Felis ISSN 2398-2950

Systemic lupus erythematosus

Introduction

• Multisystemic autoimmune rare disease.
• Cause: autoantibodies produced against self antigens.
• Signs: depression, stiffness, glomerulonephropathy, neurological disease.
• Diagnosis: hematology, ANA titer, histopathology.
• Treatment: immunosuppressive therapy.
• Prognosis: guarded.

Pathogenesis

Etiology

• Unknown but probably multifactorial.
• Genetic, viral and hormonal influences have been implicated.

Pathophysiology

• Loss of self tolerance   →   autoantibodies and cytotoxic lymphocytes acting against 'self'   →   tissue pathology.

• Autoantibodies react with self antigens in multiple organ systems.
• Direct effects caused by antibody binding to surface antigens:
  • Hemolysis of red cells   →   anemia.
  • Destruction of platelets   →   thrombocytopenia.
  • Damage to white cells   →   leucopenia.
• Indirect effects due to circulating antibody-antigen complexes:
  • Deposition in glomeruli   →   glomerulonephropathy   →   CRF and protein loss   →   hypoproteinemia Hypoproteinemia.
  • Deposition in basement membrane in epithelium   →   mucocutaneous junction lesions.
  • Circulating complexes can   →   macrophage and complement activation.
• Cytotoxic lymphocyte infiltration of tissue.
• Interface dermatitis.
• Synovitis.

Timecourse

• Weeks to months.

Diagnosis

Treatment

Outcomes