The renal system is a major target in diseases that involve immune dysfunction such as vasculitis, production of autoantibodies, as well as abnormal protein load seen in amyloidosis and myeloma.
Lupus nephritis
Renal involvement is common in SLE, leading to immune-complex glomerulonephritis.
- Antibodies against nuclear elements circulate within the blood, form immune complexes, and deposite in the glomeruli.
- Nearly all patients with SLE have some degree of renal damage.
- Presents with SLE-related symptoms (rashes), along with symptoms seen in glomerulonephritis (hematuria, nephrotic-range proteinuria, edema and hypertension).
- Can be classified based on the severity and involvement into 6 classes (I-VI):
- Class I minimum mesangial
- Class II mesangial proliferative
- Class III focal (<50%) proliferative
- Class IV diffuse (>50%) proliferative
- Class V membranous
- Class VI advanced sclerosing
- Antiphospholipid syndrome may occur as a part of SLE (or by itself), where circulating lupus anticoagulants cause microthrombi, ischemia, and tissue damage.
Diagnosis
- Serology (ANAs)
- Urinalysis and measurement of serum creatinine
- Biopsy
Treatment
- ACEi/ARB
- Prednisone and cyclophosphamide
- Dialysis
- Renal transplantation
Amyloidosis
Amyloids are misfolded fibrillar proteins that