Glomerulonephritis in a patient with chronic active Epstein-Barr virus infection

EBV load is associated with cfDNA fragmentation and renal damage in SLE patients

BACKGROUND

For long Epstein-Barr virus (EBV) has been suspected to be involved in the pathogenesis of systemic lupus erythematosus (SLE). The aim of this study was to verify the association between EBV, cell-free DNA (cfDNA) and kidney disease in SLE.

METHODS

Blood samples were obtained from 43 SLE patients and 50 healthy individuals. EBV load was measured via real-time PCR assay. Sizing and quantification of plasma cfDNA was performed on Bioanalyzer. We proposed that the uniformity of cfDNA fragmentation can be described using cfDNA fragmentation index.

RESULTS

SLE patients with chronic kidney disease (CKD +) had higher EBV load compared to CKD(-) patients (P = 0.042). Patients with high cfDNA level had higher EBV load (P = 0.041) and higher cfDNA fragmentation index (P < 0.001) compared to patients with low cfDNA level. Among patients with high cfDNA level, EBV load was higher in CKD(+) group compared to CKD(-) group (P = 0.035). EBV load was positively correlated with the fragmentation index in all SLE patients (P = 0.028, R² = 0.13), and the correlation was even more pronounced in CKD (+) patients (P < 0.001, R² = 0.20).

CONCLUSIONS

We showed that EBV load was associated with non-uniform cfDNA fragmentation, higher cfDNA levels, and kidney disease in SLE patients. Although the causality of this relationship could not be determined with the current study, it brings rationale for further investigations on the role of EBV and cfDNA interplay in SLE pathogenesis.

Acute kidney injury in an adult patient with IgA nephropathy and chronic replicative Epstein-Barr virus infection

Most of the adult population are infected with Epstein-Barr virus (EBV), but as EBV replication is usually under immune system control, the majority of individuals remain asymptomatic. On the other hand, some individuals continuously retain a high EBV antibody titer and a high EBV DNA load in their blood, suggesting a defect of EBV replication control. To date, only a limited number of reports have addressed the relationship between this chronic form of EBV infection and renal involvement. Here, we describe an 80-year-old woman who developed acute kidney injury shortly after an episode of mosquito bites, accompanied by a severe skin rash, which raised a suspicion of chronic EBV infection. She was subsequently diagnosed as having chronic replicative EBV infection. Renal biopsy revealed a diagnosis of IgA nephropathy with crescent formation. Although the relationship between IgA nephropathy and EBV infection has been discussed, no substantial understanding has yet emerged. The patient's characteristic clinical course suggested that the renal failure may have been partly attributable to chronic EBV infection. This case suggests that physicians may need to consider the possibility that chronic EBV infection may affect the clinical course of IgA nephropathy, or exacerbate the disease.

Viral-associated glomerulopathies in children

Viral infections associate temporally with the onset of many glomerular diseases, particularly in children. In other cases of glomerulonephritis, when infection is clinically silent, viral syndromes can still be implicated as a trigger. However, strong evidence for viral causality in most glomerular disease is still lacking. While numerous case reports in children document the occurrence of specific forms of glomerular disease after seroconversion to a wide range of viruses, relatively few reports provide pathologic evidence of viral infection associated with glomerular lesions on kidney biopsy. Strong associations between hepatitis viruses and glomerular injury have been acknowledged in adults, but hepatitis C virus appears not to be an etiology in children. In the context of treating glomerular diseases, when diagnosed, the treatment of hepatitis B virus, cytomegalovirus and human immunodeficiency virus in children with membranoproliferative, membranous and collapsing glomerulopathy plays an important role. Otherwise, there is no evidence suggesting that the identification of a viral infection in a child with glomerulopathy should change the management of the infection or the glomerulonephritis. Therefore, additional research into this topic is very much needed.

EBV-Positive T/NK-Cell Lymphoproliferative Disease of Childhood

Background

Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (HLH), EBV-positive systemic T-cell lymphoproliferative disease (STLPD) of childhood, and chronic active EBV (CAEBV) infection may develop after primary EBV infection. This study reviewed the clinicopathological spectrum of EBV-associated T- and natural killer (NK)-cell LPD, including STLPD and CAEBV infection, with an analysis of T-cell clonality.

Methods

Clinicopathological features of seven patients with EBV-associated HLH or STLPD and 12 patients with CAEBV infection were reviewed. Immunohistochemical staining and a T-cell receptor (TCR) gene rearrangement study were performed.

Results

STLPD and EBV-positive HLH showed significantly overlapping clinicopathological findings. One patient with STLPD and one patient with EBV-positive HLH demonstrated moderate to severe atypia of the infiltrating lymphocytes, whereas the remaining patients lacked significant atypia. Twelve patients had CAEBV infection, four of whom suffered mosquito-bite hypersensitivity, five showed NK lymphocytosis, and one suffered hydroa vacciniforme. Infiltrating lymphocytes were predominantly small and devoid of atypia. Hemophagocytic histiocytosis was found in seven of 11 patients. Monoclonality was detected in three (50%) of the six patients with successful TCR gene analysis.

Conclusions

EBV-positive HLH and STLPD share similar clinicopathological findings and may constitute a continuous spectrum of acute EBV-associated T- or NK-cell proliferative disorders. The distinction of EBV-positive T-cell LPD from EBV-positive HLH may be difficult during routine diagnoses because of the technical limitations of clonality assessment.

Acute Epstein-Barr virus infection-associated collapsing glomerulopathy

A 21-year-old woman presenting with acute Epstein–Barr virus (EBV) infection (infectious mononucleosis) was noted to have renal involvement. She had proteinuria, leukocyturia and microscopic hematuria, and 10 days after admission became nephrotic (23 g of protein per g of creatinine). Renal biopsy revealed glomerular tuft collapse, visceral epithelial cell proliferation and vacuolization consistent with collapsing glomerulopathy. She had only transient deterioration in renal function, attributed to contrast nephropathy, but after recovery remained proteinuric. Renal disease is well described in EBV infection, but collapsing glomerulopathy has not been reported previously.

An adult case of fulminant Epstein-Barr virus infection with acute tubulointerstitial nephritis

Epstein-Barr virus (EBV) infection is common in adolescence, but fulminant infection is very rare. A 40-year-old man presented with high fever and sore throat. Symptoms, including cervical lymphadenopathy, jaundice, atypical lymphocytosis, respiratory distress and oliguria, suggested infectious mononucleosis with multiple organ failure that required mechanical ventilation and renal replacement therapy. Virus markers were consistent with primary EBV infection. Renal function was gradually improved by corticosteroid therapy. Renal biopsy revealed acute tubulointerstitial nephritis. In situ hybridizaion EBV-encoded RNA 1 did not show the presence of virus in the kidney, but acute kidney injury may be explained by cytotoxic/suppressor T lymphocyte infiltration.

Proteinuria in a boy with infectious mononucleosis, C1q nephropathy, and Dent's disease

C1q nephropathy is a proliferative glomerulopathy with extensive mesangial deposition of C1q. A three-year old boy presented with a nephrotic-range proteinuria during an acute phase of Epstein-Barr virus (EBV) infection, and he had a family history of Dent's disease. The renal biopsy findings were compatible with C1q nephropathy. However, EBV in situ hybridization was negative. The CLCN5 gene analysis revealed an R637X hemizygous mutation, which was the same as that detected in his maternal cousin, the proband of the family. The causal relationship between EBV infection and C1q nephropathy remains to be determined. Moreover, the effects of underlying Dent's disease in the process of C1q nephropathy has to be considered.