Characterization of Herpesviridae Family Members, BK Virus, and Adenovirus in Children and Adolescents with Nephrotic Syndrome

Since the significance of viral infections in children and adolescents with nephrotic syndrome (NS) is yet to be defined, this study intended to estimate the occurrence, pattern, and outcomes of some DNA viral infections in children with NS.

METHODS

A prospective study was conducted to determine the genome identification of the viruses Epstein-Barr (EBV), human cytomegalovirus (HCMV), human herpesvirus 6 (HHV-6 type A and type B) and 7 (HHV-7), polyomavirus (BKV), and human adenovirus (HAdV) in plasma and urine samples of pediatric patients with NS.

RESULTS

A total of 35 patients aged 1 to 18 years with NS and under immunosuppressant drugs participated in the study. Plasma and urine samples were collected at regular intervals during a median follow-up of 266 days (range 133-595), and DNA was analyzed to detect the selected DNA viruses. Eleven patients (31.4%) had active virus infections, and patterns were classified as coinfection, recurrent, and consecutive. Of these, six patients (54.5%) presented viral coinfection, six (54.5%) viral recurrence, and seven patients (63.3%) had viral consecutive infection. Ten of the eleven patients with active infection had a proteinuria relapse (91%) and eight (72.7%) were hospitalized (p = 0.0022). Active HCMV infection was the most frequent infection and was observed in six patients (54.5%), three of the eleven patients (27.2%) had suspected HCMV disease in the gastrointestinal tract, and one had HHV-7 coinfection. The frequency of other infections was: 9% for HHV-6, 45.5% for BKV, 27.3% for HHV-7, 18.2% for EBV, and 18.2% for HAdV.

CONCLUSION

viral infections, especially HCMV, can be an important cause of morbidity and nephrotic syndrome relapse in children.

Glomerular Diseases and Renal Transplantation: Pathogenic Pathways and Evolution of Therapeutic Interventions

Glomerular diseases and renal transplantation are the main fields of nephrology in which the immune system plays a prevalent role. Glomerular diseases have traditionally been attributed to auto-immune conditions, whereas allograft rejection has been considered an allo-immune response. However, common immunopathologic mechanisms that include Toll-like receptors, complement and B-cell activation, as well as genetic and infectious factors appear to be involved in the pathogenesis of both entities. Novel therapeutic regimens directed against specific targets of the immune system show promising results in glomerulopathies as well as in renal transplantation.

Immune Renal Injury: Similarities and Differences Between Glomerular Diseases and Transplantation

Glomerular diseases and renal transplantation are the main fields in nephrology in which the immune system plays a prevalent role. They have for long been considered as independent conditions due to the prominent role of autoimmunity in glomerular diseases and of alloimmunity in renal transplantation.

Moreover, histologic features differ between glomerular diseases and transplantation: in glomerular diseases, histologic damage involves primarily the glomeruli and secondarily the tubulointerstitium and small vessels, whereas in transplantation, allograft injury comprises primarily the tubulointerstitium and vessels and to a lesser degree the glomeruli.

However, recent research has shown that the pathogenetic mechanisms in both conditions share common pathways and that there is cross-reaction between innate and adaptive immunity as well as between auto- and alloimmunity [1].

IgA NEPHROPATHY IN PATIENTS RECEIVING A RENAL TRANSPLANT

BACKGROUND

IgA nephropathy (IgAN) is the third most frequent cause of renal graft loss among patients with primary glomerulonephritis.

OBJECTIVES

To assess clinical and laboratorial profile of patients with pre and/or post transplant IgAN, in addition to patient and graft survival in both groups.

DESIGN

Data from 146 patients who had received a renal transplant were retrospectively collected and were divided in two groups: group 1-patients with biopsy-documented IgAN as the underlying native kidney disease (n = 128); group 2-patients who developed post-transplant IgAN independent of the underlying disease (n = 18).

PARTICIPANTS

Patients submitted to renal transplantation (1998-2010) with pre and/or post transplant IgAN.

MEASUREMENTS

Clinical and laboratorial evaluation of renal function of 146 post transplant IgAN patients.

RESULTS

Recipients and deceased donors exhibited a higher degree of HLA compatibility (1.0 vs. 2.5 mismatches for groups 1 and 2, respectively). The main post-transplant IgAN presentation was haematuria associated with non-nephrotic proteinuria (44.4%). A histological pattern of focal segmental glomerulosclerosis was observed in 59.2% of biopsy samples. The 10-year patient survival was 93.5% in group 1 and 100% in group 2, and the graft survival rates were 58.5 and 87.2%, respectively.

CONCLUSION

The rate of post-transplant IgA diagnosis in our case series was 11%, and IgAN was diagnosed late in the course of transplantation. In most cases, IgAN manifested as haematuria and non-nephrotic proteinuria, without renal graft dysfunction, and this picture might explain late indication of graft biopsies. The 10-year patient survival rates were excellent.

Basic and translational concepts of immune-mediated glomerular diseases

Genetically modified immune responses to infections and self-antigens initiate most forms of GN by generating pathogen- and danger-associated molecular patterns that stimulate Toll-like receptors and complement. These innate immune responses activate circulating monocytes and resident glomerular cells to release inflammatory mediators and initiate adaptive, antigen-specific immune responses that collectively damage glomerular structures. CD4 T cells are needed for B cell-driven antibody production that leads to immune complex formation in glomeruli, complement activation, and injury induced by both circulating inflammatory and resident glomerular effector cells. Th17 cells can also induce glomerular injury directly. In this review, information derived from studies in vitro, well characterized experimental models, and humans summarize and update likely pathogenic mechanisms involved in human diseases presenting as nephritis (postinfectious GN, IgA nephropathy, antiglomerular basement membrane and antineutrophil cytoplasmic antibody-mediated crescentic GN, lupus nephritis, type I membranoproliferative GN), and nephrotic syndrome (minimal change/FSGS, membranous nephropathy, and C3 glomerulopathies). Advances in understanding the immunopathogenesis of each of these entities offer many opportunities for future therapeutic interventions.