytopenias and lymphoproliferative disease, than the other antibody deficiency disorders. The presence of non-infectious complications was associated with significantly reduced survival in the cohort.

Conclusion

Our data are largely consistent with the experience of other centers internationally, with clear areas for improvement, including reducing diagnostic delay for patients with PADs. It is likely that these challenges will be in part overcome by continued advances in implementation of genomic sequencing for diagnosis of PADs, and with that opportunities for targeted treatment of non-infectious complications.

The Clinical Utility of Measuring IgG Subclass Immunoglobulins During Immunological Investigation for Suspected Primary Antibody Deficiencies

Measurement of IgG subclass concentrations is a standard laboratory test run as part of a panel to investigate the suspicion of antibody deficiency. The assessment is clinically important when total IgG is within the normal age-specific reference range. The measurement is useful for diagnosis of IgG subclass deficiency, to aid the diagnosis of specific antibody deficiency, as a supporting test for the diagnosis of common variable immunodeficiency, as well as for risk stratification of patients with low IgA. The measurement of IgG subclasses may also help determine a revaccination strategy for patients and support patient management. In certain circumstances, the measurement of IgG subclasses may be used to monitor a patient’s humoral immune system. In this review, we discuss the utility of measuring IgG subclass concentrations.

Implanted ports in adults with primary immunodeficiency

BACKGROUND

We sought to learn more about the utility and safety of implanted ports for monthly immunoglobulin G infusions in adults with primary immune deficiency.

METHODS

We reviewed charts of adults who were referred to a single practice during the interval 2006-2016 for evaluation and management of frequent or severe upper and lower respiratory tract and other infections, subnormal total immunoglobulin G or immunoglobulin G subclasses, and suboptimal responses to polyvalent pneumococcal polysaccharide vaccinations; were diagnosed to have primary immune deficiency; and were advised to undergo immunoglobulin G therapy.

RESULTS

Of 606 patients, 20 (19 women, 1 man; 16 immunoglobulin G subclass deficiency, 4 common variable immunodeficiency; 3.3%) needed implanted ports because they had inadequate upper extremity superficial venous access. Median age at diagnosis was 48 years (range: 32-65 years). In total, 17 of the 20 patients preferred monthly in-office intravenous immunoglobulin G treatment to weekly at-home subcutaneous immunoglobulin G. The other three patients could not be treated with subcutaneous immunoglobulin G (unfavorable self-treatment experiences and insurance limitations). Median duration of treatment via implanted ports was 73 months (range: 10-153 months). In the man, the first implanted port was replaced after 26 months due to catheter fracture of unknown cause. His second port has been used for 112 months. We observed no other port-related failure, infections, thrombosis, or other adverse events.

CONCLUSION

The utility and safety of implanted ports in adults with primary immune deficiency for whom subcutaneous immunoglobulin G therapy is not desired or feasible are probably similar to those of ports in patients without primary immune deficiency.

The immunophenotypic fingerprint of patients with primary antibody deficiencies is partially present in their asymptomatic first-degree relatives

The etiology of primary antibody deficiencies is largely unknown. Beside rare monogenic forms, the majority of cases seem to have a more complex genetic basis. Whereas common variable immunodeficiency has been investigated in depth, there are only a few reports on milder primary antibody deficiencies such as idiopathic primary hypogammaglobulinemia and IgG subclass deficiency. We performed flow cytometric immunophenotyping in 33 patients with common variable immunodeficiency, 23 with idiopathic primary hypogammaglobulinemia and 21 with IgG subclass deficiency, as well as in 47 asymptomatic first-degree family members of patients and 101 unrelated healthy controls. All three groups of patients showed decreased memory B- and naïve T-cell subsets and decreased B-cell activating factor receptor expression. In contrast, circulating follicular helper T-cell frequency and expression of inducible T-cell co-stimulator and chemokine receptors were only significantly altered in patients with common variable immunodeficiency. Asymptomatic first-degree family members of patients demonstrated similar, albeit intermediate, alterations in naïve and memory B- and T-cell subsets. About 13% of asymptomatic relatives had an abnormal peripheral B-cell composition. Furthermore, asymptomatic relatives showed decreased levels of CD4⁺ recent thymic emigrants and increased central memory T cells. Serum IgG and IgM levels were also significantly lower in asymptomatic relatives than in healthy controls. We conclude that, in our cohort, the immunophenotypic landscape of primary antibody deficiencies comprises a spectrum, in which some alterations are shared between all primary antibody deficiencies whereas others are only associated with common variable immunodeficiency. Importantly, asymptomatic first-degree family members of patients were found to have an intermediate phenotype for peripheral B- and T-cell subsets.

Selective Subnormal IgG1 in 54 Adult Index Patients with Frequent or Severe Bacterial Respiratory Tract Infections

We characterized 54 adult index patients with reports of frequent or severe bacterial respiratory tract infections at diagnosis of selective subnormal IgG1. Mean age was 50 ± 13 (SD) y; 87.0% were women. Associated disorders included the following: autoimmune conditions 50.0%; hypothyroidism 24.1%; atopy 38.9%; and other allergy 31.5%. In 35.5%, proportions of protective S. pneumoniae serotype-specific IgG levels did not increase after polyvalent pneumococcal polysaccharide vaccination (PPPV). Blood lymphocyte subset levels were within reference limits in most patients. Regressions on IgG1 and IgG3 revealed no significant association with age, sex, autoimmune conditions, hypothyroidism, atopy, other allergy, corticosteroid therapy, or lymphocyte subsets. Regression on IgG2 revealed significant associations with PPPV response (negative) and CD19+ lymphocytes (positive). Regression on IgG4 revealed significant positive associations with episodic corticosteroid use and IgA. Regression on IgA revealed positive associations with IgG2 and IgG4. Regression on IgM revealed negative associations with CD56+/CD16+ lymphocytes. Regressions on categories of infection revealed a negative association of urinary tract infections and IgG1. HLA-A^⁎03, HLA-B^⁎55 and HLA-A^⁎24, HLA-B^⁎35 haplotype frequencies were greater in 38 patients than 751 controls. We conclude that nonprotective S. pneumoniae IgG levels and atopy contribute to increased susceptibility to respiratory tract infections in patients with selective subnormal IgG1.