Immune complex glomerulonephritis associated with Staphylococcus aureus bacteremia: response to corticosteroid therapy

Vasculitides and glomerulonephritis associated with Staphylocococcus aureus infective endocarditis: cases reports and mini-review of the literature

We reported two cases of Staphylococcus aureus Infective Endocarditis associated with vasculitides and glomerulonephritis respectively, before conducting an online search of previously published similar cases reports. Twenty five references were selected: 15 cases of glomerulonephritis; 2 cases of vasculitis and 8 cases involving both glomerulonephritis and vasculitis. Vasculitides and glomerulonephritis associated with Staphylococcus aureus definite Infective Endocarditis have been reported since 1976. All cases except one described clinical symptoms occurring before or during initial antibiotics treatment. Except kidney, organs that were more frequently affected by vasculitis process were skin, gastrointestinal tract and peripheral nerve and the vessels involved were small to medium size vessels. When antineutrophil cytoplasmic antibodies were evidenced (6 out of the 25 cases (24%)), kidney was the most frequently affected organ. The most commonly observed pattern in Kidney biopsy was membranoproliferative glomerulonephritis with endocapillary proliferation sometimes associated with extra capillary crescents, whether or not antineutrophil cytoplasmic antibodies were evidenced. Right-sided Infective Endocarditis (especially in intravenous drug users) were overrepresented (14 of the 25 cases (56.0%)) in this review. Besides antibiotics, corticosteroids were the most frequently prescribed immunosuppressive treatment both for vasculitides or glomerulonephritis. KEY MESSAGES Vasculitides and glomerulonephritis associated with Staphylococcus aureus definite Infective Endocarditis have been reported since 1976. Except kidney, organs that were more frequently affected (by small to medium size vessel vasculitis) were skin, gastrointestinal tract and peripheral nerve. The most commonly observed pattern in Kidney biopsy was membranoproliferative glomerulonephritis with endocapillary proliferation and right-sided Infective Endocarditis (especially in intravenous drug users) were overrepresented in this review.

Should all adjunctive corticosteroid therapy be avoided in the management of hemodynamically stabile Staphylococcus aureus bacteremia?

The purpose of this study was to examine the prognostic impact of corticosteroids in hemodynamically stabile Staphylococcus aureus bacteremia (SAB). There were 361 hemodynamically stabile methicillin-sensitive SAB patients with prospective follow-up and grouping according to time-point, dose and indication for corticosteroid therapy. To enable analyses without external interfering corticosteroid therapy all patients with corticosteroid therapy equivalent to prednisone >10 mg/day for ≥1 month prior to positive blood culture results were excluded. Twenty-five percent (92) of patients received corticosteroid therapy of which 11 % (40) had therapy initiated within 1 week (early initiation) and 9 % (31) had therapy initiated 2-4 weeks after (delayed initiation) positive blood culture. Twenty-one patients (6 %) had corticosteroid initiated after 4 weeks and were not included in the analyses. A total of 55 % (51/92) received a weekly prednisone dose >100 mg. Patients with early initiated corticosteroid therapy had higher mortality compared to patients treated without corticosteroid therapy at 28 days (20 % vs. 7 %) (OR, 3.11; 95%CI, 1.27-7.65; p < 0.05) and at 90 days (30 % vs. 10 %) (OR, 4.01; 95%CI, 1.82-8.81; p < 0.001). Considering all prognostic markers, early initiated corticosteroid therapy predicted 28-day (HR, 3.75; 95%CI, 1.60-8.79; p = 0.002) and 90-day (HR, 3.10; 95%CI, 1.50-6.39; p = 0.002) mortality in Cox proportional hazards regression analysis. When including only patients receiving early initiated corticosteroid therapy with prednisone ≥100 mg/week the negative prognostic impact on 28-day mortality was accentuated (HR 4.8, p = 0.001). Corticosteroid therapy initiation after 1 week of positive blood cultures had no independent prognostic impact. Early initiation of corticosteroid therapy may be associate to increased mortality in hemodynamically stabile SAB.

Tunneled right atrial catheter infection presenting as renal failure

We report two cases of progressive renal failure secondary to membranoproliferative glomerulonephritis associated with subclinical septicemia from a tunneled right atrial catheter used for home parenteral nutrition administration. Although the occurrence of line infection and septicemia is a common complication of central venous catheters, a review of the literature reveals only one case report of renal failure secondary to an infected implanted central venous device. Both patients presented with azotemia and had biopsy-proven membranoproliferative glomerulonephritis, accompanied by leukocytoclastic vasculitis. In both cases, removal of the right atrial catheter and prolonged antibiotic therapy was effective in resolving the ongoing infection and resulted in marked improvement in renal function. A high index of suspicion for catheter sepsis should be maintained in patients with tunneled right atrial catheters presenting with subacute renal failure.

Experimental endocarditis in the rat secondary to septic arthritis induced by Staphylococcus aureus

OBJECTIVE: To develop a modified model for experimental infective endocarditis (IE) in the rat. The goal was to induce a primary infectious focus in the temporomandibular joint (TMJ) of a rat. Hematogenous translocation of the bacteria to the traumatized aortic valve was desired. METHODS: Catheterization of the right carotid artery through the aortic valve was performed 7 days after induction of arthritis, which was done by intra-articular injection of glucocorticosteroid (triamcinolone acetonide, 1 mg) and intravenous challenge with 107 CFU Staphylococcus aureus. RESULTS: TMJ arthritis could be induced by intra-articular triamcinolone acetonide followed by intravenous bacterial challenge. Joints not given glucocorticosteroid were not affected. Only rats with arthritis developed IE subsequent to catheterization as a result of bacteremia generated from the arthritis. CONCLUSIONS: The present model may serve as a complement to the conventional method for induction of IE, in which a high intravenous challenge has to be given. In the present model, IE was instead the result of a continuous low level of bacteremia from an infectious focus in the TMJ. This model mimics the natural development of IE in patients, and may assist as a setting for prophylactic and therapeutic trials.

Bacterial endocarditis associated with crescentic glomerulonephritis in a kidney transplant patient: first case report

BACKGROUND

Endocarditis-induced crescentic glomerulonephritis is a well-described complication in nontransplant patients. Its occurrence in transplant patients has not been reported to date.

METHODS

A 50-year-old man who had received a renal allograft 13 years before and been treated with prednisone, 10 mg/day, was admitted for progressive renal failure, purpura, edema of the lower limbs, and fever.

RESULTS

Blood cultures isolated Streptococcus bovis and cardiac ultrasound examination revealed a 23-mm-large vegetation on the mitral valve. His plasma creatinine level was 478 micromol/L and his proteinuria was 5.5 g/day. A renal biopsy showed diffuse crescentic glomerulonephritis. Long-term antibiotic treatment and three methylprednisolone pulses were effective in treating the endocarditis and glomerulonephritis.

CONCLUSION

Endocarditis-induced glomerulonephritis is an immune-mediated disease that can also occur on a renal allograft. It is likely that a low daily dose of immunosuppressive treatment may have been a facilitating factor.

Induction of glomerulonephritis in rats with staphylococcal phosphatase: new aspects in post-infectious ICGN

Staphylococcal neutral phosphatase (NPtase) is a highly cationic bacterial surface bound protein. It has significant affinity for human and rat immunoglobulins in vitro and an electrostatic interaction may be involved. Radioisotopic studies showed that NPtase had a high affinity for the polyanionic structures of the rat renal glomerulus. When the left kidneys of germ-free or naive (non-immune) Wistar rats were perfused with 80 micrograms of I125 NPtase, 21 micrograms of NPtase were found in the left kidneys and 11 micrograms in the isolated glomeruli 15 minutes after perfusion. Deposits of autologous immunoglobulin and C3 were seen in the glomeruli of rats immediately after perfusion with NPtase (15 min) and persisted throughout the 14-day observation period. Histologically, neutrophil influx into the glomerulus was seen at 15 minutes and increased until three hours; subepithelial electron-dense deposits were found after three days and were still visible on day 14. Proteinuria started within the first 24 hours despite the absence of an immune response at this time and was still present on day 14. Similar results were observed in immune deficient athymic nude rats in the early phase. Perfusion of heparin after NPtase inhibited the deposition of IgG and C3 and prevented proteinuria in naive but not in actively immunized rats. This result provides further evidence that specific antibodies to NPtase were not involved in the immune complex-like deposits seen in the early phase. NPtase is a novel molecule, as it reveals both high affinity for the GBM and binding of circulating immunoglobulins, by a non-antigen-antibody mechanism, to form IC-like deposits on the GBM. These deposits are capable of activating the complement system, thus triggering a series of events leading to glomerulonephritis. These results delineate an additional pathway for the pathogenesis of ICGN related to bacterial infection.

The current spectrum of infectious glomerulonephritis. Experience with 76 patients and review of the literature

To identify the demographic, clinical, and pathologic features and the prognosis of renal disease in a series of patients with infectious or postinfectious proliferative glomerulonephritis (GN), data were collected from records of 76 adult patients admitted from 1976 to 1993 to 2 neighboring suburban hospital nephrology units, whose catchment population consists of patients living in a suburban borough of Paris with a below-average socioeconomic status. Thirty-four patients (45%) were alcoholics, diabetics, or intravenous illicit-drug users. Sixty-six patients presented with acute nephritic and/or nephrotic syndrome. Acute renal failure was present in 56 (76%) and required dialysis in 14. The diagnostic workup comprised at least 1 renal biopsy in each case. The patient's background, site of infection, clinical course, laboratory variables, and, when available, bacteriologic findings were analyzed in each case to interpret the evolution of the disease. Initial renal biopsy disclosed endocapillary GN in 44 patients, crescentic GN in 26, and membranoproliferative GN in 6. Ten patients had endocarditis. Staphylococci and Gram-negative strains, not streptococci, were the most common bacteria identified. The origin of sepsis was mainly the oropharynx (21), the skin (19) and the lung (14); 19 cases involved multiple sites of infection. Eight patients died (11%), and 20 (26%) recovered renal function, but GN followed a chronic course in 38 (50%), rapidly requiring maintenance dialysis in 6. Poor prognostic factors included age over 50 years, purpura, endocarditis, and glomerular extracapillary proliferation. Twenty-six patients underwent repeat renal biopsy 1 month to 11 years after the initial presentation. The main finding, irrespective of the interval since the first biopsy, was that ongoing or new iatrogenic infection acquired during hospitalization was almost invariably acquired during hospitalization was almost invariably associated with developing glomerular proliferative changes. This study shows that infectious proliferative GN remains common, but that its epidemiology has changed from what was observed until 2 decades ago. The responsible bacteria, when identified, now comprise a majority of staphylococci and Gram-negative strains, in contrast to the streptococci which predominated 3 decades ago. Infectious GN affects with increasing frequency patients with an underlying condition responsible for immunosuppression, especially alcoholism, even in the absence of cirrhosis. Destructive glomerular proliferation persists, especially but not exclusively until infection has been eradicated, and despite rescue treatment with corticosteroids and/or cytostatic drugs. Thus, the prognosis is poor, and infectious GN often ends in renal death. Infection continues in this decade to represent a frequent and probably often overlooked cause of end-stage renal failure.(ABSTRACT TRUNCATED AT 400 WORDS)