Rheumatic manifestations of primary immunodeficiencies in children

Differing Performance of the Warning Signs for Immunodeficiency in the Diagnosis of Pediatric Versus Adult Patients in a Two-Center Tertiary Referral Population

PURPOSE

Primary immunodeficiency (PID) represents disorders with a spectrum of clinical presentations. The medical community seeks clinical features to prompt evaluation for immunodeficiency given improved prognosis with early identification. We hoped to identify clinical characteristics that would improve the diagnostic accuracy of the widely disseminated Jeffrey Modell Foundation warning signs for immunodeficiency.

METHODS

We performed a retrospective chart review in a two-center North American cohort of patients with PID. Charts of 137 pediatric and 400 adult patients with PID were evaluated for the presence of these warning signs and compared to controls with normal preliminary biochemical immune evaluation.

RESULTS

Fewer than 45% of adults with PID presented with ≥ 2 warning signs, while diagnostic utility was improved in the pediatric population where the warning signs were found to be 64% sensitive. The warning signs found in a significantly increased proportion compared to controls differed for pediatric PID patients (recurrent pneumonia (OR 2.9, p < 0.001), failure to thrive (OR 2.1, p < 0.001), need for IV antibiotics (OR 2.1, p < 0.001), serious bacterial infection (OR 4.8, p < 0.001), recurrent otitis media (OR 1.5, p = 0.027)), versus adult PID patients (recurrent otitis media (OR 2.9, p < 0.001), recurrent sinusitis (OR 2.1, p < 0.001), diarrhea with weight loss (OR 2.2, p < 0.001), recurrent viral infection (OR 3.3 p < 0.001)). In evaluation for additional criteria to promote identification of immunodeficiency, linear regression models showed slightly improved diagnostic accuracy of the warning signs with the addition of autoimmunity in our pediatric PID cohort (8.7% v 2.8%, p < 0.001, ROC 0.58). Adult PID patients demonstrated atopy more frequently than controls (48.0% vs 40.3%, p = 0.011), while atopy was found to have a negative association with the presence of PID in the pediatric age group (OR 0.3, p < 0.01). No improvement in diagnostic accuracy of the warning signs was found with the addition of allergic disease, autoimmunity, or malignant and benign proliferative disease in the adult cohort.

CONCLUSIONS

We demonstrate poor diagnostic performance of warning signs for immunodeficiency in patients with PID in a retrospective chart review. Divergent warning signs of statistically significant diagnostic utility were found in pediatric versus adult patients. We suggest education of physicians on differing presentations of possible immunodeficiency between age groups, and expansion of the warning signs to include non-infectious comorbidities such as autoimmunity in pediatric patients.

Phenotypic characterization of patients with rheumatologic manifestations of common variable immunodeficiency

Patients with common variable immunodeficiency (CVID) have a higher incidence of rheumatologic disorders. To delineate this clinical association, we investigated the phenotypic features of patients with CVID affected by these conditions.

METHODS

We conducted a retrospective analysis of 870 pediatric and adult patients with CVID included in the United States Immunodeficiency Network (USIDNET) registry. Outcomes included clinical characteristics (age, gender, ethnicity, rheumatologic diagnosis, and comorbidities), infectious history and basic immunophenotype (serum immunoglobulin levels, CD19+ B cells, and CD4/CD8 ratio) in patients with CVID and rheumatologic disorders compared to those with non-inflammatory CVID. Demographic and clinical data were compared using chi-square, Fisher's exact or Wilcoxon-Mann-Whitney tests. Non-parametric tests, single and multiple logistic regression models were used to evaluate the relationship between CVID-associated rheumatologic disorders and basic immunophenotypic parameters (IgA, IgM, CD19+ B-cell counts, and CD4/CD8 ratios).

RESULTS

Physician-reported rheumatic diseases were present in 5.9% of patients with CVID (n = 51) included in the registry. Although CVID affects both sexes equally, and patients are of predominantly White-Caucasian ethnicity, there were more females (3.3:1 female to male ratio) and increased proportion of non-white patients in the rheumatologic disease group (p < 0.05). Specific disorders included: inflammatory arthritis (n = 18), Sjogren's syndrome (n = 11), SLE (n = 8), Raynaud's syndrome (n = 8), vasculitis (n = 9), MCTD (n = 3), and other (n = 5). In about one-third of patients, a rheumatologic condition was associated with an additional inflammatory complication or malignancy. In regards to the immunophenotype parameters compared (CD19+ B-cell counts, CD4/CD8 ratio, IgA, and IgM), no significant differences were demonstrated between the two groups.

CONCLUSION

Our findings highlight the coexistence of primary antibody immunodeficiencies and systemic rheumatologic disorders, describe the spectrum of rheumatologic manifestations, and contrast differences in relevant demographic, clinical and immunophenotype parameters in the largest registry of CVID patients in the U.S. In spite of its limitations, our study details the intersection of systemic autoimmunity and CVID and provides valuable insights into these two groups of disorders. Further delineating the link between systemic autoimmunity and humoral immunodeficiencies can provide novel insights into the immune abnormalities underlying these related conditions.