human
***task***
the task is to summarize an input biomedical literature in six sentences

***input***
the input is a biomedical literature

***output***
the output is the summary of an input biomedical literature in six sentences

***documentation***

***examples***

input: infection related glomerulonephritis ( irgn ) is an immunologically mediated glomerular injury triggered by extrarenal infection . in the past , the majority of irgn cases were related to infection with nephritogenic streptococcal strains . as the prevalence of streptococcus pyogenes disease in developed countries has declined , other causative pathogens are recognized more frequently . a recent review of 86 patients with renal biopsy - confirmed irgn identified streptococcus spp . in 27.9 % and staphylococcus sppadults over 55 years accounted for 54.6 % of the cases , in contrast to previous studies ( 1974 and before ) , which reported irgn to be a disease predominantly of children . emerging risk factors for irgn identified in the recent studies include diabetes mellitus , alcoholism , hiv infection , malignancy , and injection drug use . whereas poststreptococcal gn typically occurs 14 weeks following a cutaneous infection , the majority of nonstreptococcal irgn cases occur concurrently and at times precede the diagnosis of the infection . more accurately describes this pathology compared to the old term of postinfectious gn . staphylococcus epidermidis is a well - established cause of shunt nephritis , accounting for 75 % of cases . herein , we describe a case of irgn in the setting of severe spine infection with s. epidermidis , which occurred in the absence of foreign body . a 72 - year - old male with a history of type 2 diabetes mellitus and hypertension presented to the hospital with a 2 - week history of progressive lower back pain and generalized weakness which culminated in inability to arise after a mechanical fall . on presentationhe had a temperature of 36.7 c , bp 153/73 mm hg , pulse 73 bpm , and respiratory rate 24 / min . pertinent physical exam findings included tenderness to palpation of the spine and left upper arm edema and tenderness . initial laboratory results were notable for leukocytosis ( wbc 16,900 / mm with 92.6 % neutrophils ) , acute kidney injury ( creatinine 1.6 mg / dl [ 144mol / l ] baseline 0.9 mg / dl [ 80 mol / l ] and , bun 57 mg / dl ) , hyponatremia ( sodium 128mmol / l ) , rhabdomyolysis ( ck 3760 u / l ) , and abnormal urinalysis ( specific gravity 1.025 , large blood with sediment showing 610 rbc / hpf , wbc 1120 / hpf , moderate bacteria , and protein 100 mg / dl ) . ultrasound of the left arm disclosed a 7 cm subcutaneous fluid collection , which was drained . admission blood , urine , and left arm aspirate cultures grew methicillin - sensitive s. epidermidis . magnetic resonance imaging of the spine revealed large subdural empyema and phlegmon extending from mid - thoracic to lumbar spine , nerve root inflammation , marked canal stenosis , and cord compression . he underwent emergent surgery for debridement of the infectious collections and t4 - t5 , t8 - t9 , and l4 - l5 laminectomies . his postoperative course was complicated by acute blood loss anemia and hypotension attributed to hemorrhagic and septic shock requiring vasopressors and blood transfusion . he developed oligoanuria ( responding to diuretics ) and progressive increase in serum creatinine up to 5.7 mg / dl ( 504 mol / l ) , presumptively from acute tubular necrosis ( atn ) , necessitating initiation of renal replacement therapy . light microscopy ( lm ) ( figure 1 ) of the kidney specimen showed flattening of the tubular epithelium ( figure 1 ( a ) ) with tubular necrosis and edema suggesting acute tubular necrosis ( atn ) . additionally , diffuse and nodular mesangial expansion ( figure 1 ( b ) ) as well as arteriolar hyaline were present consistent with an underlying diabetic nephropathy ( dn ) . mild patchy interstitial inflammatory cell infiltrates , predominantly mononuclear cells , were seen suggesting an underlying inflammatory process . electron microscopy ( em ) ( figure 2 ) showed mesangial and scattered subepithelial humps with electron dense immune type deposits ( figure 2 ( a ) ) , moderate podocyte effacement , and thickening of the glomerular basement membrane at 50695 nm ( normal 37156 nm ) ( figure 2 ( b ) ) . direct immunofluorescence ( if ) ( figure 3 ) showed mild mesangial staining of c3 , iga , and igm . there was gradual improvement of his renal function and after 6 weeks he was no longer hemodialysis ( hd ) dependent . s. epidermidis infection was aggressively treated with 8 weeks of ceftriaxone followed by 12 months of oral minocycline . at 12 - month follow - up , staphylococcus epidermidis , typically considered a low - virulence microbe , is a well - recognized cause of irgn in association with prosthetic material , such as central venous catheters and shunts . however , severe s. epidermidis infection in the absence of prosthetic material is distinctly unusual . we hypothesize that our patient acquired the infection following a difficult peripheral venipuncture , which resulted in an infected hematoma . immunosuppression , due to advanced age and underlying diabetes mellitus , facilitated hematogenous dissemination of s. epidermidis to the spine resulting in multifocal vertebral osteomyelitis as well as evolution of irgn in the absence of prosthetic material . in addition to dn , superimposed irgn delayed recovery from atn and prolonged his dependence on hd . the distribution of these deposits varies depending on the stage of the disease but most commonly are found in the mesangium . subepithelial deposits , classically seen in s. pyogenes irgn , are also identified in s. aureus irgn , however not as frequent in cases with comorbid dn . on if , predominant c3 and igg deposits with minimal iga , c1q , and igm are seen . predominant iga deposition mimicking iga nephropathy is an emerging entity described with s. aureus and must be differentiated from primary iga nephropathy . codominant iga deposition is commonly seen in irgn but is usually of mild to moderate intensity . the kidney biopsy of our patient disclosed mesangial hypercellularity with electron dense immune deposits consistent with a mesangial pattern , likely representing a late stage of disease when the biopsy was performed . only trace iga was identified that was codominant with c3 and igm , a finding consistent with reported cases of s. aureus associated irgn . atn was the major finding on biopsy and appears to be the predominant cause of acute renal failure in this patient . the mainstay therapy for irgn is aggressive management of the infection and complications of nephritis . our patient 's good outcome was likely result of the aggressive surgical and medical treatment of his infection despite significant risk for poor outcome . this case highlights the change in epidemiology of irgn . clinicians should consider irgn when renal injury occurs in the course of s. epidermidis infection even in the absence of prosthetic material , especially when risk factors such as advanced age and diabetes mellitus type 2 are present . aggressive treatment of infection is warranted and may lead to full recovery of renal function .
output:

agent
we report a case of a 72 - year - old diabetic male who developed infection - related glomerulonephritis ( irgn ) in the setting of severe staphylococcus epidermidis infection . he required renal replacement therapy for 6 weeks , but had full recovery of his kidney function with aggressive treatment of the infection . while this pathogen has been previously implicated as the cause of shunt nephritis , it is exceptionally rare to be associated with irgn in the absence of a shunt or other prosthetic material .
***task***
the task is to summarize an input biomedical literature in six sentences

***input***
the input is a biomedical literature

***output***
the output is the summary of an input biomedical literature in six sentences

***documentation***

***examples***

input: infection related glomerulonephritis ( irgn ) is an immunologically mediated glomerular injury triggered by extrarenal infection . in the past , the majority of irgn cases were related to infection with nephritogenic streptococcal strains . as the prevalence of streptococcus pyogenes disease in developed countries has declined , other causative pathogens are recognized more frequently . a recent review of 86 patients with renal biopsy - confirmed irgn identified streptococcus spp . in 27.9 % and staphylococcus sppadults over 55 years accounted for 54.6 % of the cases , in contrast to previous studies ( 1974 and before ) , which reported irgn to be a disease predominantly of children . emerging risk factors for irgn identified in the recent studies include diabetes mellitus , alcoholism , hiv infection , malignancy , and injection drug use . whereas poststreptococcal gn typically occurs 14 weeks following a cutaneous infection , the majority of nonstreptococcal irgn cases occur concurrently and at times precede the diagnosis of the infection . more accurately describes this pathology compared to the old term of postinfectious gn . staphylococcus epidermidis is a well - established cause of shunt nephritis , accounting for 75 % of cases . herein , we describe a case of irgn in the setting of severe spine infection with s. epidermidis , which occurred in the absence of foreign body . a 72 - year - old male with a history of type 2 diabetes mellitus and hypertension presented to the hospital with a 2 - week history of progressive lower back pain and generalized weakness which culminated in inability to arise after a mechanical fall . on presentationhe had a temperature of 36.7 c , bp 153/73 mm hg , pulse 73 bpm , and respiratory rate 24 / min . pertinent physical exam findings included tenderness to palpation of the spine and left upper arm edema and tenderness . initial laboratory results were notable for leukocytosis ( wbc 16,900 / mm with 92.6 % neutrophils ) , acute kidney injury ( creatinine 1.6 mg / dl [ 144mol / l ] baseline 0.9 mg / dl [ 80 mol / l ] and , bun 57 mg / dl ) , hyponatremia ( sodium 128mmol / l ) , rhabdomyolysis ( ck 3760 u / l ) , and abnormal urinalysis ( specific gravity 1.025 , large blood with sediment showing 610 rbc / hpf , wbc 1120 / hpf , moderate bacteria , and protein 100 mg / dl ) . ultrasound of the left arm disclosed a 7 cm subcutaneous fluid collection , which was drained . admission blood , urine , and left arm aspirate cultures grew methicillin - sensitive s. epidermidis . magnetic resonance imaging of the spine revealed large subdural empyema and phlegmon extending from mid - thoracic to lumbar spine , nerve root inflammation , marked canal stenosis , and cord compression . he underwent emergent surgery for debridement of the infectious collections and t4 - t5 , t8 - t9 , and l4 - l5 laminectomies . his postoperative course was complicated by acute blood loss anemia and hypotension attributed to hemorrhagic and septic shock requiring vasopressors and blood transfusion . he developed oligoanuria ( responding to diuretics ) and progressive increase in serum creatinine up to 5.7 mg / dl ( 504 mol / l ) , presumptively from acute tubular necrosis ( atn ) , necessitating initiation of renal replacement therapy . light microscopy ( lm ) ( figure 1 ) of the kidney specimen showed flattening of the tubular epithelium ( figure 1 ( a ) ) with tubular necrosis and edema suggesting acute tubular necrosis ( atn ) . additionally , diffuse and nodular mesangial expansion ( figure 1 ( b ) ) as well as arteriolar hyaline were present consistent with an underlying diabetic nephropathy ( dn ) . mild patchy interstitial inflammatory cell infiltrates , predominantly mononuclear cells , were seen suggesting an underlying inflammatory process . electron microscopy ( em ) ( figure 2 ) showed mesangial and scattered subepithelial humps with electron dense immune type deposits ( figure 2 ( a ) ) , moderate podocyte effacement , and thickening of the glomerular basement membrane at 50695 nm ( normal 37156 nm ) ( figure 2 ( b ) ) . direct immunofluorescence ( if ) ( figure 3 ) showed mild mesangial staining of c3 , iga , and igm . there was gradual improvement of his renal function and after 6 weeks he was no longer hemodialysis ( hd ) dependent . s. epidermidis infection was aggressively treated with 8 weeks of ceftriaxone followed by 12 months of oral minocycline . at 12 - month follow - up , staphylococcus epidermidis , typically considered a low - virulence microbe , is a well - recognized cause of irgn in association with prosthetic material , such as central venous catheters and shunts . however , severe s. epidermidis infection in the absence of prosthetic material is distinctly unusual . we hypothesize that our patient acquired the infection following a difficult peripheral venipuncture , which resulted in an infected hematoma . immunosuppression , due to advanced age and underlying diabetes mellitus , facilitated hematogenous dissemination of s. epidermidis to the spine resulting in multifocal vertebral osteomyelitis as well as evolution of irgn in the absence of prosthetic material . in addition to dn , superimposed irgn delayed recovery from atn and prolonged his dependence on hd . the distribution of these deposits varies depending on the stage of the disease but most commonly are found in the mesangium . subepithelial deposits , classically seen in s. pyogenes irgn , are also identified in s. aureus irgn , however not as frequent in cases with comorbid dn . on if , predominant c3 and igg deposits with minimal iga , c1q , and igm are seen . predominant iga deposition mimicking iga nephropathy is an emerging entity described with s. aureus and must be differentiated from primary iga nephropathy . codominant iga deposition is commonly seen in irgn but is usually of mild to moderate intensity . the kidney biopsy of our patient disclosed mesangial hypercellularity with electron dense immune deposits consistent with a mesangial pattern , likely representing a late stage of disease when the biopsy was performed . only trace iga was identified that was codominant with c3 and igm , a finding consistent with reported cases of s. aureus associated irgn . atn was the major finding on biopsy and appears to be the predominant cause of acute renal failure in this patient . the mainstay therapy for irgn is aggressive management of the infection and complications of nephritis . our patient 's good outcome was likely result of the aggressive surgical and medical treatment of his infection despite significant risk for poor outcome . this case highlights the change in epidemiology of irgn . clinicians should consider irgn when renal injury occurs in the course of s. epidermidis infection even in the absence of prosthetic material , especially when risk factors such as advanced age and diabetes mellitus type 2 are present . aggressive treatment of infection is warranted and may lead to full recovery of renal function .
output:
