What is considered the most serious organ involvement in SLE?

• A. polyarthritis
• B. lupus nephritis
• C. acute cutaneous eruption
• D. pleuritis

Answer: (B)

The most serious organ involvement in SLE is kidney disease. Lupus nephritis results from immune complex deposition in the glomeruli, triggering inflammation that can rapidly impair filtration. Patients may present with proteinuria, hematuria, and rising creatinine, and without effective treatment this can progress to nephrotic syndrome, irreversible kidney scarring, and eventual end-stage renal disease requiring dialysis or transplant. Because loss of renal function is a major driver of morbidity and mortality in SLE, kidney involvement stands out as the most critical organ system to monitor and treat early.

Joint involvement is common and can cause significant disability, but it is usually non-life-threatening and non-renal in nature. Skin eruptions and serositis can be troublesome and reflect disease activity, yet they do not carry the same risk of irreversible organ failure as lupus nephritis.