Renal Evaluation in Common Variable Immunodeficiency

Renal complications in patients with predominantly antibody deficiency in the United States Immune Deficiency Network (USIDNET)

BACKGROUND

Prior studies have reported that renal insufficiency occurs in a small percentage of patients with predominantly antibody deficiency (PAD) and in about 2% of patients with common variable immunodeficiency.

OBJECTIVE

The goal of our study was to understand and evaluate the prevalence and type of renal complications in patients with PAD in the United States Immunodeficiency Network (USIDNET) cohort. We hypothesized that there is an association between certain renal complications and severity of immunophenotype in patients with PAD.

METHODS

We performed a query of patients with PAD from the USIDNET cohort with renal complications. Patients with documented renal disease such as chronic kidney disease (CKD), nephrolithiasis, nephritis, and renal failure syndrome were included. We compared immunophenotype, flow cytometry findings, and immunoglobulin levels of patients with PAD accompanied by renal complications with those of the total USIDNET cohort of patients with PAD.

RESULTS

We determined that 140 of 2071 patients with PAD (6.8%) had renal complications. Of these 140 patients, 50 (35.7%) had CKD, 46 (32.9%) had nephrolithiasis, 18 (12.9 %) had nephritis, and 50 (35.7%) had other renal complications. Compared with the total USIDNET cohort of patients with PAD, patients with CKD had lower absolute lymphocyte counts, CD3+ T-cell counts, CD4+ T-cell counts, CD19+ B-cell counts, CD20+ B-cell counts, and CD27+IgD- B-cell counts (P < .05 for all). Patients with nephritis had lower absolute lymphocyte counts, CD19+ B-cell counts, CD27+ B-cell counts, and IgE levels (P < .05 for all) than patients with PAD without renal disease.

CONCLUSIONS

We determined that 6.8% of the USIDNET cohort of patients with PAD had a documented renal complication. Compared with the overall cohort of patients with PAD, those patients with nephritis and CKD had a more severe immunophenotype.

Urine microbiome in individuals with an impaired immune system

With the advent of next generation sequencing, it is now appreciated that human urine is not sterile. Recent investigations of the urinary microbiome (urobiome) have provided insights into several urological diseases. Urobiome dysbiosis, defined as non-optimal urine microbiome composition, has been observed in many disorders; however, it is not clear whether this dysbiosis is the cause of urinary tract disorders or a consequence. In addition, immunologically altered disorders are associated with higher rates of urinary tract infections. These disorders include immunoproliferative and immunodeficiency diseases, cancer, and immunosuppressant therapy in transplant recipients. In this review, we examine the current state of knowledge of the urobiome in immunologically altered diseases, its composition and metabolomic consequences. We conclude that more data are required to describe the urobiome in immune altered states, knowledge that could facilitate understanding the role of the urobiome and its pathophysiological effects on urinary tract infections and other disorders of the urinary tract.

Nephrological factors may cause kidney dysfunction in patients with common variable immunodeficiency

Background/aim

Common variable immunodeficiency (CVID) is a heterogeneous primary deficiency characterized by hypogammaglobulinemia, recurrent infections, an increased risk of autoimmune disease, malignancy, and chronic inflammation. Proteinuria is one of the most important prognostic factors causing progression in kidney disease. Proteinuria causes tubulotoxicity, activates inflammatory markers that cause fibrosis, and consequently nephropathy progression. The data is scant in the literature regarding the inflammation and nephropathy in CVID. Hence, in the present study, we aimed to investigate the relationship between tubular dysfunction, proteinuria, and inflammation in patients with CVID.

Materials and methods

This was a cross-sectional study involving 27 patients with CVID (15 females, 12 males; mean age, 39.88 ± 13.47 years) and 18 control subjects (10 females, 8 males; mean age, 33.83 ± 7.97 years). Patients were evaluated for kidney functions including glomerular filtration rate, fractional excretion of sodium, metabolic acidosis, serum/urine anion gap, 24-h urine proteinuria and, were grouped in terms of proteinuria. Blood samples obtained from the patients with CVID were taken into 2 mL EDTA tube to evaluate peripheral NK cell subgroups according to CD56 and CD16 expression and CD3, CD4, CD 8 expression to determine subtypes T cells. These cells were evaluated by flow cytometry technique.

Results

Urinary density, fractional excretion of sodium, proteinuria, and metabolic acidosis are found to be higher in patients with CVID when compared to healthy controls. In the bivariate correlation analysis, proteinuria was positively correlated with age (r = 0.496, p = < 0.001), CD8+T cells percentage (r = 0.427, p = 0.02). Albumin, CRP, and CD8+T cell percentage were found to be independent variables of proteinuria.

Conclusion

Increased chronic ongoing inflammation was found to be associated with proteinuria in patients with CVID. Hence, in routine outpatient clinics, proteinuria should not be overlooked in this group of patients.

Primary immunodeficiency diseases treated with immunoglobulin and associated comorbidities

Background: Primary immunodeficiency diseases (PIDD) consist of a heterogeneous group of disorders characterized by various aspects of immune dysregulation. Although the most universally recognized manifestation of PIDD is an increased susceptibility to infections, there is a growing body of evidence that patients with PIDD often have a higher incidence of lung disease, autoimmunity, autoinflammatory disorders, and malignancy. Objective: The purpose of this study was to better understand the noninfectious complications of PIDD by determining the comorbid disease prevalence across various age groups, genders, and immunoglobulin replacement types compared with the general population. Methods: A large U.S. insurance claims database was retrospectively analyzed for patients who had a diagnosis of PIDD and who had received intravenous immunoglobulin (IVIG) or subcutaneous immunoglobulin (SCIG). The prevalences of 31 different comorbid conditions in the Elixhauser comorbidity index were compared among the 3125 patients in the PIDD population to > 37 million controls separated by gender and by 10-year age cohorts. Results: In the PIDD population, statistically significantly higher comorbid diagnoses included chronic obstructive pulmonary disease-asthma in 51.5%, rheumatoid disease in 14%, deficiency anemia in 11.8%, hypothyroidism in 21.2%, lymphoma in 16.7%, neurologic disorders in 9.7%, arrhythmias in 19.9%, electrolyte disorders in 23.6%, coagulopathies in 16.9%, and weight loss in 8.4%. Conclusion: PIDD that require immunoglobulin replacement are associated with an increased risk of numerous comorbid conditions that affect morbidity and mortality. Recognition and increased awareness of these noninfectious complications can allow for better monitoring, care coordination, targeted treatments, and improved prognosis.