Renal pathological findings in infective endocarditis

Native and prosthetic valve infective endocarditis complicated by rapidly progressive glomerulonephritis and its diagnostic challenges and therapeutic implications

Key Clinical Message

Concomitant native and prosthetic valve infective endocarditis (IE) is very rare, and both can rarely be complicated by rapidly progressive glomerulonephritis (RPGN). This diagnosis has therapeutic implications, as not all RPGN need immunosuppression therapy.

Abstract

Native and prosthetic valve infective endocarditis (IE) may be rarely complicated by rapidly progressive glomerulonephritis (RPGN). The diagnosis of IE as a cause of RPGN may be missed, and patients may be subjected to inappropriate immune suppressive therapy. Moreover, IE involving multi-valves has rarely been described, and there are only few case reports of simultaneous native and prosthetic valve endocarditis. Here, we present a case of 34-year-old female patient who has RPGN and whose initial workup missed IE. However, further workup revealed a diagnosis of native and prosthetic valve IE and our patient, who would have been subjected to inappropriate immune suppressive therapy, was treated with intravenous antibiotics alone and discharged with improvement.

Infective Endocarditis Caused by Streptococcus sanguinis Resulting in Stroke, Ruptured Infected Pseudoaneurysm of Superior Mesenteric Artery, and Rapidly Progressive Glomerulonephritis

A 71-year-old-man was admitted to our hospital with a cerebral embolism and diagnosed with infective endocarditis (IE) caused by Streptococcus sanguinis. Mitral valve replacement was performed. About one month later, he experienced sudden abdominal pain and shock due to a ruptured infected mesenteric artery pseudoaneurysm. Forty-four days after abdominal surgery, he presented with rapidly progressive glomerulonephritis with anti-glomerular basement membrane antibodies. He was treated with plasma exchange and prednisolone, and his renal function gradually improved. Since postoperative complications often occur within a few years after surgery for IE, careful follow-up is important, even after antimicrobial therapy and valve surgery.

Vasculitis Mimics and Other Related Conditions

The approach to diagnosis of primary systemic vasculitis can be challenging, often requiring consideration of important secondary causes of vasculitis and non-inflammatory mimics. An atypical pattern of vascular involvement and/or atypical features of primary vasculitis (eg, cytopenia, lymphadenopathy) should prompt a more thorough investigation into other diseases. Herein, we review selected mimics organized by the size of blood vessels typically affected.

Staphylococcus aureus Infection-Related Glomerulonephritis with Dominant IgA Deposition

Since 1995, when we reported the case of a patient with glomerulonephritis with IgA deposition that occurred after a methicillin-resistant Staphylococcus aureus (MRSA) infection, many reports of MRSA infection-associated glomerulonephritis have accumulated. This disease is being systematized as Staphylococcus infection-associated glomerulonephritis (SAGN) in light of the apparent cause of infection, and as immunoglobulin A-dominant deposition infection-related glomerulonephritis (IgA-IRGN) in light of its histopathology. This glomerulonephritis usually presents as rapidly progressive glomerulonephritis or acute kidney injury with various degrees of proteinuria and microscopic hematuria along with an ongoing infection. Its renal pathology has shown several types of mesangial and/or endocapillary proliferative glomerulonephritis with various degrees of crescent formation and tubulointerstitial nephritis. IgA, IgG, and C₃ staining in the mesangium and along the glomerular capillary walls have been observed on immunofluorescence examinations. A marked activation of T cells, an increase in specific variable regions of the T-cell receptor β-chain-positive cells, hypercytokinemia, and increased polyclonal immune complexes have also been observed in this glomerulonephritis. In the development of this disease, staphylococcal enterotoxin may be involved as a superantigen, but further investigations are needed to clarify the mechanisms underlying this disease. Here, we review 336 cases of IgA-IRGN and 218 cases of SAGN.

A Case of Immunoglobulin A (IgA)-Dominant Infection-Related Glomerulonephritis Treated With Plasmapheresis

Immunoglobulin A (IgA)-dominant infection-related glomerulonephritis (IRGN) is mostly associated with Staphylococcal or other bacterial infections like Streptococcus and Gram-negative bacilli. Antibiotics are the cornerstone of treatment in these cases. When the bacterial infection can’t be recognized or IRGN persists despite treating the underlying infection, controlling the kidney injury becomes cumbersome and lacks a strong evidence-based approach. In this report, we describe a 38-year-old male patient with a history of polysubstance abuse and chronic hepatitis B and hepatitis C infections who presented with acute kidney injury and nephrotic syndrome due to IgA-dominant IRGN without an active concurrent bacterial infection who responded well to plasmapheresis.

Systemic Bartonellosis Manifesting With Endocarditis and Membranoproliferative Glomerulonephritis

Cat scratch disease caused by Bartonella species is mostly benign and self-limiting condition. Systemic infection is uncommon in immunocompetent host. We describe the case of a 66-year-old male who presented with sudden painless left eye blindness and brown-colored urine. Laboratory findings revealed progressively rising serum creatinine in association with nephrotic-range proteinuria at 7 g/day and glomerular hematuria on urinalysis. An echocardiogram demonstrated mitral and tricuspid valve vegetations despite multiple negative blood cultures. The left eye blindness was attributed to retinal artery occlusion from septic valvular embolus. Kidney biopsy showed membranoproliferative glomerulonephritis pattern of injury with "full house" pattern on immunofluorescent staining with subendothelial deposits on electron microscopy. Markedly elevated IgG (immunoglobulin G) titers for B henselae and B quintana were discovered. The patient had several cats at home. Kidney failure rapidly progressed to require hemodialysis. Once the diagnosis of systemic bartonellosis was confirmed, doxycycline (for 4 months) with rifampicin (for 3 months) were initiated. Repeat echocardiogram in 4 months demonstrated a resolution of valvular vegetations; however, the left eye blindness was permanent. In the present case the correct diagnosis of systemic bartonellosis allowed institution of appropriate antibiotic therapy and to also achieve a partial recovery of renal function and to discontinue hemodialysis.

Infective endocarditis with embolic renal infarct presenting as acute abdomen

Infective endocarditis (IE) is a disease that is rare but potentially fatal and challenging to diagnose. A 28-year-old man with sickle cell trait and a history of intravenous drug use presented with abdominal pain and hematuria mimicking a surgical abdomen. The preliminary diagnosis was cholecystitis or perforated viscus. The chest radiograph was indicative of pulmonary septic emboli. Computed tomography was initially thought to show pyelonephritis, but further review of images revealed renal infarct. The patient was found to have endocarditis which resulted in an embolic renal infarct. The patient recovered remarkably well after 60 days of intravenous antibiotics. This case demonstrates that a surgical abdomen may also be a sign of endocarditis, and multiple imaging studies may be required to confirm the diagnosis. In patients such as intravenous drug users with an increased risk of IE, unexplained flank pain should raise a suspicion of acute renal infarction.

Bartonella-Associated Endocarditis with Severe Active Crescentic Glomerulonephritis and Acute Renal Failure

We report a case of severe acute kidney failure due to crescentic glomerulonephritis who presented initially with culture-negative endocarditis with vegetations on the aortic valve. Anti-nuclear and anti-phospholipid antibodies were positive with initially negative anti-neutrophil cytoplasmic antibodies (ANCAs). Kidney biopsy revealed severe acute crescentic glomerulonephritis with mesangial immune complex deposition. PR3-ANCA subsequently become positive, and the patient developed worsening kidney failure requiring hemodialysis. This case illustrates that Bartonella can present as culture-negative endocarditis with severe crescentic glomerulonephritis with positive PR-3 ANCAs and can mimic ANCA-associated crescentic glomerulonephritis.

Outcome of Dialysis-Requiring Acute Kidney Injury in Patients With Infective Endocarditis: A Nationwide Study

BACKGROUND

Infective endocarditis (IE) may be complicated by acute kidney injury, yet data on the use of dialysis and subsequent reversibility are sparse.

METHODS

Using Danish nationwide registries, we identified patients with first-time IE from 2000 to 2017. Dialysis-naïve patients were grouped into: those with and those without dialysis during admission with IE. Continuation of dialysis was followed 1 year postdischarge. Multivariable adjusted Cox proportional hazard analysis was used to examine 1-year mortality for patients surviving IE according to use of dialysis.

RESULTS

We included 7307 patients with IE; 416 patients (5.7%) initiated dialysis treatment during admission with IE and these were younger, had more comorbidities and more often underwent cardiac valve surgery compared with nondialysis patients (47.4% vs 20.9%). In patients with both cardiac valve surgery and dialysis treatment (n = 197), 153 (77.7%) initiated dialysis on or after the date of surgery. The in-hospital mortality was 40.4% and 19.0% for patients with and without dialysis, respectively (P < .0001). Of those who started dialysis and survived hospitalization, 21.6% continued dialysis treatment within 1 year after discharge. In multivariable adjusted analysis, dialysis during admission with IE was associated with an increased 1-year mortality from IE discharge, hazard ratio = 1.64 (95% confidence interval, 1.21-2.23).

CONCLUSION

In dialysis-naïve patients with IE, approximately 1 in 20 patients initiated dialysis treatment during admission with IE. Dialysis identified a high-risk group with an in-hospital mortality of 40% and an approximate 20% risk of continued dialysis. Those with dialysis during admission with IE showed worse long-term outcomes than those without.

Infection-Related Glomerulonephritis

Background

There has been a long, storied relationship between various bacterial infections and glomerular injury, which is now encompassed under the term of infection-related glomerulonephritis (GN). The clinical and pathologic manifestations vary depending on the duration, magnitude, and underlying pathogen associated with the inciting infectious process. A brief and acute episode may lead to a self-limiting glomerular manifestation while a chronic or repetitive infection can result in persistent and irreversible injury. In this review, we will discuss the clinical and pathologic findings associated with the infection-related glomerulonephritides.

Summary

An acute exudative GN with an influx of neutrophils is the most characteristic morphologic alteration associated with infection-related glomerular injury. The immunofluorescence staining pattern often reveals prominent complement component C3 deposition in both capillary walls and mesangial regions with or without accompanying immunoglobulin. Large subepithelial electron-dense deposits known as "humps" are the hallmark ultrastructural finding; however, these features can also be present in C3 glomerulopathies, which are often triggered by infections and may have similar underlying abnormalities in alternative pathway complement activation. In addition, other glomerular injuries can simultaneously be present along with infection-related GN, such as diabetic nephropathy, lupus nephritis, or immunoglobulin A nephropathy, constituting a true diagnostic challenge for the pathologist.

Key Messages

Bacterial infection-related GN represents a spectrum of glomerular injury with variable clinical and pathologic presentations. The pathologic findings can show overlap with other glomerular diseases, and different forms of infection-related GN vary in terms of prognosis and treatment approach.

Crescentic postinfectious glomerulonephritis in an adult patient with juvenile nasopharyngeal angiofibroma

Crescentic glomerulonephritis is usually associated with an acute nephritic syndrome with rapidly declining renal function. Postinfectious cases usually have a higher possibility of recovery. Juvenile nasopharyngeal angiofibroma (JNA) is a rare, locally aggressive tumour affecting mostly young men. A 28-year-old man presented with recurrent JNA initially excised 2 years prior. The patient was initially managed as a case of airway obstruction and pneumonia. He developed tea-coloured urine, oedema and acute kidney failure requiring dialysis while awaiting surgery. Urine and immunological studies (low C3, negative antineutrophil cytoplasmic antibody and antinucleosomal antibody and high antistreptolysin O) suggested a nephritic aetiology. Nasopharyngeal swab cultures of the mass revealed gram-negative organisms. Kidney biopsy showed diffuse proliferative glomerulonephritis compatible with a postinfectious glomerulonephritis with 77% cellular crescents. The mass was excised with histopathology consistent with JNA. The patient was eventually discharged off dialysis.

Clinical Implications of Steroid Therapy for Crescentic Glomerulonephritis and Gemella morbillorum-associated Infective Endocarditis

A 54-year-old man was admitted to our institute with a diagnosis of infective endocarditis (IE) with vegetation on the mitral valve and severe regurgitation due to Gemella morbillorum infection together with renal dysfunction, which was eventually diagnosed as infection-related pauci-immune necrotizing crescentic glomerulonephritis. Given the refractoriness to antibiotics, the persistent activity of nephritis, and repeated cerebral hemorrhaging, we prioritized steroid therapy over early surgical mitral valve replacement. Following steroid therapy, the glomerulonephritis completely improved. Although the administration of steroid therapy in the active phase of IE remains controversial, it might be indicated if comorbid glomerulonephritis is critical.

The clinical features of overlap syndrome (ANCA-associated crescentic glomerulonephritis [AACGN] and immune complex-mediated glomerulonephritis) are similar to those of AACGN alone

The overlap syndromes of anti-neutrophil cytoplasmic antibodies (ANCA)-associated crescentic glomerulonephritis (AACGN) and variants of immune complex medicated glomerulopathy (ICMGN) have been reported. But very few have compared AACGN alone with the overlap syndromes (AACGN plus ICMGN). The aim of this retrospective study was to make that comparison, following serum creatinine (sCr) to determine whether the two groups (AACGN-only group versus overlap group) would behave differently over time. We identified 14 cases with dual diagnoses of AACGN and various ICMGN in the overlap group. Data were collected and compared with 15 randomly selected AACGN-only cases over the similar period of time. The overlap syndrome represented 0.35% of our overall biopsies (14/4049). All 14 patients were ANCA positive and had crescentic formation. The percentage of crescents in the biopsies ranged from 10 to 78%. ICMGN included the following: membranoproliferative glomerulonephritis, post-infectious glomerulonephritis, membranous glomerulopathies, idiopathic mesangial proliferative glomerulonephritis, lupus nephritis, and IgA nephropathy. With the exception one biopsy revealing lupus nephritis class III, most of the ICMGN were mild. When compared to the AACGN-only group, there were no significant differences in clinical and histologic indices including age, percent of crescents, and sCr (on biopsy days, and over the follow-up periods), although the numbers of follow-up cases were limited over time. Our findings suggest that AACGN was the dominant disease process in the majority of overlap syndromes between AACGN and ICMGN, similar to the clinical processes of AACGN-only disease, therefore, the AACGN in overlap syndrome cases should be the main target for clinical management.

Status Quo of Diagnostic Procedures and Treatment of Inpatients with Infective Endocarditis at the Department of General Medicine at a University Hospital in a Suburban City in Japan: A Single-Hospital-Based Retrospective Study

Background

Our hospital’s department of general medicine is often involved in the diagnosis and treatment of diseases that are considered by other hospitals or other departments in our hospital to be difficult to diagnose correctly.

Objective

The aim of this study was to clarify how patients with infective endocarditis (IE) being admitted to our hospital’s department of general medicine were examined and treated and to elucidate their prognosis compared with patients admitted to other departments.

Materials and Methods

Inpatients of Saga University Hospital with definite IE from September 2007 to August 2017 were divided into 2 groups: those admitted to the general medicine department (the GM group) and those admitted to other departments (the non-GM group).

Results

Seventy-four patients were included; 17 (23%) were admitted to the general medicine department. In the GM group, the percentage of patients diagnosed with definite or suspected IE was lower (0% vs 32%, p=0.008), as was the rate of patients with echocardiographic findings that fulfilled the major modified Duke’s criteria (71% vs 98%, p≤0.001), preadmission. The GM group had higher percentages of patients with back or joint pain (41% vs 9%, p=0.001) and complications, including pyogenic spondylitis (35% vs 2%, p≤0.001), deep-seated abscesses (24% vs 5%, p=0.024), pyogenic arthritis (18% vs 0%, p=0.001), and glomerulonephritis (77% vs 37%, p=0.004) than did the non-GM group. Mortality within 30 days of admission to our hospital (12% vs 14%, p=0.753) and overall in-hospital mortality (12% vs 18%, p=0.570) did not significantly differ.

Conclusion

The general medicine department could have accurately diagnosed IE, given appropriate treatments, and obtained similar prognoses to those of IE patients treated by other departments, including cardiology and cardiovascular surgery, even in patients for whom diagnosing IE was more difficult or who had less typical echocardiographic findings preadmission.

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.

Risk factors and outcomes of early acute kidney injury in infective endocarditis: A retrospective cohort study

OBJECTIVES

The incidence of acute kidney injury (AKI) in infective endocarditis (IE), its risk factors and consequences on patient and renal survival remain debated.

METHODS

Patients hospitalized for a first episode of IE (possible or definite according to modified Duke criteria) between 2013 and 2016 were included. The primary endpoint was to determine risk factors for early AKI (E-AKI) during the first week of management of IE.

RESULTS

A total of 276 patients were included: 220 (79.7%) had definite IE and 56 (20.3%) had possible IE. E-AKI occurred in 150 patients (53%). IE due to Staphylococcus aureus (OR 3.41; 95% CI 1.83-6.39; p<0.01), history of diabetes (OR 2.34; 95% CI 1.25-4.37; p<0.01), peripheral arterial disease (OR 2.59; 95% CI 1.07-6.23; p<0.05), immunological manifestations (OR 3.11; 95% CI 1.31-7.39; p=0.01), and use of norepinephrine (OR 3.44; 95% CI 1.72-7.02; p<0.01) were associated with E-AKI. In subgroup analysis, infectious disease consultation was associated with a lower risk of AKI at day 7 (OR 0.41; 95% CI 0.16-0.88; p=0.04). E-AKI was associated with 1-year mortality (OR 1.65; 95% CI 1.03-2.64; p=0.04) and chronic kidney disease progression (OR 2.23; 95% CI 1.30-3.82; p<0.01).

CONCLUSIONS

E-AKI is common in IE and often associated with non-modifiable variables. Multidisciplinary management should be mandatory, and awareness of AKI diagnosis and etiological explorations should be raised.

Infective endocarditis mimicking ANCA-associated vasculitis: does it require immunosuppressive therapy?: A case report and literature review

RATIONALE

In the course of endocarditis, the development of antineutrophil cytoplasmic antibody (ANCA)-mediated disease introduces the dilemma of determining the best treatment approach for immune conditions, whether immunosuppressant therapy should be added to antibiotic treatment has remained controversial.

PATIENT CONCERNS

A 33-year-old man presented with progressive fever lasting for 7 months, and swelling, pain, and purpura in the arms and legs. The patient showed multiple autoantibodies including cytoplasmic ANCA, antiproteinase 3, rheumatoid factor, and anti-beta 2 glycoprotein I. Blood culture was positive for viridans streptococcus, and renal biopsy revealed glomerulonephritis and interstitial nephritis.

DIAGNOSIS

Endocarditis caused by viridans streptococci, ANCA-associated vasculitis, and congenital ventricular septal defect.

INTERVENTIONS

In addition to effective antibiotics, he also received twice intravenous corticosteroids and intravenous immunoglobulin therapy, and a low dose of cyclophosphamide. At last, the patient received congenital ventricular septal defect repair and debridement.

OUTCOMES

The abnormal clinical manifestations, including renal failure and loss of strength, recovered rapidly with corticosteroid therapy in addition to antibiotic treatment. After 6 months without any medications, he remained asymptomatic and was able to live normally.

LESSONS

In this case with endocarditis and ANCA-associated vasculitis, we highlighted the importance of biopsy and immunosuppressive therapy. Histopathologic examination is required for diagnosis and treatment in such case. Identifying patients who have endocarditis and ANCA positivity with vasculitis pathologic features will require corticosteroid/immunosuppressives in addition to the antibiotics therapy.

Antineutrophil cytoplasmic antibodies (ANCA)-positive patient with infective endocarditis and chronic hepatitis B virus: a case report and review of the literature

Background

Antineutrophil cytoplasmic antibodies comprise a family of autoantibodies that are often used as biomarkers for certain forms of small-vessel vasculitis; however, chronic infections tend to induce the production of antineutrophil cytoplasmic antibodies. Infective endocarditis and hepatitis B virus infection have been reported to exhibit antineutrophil cytoplasmic antibody positivity and to mimic antineutrophil cytoplasmic antibody–associated vasculitis, which may lead to misdiagnosis and inappropriate treatment.

Case presentation

We report a case of a 46-year-old Han Chinese man with untreated chronic hepatitis B virus infection who featured proteinase-3 antineutrophil cytoplasmic antibody positivity while hospitalized with infective endocarditis. Cardiac ultrasound echocardiography disclosed mitral and aortic regurgitation with vegetation. On the 15th hospital day, the patient underwent mitral and aortic valve replacement and was then treated with antibiotics for more than 1 month. On the 57th hospital day, the patient was discharged. His urinary abnormalities and renal function were gradually recovering. Four months after being discharged, his proteinase-3 antineutrophil cytoplasmic antibody levels had returned to the normal range.

Conclusions

The findings in this study update and expand current understanding of antineutrophil cytoplasmic antibody positivity in patients with both infective endocarditis and hepatitis B virus. Treatment (including surgery, antibiotics, corticosteroids and/or cyclophosphamide, antiviral agents, and even plasma exchange) is challenging when several diseases are combined. Renal biopsy is suggested if the patient’s condition allows. Antineutrophil cytoplasmic antibody testing should be repeated after therapy, because some cases might require more aggressive treatment.

Exploring the putative interactions between chronic kidney disease and chronic periodontitis

Chronic kidney disease (CKD) and chronic periodontitis (CP) are both common diseases, which are found disproportionately comorbid with each other and have been reported to have a detrimental effect on the progression of each respective disease. They have an overlap in risk factors and both are a source of systemic inflammation along with a wide selection of immunological and non-specific effects that can affect the body over the lifespan of the conditions. Previous studies have investigated the directionality of the relationship between these two diseases; however, there is a lack of literature that has examined how these diseases may be interacting at the localized and systemic level. This review discusses how oral microorganisms have the ability to translocate and have distal effects and provides evidence for microbial involvement in a systemic disease. Furthermore, it summarizes the reported local and systemic effects of CKD and CP and discusses how the interaction of these effects may be responsible for directionality associations reported.

Double-Valve Heart Disease and Glomerulonephritis Consequent to Abiotrophia defectiva Endocarditis

Abiotrophia defectiva, a nutritionally deficient streptococcus, is a rare cause of infective endocarditis. It has been associated with hemophagocytic syndrome. We present the first case of A. defectiva infective endocarditis that led to antineutrophil cytoplasmic antibody-associated glomerulonephritis. The patient was a 55-year-old man whose endocarditis affected the mitral and aortic valves. His course was complicated by atrial fibrillation, stroke, and glomerulonephritis. He was successfully treated with antibiotics and dual valve replacement.

Clinical Status Quo of Infective Endocarditis in a University Hospital in Japan: A Single-hospital-based Retrospective Cohort Study

Objective No research on infective endocarditis (IE) concerning populations of more than 40 patients from all departments of the hospitals they may have visited in Japan has been conducted since 2000. The present study clarified the status quo of IE in a university hospital in Japan. Methods Data of inpatients of Saga University Hospital with definite IE from September 2007 to August 2017 were retrospectively analyzed. Patients Records of inpatients with diagnosed IE admitted to any department were scrutinized; those with "definite IE" according to the modified Duke's criteria comprised the study cohort. Results The study cohort was 74 patients with a median age 66.5 years old. Symptoms within 2 months before the first visit to our hospital included a fever (73.0%), general malaise (33.8%), disturbance of consciousness (24.3%), and dyspnea (24.3%). High-frequency causative microorganisms were Staphylococcus aureus (28.4%), followed by Streptococcus viridans (18.9%) and Enterococcus spp. (6.8%). The most frequently involved valves were the mitral valve (48.6%), followed by the aortic valve (25.7%) and multiple valves (14.9%). Patients without cardiac murmurs accounted for 37.8%, and those without or with only mild valvular disease accounted for 32.4%. The incidence of complications was 93.2%, and high-frequency complications were central nervous system disorder (60.8%), followed by glomerulonephritis (45.9%) and extracranial embolism (36.5%). Conclusion The incidences of IE without cardiac murmurs and IE without or with only minor valvular disease were higher than those values previously reported in 2000 in Japan. When IE is suspected clinically, clinicians must check thoroughly for common complications, even in patients without cardiac murmurs or valvular disease.

Epidemiology, pathogenesis, treatment and outcomes of infection-associated glomerulonephritis

For over a century, acute 'post-streptococcal glomerulonephritis' (APSGN) was the prototypical form of bacterial infection-associated glomerulonephritis, typically occurring after resolution of infection and a distinct infection-free latent period. Other less common forms of infection-associated glomerulonephritides resulted from persistent bacteraemia in association with subacute bacterial endocarditis and shunt nephritis. However, a major paradigm shift in the epidemiology and bacteriology of infection-associated glomerulonephritides has occurred over the past few decades. The incidence of APSGN has sharply declined in the Western world, whereas the number of Staphylococcus infection-associated glomerulonephritis (SAGN) cases increased owing to a surge in drug-resistant Staphylococcus aureus infections, both in the hospital and community settings. These Staphylococcus infections range from superficial skin infections to deep-seated invasive infections such as endocarditis, which is on the rise among young adults owing to the ongoing intravenous drug use epidemic. SAGN is markedly different from APSGN in terms of its demographic profile, temporal association with active infection and disease outcomes. The diagnosis and management of SAGN is challenging because of the lack of unique histological features, the frequently occult nature of the underlying infection and the older age and co-morbidities in the affected patients. The emergence of multi-drug-resistant bacterial strains further complicates patient treatment.

Incidence and Cost of Acute Kidney Injury in Hospitalized Patients with Infective Endocarditis

Acute kidney injury (AKI) is a frequent complication of hospitalized patients with infective endocarditis (IE). Further, AKI in the setting of IE is associated with high morbidity and mortality. We aimed to examine the incidence, clinical parameters, and hospital costs associated with AKI in hospitalized patients with IE in an endemic area with an increasing prevalence of opioid use. This retrospective cohort study included 269 patients admitted to a major referral center in Kentucky with a primary diagnosis of IE from January 2013 to December 2015. Of these, 178 (66.2%) patients had AKI by Kidney Disease Improving Global Outcomes (KDIGO) serum creatinine criteria: 74 (41.6%) had AKI stage 1 and 104 (58.4%) had AKI stage ≥2. In multivariable analysis, higher comorbidity scores and the need for diuretics were independently associated with AKI, while the involvement of the tricuspid valve and the need for vasopressor/inotrope support were independently associated with severe AKI (stage ≥2). The median total direct cost of hospitalization was progressively higher according to each stage of AKI ($17,069 for no AKI; $37,111 for AKI stage 1; and $61,357 for AKI stage ≥2; p < 0.001). In conclusion, two-thirds of patients admitted to the hospital due to IE had incident AKI. The occurrence of AKI significantly increased healthcare costs. The higher level of comorbidity, the affection of the tricuspid valve, and the need for diuretics and/or vasoactive drugs were associated with severe AKI in this susceptible population.

Acute kidney injury in infective endocarditis: A retrospective analysis

BACKGROUND

Acute kidney injury (AKI) is associated with high case fatality in infective endocarditis (IE), but epidemiological data on the frequency of AKI during IE is scarce. We aimed to describe the frequency and risk factors for AKI during the course of IE using Kidney Disease: Improving Global Outcomes consensual criteria.

METHODS

Using the French hospital discharge database (French acronym PMSI), we retrospectively reviewed the charts of 112 patients presenting with a first episode of probable or definite IE between January 2010 and May 2015.

RESULTS

Seventy-seven patients (68.8%) developed AKI. In univariate analysis, risk factors for AKI were cardiac surgery for IE (n=29, 37.7% vs. n=4, 1.4%, P<0.0005), cardiac failure (n=29, 36.7% vs. n=1, 2.9%, P<0.0005), diabetes mellitus (n=14, 18.2% vs. n=1, 0.9%, P=0.034), and prosthetic valve IEs (n=24, 31.2% vs. n=4, 11.4%). No differences were observed for gentamicin exposure (n=57, 64% vs. n=32, 86.5%, P=0.286). Prosthetic valve IE, cardiac failure, and vancomycin exposure were independently associated with AKI with respective odds ratio of 5.49 (95% CI 1.92-17.9), 4.37 (95% CI 4.37-465.7), and 1.084 (1.084-16.2). Mean length of hospital stay was significantly longer in patients presenting with AKI than in controls (respectively 52.4±22.1 days vs. 39.6±12.6, P<0.005).

CONCLUSION

AKI is very frequent during IE, particularly in patients with prosthetic valve IE, cardiac failure, and those receiving vancomycin.

Plasmapheresis and corticosteroids in infective endocarditis-related crescentic glomerulonephritis

Infective endocarditis (IE)-related glomerulonephritis (GN) typically resolves with the treatment of IE. A 59-year-old woman with a baseline creatinine of 0.7 mg/dL presented with rash on her legs, night sweats and weight loss for 3 weeks. Further evaluation revealed IE. Her blood cultures grew gamma-haemolytic streptococcus, which subsequently cleared on appropriate antibiotic therapy. Her creatinine, however, progressively worsened requiring haemodialysis. Kidney biopsy showed immune complex-mediated necrotising and crescentic GN. She was started on plasmapheresis (PE) and high-dose steroids with rapid taper, with subsequent improvement in her creatinine to 0.8 mg/dL. She subsequently had aortic valve replacement and ventricular septal defect closure. She did not improve as expected with antibiotic therapy but turned around dramatically with steroids and PE. Our case supports the possible beneficial role of PE and steroids in IE-related crescentic GN that worsens despite appropriate antibiotic therapy, although the risks of immunosuppression and aggravating endocarditis need to be considered.

Plasmapheresis for treatment of immune complex-mediated glomerulonephritis in infective endocarditis: a case report and literature review

We report the case of a 57-year-old man who presented with subacute bacterial endocarditis secondary to Streptococcus mutans complicated by biopsy-proven immune complex-mediated glomerulonephritis (ICGN). Despite initial treatment with antibiotics and a short course of corticosteroids, the kidney function further deteriorated, and plasmapheresis was introduced as third-line therapy to remove circulating immune complexes. Following 7 treatment sessions, the patient recovered kidney function. We discuss the potential merit of plasmapheresis for patients with subacute bacterial endocarditis who develop ICGN.

Successful treatment of acute renal failure secondary to complicated infective endocarditis by peritoneal dialysis: a case report

BACKGROUND

Infective endocarditis is one of the most common infections among intravenous drug addicts. Its complications can affect many systems, and these can include acute renal failure. There is a scarcity of cases in the literature related to acute renal failure secondary to infective endocarditis treated with peritoneal dialysis. In this paper, the case of a 48-year-old Saudi male is reported, who presented with features suggestive of infective endocarditis and who developed acute kidney injury that was treated successfully with high tidal volume automated peritoneal dialysis. To our knowledge, this is the second report of such an association in the literature.

CASE PRESENTATION

A 48-year-old Saudi gentleman diagnosed to have a glucose-6-phosphate dehydrogenase deficiency and hepatitis C infection for the last 9 years, presented to the emergency department with a history of fever of 2 days' duration. On examination: his temperature = 41 °C, there was clubbing of the fingers bilaterally and a pansystolic murmur in the left parasternal area. The results of the blood cultures and echocardiogram were supportive of the diagnosis of infective endocarditis, and the patient subsequently developed acute kidney injury, and his creatinine reached 5.2 mg/dl, a level for which dialysis is essential for the patient to survive.

CONCLUSION

High tidal volume automated peritoneal dialysis is highly effective as a renal replacement therapy in acute renal failure secondary to infective endocarditis if no contraindication is present.

Severe acute kidney injury in children owing to infective endocarditis-associated immune complex glomerulonephritis: a report of two cases

Renal involvement in infective endocarditis (IE) may manifest with different clinical patterns, including diffuse proliferative glomerulonephritis and crescentic glomerulonephritis, which may lead to haematuria and/or proteinuria. However, severe acute kidney injury (AKI) in such cases is extremely uncommon and is reported mostly in adults. Two children with rheumatic heart disease and a peri-membranous ventricular septal defect, respectively, who developed haematuria, proteinuria and severe AKI in association with IE are reported. The first case had diffuse proliferative glomerulonephritis with 10% cellular crescents, and made a complete renal recovery with antibiotics and intravenous methylprednisolone followed by oral prednisolone. However, the second case had severe crescentic glomerulonephritis which led to residual renal injury despite intravenous methylprednisolone and cyclophosphamide in combination with antibiotics. The cases illustrate that crescentic glomerulonephritis or severe diffuse proliferative glomerulonephritis should be considered as possible complications in children presenting with haematuria, proteinuria and severe AKI. Renal biopsy along with antibiotic therapy and prompt immunosuppressive therapy should be considered for the management of this potentially life-threatening condition.

ANCA-associated pauci-immune glomerulonephritis in a patient with bacterial endocarditis: a challenging clinical dilemma

Purpose: We report the case of a 59-year-old man with chronic hepatitis B and C infection presenting with acute kidney injury and enterococcus faecalis-infective endocarditis (IE). An elevated proteinase-3 (PR3)-ANCA and pauci-immune glomerulonephritis (GN) on renal biopsy were discovered, corresponding to ANCA-mediated GN. We conducted a literature review to assess the role of ANCA in IE and treatment implications. Methods: On systematic review of the literature, we found five previous cases whereby IE caused by streptococcus and bartonella species were related to ANCA vasculitis-associated GN. Results: Most reports of IE-related GN are mediated by immune complex deposition and resolve following microbial clearance. Of the 5 cases of ANCA GN in the setting of IE, all had markedly elevated levels of PR3-ANCA with either a subacute or chronic course of infection. Patients were treated with a combination of steroids and cyclophosphamide (2/5), steroids and antibiotics alone (1/5), or with valvular replacement (2/5). Renal function was recovered in 4/5 patients. Conclusion: Infection is a major etiologic player in the formation of ANCA; however, the role of PR3-ANCA in IE remains unclear. Kidney biopsy is essential in differentiating IE-related GN due to infection and immune complex deposition versus ANCA-associated vasculitis. A paucity of reports on the development of GN in IE-associated ANCA vasculitis exists, highlighting the rarity of our case and lack of clear therapeutic strategies in a patient with active infection requiring immunosuppression. In this case, the patient’s chronic hepatitis B and C coinfection presented a unique challenge.

Aetiology of renal failure in patients with infective endocarditis. The role of antibiotics

BACKGROUND AND OBJECTIVES

The possible renal toxicity of certain antibiotics (AB) is well known. The objective of our work is to know the possible effect of AB treatments in the development of renal failure (RF) in patients with infective endocarditis (IE).

MATERIAL AND METHOD

Collection from a national multi-centre registry of collection on renal function, both prior and its impairment, if any, during the treatment of IE and in relation to possible causative factors, including the use of AB.

RESULTS

Between 2008 and 2012, 1,853 episodes of IE reported from 26 Spanish centres were analysed. Of these, 21.6% had prior RF. They developed new RF or impairment of renal function in 38.7% of the cases. In patients with prior RF, impairment was more frequent (64 vs. 31.7%, P<.001). Overall, patients with RF were older (70.6 vs. 67 years, P<.01), had more comorbidities (Charlson index 5 vs. 4, P<.01), and IE by Staphylococcus aureus (32.1 vs. 16.5%, P<.01). Potentially nephrotoxic AB use was only associated with RF in patients without prior RF (aminoglycosides: OR=1.47 [95% CI 1.096-1.988], P=.010; aminoglycosides with vancomycin: OR=1.49 [95% CI 1.069-2.09], P=.019).

CONCLUSIONS

In patients without prior RF, the use of nephrotoxic AB is associated with impairment of renal function. In patients with RF prior to the IE episode, impairment of renal function was more frequent but appears to be more related to the severity of infection.

Risk factors for acute kidney injury associated with the treatment of bacterial endocarditis at a tertiary academic medical center

BACKGROUND

Acute kidney injury (AKI) is a common complication of endocarditis.

OBJECTIVE

To determine risk factors for the development of AKI in patients treated for endocarditis.

METHODS

This single centre, retrospective univariate and multivariate analysis to determine risk factors for the development of AKI included patients diagnosed with endocarditis between January 2009 and October 2013.

RESULTS

Of 211 included patients, a total of 84 (39.8%) patients developed AKI. We identified multiple independent variables associated with the development of AKI, including: age ≥ 65 years, presence of hardware, chronic kidney disease, AKI on admission, infection with Staphylococcus spp, receipt of nafcillin or oxacillin or aminoglycoside and nafcillin or oxacillin or aminoglycoside and vancomycin, vancomycin trough level ≥ 20.0 mcg/ml, aminoglycoside total daily dose reduction, duration of vancomycin exceeding three days, receipt of loop diuretic or more than three concomitant nephrotoxins and duration of loop diuretic or non-steroidal anti-inflammatory drug therapy exceeding seven days.

CONCLUSIONS

In patients treated for endocarditis, multiple risk factors for AKI were identified. Prospective studies are needed to evaluate these variables for causation of AKI in patients treated for endocarditis.

A wolf in another wolf's clothing

This case of infective endocarditis masquerading as mixed cryoglobulinemia in a man with a history of intravenous drug use (IVDU) and hepatitis C virus (HCV) highlights the importance of maintaining a broad differential and continually re-evaluating the working diagnosis as new information presents itself. The patient presented to an outside hospital and was treated for presumptive mixed cryoglobulinemia with corticosteroid therapy. When the patient did not improve, he was transferred to a tertiary care center for possible Rituximab and/or plasmapheresis. Further investigation revealed Enterococcus bacteremia with subsequent workup consistent with infective endocarditis (IE). This case highlights a diagnostic dilemma and demonstrates the importance of a thorough evaluation as it pertains to overlapping features of IE and mixed cryoglobulinemia.

Bartonella Endocarditis and Pauci-Immune Glomerulonephritis: A Case Report and Review of the Literature

Among culture-negative endocarditis in the United States, Bartonella species are the most common cause, with Bartonella henselae and Bartonella quintana comprising the majority of cases. Kidney manifestations, particularly glomerulonephritis, are common sequelae of infectious endocarditis, with nearly half of all Bartonella patients demonstrating renal involvement. Although a pauci-immune pattern is a frequent finding in infectious endocarditis-associated glomerulonephritis, it is rarely reported in Bartonella endocarditis. Anti-neutrophil cytoplasmic antibody (ANCA) positivity can be seen with many pathogens causing endocarditis and has been previously reported with Bartonella species. In addition, ANCA-associated vasculitis can also present with renal and cardiac involvement, including noninfectious valvular vegetations and pauci-immune glomerulonephritis. Given the overlap in their clinical presentation, it is difficult to differentiate between Bartonella endocarditis and ANCA-associated vasculitis but imperative to do so to guide management decisions. We present a case of ANCA-positive Bartonella endocarditis with associated pauci-immune glomerulonephritis that was successfully treated with medical management alone.

Antineutrophil Cytoplasmic Antibody Induction due to Infection: A Patient with Infective Endocarditis and Chronic Hepatitis C

While antineutrophil cytoplasmic antibody (ANCA) is often used as a diagnostic marker for certain vasculitides, ANCA induction in the setting of infection is much less common. In the case of infective endocarditis, patients may present with multisystem disturbances resembling an autoimmune process, cases that may be rendered even trickier to diagnose in the face of a positive ANCA. Though not always straightforward, distinguishing an infective from an inflammatory process is pivotal in order to guide appropriate therapy. We describe an encounter with a 43-year-old male with chronically untreated hepatitis C virus infection who featured ANCA positivity while hospitalized with acute bacterial endocarditis. His case serves as a reminder of two of the few infections known to uncommonly generate ANCA positivity. We also summarize previously reported cases of ANCA positivity in the context of endocarditis and hepatitis C infections.

Infectious Diseases and the Kidney in Children

The kidney is involved in a wide range of bacterial, viral, fungal, and parasitic diseases. In most systemic infections, renal involvement is a minor component of the illness, but in some, renal failure may be the presenting feature and the major problem in management. Although individual infectious processes may have a predilection to involve the renal vasculature, glomeruli, interstitium, or collecting systems, a purely anatomic approach to the classification of infectious diseases affecting the kidney is rarely helpful because most infections may involve several different aspects of renal function. In this chapter, a microbiological classification of the organisms affecting the kidney is adopted. Although they are important causes of renal dysfunction in infectious diseases, urinary tract infections and hemolytic uremic syndrome (HUS) are not discussed in detail because they are considered separately in chapters XX and XX, respectively.

Necrotizing ANCA-Positive Glomerulonephritis Secondary to Culture-Negative Endocarditis

Infective endocarditis (IE) and small-vessel vasculitis may have similar clinical features, including glomerulonephritis. Furthermore the association between IE and ANCA positivity is well documented, making differential diagnosis between IE- and ANCA-associated vasculitis particularly difficult, especially in case of culture-negative IE. We report on one patient with glomerulonephritis secondary to culture-negative IE caused by Bartonella henselae which illustrates this diagnostic difficulty.

CIED infection with either pocket or systemic infection presentation--complete device removal and long-term antibiotic treatment; long-term outcome

OBJECTIVE

Cardiovascular implantable electronic device (CIED) infections are increasing in numbers. The objective was to review the clinical presentation and outcome in patients affected with CIED infections with either local pocket or systemic presentation.

DESIGN

All device removals due to CIED infection during the period from 2005 to 2012 were retrospectively reviewed. CIED infections were categorized as systemic or pocket infections. Treatment included complete removal of the device, followed by antibiotic treatment of six weeks.

RESULTS

Seventy-one device removals due to infection (32 systemic and 39 pocket infections) were recorded during the study period. Median follow-up time was 26 (IQR 9-41) months, 30 day and 12 month mortality were 4% and 14%, respectively. There was no long-term difference in mortality between patients with pocket vs. systemic infection (p = 0.48). During follow-up no relapses and two cases of new infections were noted (2.8%).

CONCLUSIONS

CIED infection with systemic or pocket infection was difficult to distinguish in clinical presentation and outcome. Complete device removal and antibiotic treatment of long duration was safe and without relapses.

Update on endocarditis-associated glomerulonephritis

Glomerulonephritis (GN) due to infective endocarditis (IE) is well documented, but most available data are based on old autopsy series. To update information, we now present the largest biopsy-based clinicopathologic series on IE-associated GN. The study group included 49 patients (male-to-female ratio of 3.5:1) with a mean age of 48 years. The most common presenting feature was acute kidney injury. Over half of the patients had no known prior cardiac abnormality. However, the most common comorbidities were cardiac valve disease (30%), intravenous drug use (29%), hepatitis C (20%), and diabetes (18%). The cardiac valve infected was tricuspid in 43%, mitral in 33%, and aortic in 29% of patients. The two most common infective bacteria were Staphylococcus (53%) and Streptococcus (23%). Hypocomplementemia was found in 56% of patients tested and ANCA antibody in 28%. The most common biopsy finding was necrotizing and crescentic GN (53%), followed by endocapillary proliferative GN (37%). C3 deposition was prominent in all cases, whereas IgG deposition was seen in <30% of cases. Most patients had immune deposits detectable by electron microscopy. Thus, IE-associated GN most commonly presents with AKI and complicates staphylococcal tricuspid valve infection. Contrary to infection-associated glomerulonephritis in general, the most common pattern of glomerular injury in IE-associated glomerulonephritis was necrotizing and crescentic glomerulonephritis.

Infective Endocarditis Presenting as Acute Renal Failure and Unusual Complications

Infective endocarditis can be a diagnostic challenge. Few cases have so far reported infective endocarditis presenting as renal failure. Pseudoaneurysms of the mitral-aortic intervalvular fibrosa and splenic abscess are rare complications of infective endocarditis. We herein report a case of an 80-year-old man admitted due to anorexia, malaise, edema of the legs and renal failure. A progressive degradation of the patient's renal function was documented and hemodialysis was started. Blood cultures revealed the presence of Enterococcus faecalis, and the patient was treated with ampicillin and gentamicin. The transesophageal echocardiogram findings showed pseudoaneurysms of the mitral-aortic intervalvular fibrosa and in the aortic root wall. Due to abdominal pain, an abdominal CT scan was performed and showed a cystic lesion compatible with splenic abscess. The patient received 6 weeks of antibiotic treatment. There was progressive clinical improvement and regression of the splenic abscess, but no recovery of the renal function. This report illustrates an unusual clinical presentation of infective endocarditis with unusual complications that were successfully treated with antibiotics.

Successful treatment of infectious endocarditis associated glomerulonephritis mimicking c3 glomerulonephritis in a case with no previous cardiac disease

We report a 42-year-old man with subacute infectious endocarditis (IE) with septic pulmonary embolism, presenting rapidly progressive glomerulonephritis and positive proteinase 3-anti-neutrophil cytoplasmic antibody (PR3-ANCA). He had no previous history of heart disease. Renal histology revealed diffuse endocapillary proliferative glomerulonephritis with complement 3- (C3-) dominant staining and subendothelial electron dense deposit, mimicking C3 glomerulonephritis. Successful treatment of IE with valve plastic surgery gradually ameliorated hypocomplementemia and renal failure; thus C3 glomerulonephritis-like lesion in this case was classified as postinfectious glomerulonephritis. IE associated glomerulonephritis is relatively rare, especially in cases with no previous history of valvular disease of the heart like our case. This case also reemphasizes the broad differential diagnosis of renal involvement in IE.

Outcome of Patients with Infective Endocarditis who were Treated with Extracorporeal Membrane Oxygenation and Continuous Renal Replacement Therapy

Infective endocarditis is a potentially life threatening condition. It is associated with high mortality and morbidity resulting mostly due to cardiorespiratory failure. Extracorporeal membrane oxygenation is a modality of treatment used to support hypoxic respiratory failure especially in patients who are already on mechanical ventilation. Continuous renal replacement therapy is added mainly for maintaining fluid and electrolyte balance. Here we report a case series of patients diagnosed with infective endocarditis who were treated with combined extracorporeal membrane oxygenation and continuous renal replacement therapy. Three patients in the age group 20-60 years were admitted with clinical features suggestive of infective endocarditis. During the course of hospital stay they developed cardiorespiratory failure requiring mechanical ventilation and extracorporeal membrane oxygenation support for refractory hypoxia. It was complicated by heart failure, renal failure and fluid overload which required initiation of continuous renal replacement therapy. All the three patients succumbed in spite of the aggressive treatment. In addition to the role played by each complication, delayed start of continuous renal replacement therapy might have also contributed to the high mortality. Early initiation of continuous renal replacement therapy for management of fluid overload needs to be considered in the management of these critically ill patients.