Acute post-bacterial glomerulonephritis in renal transplant patients: description of three cases and review of the literature

Chronological Changes in the Histology of Infection-Related Glomerulonephritis in Renal Allograft: A Case Report

We report the histological changes over time for a patient with infection-related glomerulonephritis (IRGN) that developed in a transplanted kidney. A 47-year-old man had undergone renal transplantation 3 years ago for end-stage kidney disease (ESKD). After several episodes of acute rejection, the patient was in a stable CKD condition. The abrupt development of severe microscopic hematuria and renal dysfunction was observed approximately 2 weeks after the onset of a phlegmon in his right leg. An allograft biopsy showed prominent glomerular endocapillary proliferation on light microscopy, granular C3 deposition on immunofluorescent microscopy, and subepithelial electron-dense deposits on electron microscopy, suggesting IRGN accompanied by moderate interstitial fibrosis and tubular atrophy (IFTA). Positive glomerular staining for nephritis-associated plasmin receptor (NAPlr) and plasmin activity, which are biomarkers of bacterial IRGN, supported the diagnosis. Although the infection was completely cured with antibiotic therapy, renal dysfunction persisted. A re-biopsy of the allograft 2 months later revealed resolution of the glomerular endocapillary proliferation and negative staining for NAPlr/plasmin activity, with worsening IFTA. We showed, for the first time, the chronological changes in infiltrating cells and histological markers of IRGN in transplanted kidneys. Glomerular changes, including NAPlr/plasmin activity staining, almost disappeared after the cessation of infection, while interstitial changes continuously progressed, contributing to ESKD progression.

De novo Glomerular Disease and the Significance of Electron Microscopy in Renal Transplantation

Background

De novo glomerular diseases comprising those both common and unique to transplant may develop in the renal allograft leading to posttransplant proteinuria, hematuria, or allograft failure. Electron microscopy (EM) is a useful adjunct to the standard light and immunofluorescence microscopy for accurately diagnosing these diseases and subsequently aiding the clinician in initiating appropriate treatments.

Summary

De novo diseases are those new-onset diseases in renal transplantation that are unrelated to the original kidney disease in the recipient. They include virtually any primary or secondary glomerular, tubulointerstitial, or vascular diseases, ranging from subclinical to clinically overt, having acute, subacute, or chronic clinical presentations. This review focuses on common or significant, mainly glomerular, entities, with particular attention to the EM findings. The time of onset, stage, and severity of these diseases may often be modified by the current immunosuppressive protocols and other donor and recipient predisposing characteristics.

Key Messages

A renal allograft biopsy not only improves our understanding of the pathophysiology but also provides diagnostic accuracy prognostic information, and potential for reversibility. In some cases, the biopsy leads to detection of unsuspected or clinically asymptomatic de novo diseases in the setting of other concomitant rejection processes, infection, or toxicity, which can dictate appropriate therapy. Routine EM in transplant kidney biopsies is a valuable modality in recognizing fully developed or early/subtle features of evolving de novo diseases, often during the subclinical phases, in "for cause" or surveillance/protocol allograft biopsies.

Postinfectious Acute Glomerulonephritis in Renal Transplantation: An Emergent Aetiology of Renal Allograft Loss

Despite the high incidence of posttransplant infections, postinfectious acute glomerulonephritis (PIAGN) in renal allograft is a rare entity, without effective treatment and a bad prognosis. We describe two cases of PIAGN: the first one was developed 2 years after kidney transplantation, secondary to Staphylococcus aureus bacteremia with presence of extracapillary proliferation in biopsy. The patient was treated with methylprednisolone and plasma exchanges without response, remaining dialysis dependent. The second case was reported 5 years after kidney transplantation, secondary to influenza A infection. Kidney biopsy showed an IgA-dominant PIAGN and methylprednisolone boluses were initiated without clinical response, suffering a progressive worsening and loss of kidney graft. Due to the aggressive clinical course of this entity, PIAGN should be considered in the differential diagnosis of acute kidney graft failure in the context of an infection. Elderly patients have a higher risk of more severe acute renal dysfunction, requiring dialysis in a great proportion of cases.

Post-Streptococcal Glomerulonephritis in Two Patients Following Deceased Donor Kidney Transplant

Patient: Female, 25

Final Diagnosis: Post-streptococcal glomerulonephritis

Symptoms: Elevated creatinine

Medication: —

Clinical Procedure: —

Specialty: Nephrology

De Novo Postinfectious Glomerulonephritis Secondary to Nephritogenic Streptococci as the Cause of Transplant Acute Kidney Injury: A Case Report and Review of the Literature

Acute kidney injury is common among kidney transplant recipients. Postinfectious glomerulonephritis secondary to nephritogenic streptococci is one of the oldest known etiologies of acute kidney injury in native kidneys but rarely reported among kidney transplant recipients. This report is of a biopsy-proven case of acute kidney injury in a renal allograft recipient caused by de novo poststreptococcal glomerulonephritis.

De novo immune complex deposition in kidney allografts: a series of 32 patients

Immune complex deposition in kidney allografts can include both recurrent and de novo processes. Recurrent glomerulonephritis is a well-recognized phenomenon and has been shown to be a common cause of allograft failure. De novo immune complex-mediated disease remains relatively poorly characterized, likely owing to the less frequent use of immunofluorescence and electron microscopy in the transplant setting. We performed a retrospective review of kidney allograft biopsies showing glomerular immune complex deposition. Cases with de novo deposits were identified and further organized into two groups depending on whether the immune complex deposition could be clinically and/or histologically classified. Thirty-two patients with de novo immune complex deposition were identified over a 7-year period. A broad range of immune complex-mediated injuries were observed, the majority (63%) of which could be readily classified either clinically or histologically. These included cases of membranous glomerulonephropathy, IgA nephropathy, infection-related glomerulonephritis and glomerulonephritis related to an underlying autoimmune process. A smaller subset of patients (37%) demonstrated immune complex deposition that was difficult to histologically or clinically classify. These patients typically showed mild mesangial immune complex deposition with co-dominant IgG and IgM staining by immunofluorescence microscopy. The presence of concurrent antibody-mediated rejection and donor-specific antibody positivity was significantly higher in the unclassifiable group. The significance of these deposits and their possible relationship to allograft rejection deserves further investigation.

Acute diffuse proliferative post-infectious glomerulonephritis in renal allograft--a case report and literature review

PVN is a well-known cause of renal allograft dysfunction and failure. The diagnosis is established by examination of tissue from the renal graft, and confirmed by immunohistochemical or in situ hybridization techniques. Electron microscopy can be utilized as an ancillary modality to identify the viral particles ultrastructurally. The tubular epithelial cells are the primary target of PV cytopathic effect; however, PV-associated glomerular changes have also been described. Immune-type electron-dense deposits in the TBMs have been described in the setting of PVN, and rarely, likewise have glomerular subepithelial hump-like deposits. Diffuse immune-mediated proliferative glomerulonephritis in the setting of PVN has not been reported before. In this report, we describe an 11-yr-old kidney transplant recipient boy who developed immune-mediated glomerulonephritis with light microscopic, immunofluorescence, and ultrastructural features compatible with acute PIGN superimposing chronic PVN, discuss this unusual association and the possible mechanisms of antigen clearance in PVN and present a literature review.

De novo glomerular diseases after renal transplantation

Glomerular diseases developing in the kidney allograft are more often recurrences of the original disease affecting the native kidneys. However, in an undefined number of cases de novo, glomerular diseases unrelated to the original disease in the native kidneys can develop in the transplanted kidney. The clinical presentation and histologic features of de novo diseases are often similar to those features observed in patients with primary or secondary GN in the native kidneys. However, in transplanted kidneys, the glomerular, vascular, and tubulointerstitial changes are often intertwined with structural abnormalities already present at the time of transplant or caused by antibody- or cell-mediated allograft rejection, immunosuppressive drugs, or superimposed infection (most often of a viral nature). The pathophysiology of de novo glomerular diseases is quite variable. In rare cases of de novo minimal change disease, circulating factors increasing the glomerular permeability likely participate. Maladaptive hemodynamic changes and tissue fibrosis caused by calcineurin inhibitors or other factors may be involved in the pathogenesis of de novo FSGS. The exposure of cryptic podocyte antigens may favor the development of de novo membranous nephropathy. Many cases of de novo membranoproliferative GN are related to hepatitis C virus infection. Patients with Alport syndrome lacking antigenic epitopes in their glomerular basement membrane may develop antibodies against these glomerular basement membrane antigens expressed in the transplanted kidney. Infection may cause acute GN to have a heterogeneous clinical presentation and outcome. De novo pauci-immune GN in renal transplant is rare. Preexisting or acquired intolerance to glucose may, in the long term, cause diabetic nephropathy. The prognosis of de novo diseases depends on the type of GN, the severity of lesions caused by the alloimmune response, or the efficacy of immunosuppressive therapy. In most cases, the management of de novo glomerular diseases is empirical or elusive.

Bacterial infection-related glomerulonephritis in adults

In the past, most cases of bacterial infection-related glomerulonephritis (IRGN) occurred in children following streptococcal upper respiratory tract or skin infections and were called postinfectious GN. Over the past 3 decades, there has been an important shift in epidemiology, bacteriology, and outcome of IRGN. A significant percentage of cases now target adults, particularly the elderly or immunocompromised. Because adult infections are often ongoing at the time of diagnosis, the term IRGN appears more appropriate. The sites of infection in adult IRGN are more heterogeneous than in children, and include the upper respiratory tract, skin, lung, heart, urinary tract, teeth/oral mucosa, and bone. In adults, the disease is more likely to be secondary to non-streptococcal infections, particularly staphylococcal infection. In contrast to the favorable course in children, a significant proportion of adults with IRGN, especially the elderly and diabetics, do not recover renal function. Whereas the pathogenesis of post-streptococcal glomerulonephritis has been studied extensively, leading to the identification of two candidate nephritogenic streptococcal antigens, glyceraldehyde-3-phosphate dehydrogenase and pyrogenic exotoxin B, few investigations have focused on IRGN caused by other bacteria. This review will address the current status of sporadic bacterial IRGN in adults.

[Acute postinfectious glomerulonephritis]

Acute postinfectious glomerulonephritis are defined by an acute nonsuppurative inflammatory insult predominantly glomerular. Its current incidence is uncertain because of the frequency of subclinical forms. The most common infectious agent involved is beta hemolytic streptococcus group A. Acute postinfectious glomerulonephritis is uncommon in adults, and its incidence is progressively declining in developed countries. Humoral immunity plays a key role in the pathogenesis of kidney damage. Complement activation by the alternative pathway is the dominant mechanism, but a third way (lectin pathway) has been recently identified. The classic clinical presentation is sudden onset of acute nephritic syndrome after a free interval from a streptococcal infection. Treatment is essentially symptomatic and prevention is possible through improved hygiene and early treatment of infections.

Postinfectious glomerulonephritis in renal allograft recipients

Postinfectious glomerulonephritis (PIGN) is a rare etiology of de novo glomerulonephritis following kidney transplantation. To date, there have only been eight cases reported in the literature. We report an additional three patients transplanted at our institution between January 2000 and October 2004 who had clinical and pathologic findings consistent with posttransplant PIGN. All three patients were type 1 diabetics. One had received a cadaveric kidney transplant, one a simultaneous kidney-pancreas transplant, and the third a living related kidney transplant followed by a pancreas transplant. All patients were on triple immunosuppressive therapy with tacrolimus, mycophenolate mofetil, and prednisone. In each case, an acute decline in allograft function developed in association with a known or suspected infectious process, and renal biopsies revealed an immune complex glomerulonephritis with features of PIGN. All regained renal function with treatment of their known or suspected infections and without specific therapies for their glomerulonephritis, including corticosteroids.

Infection in Renal Transplantation: A Case of Acute Q Fever

Acute Q fever is a zoonotic infection that most often occurs as an asymptomatic or very mild febrile illness. A small percentage of patients go on to develop chronic Q fever months or even years after the acute infection. We present a case of acute Q fever occurring in a renal transplant recipient who developed severe systemic disease with renal involvement. Serological diagnosis was carried out, and the patient was treated successfully with antibiotic therapy. This case emphasizes Q fever as one of the atypical infectious agents that may have serious consequences in immunocompromised renal transplant recipients and reminds us of the importance of careful inquiry regarding personal or occupational activities that could lead to exposure to specific organisms.

Renal transplantation 2004: where do we stand today?

In spite of considerable progress in immunosuppressive and supportive treatment, numerous problems persist which interfere with the success of renal transplantation. Before transplantation has been performed, factors impacting on outcome include the donor (living vs cadaver, age and HLA system) as well as the recipient (age, immunological reactivity, potential sensitization and duration of dialysis). These are the main factors that affect the outcome of the transplant, particularly in the long-term. After transplantation a number of events may put graft function at risk: potential recurrence of the primary renal disease in the allograft; 'de novo' renal disease triggered by infections, drugs or autoimmunity; and non-specific progression promoters, such as diabetes, hypertension, proteinuria, nephrotoxic agents and/or viral infections. The two most frequent causes of chronic allograft dysfunction are (i) chronic rejection (often triggered by preceding acute rejection, delayed graft function or poor compliance) and (ii) calcineurin-inhibitor nephrotoxicity (more likely to develop in kidneys of older donors or in marginal kidneys). The differential diagnosis between these two entities is generally difficult, but some histological clues (reduplication of glomerular basement membrane, obliterating vasculopathy and C4d deposits) as well as the demonstration of humoral antibodies are pointers suggesting rejection. Treatment of chronic graft dysfunction is difficult, whatever the cause, particularly in cases with advanced renal lesions. Therefore, early diagnosis is of paramount importance. In this regard, graft biopsy can be of great help. In spite of many problems and complications, not only short-term but also long-term results of renal transplantation are improving progressively, as documented by CTS data showing that in Europe for transplants performed between 1982 and 1984 the mean graft half-life was 7 years, while for transplants performed between 1997 and 1999 it was 20 years.