Acute tubulointerstitial nephritis: Acute tubulointerstitial nephritis Dr Mohammed Abdelsattar
Kidney consist of :: Kidney consist of :
PowerPoint Presentation: The term tubulointerstitial is used to broadly refer to kidney diseases that involve structures in the kidney outside the glomerulus . These diseases generally involve tubules and/or the interstitium of the kidney and spare the glomeruli
PowerPoint Presentation: All drugs can cause interstitial nephritis But the most common are:- AB as Rifampicin PPI Vit k frusamide NSAID
histopathologic findings in ATIN: histopathologic findings in ATIN Presence of inflammatory cell infiltrate (CD41 T cells, macrophages, eosinophils , and plasma cells) Interstitial edema Normal glomeruli and vessels : This, in particular, distinguishes this disease process from inflammatory glomerular diseases (e.g., glomerulonephritides ) Granulomas located in the interstitium Immunofluorescence : linear deposition of immunoglobulin G ( IgG ) along the TBM Electron microscopy: diffuse effacement of the foot processes Interstitial fibrosis and tubular atrophy
latent period: latent period there is usually a delay between the initial insult (exposure to offending drug or infectious agent) and the onset of decline in renal function From one day to weeks to months
symptoms: symptoms
laboratory manifestations of ATIN : laboratory manifestations of ATIN > Azotemia (elevated BUN and serum creatinine ) >Peripheral eosinophilia > Eosinophiluria >Sterile pyuria (occasionally, white blood cell [WBC] casts) >Microscopic hematuria (very rarely, red blood cell [RBC] casts) > Proteinuria (usually in the non- nephrotic range) >Renal tubular acidosis
PowerPoint Presentation: However, eosinophiluria is a nonspecific finding that can be seen in a variety of conditions (e.g., acute pyelonephritis , acute glomerulonephritis , acute cystitis and prostatitis ). Its absence, however, does not exclude the diagnosis of ATIN
PowerPoint Presentation: urinary sediment can be helpful in excluding other causes of AKI. For instance, RBC casts are usually seen in acute glomerulonephritis and muddy-brown granular casts are seen in acute tubular necrosis (ATN). Normal urinalysis should not be used to exclude the diagnosis of ATIN
PowerPoint Presentation: Relation can be established Between the offending agent or drug and the onset of clinical and laboratory manifestations
PowerPoint Presentation: The only definitive and confirmatory diagnostic procedure is a renal biopsy indications for a renal biopsy in suspected ATIN : >AKI, whereby the diagnosis remains uncertain despite extensive laboratory testing, >Absence of any signs of improvement after withdrawal of suspected offending agent > In suspected ATIN cases, where immunosuppressive therapy is being considered
TTT: TTT >withdrawal of offending agent and avoidance of exposure to other potential nephrotoxic agents > Corticosteroid therapy (one mg/kg for 4-6w)