The role of complement, immunoglobulin and bacterial antigen in coagulase-negative staphylococcal shunt nephritis

Phenome-wide association study identifies new clinical phenotypes associated with Staphylococcus aureus infections

BACKGROUND

Phenome-Wide Association study (PheWAS) is a powerful tool designed to systematically screen clinical observations derived from medical records (phenotypes) for association with a variable of interest. Despite their usefulness, no systematic screening of phenotypes associated with Staphylococcus aureus infections (SAIs) has been done leaving potential novel risk factors or complications undiscovered.

METHOD AND COHORTS

We tailored the PheWAS approach into a two-stage screening procedure to identify novel phenotypes correlating with SAIs. The first stage screened for co-occurrence of SAIs with other phenotypes within medical records. In the second stage, significant findings were examined for the correlations between their age of onset with that of SAIs. The PheWAS was implemented using the medical records of 754,401 patients from the Marshfield Clinic Health System. Any novel associations discovered were subsequently validated using datasets from TriNetX and All of Us, encompassing 109,884,571 and 118,538 patients respectively.

RESULTS

Forty-one phenotypes met the significance criteria of a p-value < 3.64e-5 and odds ratios of > 5. Out of these, we classified 23 associations either as risk factors or as complications of SAIs. Three novel associations were discovered and classified either as a risk (long-term use of aspirin) or complications (iron deficiency anemia and anemia of chronic disease). All novel associations were replicated in the TriNetX cohort. In the All of Us cohort, anemia of chronic disease was replicated according to our significance criteria.

CONCLUSIONS

The PheWAS of SAIs expands our understanding of SAIs interacting phenotypes. Additionally, the novel two-stage PheWAS approach developed in this study can be applied to examine other disease-disease interactions of interest. Due to the possibility of bias inherent in observational data, the findings of this study require further investigation.

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 report of recurrent membranoproliferative glomerulonephritis after kidney transplantation due to ventriculoatrial shunt infection

Background

Transplant failure requires the consideration of numerous potential causes including rejection, acute tubular necrosis, infection, and recurrence of the original kidney disease. Kidney biopsy is generally required to approach these differential diagnoses. However, the histopathological findings on their own do not always lead to a definite diagnosis. Consequently, it is crucial to integrate them with clinical findings and patient history when discussing histopathological patterns of injury. The histopathologic finding of a membranoproliferative glomerulonephritis (MPGN) is one of the most challenging constellations since it does not refer to a specific disease entity but rather reflects a pattern of injury that is the result of many different causes. Whilst MPGN is occasionally classified as immune complex mediated, careful evaluation usually reveals an underlying disorder such as chronic infection, plasma cell dyscrasia, complement disorders, and autoimmune disease.

Case presentation

We describe the case of a 43-year-old woman who was referred to us because of a slowly rising serum creatinine 4 years after kidney transplantation. As in the native kidney, the biopsy revealed an MPGN pattern of injury. The cause of this finding had not been established prior to transplantation leading to a classification as idiopathic MPGN in the past. Further workup at the time of presentation and allograft failure revealed chronic infection of a ventriculoatrial shunt as the most probable cause.

Conclusion

This case underlines the fact that MPGN is not a disease but a histopathological description. Consequently, the causative disorder needs to be identified to avoid kidney failure and recurrence after transplantation.

Delayed Manifestation of Shunt Nephritis: A Case Report and Review of the Literature

We present an unusual case of shunt nephritis in a 39-year-old male who presented 21 years after placement of a ventriculoperitoneal (VP) shunt. He complained of fevers, headaches, dizziness, and urticarial plaques on arms, trunks, and legs and was found to have anemia, low complement levels, elevated serum creatinine, proteinuria, and new onset microhematuria. Blood and urine cultures were negative. Renal biopsy showed features of acute tubulointerstitial nephritis attributed to vancomycin use. Glomeruli showed increased mesangial hypercellularity and segmental endocapillary proliferation. Immunofluorescence showed focal IgM and C3 staining. Electron microscopy revealed small subendothelial electron-dense deposits. Symptoms and renal insufficiency appeared to improve with antibiotic therapy. He was discharged and readmitted 2 months later with similar presentation. CSF grew Propionibacterium acnes and shunt hardware grew coagulase-negative Staphylococcus. He completed an intravenous antibiotic course and was discharged. On 1-month follow-up, skin lesions persisted but he was otherwise asymptomatic. Follow-up labs showed significant improvement. We did a brief systematic review of the literature on shunt nephritis and report our findings on 79 individual cases. In this review, we comment on the presentation, lab findings, pathological features, and management of this rare, potentially fatal, but curable disease entity.

Cerebrospinal Fluid Shunting Complications in Children

Although cerebrospinal fluid (CSF) shunt placement is the most common procedure performed by pediatric neurosurgeons, shunts remain among the most failure-prone life-sustaining medical devices implanted in modern medical practice. This article provides an overview of the mechanisms of CSF shunt failure for the 3 most commonly employed definitive CSF shunts in the practice of pediatric neurosurgery: ventriculoperitoneal, ventriculopleural, and ventriculoatrial. The text has been partitioned into the broad modes of shunt failure: obstruction, infection, mechanical shunt failure, overdrainage, and distal catheter site-specific failures. Clinical management strategies for the various modes of shunt failure are discussed as are research efforts directed towards reducing shunt complication rates. As it is unlikely that CSF shunting will become an obsolete procedure in the foreseeable future, it is incumbent on the pediatric neurosurgery community to maintain focused efforts to improve our understanding of and management strategies for shunt failure and shunt-related morbidity.

The use of the ASET in the diagnosis of ventriculoatrial shunt infection

A 38-year-old man with a ventriculoatrial shunt presented with non-specific symptoms (headache, back pain, night sweats) and inconclusive laboratory results. He showed an extremely high titre of antibody to Staphylococcus epidermidis which proved diagnostic of shunt infection. This was confirmed on shunt removal and he was successfully treated.

Isolation and characterization of a highly specific serine endopeptidase from an oral strain of Staphylococcus epidermidis

Infection by Staphylococcus epidermidis, an opportunistic pathogen, has become a major problem due to the increased use of implanted medical devices and the growing number of patients who are therapeutically or infectiously immunosuppressed. These infections appear to proceed via modulation of the coagulation and complement systems. In this communication we describe the purification and characterization of a novel extracellular proteinase from an oral strain of S. epidermidis that can degrade fibrinogen, complement protein C5, and several other proteins. This proteinase has a strong preference for cleavage after glutamic acid residues, but not after aspartic acid. The S. epidermidis enzyme may be a multifunctional protein which not only provides this organism with both the ability to evade the complement defense system and to dysregulate the coagulation cascade, but also supplies nutrients for its growth through the degradation of Glu-rich proteins.

Cerebral ventricular shunts

Cerebral ventricular shunts are siphoning devices used to treat hydrocephalus. They are placed within cerebral ventricles and peripheral cavities such as the ventricular atrium or peritoneal cavity. Complications include obstruction of cerebral spinal fluid (malfunction) and infection. Morbidity and mortality rates are high when shunt malfunction and infection are not treated emergently. This report summarizes the physical examination of patients with ventricular shunts, reviews the type of shunts commonly used, discusses shunt malfunctions (causing overshunting or undershunting of cerebrospinal fluid) and infections, and makes recommendations concerning empiric antibiotic therapy for shunt infection. The technique of tapping a shunt is presented for management of patients with elevated intracranial pressure that does not respond to non-invasive maneuvers to lower the pressure.

Glomerulonephritis associated with MRSA infection: a possible role of bacterial superantigen

We report 10 cases of glomerulonephritis following methicillin-resistant Staphylococcus aureus (MRSA) infection. The clinical features of this syndrome were an abrupt or insidious onset of rapidly progressive glomerulonephritis (RPGN) with nephrotic syndrome and occasionally purpura, following MRSA infection. The renal histologic findings showed a variety of types of proliferative glomerulonephritis with varying degrees of crescent formation; immunofluorescence revealed of glomerular deposition of IgA, IgG, and C3. Laboratory findings showed polyclonal increases of serum IgA and IgG, with high levels of circulating immune complexes (ICs). Increased numbers of DR+CD4+, and DR+CD8+T cells were observed in the peripheral circulation, with a high frequency of T cell receptor (TCR) V beta + cells. MRSA produced enterotoxins C and A and toxic shock syndrome toxin (TSST)-1, all of which are known to act as superantigens. From the above observations, we speculate that post-MRSA glomerulonephritis may be induced by superantigens causing production of high levels of cytokines, and polyclonal activation of IgG and IgA. The formation of ICs containing IgA and IgG in the circulation result in development of glomerulonephritis and vasculitis. Accordingly, microbial superantigens may play an important role in the pathogenesis of this unique syndrome of nephritis and vasculitis.

Role of serological tests in the diagnosis of immune complex disease in infection of ventriculoatrial shunts for hydrocephalus

Seven cases of ventriculoatrial shunt infection with immune complex disease are reported in order to demonstrate the usefulness of measurement of levels of specific antibody to Staphylococcus epidermidis in diagnosis. Blood and cerebrospinal fluid cultures gave misleading results, and there was initial doubt about the diagnosis in all seven cases. All showed grossly elevated titres of antibody to Staphylococcus epidermidis, with raised serum C-reactive protein levels and depressed complement levels. Measurement of antibody to Staphylococcus epidermidis enables the diagnosis of chronic ventriculoatrial shunt infection to be made rapidly and reliably.

Shunt nephritis associated with Propionibacterium acnes

Membranoproliferative glomerulonephritis was observed in a 22-year-old male patient in whom a ventriculoatrial shunt and a ventricular catheter were implanted after he was diagnosed in September 1989 with a cerebral cyst. Propionibacterium acnes infection of a central nervous system shunt was diagnosed. The ventriculoatrial shunt was removed (the catheter had become embedded in tissue and was left in place) and the patient was treated with cefotaxime (3 x 2 g) for 14 days. Renal function improved, but recovery was not complete.

Renal complications of infected ventriculoatrial shunts

Contamination of a ventriculoatrial shunt (VAS) with skin organisms that are usually nonpathogenic may be followed by an immunologically mediated renal injury. The bacteria characteristically involved are coagulase-negative Staphylococci (e.g., Staphylococcus epidermidis), which strongly adhere to the plastic surface of the VAS. These bacteria are protected from the body's natural defense mechanisms and respond only poorly to antibiotics. As a result, their growth persists and produces a continuous antigenic stimulation. Circulating immune complexes (CIC) are an appropriate tool to screen for chronically infected VASs. We followed CIC in 138 VAS patients. An infected VAS was seen in 20 of the 24 patients with highly elevated CIC and in 1 of the 19 patients with moderately elevated CIC, but none of the 95 patients with normal CIC had evidence of shunt infection. Of the 21 patients with shunt infections, 8 had renal involvement (4 requiring dialysis, and 4 with proteinuria, hematuria, and/or elevated creatinine). Results from kidney biopsy specimens available from 4 patients confirmed glomerulonephritis. Of the 4 patients requiring dialysis at diagnosis, renal function recovered sufficiently to stop dialysis after successful VAS exchange in all but 1. In the other 4 patients, renal symptoms (proteinuria, creatinine) also improved after VAS revision. Chronic infection with S. epidermidis or other bacteria is a continuing problem in patients with VASs and can lead to an immune-mediated renal injury. However, the prognosis for reversal of the renal injury is relatively good if the VAS infection is treated promptly.

Shunt nephritis. Case report

The incidence of shunt nephritis has decreased over the past several years due to the increased use of ventriculoperitoneal (VP) shunts rather than the ventriculovascular systems for which this complication was originally reported in 1965. Despite this trend, the syndrome has been reported in cases of VP shunting and, for this reason, merit a renewed look. Shunt nephritis is thought to be secondary to immune complex formation and deposition in the kidney in response to Staphylococcus epidermidis. The diagnostic workup and management of this disease is discussed.

Staphylococcus epidermidis: a significant nosocomial pathogen

Staphylococcus epidermidis is an organism formerly believed to be nonpathogenic. It is now recognized as a pathogen, causing infections on implanted devices and among immunosuppressed patients. Further, it has been involved in the development of resistance to a number of antibiotics. The epidemiology of this organism, its pathogenesis, and its treatment are important to infection control practitioners.

Arthritis associated with salmonella infection

Six cases of arthritis caused by or associated with Salmonella infection are reported. It is stated that an arthritis associated with a Salmonella infection cannot be excluded on the negative results of the Widal test. Consequent upon Salmonella infection two different types of arthritis might develop: a) monoarticular infectious arthritis or b) a subacute reactive oligo-articular arthritis. In this study a patient with a chronic destructive "reactive" oligoarthritis is described, resembling experimental "Salmonella-associated arthritis" in rats. This form of arthritis might be regarded as an immune complex mediated disease associated with a chronic infection.

Shunt nephritis progressing to chronic renal failure

Shunt nephritis is an immune-complex mediated glomerular disease associated with chronically infected ventriculo-jugular shunts for hydrocephalus. In general, early diagnosis and appropriate antibiotic therapy result in marked improvement or disappearance of the concomitant urinary and renal functional abnormalities. We describe, a child in whom the diagnosis and treatment were delayed until she presented with irreversible renal insufficiency. We conclude that shunt nephritis is not an innocuous condition and that a high level of suspicion must be maintained by those caring for children with ventriculo-jugular shunts.

Ventriculo-atrial shunt nephritis

A case of immune complex glomerulonephritis with reversible renal insufficiency following ventriculoatrial shunting is described and the English language literature is reviewed. The importance of recognizing this reversible glomerulonephritic lesion is emphasized.

Shunt nephritis. Role of the complement system in its pathogenesis and management

Three cases of shunt nephritis in which serial complement levels were obtained during the course of treatment are presented to illustrate the value of monitoring complement levels in the management of this condition. In shunt nephritis, circulating immune complexes are formed which contain antigen from bacteria of low virulence. These complexes, which activate the classical complement pathway, are reflected in most cases by lowering of the serum levels of C1, C2, C4, and C3. These levels promptly return to normal after the initiation of effective therapy. Serial determinations of serum levels of complement protein provide a sensitive and reliable method for early determination of efficacy of therapy in shunt nephritis.

Renal pathology of catheterized baboons (Papio cynocephalus)

Renal disease was found at necropsy in 27 of 60 catheterized baboons (Papio cynocephalus). Primary diagnoses were infarcts in eight baboons, septic embolic nephritis in four, and mesangioproliferative glomerulonephritis in 15. Infarcts and septic embolic nephritis are multifocal renal diseases; mesangioproliferative glomerulonephritis is diffuse, progressive and often accompanied by severe proteinuria, hypoalbuminemia (less than 3 g/dl), and generalized edema. Five of the 15 baboons with glomerulonephritis also developed uremia and died of renal failure. Ten baboons with glomerulonephritis were given microbiological examination during their clinical course. Bacteria were isolated from the peripheral blood of eight baboons and from the catheter itself in two. The organisms isolated (in decreasing order of frequency) were Herellea sp., Streptococcus sp., Klebsiella sp., Staphylococcus sp., and Providencia sp. Prospective immunofluorescence studies were done on frozen sections from six catheterized baboons with glomerulonephritis and two uncatheterized controls. There were granular deposits of IgG in all six, IgM in five, C3 in four, and IgA and C4 in two. In the controls, only trace amounts of IgM were seen in one animal. The amount of IgG deposited in th glomeruli correlated with the severity of the glomerulonephritis. Bacterial antigens were found by immunofluorescence in glomeruli of three of five baboons examined. Glomerulonephritis in these baboons seems to be immunologically mediated, and in origin, pathogenesis and morphologic expression resembles shunt nephritis in humans with infected indwelling shunts and catheters.

Systemic immune complex disease following intestinal bypass surgery: bypass disease

Twenty-one patients with arthritis and dermatitis following intestinal bypass surgery were studied. The arthritis was polyarticular, remittent, and intermittent. Typically, the synovial fluid was inflammatory. The commonest inflammatory skin lesion was a vesiculopustular dermatitis. Nineteen patients and serum immmune complexes using the Raji cell technic. Seventeen patients had serum cryoproteins, primarily consisting of IgG 1, IgG 3, C3, and C4. Three patients had both Escherichia coli antigens and anti-E. coli antibody in their cryoprotein. Five patients had granular and one had linear deposits of immunoglobulin and complement at the dermoepidermal junction. Further evidence that bacterial antigens play a role in tissue injury was provided by detection of granular deposits of E. coli antigen at the dermoepidermal junctions in two patients, and at the glomerular capillary basement membrane in one patient.

Immunoglobulin E antibodies against Staphylococcus aureus cell walls in the sera of patients with hyperimmunoglobulinemia E and recurrent staphylococcal infection

The specificity of antistaphylococcal antibodies of the IgE class in five patients with hyperimmunoglobulinemia E and recurrent staphylococcal infection has been investigated. Purified cell walls were prepared from various staphylococcal strains, and serum immunoglobulin E binding was measured by using a solid-phase radioimmunoassay. Immunoglobulin E binding occurred only with cell walls from Staphylococcus aureus strains, including walls from a teichoic acid-deficient mutant. Immunoglobulin E did not bind to cell wall preparations from the coagulase-negative species S. capitis, S. sciuri subsp. lentus, S. simulans, S. xylosus, staphylococcal strains RB-11 and Armour, and from a group A streptococcus strain CS44. Since the glycan backbone and the tetrapeptide (pentapeptide) subunit of the peptidoglycan of all staphylococcal strains tested are believed to be identical, it is suggested that IgE binding is related to either the peptidoglycan interpeptide bridge or an unknown antigenic structure within the cell wall of S. aureus. The pathophysiological significance of antistaphylococcal immunoglobulin E antibodies in the disorder studied is at present unknown. The formation of immunoglobulin E antibodies to S. aureus cell wall components may be a manifestation of an aberrant immunological response to S. aureus related to the undue susceptibility to staphylococcal infections in these patients.

Endocarditis caused by coagulase-negative staphylococci

Sixteen patients with coagulase-negative staphylococcal endocarditis were treated at the University of Minnesota Hospitals between January 1970 and September 1977. In six patients, endocarditis developed after prosthetic valve surgery; among the other ten patients (the medical group), eight had known antecedent valvular disease. The skin was thought to be the source of infection in eight patients, suggesting that prompt treatment of skin infections and avoidance of injections in patients with valvular disease are important measures in the prevention of this disease. Patients with prosthetic valve endocarditis were infected with antibiotic-resistant organisms and had a higher mortality than those in the medical group (83% versus 20%). Bacterial isolates from three patients with prosthetic valve endocarditis were resistant to methicillin, and two of these three isolates also were resistant to cephalothin by quantitative susceptibility testing. The only patient with prosthetic valve endocarditis to survive was operated upon early in the course of his illness. These observation, coupled with the high mortality in this series and in others, has prompted us to advocate early surgery in prosthetic valve endocarditis.

The association of familial liver disease, subepidermal immunoproteins, and membranoproliferative glomerulonephritis

Herein we report a new familial form of hepatic disease. Each of the four patients had splenomegaly, hypersplenism, a small liver, biochemical evidence of hepatic excretory dysfunction and hepatocellular damage, kidneys without demonstrable cysts, and normal blood pressue. An evaluation of serum immunoproteins, autoantibodies, histocompatibility antigens, and mixed lymphocyte reactivity further defined the immunologic features of this syndrome. Extrahepatic manifestations included a papulosquamous dermatitis with deposition of immunoglobulins and complement in both normal and abnormal skin, a membranoproliferative glomerulonephritis with subendothelial deposits, arthritis, and pericardial, pleural, and synovial effusions.

Propionibacterium acnes: pathogen in central nervous system shunt infection. Report of three cases including immune complex glomerulonephritis

Propionibacterium acnes is a pleomorphic gram-positive anaerobic rod usually isolated as a contaminant from skin. We report three cases of P. acnes infection of central nervous system shunts for hydrocephalus. The organism was seen repeatedly on gram stain in a specimen of shunt fluid in all three cases; initially, it was regarded as a contaminant. In addition, two of the patients had precipitins to extracts of their organism. Serum from normal control subjects had no such precipitins. One of the patients had an immune-complex glomerulonephritis--an entity not previously associated with anaerobic organisms. All three patients recovered after removal of the shunt and treatment with antibiotics. P. acnes is a significant pathogen in patients with central nervous system shunts.