✆ Common Calls ✆
Hematuria

• Microscopic: dipstick ≥1+ blood, microscopy ≥5 RBCs/hpf

  • Need two samples to make diagnosis

• Gross (macroscopic): visible blood in urine and blood present on microscopy

Pitfalls

• • Always ensure any postmenarchal girls are not on menses when sample was taken (high risk of contamination)

If discrepant (positive dipstick but negative microscopy), consider:

• • Lysis of RBCs due to urine dilution

  • Myoglobinuria (rhabdomyolysis)

  • Hemoglobinuria (intravascular hemolysis)

History

• • Thorough history can help distinguish between glomerulonephritis, hypercalciuria, stones, urinary tract disorders

  • Recent illnesses?

    • Sore throat (pharyngitis) in the past 1-2 weeks or rash (impetigo) in the past 6 weeks would suggest post-infectious glomerulonephritis (PIGN)

    • Painful urination (dysuria), urinary urgency, ↑ urinary frequency,

  • If postmenarchal girl: active menses? (High risk of contamination)

Exam

• • Blood pressures: if normotensive, makes GN less likely

    • Note: ensure you know the patient's age and most recent height to be able to plot the blood pressure appropriately

  • Ensure no urethral meatus present

Labs:

• • Urine

    • Urinalysis w/ microscopy

    • Urine protein/creatinine ratio (UPC) from first morning void

    • Consider urine calcium/creatinine ratio (UCa/Cr)

  • Blood

    • Kidney function panel (BMP+Ca+Albumin+PO4)

    • Antistreptolysin O (ASO)

    • C3

    • Antinuclear antibody (ANA)

  • Imaging

    • Consider ultrasound (e.g., if concerned for anatomic abnormality, obstructing kidney stone)

• Biopsy

  • May be indicated if significant hematuria and/or concomitant proteinuria

• Differential:

Tuberculosis

MR urogram: Putty

Frequency, urgency

Bilobed cysts

Oxybutynin

Enlarged kidneys

Renal TB

• Caused by Mycobacterium tuberculosis, a low growing gram positive bacillus

• >95% airborne transmission; less commonly transplacental and sexual transmission

• 5-45% of TB patients have extrapulmonary TB

• Common sites: lymph nodes, pleura, bones, meninges, urogenital tract

  • Via hematogenous or lymphatic spread

• Most frequently diagnosed presentation of urogenital TB

• Up to 10% have active TB, CXR abnormal in 50%

• Usually bilateral

• Granulomas and caseous necrosis can occur throughout the renal tissue, particularly in the cortex or peritubular capillary bed ("putty kidney")

• Can progress to tubulointerstitial nephritis, papillary necrosis, eventually calcifications

• Dissemination into renal pelvis can lead to tuberculous pyelonephritis, scarring of the renal pelvis/ UPJ, and urinary flow obstruction leading to dilated calyces

• Can also see RPGN, crescentic GN, membranous nephropathy

• Ureteric TB

  • Can involve any part of the ureter

  • TB of ureters without renal TB has NOT been described

  • Seen in up to 50% of patients with renal tB

  • Mtb spreads from renal medullary lesions to the ureters in bladder

  • Granulomas form in the mucosa -> inflammation, ulceration and fibrosis -> stricture formation, obstruction, reflux

  • Bladder TB

    • Usually secondary to renal TB (21%)

    • Spread from primary or secondary lesions elsewhere or retrograde from testicular or prostatic TB

    • Tuberculomas

    • Narrowing of UJV due to chronic inflammation and fibrosis -> ureterovesical reflux and hydroureteronephrosis

    • Thimble bladder - small capacity, irregular bladder due to chronic inflammation and progressive thickening wall with calcifications

    • Bladder perforation and fistula fistula formation (Vesicovaginal, vesicocolic, etc.)

• Urinary TB

  • Many asymptomatic early on

  • Autopsy studies reveal ~50% of patients with renal TB reported to have symptoms

  • Can present with dysuria, increased frequency and urgency, or flank pain

  • UA - Cx negative, sterile pyuria

  • Not usually with constitutional symptoms

  • Diagnosis: 3 early morning urine samples with acid-fast stain, mycobacterial culture, and PCR for Mtb

    • Urine mycobacterial culture - wide range of sensitivity (10-90%)

    • Urine AFB stain - SN 30-40%, can be false positive as nontuberculous mycobacterium can be in urine

    • Urine PCR - SN 87-100%

    • Renal biopsy (if done) - granulomas, presence of acid fast Mtb bacilli

• Treatment: Anti-tB drugs mainstay of treatment

  • Surgical intervention necessary in upt o50% of cases

    • Urinary obstruction, abscess, nephrectomy for nonfunctioning kidneys, ureter reconstruction, bladder reconstruction to improve functional bladder capacity

    • Relapse of urogenital TB can occur after initial urine sterilization in up to 6% of cases after a mean of 5 years of treatment

    • Therefore, surveillance is warranted for 10 years (screening every 6-12 months)

  • Medical:

    • oxybutynin, solifenacin

    • Mirabegron (beta-3 agonist)