henoch - schnlein purpura ( hsp ) is a common systemic vasculitic disorder that occurs during hildhood and its course is often self - limiting ( 1 , 2 ) . multiple studies have reported less frequent but poorer outcomes in adult hspn ( 1 , 2 ) and there have been a few data on elderly - onset patients ( 3 ) . iga nephropathy is usually an indolent progressive adult disease , whereas hspn is mainly seen during childhood . hspn more often shows nephritic - nephrotic syndrome and chronic renal failure compared to iga nephropathy ( 4 ) . although the pathophysiologic mechanisms of hspn are not completely understood , thecomplement activation , vascular damage and crescent formation in glomerular injury in severe hspn appear to play an important role . however , the serum complement levels are usually normal ( 5 ) and anti - neutrophil cytoplasmic antibodies ( anca ) is negative in most patients with hspn ( 2 , 3 , 6 ) . we experienced a case of elderly - onset crescentic hspn with nephritic - nephrotic syndrome associated with hypocomplementemia and positive myeloperoxidase anca ( mpo - anca ) after a major operation and antibiotic use . a 76-yr - old man was transferred to our hospital at 7th july 2011 with 1-month history of oliguria , gross hematuria , abdominal pain , pitting edema and skin eruption ( palpable purpura ) in both legs . three months ago , he was admitted to another hospital with jaundice , but then diagnosed with early common bile duct cancer , and he underwent whipple 's operation . antibiotics were used because of leakage in the suture from the surgery but there were no further surgical problems . the antibiotics administered included ceftriaxone , amikacin , meropenem and piperacillin / tazobactam . however , serum creatinine increased from 1.0 to 6.3 mg / dl . a physical examination revealed multiple nontender purpura mixed with erythema ranging from 2 to 4 mm in diameter over his edematous lower legs and the dorsal side of his feet and toes ( fig . 1 ) . most of the skin lesions were non - indurated , although palpable or indurated purpura mixed with erythema could be identified in some areas . on admission , laboratory investigations showed a reduced serum hemoglobin level of 10.5 g / dl and an elevated serum c - reactive protein level of 5.93 mg / dl . in addition to an elevated serum creatinine level of 6.4 mg / dl ( fig . 2 ) , an increased blood urea nitrogen level of 45.7 mg / dl , urine rbc many / hpf and 24 hr urine protein showed 8,141 mg / day . c3 was low at 64.89 mg / dl , and anca was positive at mpo - anca 1:40 ( by enzyme - linked immunosorbent assay [ elisa ] and indirect inmunofluorescence [ if ] ) and serum fluorescent antinuclear antibody test , cryoglobulin and other serology findings were within the normal range . ultrasonography showed diffuse parenchymal swelling , homogenous increase cortical echogenecity , ascites and bilateral pleural effusion . renal biopsy showed crescentic glomerulonephritis on light microscopy ( lm ) , and mesangial and extracapillary ig a deposition on if . circumferential fibrocellular and cellular crescents were noted in 5 out of a total of 8 glomeruli . most glomeruli were diffuse endocapillary proliferation in size and cellularity due to endocapillary proliferation with mild lymphocytic and neutrophilic infiltration . if microscopy revealed conspicuous staining for ig a in the mesangium and segmentally subendothelial portion along the glomerular capillary walls ( fig . the patient complained of abdomen discomfort and experienced pyrexia up to 38.5. we started prednisolon 60 mg without using antibiotics , and after that the fever improved . starting steroid therapy and hd , abdomen discomfort , purpura on legs , pretibial pitting edema and pleural effusion were improved . however , his renal function was not improved and he has been under maintenance hd . hsp is a typical disease of childhood , and shows a near 20-fold disparity in incidence between adults and children ( 1.3 vs 22.1 per 100,000 population ) . adult - onset hsp may involve more severe hspn and organ injury , but there is limited data on elderly - onset hsp ( 3 ) . the classic clinical symptoms include purpuric rash , abdominal pain , arthralgias , and hematuria , but the spectrum of hsp may vary from only minimal petechial rash to severe gastrointestinal , neurologic , pulmonary , and renal disease . hspn is often triggered by antecedent infection , medication and other miscellaneous factors ( 8) . hspn and iga nephropathy are currently considered related diseases , as both are indistinguishable in the renal histologic and immunofluorescent findings , and both have been described in twins . hspn more often shows extrarenal manifestation , nephritic - nephrotic syndrome and chronic renal failure compared to iga nephropathy ( 4 ) . pathogenesis of hspn is not completely understood , but it has pathologically been regarded as a specific immune - mediated entity induced by environmental factors , particularly infections ( 9 ) . the role of infection , particularly group a beta - hemolytic streptococcal , in the etiology of hsp has interested many investigators , but the role of bacterial antigens remains questionable in a majority of cases . other causes are hypersensitivity reactions induced by numerous drugs , but no common drug has yet been identified . in a previous case report , prodromal illness and drug to hsp in three members of the same family were penicillin with sore throat and colon resection after diverticulitis with sulfonamide due to wound infection ( 10 ) . pathophysiologic mechanisms of hspn including complement activation , vascular damage and crescent formation in glomerular injury appear to play an important role . hypocomplementemia generally has not been seen in hspn , but excessive consumption and deposition of c3 in the kidneys may have been the cause of reduced c3 serum level in a severe hspn case ( 5 ) . anca with specificity for myeloperoxidase ( mpo ) was noted in primary small vessel vasculitis ( 11 ) . although the prognosis of patients with overlapping hspn with anca remains unclear , clinical correlations suggest that immune complex deposits in the kidney may potentiate the effect of anca in producing more severe glomerulonephritis than classic pauci - immune vasculitis or hspn . as hspn overlapping syndrome characterized by the synergistic effect of mpo - anca and the iga immune complex may result in a fatal outcome , aggressive immunosuppressive therapy should be initiated as early as possible ( 12 ) . we examined mpo - anca twice using an enzyme immunoassay ( elisa ) in our hospital and indirect if assay in another hospital . it was found that mpo - anca was positive and a titer of 1:40 was relatively weak . however , large multicenter studies combining indirect if and elisa have demonstrated a specificity approaching 99% for wegener 's granulomatosis , microscopic polyangitis , or their renal - limited variant ( 13 ) . the anca have an important role in pathogenicity of small vessel vasculitis , and intermittent anca positivity is an independent risk factor for relapse ( 11 - 13 ) . therefore , mpo - anca may have some role in the pathogenesis of our crescentic hspn case . in a retrospective study , 2 cases with anca out of a total of 42 hsp because the presence of crescents is a histologic feature of hspn that represents a prognostic factor and constitutes the basis for the international study group of kidney disease in childhood ( iskdc ) pathology classification , the study of crescent pathophysiology may provide useful information as a therapeutic strategy ( 14 ) . a cohort study ( 3 ) of 250 adults suffering from hsp was retrospectively analyzed for a median follow - up period of 14.8 yr . the risk of progression to renal insufficiency , which ranges from 5% to 15% in children , seems to be much higher in adults , at approximately 30% . they reported to define long - term prognosis and risk factors for severe renal failure in adults with hspn . renal function impairment and proteinuria level at presentation and , the degree of interstitial fibrosis , percentage of sclerotic glomeruli , and presence of glomeruli with fibrinoid necrosis on renal biopsy were associated with a poor renal prognosis . our elderly patient underwent a kidney biopsy - proven , sudden developed hspn associated with nephritic - nephrotic syndrome with hypocomplementemia and p - anca after a major operation for the treatment of cancer . after being initially treated with prednisolone , his purpura and edema on the legs improved , but renal function did not improve . this case implies that the prognosis of elderly - onset crescentic hsp nephritis with positive mpo - anca and hypocomplentemia may be a poor outcome . therefore , closed inspection would be helpful to monitor the progression of elderly - onset hsp , and the clinician should not delay renal biopsy to confirm the diagnosis at the time of clinical suspicion of renal involvement . earlier diagnosis and prompt treatment of elderly - onset hspn will prevent the progress of end - stage renal failure . only few cases with elderly onset hspn we describe elderly onset hspn with mpo - anca can be crescentic glomerulonephritis rapidly progressed to end stage renal failure .