Lupus Erythematosus Flashcards
What are the 3 major types of Lupus erythematosus?
Acute (ACLE), subacute (SCLE), and chronic (CCLE)
Are the 3 types of cutaneous lupus mutally exclusive?
No, every form of cutaneous lupus can be seen in a patient –> they can have more than one type
What level of ANA do you need to be considered +?
In adults <65 y/o: 1:160 In adults >65 y/o: 1:320
Are there any cutaneous lupus findings that are not associated with systemic lupus?
No, every form of cutaneous lupus may be seen in the setting of SLE or as an isolated cutaneous dz. -However, the degree of association with SLE (systemic dz) varies by cutaneous type.
What antibody do you use to monitor lupus associated nephritis?
dsDNA.
What percent of the population have + ANA’s at 1:40, 1:80, and 1:160?
30%, 13% and 5% respectively
What autoantibody is + in neuropsychiatric LE but only 7% of normal LE?
rRNP (ribosomal P protein)
How prevalent is a + ANA in lupus?
99%
How prevalent is ssDNA in LE and what is its significance when positive?
Denature DNA, + in 70% of LE cases. Possible risk for SLE in DLE patients. Also seen in RA, MCTD, localized scleroderma, systemic sclerosis, Sjogren’s syndrome.
Prevalence of Ro (SS-A) autoantibodies in LE?
LE = 50%, SCLE (75-90%), neonatal LE/congenital heart block (99%), SCLE-SjS overlap
Prevalence and significance of cardiolipin autoantibody in LE
50% in LE, cardiolipin is a negatively charged phospholipid. Important for antiphospholipid syndrome. Recurrent spontaeous abortions, thrombocytopenia, and hypercoagulable state in SLE.
Cutaneous manifestations of antiphospholipid syndrome?
Livedo reticularis, leg ulcers, acral infarction/ulceration, hemorrhagic cutaneous necrosis. -Similar associations in primary antiphospholipid antibody syndrome, clinical associations strongest with IgG class of anticardiolipin
Prevalence of Histone autoantibodies and significance in LE?
40% of LE, important in drug-induced SLE, RA
Prevalence and importance of B2 (beta 2) glycoprotein I antibody in LE?
25% in LE, it’s an important cofactor for cardiolipin in cardiolipin autoantibody assays. It confers a relatively high risk of thrombosis in SLE and primary antiphospholipid antibody syndrome.
Clinical presentation of acute cutaneous lupus erythematosus (ACLE)?
Non-scarring, facial/malar erythema, photodistributed exanthematous to urticarial eruption (favors: upper chest, extensor arms, dorsal hands w/ sparing of knuckles) and can be widespread –> to include non-photodistrubted areas.
Clinical presentation of subacute cutaneous lupus erythematosus (SCLE)?
Non-scarring, annular, or papulosquamous eruption in photodistributed sites - favor upper trunk and upper outer arms >> lateral neck, forearms, hands . Often SPARES the mid-face/malar region - long term pigmentary changes common after resolution.
What percentage of those with SCLE meet criteria for dx of SLE and what is the phenotype of their disease?
50% meet the criteria. Rarely have serious systemic sequelae, arthralgias are the most common.
What autoantibody is common in SCLE?
Anti-Ro/SSA is positive in 70%
Clinical presentation of discoid lupus or chronic cutaneous lupus erythematosus? (CCLE)
Localized, ofthen on the head and neck. Can have widespread or lesions beyond the head and neck. There is also an unusual varient, hypertropic DLE which have thick scale overlying or at periphery of lesions. -CCLE can involve mucosal surfaces, palms and soles - occur in both UV and non-UV exposed sites early lesions are inflamed, indurated plaques with surrounding scale → well-established lesions have follicular plugging (clinically hyperkeratosis), atrophy, scarring, and alopecia - examine concha bowl for follicular plugging and scarring
What percentage of patients with DLE go on to have SLE?
Those with head and neck involvment (5-10% –> SLE) Widespread involvement of the extremities and trunk (~20% –> SLE)
What are the 3 other types of chronic cutaneous LE? (CCLE)
Tumid LE, lupus panniculitis, Chilblain LE
Clinical presentation of tumid LE?
Onset is delayed by 1-2 weeks of inciting stimulus (UVR) b/c pathology is deeper -Most common on the face and upper trunk (erythema, induration, central clearing) - ABSENCE of follicular plugging, scarring, and atrophy.
What percentage of those with tumid LE go on to SLE?
<1% → SLE
Presentation of lupus panniculitis?
Absence of scale with eventual lipoatrophy favoring the face, upper outer arms, upper trunks, breasts, thighs - Presence of discoid lesions + lipoatrophy = lupus profundus
Presentation of Chilblain LE?
erythematous to dusky purple papulonodules and plaques of toes, fingers >> nose, elbows, knees, and lower extremities - lesions triggered or worsened by cold (Chilblains get’s worse when chilly outside)
What percentage of Chilblain LE goes on to SLE?
Up to 20% → SLE
What genetic mutation is Chilblain LE associated with?
Familial chilblain LE a/w TREX1 (DNA exonuclease) mutation
Clinical presentation of neonatal LE?
similar to SCLE but favor the face and periorbital areas and may be atrophic.
Pathogenesis of neonatal LE?
2/2 maternal anti-Ro/SSA (98%) but can also be mediated by anti-La/SSB or anti-U1RNP - Photosensitivity is common but not necessary for lesion formation - Lesions cease after 6-9 months (clearance of pathogenic antibodies)
Internal manifestations of neonatal LE?
(i) congenital heart block +/- cardiomyopathy (ii) hepatobiliary disease (iii) thrombocytopenia >> neutropenia or anemia (iv) macrocephaly or skeletal dysplasia - heart block presents at birth and requires pacemaker
Workup for neonatal LE?
EKG +/- ECHO, CBC w/ diff, LFTs and repeat periodically over first 6 months
Presentation of bullous SLE?
Vesicles to large tense bullae on an erythematous base favoring face, neck, upper trunk, proximal extremities, and mucosal surfaces in SLE pts
Pathogenesis of bullous SLE?
Autoantibodies direct against type VII collagen
Presentation of Acute syndrome of apoptotic pan-epidermolysis (ASAP)?
Acute and widespread epidermal cleavage from hyperacute apoptotic injury to epidermis from multiple etiologies (TEN-like ACLE, drug-induced TEN, acute GVHD) - Can be 2/2 de novo or rebound ACLE or SCLE - Internal organs commonly affected including kidney and CNS
What is Rowell’s syndrome?
LE + EM-like lesions
Presentation of SLE?
Skin findings include photosensitivity, malar rash, and discoid lesions - internal organ involved m/c include joints, hematologic, kidney, lungs and CNS
What form of cutaneous LE is most associated with SLE?
ACLE
What symptoms should be asked about to assess systemic disease?
Fever, weight loss, fatigue, myalgia, LAN, and nonspecific skin findings
What is the value of the ANA in pt’s w/ suspected SLE?
High negative predictive value (unlikely that SLE pt’s have negative ANA).
What antibodies are most specific to SLE?
Anti-dsDNA and anti-Sm
What percentage of patients with antiphospholipid antibody syndrome have LE?
1/3
What antibodies should be checked if antiphospholipid antibody syndrome is suspected?
Lupus anticoagulant, anticardiolipin antibody, and anti-β2 glycoprotein I antibody.
Most common culprit medications for drug-induced SCLE?
HCTZ, terbinafine, calcium channel blockers (like diltiazem), ACE inhibitors (enalapril), TNF-a inhibitors (infliximab), proton pump inhibitors (lansoprazole), interferons
Cutaneous findings in drug-induced SCLE?
Identical to SCLE, both have annular and papulosquamous presentations in typical photodistributed locations.
Are systemic symptoms usually present in drug-induced SCLE?
No, occasionally arthralgias
Serology for drug-induced SCLE?
+ anti-Ro/SSA antibodies
Most common medications for drug-induced SLE?
Hydralazine, procainamide, isoniazid, minocycline, TNF-a inhibitors
What is the presentation of drug-induced SLE?
Typically no skin findings! Occasionally can have malar or photodistributed erythema (more common w/ TNF-a inhibitors). -Constitutional sx’s like fever, weight loss, serositis (arthritis, pericarditis, pleuritis)
Serology for drug-induced SLE?
+Anti-histone antibodies can also be seen in patients with classic SLE (40%)
What are some nonspecific cutaneous findings that suggest systemic lupus erythematosus?
Vasculitis: urticarial vasculitis, small vessel vasculitis, polyarteritis nodosa-like lesions
Vasculopathy: Raynaud’s phenomenon, lived reticularis, nail fold telangiectasias and erythema, palmar erythema, livedoid vasculopathy
Cutaneous signs of antiphospholipid antibody syndrome: livedo reticularis (more widespread and persistent), multiple subungal splinter hemorrhages, digital gangrene and cutaneous necrosis, superficial thrombophlebitis, degos-like lesions, atrophie blanche-like lesions, anetoderma. Other: Alopecia (lupus hair, diffuse and nonscarring and telogen effluvium), papulonodular mucinosis
Workup for suspected SLE?
ANA w/ profile (anti-dsDNA, Sm), urinalysis, CBC w/ diff and platlet count, CMP, ESR, complement levels (C3/C4) -Consider adding SPEP and antiphospholipid work-up as well (lupus anticoagulant, B2-microglobulin, and anticardiolipin antibody) -skin bx for IF and H/E - choose older, well-formed lesions
Serology work-up for antiphospholipid syndrome workup?
Lupus anticoagulant, B2-microglobulin, and anticardiolipin antibody
Histology of lupus?
Interface dermatitis - m/c vacuolar - compact and follicular hyperkeratosis - thickened BMZ - superficial and deep perivascular, periadnexal, perieccrine lymphoid infiltrate - dermal mucin admixed within collagen bundles DIF - a continuous granular band of Ig-A/G/M and C3 at BMZ
Generalized treatment counseling that should be given to patients with lupus of any type?
Sun protective measures, avoid potentially photosensitizing mediations, stop smoking, oral vit D supplementation, guided by serum vit D levels.
Tx options for localized LE lesions?
Topical and intralesional CS, topical calcineurin inhibitors (facial lesions), topical retinoids maybe in hypertrophic DLE
SLE first-line treatment options?
First line: antimalarials. -Hydroxychloroquine: Adult 6-6.5mg/kg ideal body weight/day, children <5mg/kg ideal body weight/day -Chloroquine: Adult 3.5-4.0mg/kg ideal body weight/da; Children <3.5 mg/kg ideal body weight/day -Quinacrine (in case of retinopathy) adult and children are 100mg/day. This can also be added to hydroxychloroquine
Second-line agents for SLE?
(These may be used second-line alone or in combination with antimalarials) -Methotrexate (7.25-25 mg/week, orally, IM, SC) -Mycophenolate mofetil (1000-2000mg/day) -Thalidomide (25-100mg/day) -Oral Retinoids (acitretin, isotretinoin) -Dapsone (50-150mg/day)
Third-line agents for SLE?
For refractory cases -IVIg -Belimumab
What agents should be used in life-threatening or severe inflammatory cutaneous disease in LE like ASAP/Rowell’s syndrome?
Systemic CS
What type of sunscreen should be recommended in patients with LE?
Broad Spectrum
What is lupus profundus?
Lipoatrophy + discoid lupus-like lesions
What is the lupus band test?
It is from DIF, the deposition of antibodies, C3/C5-9 @ the DEJ in either lesional or non-lesional skin depending on the source of the nomenclature
What is the significance of an increased number of immunoreactants at the lupus band area?
More immunoreactants at the DEJ suggests SLE
Where can you see false + lupus band test?
Rosacea, telangiectasias, and PMLE
-Band should be weaker in intensity and more focal/interrupted
Why do you treat DLE?
It is not to prevent progression, that will happen or not
-We tx because we don’t know beforehand how extensive it will be/chance –> scarring, progression to SLE, etc
What things can tip you off to the risk of SLE in DLE?
- More wide-spread DLE (below the neck)
- More intense DIF (more immunoprecipitants, especially IgG/C3)
- Acral DLE
- dsDNA serology
- Low complement
- Childhood onset
Most typical locations for DLE?
Conchal bowls (often first spot), scalp (cicatricial alopecia)
What can be a clinical distinguisher between hypertrophic DLE and hypertrophic LP?
Hypertrophic DLE tends to be on the upper half of the body, LP tends to be on the lower extremity
-Ultimately DIF/histology will be key
What is a key clinical distinguisher between lupus-associated chilblains vs non-lupus-associated chilblains?
Both precipitated by cold, but the lupus one will persist year-round, rather than going away in summer
What does “tumid” mean in Latin?
Engorged, so that can help with tumid LE, edematous/infiltrated plaques w/ no epidermal involvement
What are the typical locations of tumid lupus?
Face and trunk
Is tumid LE photosensitive?
Yes, but it is a delayed effect (2-3 weeks after)
Clinical presentation of tumid lupus?
Edematous, indurated, erythematous, often annular plaques on face and trunk
How does tumid LE respond to tx?
Responds well to HCQ
What is the prognosis of tumid LE?
Tends to self-resolve in 3-4 months w/o re-exposure to sunlight. Then will come back
- Can be mistaken as PMLE b/c of this
What is the difference between tumid lupus and Jessner’s disease?
Jessner’s = similar clinical but has CD8+ predominant infiltrate w/ decreased mucin
What is the difference between reticular erythematous mucinosis?
Histologically the same but is morphologically different (erythematous macules and papules or plaques on mid-back/chest in a reticular pattern)
What are the typical locations for lupus panniculitis?
Face, upper arms, upper trunk, breasts, buttocks, thighs
- Lateral areas of these–> think trauma
Important ddx that must be ruled out for lupus panniculitis?
CTCL
What sx’s of lupus dermatoses or disease are more B-cell mediated?
Vasculitis, nephritis
What percent of tumid LE cases are a/w SLE?
15%
Is mucosal LE synonymous with the mouth ulcers that occur in SLE?
No!
Ulcers in SLE are not lupus-specific. The lupus specific look like DLE (most commonly), white keratotic border, usually on the hard palate, can have DLE lesions on the lip
Is there an increased risk of SCC in pts w/ mucosal LE?
Yes
What is the significance of ulceration overlying mucosal LE?
Increased risk of systemic dz
What are the key histologic findings in DLE?
Compact orthohyperkeratosis, vacuolar interface w/ necrotic keratinocytes and pigment incontinence, epidermal atrophy, BMZ thickening, follicular plugging, deep/perivascular/periadnexal lymphohistiocytic inflammation w/ plasma cells, and mucin deposition
What type of DLE lesion should be selected for DIF bx?
Lesion that has been present for few months or more (well established)
Better to choose a lesion on head >extremitties> trunk
What are some histologic differences between DLE and hypertrophic DLE?
Findings of DLE + more orthohyperkeratois and endophytic buds of hyperplastic follicular epithelium
- The hyperplastic follicular epi/pseudoepitheliomatous hyperplasia can be confused for SCC
What are the histologic findings in tumid LE?
No epidermal changes
- Otherwise similar findings to dermal DLE
- Tons of mucin! (think how indurated/infiltrated looks clinically)
What percentage of tumid LE cases are + for DIF?
50%
note, this may be b/c people look at the same areas as DLE…but it doesn’t affect epidermis, have to check the eccrine glands for DIF
Histology of LE panniculitis?
May have findings of overlying DLE, dermal mucin, lymphocytic lobular panniculitis, hyaline (“waxy pink”) fat necrosis, nodular lymphoid aggregates
Can see rimming around fat lobules still
Differences between LE panniculitis and subcutaneous T-cell lymphoma?
Subcutaneous T-cell lymphoma has atypical cells, lacks dermal lymphoid nodules, and lacks mucin
Also, immunohistologic profile
What percentage of patients with SCLE progress to SLE?
30-50%
What HLA subtypes are a/w SCLE?
HLA-B8 (strongest), HLA-DR3, and others
-Can also have predisposition w/ hereditary complement def (C4, C1q etc)
What diseases are Ro/SSA + classically?
Sjogrens, neonatal lupus, SCLE, antiphospholipid syndrome
Pathogenesis of SCLE?
Theory= UVR –> apoptosis of keratinocytes –> apoptotic bodies containing high levels of nuclear antigens (Ro/La/DNA) and reduced clearance of debris (especially important in complement deficiency subtypes) –> loss of immune tolerance –> release of proinflammatory cytokines and production of ANA (SSA most commonly)
What complement deficiences are a/w SCLE?
C1q/r/s, C2, C4 (early complement)
What are the 2 main subtypes of SCLE?
Psoriasisform plaques and annular plaques (polycyclic)
How might the presentation of SCLE differ from DM on the hands?
SCLE often wont affect the skin overlying the knuckles/joints (as opposed to DM)
What is the most common systemic finding in SCLE?
Arthritis/arthralgias = 70%
What is the histology of SCLE?
Compact hyperkeratosis, prominent epidermal atrophy, vacuolar interface dermatitis w/ pigment incontinence, BMZ thickening, PV/PA lymphoid aggregates (limited to superficial dermis) w/ scattered plasma cells and mucin
No eos or follicular plugging
SCLE DIF findings?
+ in 60-85%, not as thick as DLE (not as chronic)
How common is the systemic involvement of drug-induced SCLE?
RARE
What antibodies are most commonly + in drug-induced SCLE?
Ro/SSA
What is the clinical appearance of drug-induced SCLE?
Photosensitive distribution, psoriasiform to lichenoid appliance w/ annular plaques on the upper body and extensor upper extremities
What are the most commonly involved drugs in drug-induced SCLE?
HCTZ (most common!), terbinafine, griseofulvin, NSAIDs (piroxicam), CCB’s, antihistamines, PPI’s, docetaxel, ACE inhibitors, and TNF-alpha inhibitors (etanercept)
What is the connection between age and SCLE?
If the pt is older (>65) need to consider or r/o drug-induced SCLE until considering other causes
If the mother has Anti-Ro/SS-A autoantibodies, what is the chance of neonatal lupus in the child?
1-2%
If a women w/ SS-A/Ro antibodies previously had a child w/ neonatal lupus, what is the chance of the next child having it?
25%
What are the cutaneous lesions seen in neonatal lupus?
Photosensitive, facial involvement more common than adult SCLE w/raccoon eyes (periorbital erythema), annular polycyclic erythematous plaques w/ central clearing and raised red border, fine-scale, typically located on scalp, neck, and face
What are the systemic findings in neonatal lupus?
Cardiac (70%, 30-40% have heart block), Hepatobiliary dz (50%), Hematologic abnormalities
What are the cardiac issues that can be caused by neonatal lupus?
Heart block almost always present by birth, b/c develops in utero between 16-24 weeks
-Usually presents with bradycardia and irreversible complete heart block (3rd degree). Second degree less common
What are the hepatobiliary issues that can be caused by neonatal lupus?
Transient conjugated hyperbilirubinemia in first weeks of life and transient elevations of aminotransferases
What are the hematologic abnormalitites that can be caused by neonatal lupus?
Thrombocytopenia, neutropenia, lymphopenia, and hemolytic anemia
Treatment for neonatal lupus?
Sun protection + topical CS for skin dz
Prenatal systemic CS may decrease risk of getting congenital heart block
HCQ through pregnancy –> decreased risk of cardiac dz
Prognosis of neonatal lupus?
20-30% mortality rate in the cardiac dz if not treated
- Skin dz heals w/o scarring but the dyspigmentation and telangiectasias persist for months to years
- Increased risk of SLE or autoimmune dz later in life
What is the most common hereditary complement deficiency?
Primary C2 deficiency
What is the risk of SLE in homozygous C2 deficiency?
Low risk (10-20%)
What is the most common underlying complement deficiency in complement deficiency-related SLE?
C2
-This is b/c it is by far the most common, so even though the risk is low in these patients, they still have the most (highest prevalence)
What is the risk of getting SLE in the C1q and C4 hereditary deficiencies?
Very rare but SLE much more common
C1q= 90% >C1r/s>C4>C2 (10-20%)
What is the clinical presentation of C2 deficiency associated SLE cases?
Infections w/ encapsulated bacteria ,specially strep pneumoniae
- Adult-onset (30’s), F>M, SLE has less severe course (mild or absent renal dz)
- Prominent photosensitivity of SCLE lesions (think pathophysiology)
What is the clinical presentation of C1q/r/s and C4 deficiency associated SLE cases?
Childhood-onset, Severe, recalcitrant renal dz, photosensitivity, palmoplantar keratoses (C4 deficiency only!), increased risk of encapsulated bacteria and candida
What antibodies can be seen in SLE and always in urticarial vasculitis?
Anti-C1q
What are the common lab findings in hereditary complement deficiency-related lupus?
Low or absent ANA titers
Anti-Ro/SS-A antibodies in most
Decreased complement levels (test is CH50 which is the total levels) which should be markedly decreased
What percentage of SLE patients get a malar rash?
About 60%
What is the clinical presentation of the malar rash in lupus?
Transient eruption following sun exposure lasting hours to weeks
- Involves the nasal bridge and bilateral malar eminence (spares the nasolabial folds)
- Usually macular, but can be indurated, erosions, papules, poikiloderma, atrophy, depigmentation
What groups are typically affected by bullous lupus?
Female predominance
-Predominantly African Americans
What type of LE must patients have for bullous lupus?
SLE (must meet ACR criteria)
Basically SLE + EBA
Presentation of bullous lupus?
Widespread eruption of tense, subepidermal bullae on erythematous to urticarial base
-Occurs on sun-exposed and no-exposed areas
What are the typical locations of bullous lupus?
Face, neck, upper trunk, and proximal extremities
-Commonly involves the mucosa
Histology of bullous lesions in bullous lupus?
Subepidermal bulla w/ neutrophils at the DEJ and in dermal papillae
What is the DIF of bullous lupus?
Continuous granular to linear deposition of IgG, IgM, IgA, and/or C3 along BMZ
What side of salt split skin does bullous lupus reactivity go to?
Dermal (remember to think of EBA)
Treatment for bullous lupus?
Dapsone for skin lesions
-Dramatic response tends to differentiate
What is Rowell’s syndrome?
Targetoid lesions clinically resembling EM, arising in setting of ACLE, SCLE or DLE (usually Ro/SS-A+)
How can toxic epidermal necrolysis-like lupus erythematosus be triggered?
Excessive UV exposure in patients with preexisting ACLE or SCLE
What percentage of SLE patients have skin findings of any type?
80%
What genes lead to susceptibility to SLE?
Early complement components: C1,C2,C4
TREX1 (Chilblains as well)
ITGAM
What are triggers of SLE?
Sunlight, cigarettes, infections, vitamin D deficiency, estrogen
What types of vasculitits can be seen in SLE?
LCV (most common), urticarial vasculitis (HUV especially), medium vessel PAN-like lesions, PNGD/IGDA
What is the appearance of the periungual telangiectasias in SLE?
Wandering dilated glomeruloid loops, as compared to symmetric dilation and dropout seen in DM and SSc
What are some cutaneous signs of antiphospholipid syndrome?
LIvedo reticularis (This + ischemic strokes = Sneddon syndrome)
- Atrophie blanche-like lesions
- Ulcerations
- Degos’-like lesions
- Purpura fulminans and retiform purpura due to catastrophic APLS
What is the appearance of papulonodular mucinosis seen in SLE?
Asymptomatic skin-colored to red papules w/ central depression and pigmentation; favors V-neck, upper chest/back and upper extremities
What is the highest risk for a pregnant women w/ SLE?
Postpartum period
Fetal complications in SLE?
Preterm birth, Preeclampsia, especially w/ lupus nephritis, anti-cardiolipin antibodies (increased risk of fetal loss), and neonatal LE
What treatments should be given if a woman is pregnant w/ SLE?
Continue HCQ and steroids (low dose steroids)
- Consider azathioprine
- Anticoagulation for APLS
What renal abnormalities can be seen in SLE lab-wise?
Persistent proteinuria greater than 0.5g/day or greater than 3+ if quantification is not performed
Cellular casts - can be RBC, hemoglobin, granular, tubular, or mixed
What systemic findings can be seen in SLE?
Arthritis (non-erosive), serositis (pleuritis or pericarditis), renal dz, neurologic dz (seizures or psychosis), hematologic disorder (hemolytic anemia, leukopenia, lymphopenia, or thrombocytopenia)
Does the Anti-dsDNA contribute to the pathogenesis of SLE?
Yes, likely
Not sensitive but highly specific for SLE
What is the significance of the ssDNA antibody in SLE?
Can be present but is neither sensitive nor specific
What is the significance of dsDNA for SLE?
Not sensitive but high specific, useful for monitoring dz activity (especially nephritis)
correlates strongly with + lupus band test from sun-protected areas
What is the significance of the anti-Smith antibodies?
Present in 10-30% of cases of SLE, not sensitive but highly specific
What is the importance of the Anti-U1RNP antibody?
Present in 50%
Present w/ lower titers in SLE than in mixed connective tissue disease
What percentage of drug-induced SLE have an anti-histone antibody?
95%
What is the significance of anti-RNP antibodies in SLE?
More likely to have neuropsychiatric dz
High specificity and low sensitivity
When should rituximab be considered in patients with SLE?
Moderate to severe dz w/ lupus nephritis
What is the mechanism of Belimumab?
Monoclonal antibody that inactivates BLyS (B-lymphocyte stimulator) causing apoptosis and inhibition of B-cell maturation
What types of disease does belimumab help with?
2 trials have shown benefit in recalcitrate SLE but skin dz was not assessed independently
What are the most common causes of death in SLE?
- First 5 years: Inflammatory lesions of SLE and infection
- Beyond 5 years: arterial and venous thromboses: increased risk of thrombosis w/ anticardiolipin antibodies and OCP’s
What is the timing of drug-induced SLE?
Related to continuous drug exposure, usually after >1 yr of exposure
Usually takes 4-6 weeks after stopping the offending drug
What medications are associated with drug-induced LE?
High risk: procainamide, hydralazine (a/w slow acetelators)
Medium and low risk: quinidine, methyldopa, isoniazid, chlorpromazine, D-penicillamine, propylthiouracil, PUVA, minocycline, TNF-a inhibitors (infliximab and etanercept >adalimumab)
How does minocycline-induced drug-induced LE differ from traditional drug-induced LE?
Often negative for anti-histone antibodies, + ANCA against MPO or elastase
How does TNF-a inhibitors differ from traditional drug-induced LE?
Anti-dsDNA antidotes frequently +, more so than anti-histone
-This group tends to be more likely to have skin involvement (malar rash, photosensitivity, SCLE, and DLE lesions)
