Urinalysis Chapter 8: Renal Disease

3 classifications of renal disease

glomerular, tubular, interstitial

Non-immunological causes of glomerular damage

chemical and toxin exposure; disruption of electrical charges; deposition of amyloid material and acute phase reactants; thickening of basement membrane with diabetic nephropathy

glomerulonephritis

inflammatory process affects glomerulus; associated with increased blood, protein, casts in the urine

Types of glomerulonephritis

acute poststreptococcal, rapidly progressive (crescentic), goodpasture, granulomatosis w/ polyangiitis, Henoch-Schonlein Purpura, Membranous, Membranoproliferative, Chronic, Immunoglobulin Nephropathy

Acute glomerulonephritis (AGN)

sudden onset of symptoms corresponding to glomerular membrane damage: fever, edema, fatigue, nausea, hypertension, oliguria, proteinuria, hematuria

-immune complexes clog the kidneys

Rapidly progressive (crescentic) glomerulonephritis (RPGN)

initiated by deposition of immune complexes

-crescentic formations of macrophages, fibroblasts, polymerized fibrin

Goodpasture Syndrome

autoimmune disorder; cytotoxic Ab against basement membrane after viral respiratory infections (antiglomerular basement membrane antibody);

-proteinuria, hematuria, RBC casts

Granulomatosis w/ Polyangiitis

granuloma-producing inflammation of the kidney blood vessels

-ANCA: antineutrophilic cytoplasmic antibody

-pulmonary symptoms, hematuria, proteinuria, RBC casts, elevated serum creatinine and BUN

Henoch-Schonlein Purpura

mild-heavy proteinuria, hematuria, RBC casts

-occurs after upper respiratory infection

Membranous Glomerulonephritis (MGN)

thickening of the glomerular basement membrane via IgG complexes; tendency towards nephrotic syndrome and thrombosis

-microscopic hematuria and elevated proteinuria

Membranoproliferative Glomerulonephritis (MPGN)

alterations in the cellularity of the glomerulus and peripheral capillaries

-hematuria, proteinuria, decreased serum complement levels

Chronic Glomerulonephritis (CSGN)

Worsening symptoms: fatigue, anemia, hypertension, edema, oliguria

-hematuria, proteinuria, glucosuria, broad casts, decreased GFR, increased serum BUN, electrolyte imbalance

Immunoglobulin A nephropathy (Berger disease)

deposits of IgA complexes; macroscopic hematuria after infection or strenuous exercise; gradual progression to ESRD

What is the most common cause of glomerulonephritis

IgA nephropathy

Nephrotic Syndrome

massive proteinuria, low serum albumin, edema

-due to a progression of glomerulonephritis or acute circulatory disruption and systemic shock

-damaged shield of negativity

-proteinuria, fat droplets, oval fat bodies, RTEs, epithelial fatty and waxy casts, microscopic hematuria

Minimal change disease (MCD)

aka: lipid nephrosis, nil disease

-increased protein filtration

-edema, proteinuria, transient hematuria, normal BUN + creatinine

-most common cause of nephrotic syndrome in kids

Focal segmental glomerulosclerosis (FSGS)

-seen in association with heroin abuse, analgesics, HIV, hepatitis

-moderate-heavy proteinuria, microscopic hematuria

Major Tubular Disorders

Acute Tubular Necrosis, Fanconi syndrome, Alport syndrome, Uromodulin-Associated kidney disease, diabetic nephropathy, nephrogenic diabetes insipidus, renal glycosuria

Acute tubular necrosis (ATN)

-primary disorder associated with damage to the tubules produced by ischemia 9acute) or toxic substances (gradual)

-mild proteinuria, microscopic hematuria, RTE cells and casts

-may have hyaline, granular, waxy, and broad casts

Fanconi syndrome

disorder most frequently associated with tubular dysfunction (PCT)

-affected reabsorption of glucose, a.a., phosphorous, sodium, potassium, bicarbonate, water

-glycosuria, mild proteinuria, low pH

Causes of Fanconi syndrome

1. Inherited in association with Hartnup disease and cystinosis

2. Acquired through exposure to toxic agents (metals & outdated tetracycline); complication of multiple myeloma or renal transplant

Alport Syndrome

-inherited disorder of collagen production affecting the basement membrane - lamellated thinning

-hematuria, proteinuria, renal insufficiency

Uromodulin-Associated kidney disease

-autosomal mutation in the gene that produces uromodulin

-abnormal uromodulin builds up in RTEs causing their destruction

-serum uric acid buildup causing gout

Diabetic Nephropathy

excessive excretion of urine with inability to respond to ADH and causes glomerular damage

-low sg, pale yellow color, potential false negative chemical tests

-microalbuminuria

Renal Glycosuria

-only affects reabsorption of glucose

-inherited increase in transporters or decrease in transporter affinity

Major interstitial disorders

UTI, Acute pyelonephritis, chronic pyelonephritis, acute interstitial nephritis

UTI

-most common renal disease (most often in the bladder) cystitis

-WBCs, bacteria, mild proteinuria, hematuria, increased pH; absence of pathological casts

Acute pyelonephritis

infection of the URT including the tubules and interstitium (pyelonephritis)

-enhanced by obstructed urination via renal calculi, pregnancy, vesicoureteral reflux

High correlation with bacteremia

-WBCs, bacteria, mild protein and hematuria; WBC casts

Chronic pyelonephritis

-permanent damage to the renal tubules

-most frequently caused by congenital structural defects producing reflux nephropathy

-diagnosed in children

-granular, broad, waxy casts present in later stages; hemat- and proteinuria; renal concentration is decreased

Acute interstitial nephritis (AIN)

inflammation of the renal interstitium followed by the tubules

-rapid onset of oliguria, edema, decreased renal concentrating ability, decrease in GFR, fever, skin rash

-primarily associated with allergic reaction to medication (binding to the interstitial protein)

-may need supportive renal dialysis

-hematuria, proteinuria, WBCs and casts w/o bacteria, eosinophils

-Wright stain

progression to ESRD

GFR less than 25 mL/min; increase in serum BUN and creatinine; electrolyte imbalance; lack of concentrating ability/isosthenuric urine; proteinuria; renal glycosuria; abundance of granular waxy and broad casts

Primary causes of acute renal failure (ARF)

sudden decrease in blood flow to the kidney, acute glomerular and tubular diseases, renal calculi, tumor obstructions

Signs of ARF

-decreased GFR, oliguria, edema, azotemia

-symptoms vary based on the primary cause

Renal Lithiasis

calculi form in the calyces, renal pelvis, ureters, and bladder

-will present with microscopic hematuria

-lithotripsy is used to break stones

major constituents of renal calculi

75% are made of calcium oxalate or calcium phosphate

-others may contain magnesium ammonium phosphate (Struvite), uric acid, cystine