Pocket Pediatrics: The Massachusetts General Hospital for Children Handbook of Pediatrics (Pocket Notebook Series), 2 Ed.

SYSTEMIC LUPUS ERYTHEMATOSUS

Definition (Pediatr Rev 2012;33:62)

• SLE: Chronic, episodic, multisystem, AI dz w/ presence of antinuclear auto-Abs to ds-DNA & w/ widespread vascular & connective tissue inflammation; more severe in children

• Neonatal lupus syndrome: Passively transferred AI dz in 1% of neonates born to moms w/ AI dz (SLE, Sjögren), by transplacental passage of maternal anti-Ro or anti-La Abs; clinically w/ congenital heart block (30%), rash, and rarely hepatobiliary or hematologic manifestations (anemia, thrombocytopenia)

• “Drug-induced lupus” syndrome: Variant form of lupus that resolves w/i d to 

mos after w/d of drug in pt w/ no underlying immune dysfxn. Most commonly w/ hydralazine, procainamide, quinidine, isoniazid, diltiazem, phenytoin, α-methyldopa, ethosuximide, trimethadione, carbamazepine, and minocycline

Epidemiology

• 20% of cases dx’d <20 yo; avg onset is at 12 yo; pre-puberty 3:1 :, post-puberty 9:1

• Incidence and severity greater in AA, Hispanics, and Asians compared to Caucasians

• With aggressive therapy 5 yr survival in pediatric SLE 100%; 10 yr survival 86%

Pathophysiology

• Combination of hormonal and environmental factors in predisposed individuals

• 10% patients w/ +1st-degree family member w/ SLE

• Autoreactive B- and T-cells → antigen–Ab complexes in circulation and deposit in tissues, such as renal glomerulus, dermal–epidermoid junction, and choroid plexus

• Immune complexes activate complement system, resulting in hypocomplementemia during the active phase and presence of complement activation products

Clinical Manifestations (Pediatr Rev 2012;33:62)

• Dx based on ACR criteria used for adults w/ 4+ criteria simultaneously or serially

• W/ +ANA titers, 4 classifications exist: Classical SLE (many criteria), definite SLE 

(≥4 criteria), probable SLE (3 criteria), possible SLE (2 criteria present)

• ACR criteria for dx of SLE from (Arthritis Rheum 1982;52: revised in 1997)

Adapted from prevalence data from French multicenter study published in J Pediatr 2005;146:648.

Diagnostic Studies

• Autoantibodies in SLE (N Engl J Med 2008;358:929); ANA+ in 99% pts w/ SLE

• Dx based on ACR criteria. Other abn labs: ↓ C3 and C4, ↑ ESR and CRP, ↑ serum Cr, ↓ serum albumin, ↓ Hgb, WBC or Plts, abn values found on 24-hr urine collection for calc of CrCl and quantification of proteinuria, GN, or mesangial dz on renal bx

Management

• Mild SLE: NSAIDs, hydroxychloroquine 200–400 mg qd, low-dose corticosteroids, dapsone may be used for dermatologic manifestations

• Mod SLE: Longer-term corticosteroids, mycophenolate mofetil, azathioprine, MTX

• Severe SLE: IV cyclophosphamide, mycophenolate mofetil, Rituximab (anti-CD-20 monoclonal Ab), stem cell transplantation, renal transplantation

Complications

• Risk for Libman–Sacks endocarditis and superimposed bacterial endocarditis

• Early atherosclerosis and coronary artery disease

• Antiphospholipid Abs ↑ risks of VTE (2–6× ↑), risk further ↑’d w/ OCP/pregnancies

• Morbidity & mortality in children primarily affected by degree of renal involv, in adults morbidity & mortality is most affected by long-term cardiovascular dz