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Renal 14 Tubulo. Dz
Ryan: Tubulointerstital Disease
Question | Answer |
---|---|
What are the different types of tubulointerstitial disease? | Acute interstitial nephritis Chronic interstitial nephritis Acute tubular necrosis Renal tubular acidosis Multiple myeloma |
List the general features of tubulointerstitial disease. | Proteinuria <1g/day Anemia Acidosis Hypertension WBCs and WBC casts on UA Na and K abnormalities |
List the general features of glomerular disease. | Proteinuria >3-3.5 g/day Anemia is uncommon Acidosis is uncommon Hypertension Oval fat bodies on UA May see low Na |
Acute interstitial nephritis (AIN) is also known as what? | Drug-induced hypersensitivity |
What may be seen on UA? | Eosinophils, RBCs, WBCs, and WBC casts NO RBC casts or fat bodies |
Which drugs normally cause AIN? | Antibiotics NSAIDS Cimetidine Thiazides Allopurinol |
What infections can cause AIN? | CMV Legionella Leptospiosis Streptococcus |
What clinical features will you see in a pt with AIN? | Rash Fever Azotemia (RF) Malaise Arthalgias |
How soon after starting a new medication can these symptoms be seen? | 7-10 days after starting a new medication |
What would you expect to see in a pts lab? | Eosinophilia Elevated sed rate Low C3&C4 WBCs and WBC casts |
What stain is associated with AIN? | *Hansel's stain* ---BUZZWORD--- |
Which antibiotics most commonly cause AIN? | Beta-lactams TMP/SMX (sulfa) Ripfampin Fluoroquinolones (rarely in kids) |
What is the classic triad of AIN? | Fever Rash Eosinophils |
What is this response related to? | No clue, not related to dose or duration |
How long do you have to be taking NSAIDs before you start to see symptoms? | Several months |
Why might the AIN triad not occur? | Anti-inflammatory drugs block the inflammatory response |
What systemic diseases can cause AIN? | Sarcoidosis SLE Any infection (pyelonephritis) Transplant rejection (drugs) |
Tx of AIN | STOP THE DRUG!!! Usually brings about an improvement of renal fxn |
Chronic Interstitial Nephritis (CIN) | Chronic condition involving fibrosis of the interstitium and tubular destruction |
What pts should this be on your DDx for? | Hx of frequent pain who present with proteinuria & elevated creatintine Glucosuria with normal serum glucose |
Check for _____ in kids | *lead toxicity* |
What drug class may be responsible? | NSAIDs Can cause acute or chronic IN |
Name the post renal causes of CIN. | Chronic Obstructive Uropathy (urethral reflux) Chronic Pyelonephritis Chronic Renal Lithiasis |
List the other causes of CIN | Medications Post acute Tubular Necrosis Autoimmune- Sjogren's syndrome Raditaion |
The hallmark of CIN | **Sterile Pyuria** Inflammatory response to something |
Clinical features of CIN | Usually asymptomatic Anemia Acidosis RTA Minimal Proteinuria Hypertension |
Tx of CIN | BP control is the MOST IMPORTANT ACEI/ARB are DoC Anemia control Acidosis control Phosphorus control |
Do you give a pt with CIN pyuria antibiotics? | NO Not unless there is bacteria present It's inflammatory, NOT an infxn |
Acute Tubular Necrosis (ATN) | Most common RENAL ARF Necrosis due to microthrombi Frequently due to prolonged hypotension and augmentation of the immune system from sepsis. |
Causes of ATN | Sepsis Drugs (NSAIDs) Post-operative-post CABG Pancreatitis Prolonged and Untreated prerenal conditions |
Clinical features of ATN | Oliguric or non-oliguric Azotemia Elevations in serum Creatinine may not reflect the degree of renal dysfxn Acidosis/hyperkalemia |
ATN labs | Uosm <350, Una >40, FeNa >2 Plasma BUN/Cr <10-15 Ucr/Pcr <20 **Muddy brown casts on Urine Sed.** |
Tx of ATN | Treat underlying condition Dopamine doesn't work ANP doesn't work High dose Loops: limited Dialysis MAY increase survival |
Rental tubular acidosis (RTA) | Met. acidosis usually caused by a defect in renal tubular fxn (genetic) |
How many types of RTA exist? | 3 types: 1 proximal (type 2) 2 distal (types 1 & 4) |
What does the anion gap look like in RTA? | Normal gap metabolic acidosis |
Relate RTA types with serum K | Type 1: Low K Type 2: Normal L Type 3: High K |
Type 2 RTAs | Mechanism similar to acetazolamide (decreased HCO3 reabsorption in the proximal tubule) |
Causes Type 2 RTA in children | Fanconi Syndrome |
Fanconi syndrome | Rare disorder of tubule fxn Results in excess glucose, HCO3, phosphates, uric acid, K, Na, and some amino acids in the urine May be hereditary |
Etiologies of Type 2 RTA | Drugs Heavy Metals Disorders or protein, carbs, or amino acid metabolism Multiple myeloma (adults) |
Type 4 RTA | Affects Na/K-H exchange in the DCT Similar to spirnolactone |
Common etiologies of Type 4 RTA in kids | Obstructive uropathy Interstitial renal dz Multicystic dysplastic kidneys |
Etiologies of Type 4 RTA | Type 1 pseudoaldosteronism Diabetic nephropathy 21-hydroxylase deficiency Renal transplant |
RTA Type 4 Tx | Tx aimed at treatingthe primary dz Try to give HCO3 but MUST restrict K |
Type 1 RTA | Distal defect in H secretion Pts become acidotic and hypokalemic Commonly causes renal stones |
How do children with Type 1 RTA present? | Commonly with failure to thrive |
Etiologies of Type 1 RTA | Amphotericin B Toluene Lithium SLE Sjogren's Syndrome Chronic active hepatitis |
Multiple Myeloma | Blood cancer in which plasma cells grow uncontrollably, usually in the bone marrow |
Associated bone lesions | Cause structural damage and/or fractures from overproduction of myeloma cells |
Why is it referred to as Multiple Myeloma? | Because 90% of patients have multiple bone lesions |
Causes of renal failure in MM | Cast nephropathy Light chain deposition dz Primary amyloidosis Hypercalcemia Renal tubular dysfunction Volume depletion |
Myeloma Kidney mechanisms | Intracellular cast formation Direct tubular toxicity by light chains |
Cast nephropathy | Most common pathological Dx on renal biopsy in MM |
Light chains bind with this | Tamm-Horsfall Mucoprotein |
Where is the Tamm-Horsfall mucoprotein secreted? | From tubular cells in the ascending loop on Henle |
This will worsen cast nephropathy | Dehydration Due to decreased flow and increase in [light chain] |
Light chain deposition disease | Most commonly presents with both renal insufficiency and nephrotic syndrome |
Which Ig id responsible? | Kappa Ig |
What takes up/metabolizes the light chains? | Macrophages |
Amyloidosis | Usually due to lambda light chains |
What stain is used for amyloidosis? | **Congo Red** Beta-pleated |
Why does renal failure develop? | From tubular injury Also presents as nephrotic syndrome |
Hypercalcemia in MM | Occurs from bone reabsorption 15% of pts with MM |
Contributes to renal failure by... | Renal vasoconstriction Leads to intratubular calcium deposition. |
Acquired Fanconi syndrome | Light chains cause tubular dysfunction w/o renal insufficiency Mostly kappa light chains |
Light chains are resistant to ___ and form ___ | Degradation Crystals |
Two ways tubular damage is caused | Light chain toxic effects Indirectly from the release of intracellular lysosomal enzymes |
MM lab findings | Elevated BUN and Creatinine Hypercalcemia, uricemia Low anion gap UA shows NO protein Elevations in the gamma fraction-Bence-Jones Protein |
Tx of renal failure in MM | Hydration with IV fluids Tx of hypercalcemia (Loops) Tx of myeloma (steroids) Possible plasmapheresis Dialysis |
***MM Buzzwords*** | Chronin back pain Males >50 African-American Hepatosplenomegaly Cardiomyopathy |