Lupus Nephritis (LN)

Lupus cystitis: Rare (0.02%-2%) complication resulting from immune complex vasculitis of the small vessels of the bladder

• Female > male (90% female)

• dsDNA positive in ~75% of cases

• May be more likely to have lupus enteritis or central nervous system involvement; often occurs along with GI involvement

• Can happen at any time in illness course and even precede SLE diagnosis

• Symptoms:

  • Frequency, urgency most common

  • Suprapubic pain, nocturia, dysuria

  • Often occurs along with GI involvement, and GI symptoms may present first: nausea, abdominal pain, constipation

• Diagnosis:

  • UA: may be normal or demonstrate hematuria

  • Imaging:

    • Bladder inflammation: Bladder wall thickening, ↓ bladder capacity

    • GI involvement: bowel wall thickening, ascites, "target" or "comb" signs

      • Target = thickened bowel wall demonstrating 3 layers (on contrast CT): high attenuation (brightness) on inner and outer layers, with decreased attenuation in between

      • Comb = inflammation of mesentery: increased density of the distended intestinal arcades which makes it look like the teeth of a comb

  • Bladder biopsy: leukocytic filtration of bladder vessel walls, deposition of IgG, IgA, IgM, C3 and C1q

    • Immune complex-mediated vasculitis thought to be the cause of lupus cystitis

• Treatment with immunosuppresssion - no standard regimen

  • pulse steroids, MMF, cyclophosphamide, rituximab

    • Caution with cyclophosphamide given risk of hemorrhagic cystitis

  • Cetirizine hydrochloride?? Has been reported in small case series

SLE can cause transverse myelitis, inflammatory polyneuropathy which can affect bladder

• Sacral spinal cord inflammation -> impaired bladder sensation and paralysis, which could lead to VUR, hydronephrosis, and hydroureter

  • Should have other symptoms like weakness, numbness/tingling, coldness, burning sensation