About 20-40% of adult lupus patients and 30-80% of children develop kidney damage. This is more common in Asians and patients of African descent than in Caucasians.

The result of the kidney biopsy will define the severity of this kidney involvement and will largely dictate the treatment needed to control it. Severe forms of lupus nephritis (called proliferative) justify treatment combining corticosteroids at initially high doses (prednisone: 0.5 to 1 mg / kg / day) and immunosuppressive treatment (mycophenolate mofetil or cyclophosphamide) in addition to hydroxychloroquine-, which will reduce inflammation of the kidney.

This therapeutic strategy almost always makes it possible to improve the lupus kidney damage, often even to cure it, or at least stabilise it. The benefit is mostly seen in the long term. For this reason, it is important to continue immunosuppressive therapy for a long time (at least 2 years). Sometimes it is necessary to carry out a control renal biopsy after a few months to check the effectiveness of the treatment. If you have high blood pressure, or if significant proteinuria persists even without hypertension, you will be prescribed a medication that reduces blood pressure and pressure in the renal filters, to reduce the leakage of protein into the urine and to protect the kidney (this is called "nephroprotection").

There is still a risk of relapse that requires regular monitoring and continued use of hydroxychloroquine, even if immunosuppressive therapy may have been stopped.

Rarely, despite all these treatments, kidney damage can continue to worsen, gradually leading to the need for kidney transplant or dialysis (this is called "end-stage" renal failure to say that the kidneys no longer perform their purification functions at all).