Sindrome da Anticorpi Antifosfolipidi

Prof. Fabrizio ContiReumatologia

DEFINIZIONE

La sindrome da anticorpi antifosfolipidi (APS) èuna malattia autoimmune caratterizzata da trombosi arteriose o venose e/o patologia

gravidica in associazione con la presenza in circolo di anticorpi anti-fosfolipidi (aPL)

THROMBOSIS, ABORTION, CEREBRAL DISEASE, AND THE LUPUS

ANTICOAGULANT

G.R.V. HUGHESG.R.V. HUGHESBr. Med. J. 1983; 287: Br. Med. J. 1983; 287:

10881088--89.89.

CLASSIFICAZIONE DELLA APS

APS primaria (53%)

APS secondaria (47%)

Malattie autoimmuni(LES, AR, S. di Sjogren, Sclerosi Sistemica, Vasculiti ecc.)

Epidemiologia e rischio trombotico

Su 227 pazienti consecutivi con trombosi venosa profonda o emboliapolmonare il 30.8% presentava aPL e/o LAC.

Zanon E et a l. Thromb Res 1999; 15 : 269- 74

La prevalenza degli aPL nello stroke giovanile (al di sotto dei 50 anni dietà) varia nei diversi studi tra il 2 e il 40%.

Petri M . J Autoimmun 2000; 15 : 145- 51

Uno studio condotto su 524 soggetti con stroke acuto ed età media di71 anni ha evidenziato una positività per aCL nel 34% dei pazienti(odds ratio = 4)

Tuhrim S et a l. Stroke 1999; 30 : 1561- 65

Population studies usually identify the antiphospholipid

syndrome and factor V Leiden as the most common causes

of thrombophilia, each accounting for about 20% of cases of

recurrent thrombosis among young patients.

Approximately 15% of women with recurrent pregnancy loss

have the antiphospholipid syndrome.

Epidemiologia

Clinical criteria1. Vascular thrombosisOne or more clinical episodes of arterial, venous, or small vessel thrombosis, in any tissue or organ.

2. Pregnancy morbiditya) One or more unexplained deaths of a morphologically normal fetus at or beyond the 10th week of gestation, orb) One or more premature births of a morphologically normal neonate before the 34th week of gestation because of: (i) eclampsia or severe preeclampsia, or (ii) recognized features of placental insufficiency, orc) Three or more unexplained consecutive spontaneous abortions before the 10th week of gestation.

Laboratory criteria (present on two or more occasions, at least 12 weeks apart)

1. Anticardiolipin (aCL) antibody of IgG and/or IgM isotype in serum or plasma, present in medium or high titer (i.e. >40 GPL or MPL, or >the 99th percentile), measured by a standardized ELISA.2. Anti-bbbb2 glycoprotein-I antibody of IgG and/or IgM isotype in serum or plasma (in titer >the 99th percentile), measured by a standardized ELISA, according to recommended procedures3. Lupus anticoagulant (LA) present in plasma.

Miyakis S. et al 2006

Miyakis S. et al 2006

Procedure per l’identificazione del LAC

Step 1Tempo di tromboplastina parziale (aPTT);Dilute Russel viper venom time (dRVVT);

Kaolin clotting time (KCT);(diagnosi di LAC possibile se 1 o più test coagulatori risultano allungati)

Step 2Mixing test: aggiunta di plasma normale al plasma del paziente (1:1)

(diagnosi di LAC se il test rimane prolungato)

Step 3

Test di neutralizzazione: aggiunta di fosfolipidi o piastrine scongelate al plasma del paziente

(diagnosi di LAC se il test si normalizza)

APS - Manifestazioni cliniche

Trombosi arti inferiori: TVP (in 1/3 dei casi TEP)

Cuore: vegetazioni mitro-aortiche, IMA

Cute: Livedo reticularis, ulcere, necrosi

Ematologiche: piastrinopenia, anemia emolitica autoimmune

Hypertension is a common feature of the primary and secondary APS

aPL-associated nephropathy (APLN)

The most commonly reported and characteristic intrarenal vascular lesion is thrombotic microangiopathy without eitherhistological evidence of inflammation or immune complex deposition (hypertension, proteinuria, and renal impairment)

Uthman. Sem Arthritis Rheum 2006

Manifestazioni neurologiche associate agli anticorpi antifosfolipidi

EVENTI ISCHEMICI ARTERIOSI(Stroke, TIA, demenza multinfartuale)

TROMBOSI VENOSA (occlusione seno sagittale, occlusione seno cavernoso)

STROKE EMBOLICO

SINDROME DEMIELINIZZANTE

DISORDINI DEL MOVIMENTO (corea, emiballismo, atassia cerebellare)

SINDROMI SPINALI (mielite trasversa, Guillan-Barré)

EPILESSIA

EMICRANIA

DISTURBI COGNITIVIToubi E et al. Am J Med 1995, Menon S et al. Arthritis Rheum 1999, Hanly JG et al. Arthritis Rheum 1999, Karassa FB et al. QJM 2000, Mok CC et al. J Rheumatol 2001, Afeltra A et al. Neurology 2003, Sanna G et al. J Rheumatol 2003, Mikdashi J et al. Rheumatology 2004

The clinical similarities between APS and MS are striking, and brain magnetic resonance imaging appearance was often indistinguishable.

APS and MS are autoimmune conditions which affect similar age groups (age 20 to 50) and may have similar neurological manifestations

APS and multiple sclerosisAPS and multiple sclerosis

282 consecutive patients with SLE and/or APS were asked the standard question “Did any of your doctors at any stage of your illness consider the diagnosis of MS ? ” .

Out of 90 patients with aPL+ tests, 26 (28.8%) recorded a positive response to the question, as compared with 10 (8.4%) of the aPL- patients [RR: 5.5 (95% CI: 2.8- 11) p < 0.0001].

Cuadrado MJ et al. Clin Exp Rheum 2004

282 consecutive patients with SLE and/or APS were asked the standard question “Did any of your doctors at any stage of your illness consider the diagnosis of MS ? ” .

Out of 90 patients with aPL+ tests, 26 (28.8%) recorded a positive response to the question, as compared with 10 (8.4%) of the aPL- patients [RR: 5.5 (95% CI: 2.8- 11) p < 0.0001].

Cuadrado MJ et al. Clin Exp Rheum 2004

MRI from a patient with antiphospholipid syndrome.

A, B: Brain MRI showing periventricular lesions indistinguishable from those seen in MS.

C: T2-high-signal widespread lesions in spinal levels C2–5, T1–3, T5–7.

APS and multiple sclerosisAPS and multiple sclerosis

Several cases have been published about a syndrome that simulates MS in the presence of aPL. These patients usually experienced a good clinical response after the initiation of anticoagulation.

Scott TF et al. Arch Intern Med 1994, Siam AM et al. Lupus 1998, Ijdo JW et al. Lupus 1999

APS and multiple sclerosisAPS and multiple sclerosis

APS can sometimes simulate MS, and distinguishing the two can be very difficult.

Differentiation is important for their treatment and evolution. Anticoagulation is the therapy of choice in APS, and prognosis is better than in MS patients.

The most frequent clinical presentation of patients with APS that simulate MS is myelopathy, although other neurological deficiencies have also been described, such as cerebellar syndrome or optic neuritis.

Therefore, it is important to make an exhaustive anamnesis, with special attention to previous history of thrombosis or fetal loss, which could suggest the diagnosis of APS.

APS and multiple sclerosisAPS and multiple sclerosis

Peripheral thrombosis Neurologic involvementDVT 38.9% Stroke 19.8%Sup. Thrombophlebitis 11.7% TIA 11.1%Leg arterial thrombosis 4.3% Multiinfarct dementia 2.5%Arm venous thrombosis 3.4% Cerebral venous thrombosis 0.7%Pulmonary manifestations Cardiac manifestationsPulmonary embolism 14.1% MI 5.5%Pulmonary microthrombosis 1.5% By-pass re-thombosis 1.1%Skin manifestations Intra-abdominal manifestationsDigital necrosis 3.3% Renal vein thrombosis <1.5% Cutaneous necrosis 2.1% G.I. 1.5% OthersRetinal arterial/vein thrombosis <2% Nasal septum perforation 0.8%

MAIN VENOUS AND ARTERIAL THROMBOTIC MANIFESTATIONS IN THE COHORT OF 1,000 APS PATIENTS ENROLLED BY THE

EUROPEAN APL FORUM Cervera R et a l. Arthritis Rheum 2002

PERCENTAGE OF THE INITIAL CLINICAL FEATURES REPORTED IN THE COHORT OF 1,000 APS PATIENTS ENROLLED BY THE

EUROPEAN APL FORUM

Manifestations % Deep vein thrombosis 32Thrombocytopenia 22Livedo reticularis 20Stroke 13Superficial thrombophlebitis 9Pulmonary embolism 9Fetal loss 8Transient ischemic attack 7Hemolytic anemia 7Skin ulcers 4

Cervera R et a l. Arthritis Rheum 2002

Obstetric manifestations %

Pre-eclampsia 9,5

Eclampsia 4,4

Fetal manifestations

Early fetal losses 35,4

Late fetal losses 16,9

OBSTETRICAL AND FETAL MANIFESTATIONS IN THE COHORT OF 1,000 APS PATIENTS ENROLLED BY THE EUROPEAN APL FORUM

Cervera R et a l. Arthritis Rheum 2002

Main clinical manifestations related to the APS that appeared during the 5- year follow- up (1999- 2004) of the total cohort of 1,000 patients.

Cervera R et al. Ann Rheum Dis. Sept 2008

APS manifestations* No. (% of the total cohort)

Thrombocytopenia 37 (3.7)Livedo reticularis 26 (2.6)Stroke 24 (2.4)Transient ischemic attacks 23 (2.3)Deep vein thrombosis 21 (2.1)Pulmonary embolism 21 (2.1)Epilepsy 17 (1.7)Skin ulcers 17 (1.7)Valve thickening/dysfunction 17 (1.7)Vegetations 14 (1.4)Myocardial infarction 9 (0.9)Inferior extremity superficial thrombophlebitis 9 (0.9)Autoimmune hemolytic anemia 9 (0.9)Pre-eclampsia / eclampsia 8 (0.8)Early pregnancy loss 18 (1.8)Late pregnancy loss 7 (0.7)Live birth with prematurity 28 (2.8)Live birth with intrauterine growth restriction 11 (1.1)*Several patients developed more than one APS-related manifestation.

200 (20%) patients developed APS-related manifestations.

Recurrent thrombotic events appeared in 166 (16.6%) patients. When the thrombotic events occurred, 90 patients were on oral anticoagulants and 49 were using aspirin. 31 out of 420 (7.4%) patients on oral anticoagulants presented with hemorrhage.

3 out of 121 (2.5%) women with only obstetric APS manifestations at the beginning of the study developed a new thrombotic event.

A total of 77 women (9.4% of female patients) experienced one or more pregnancies and 63 (81.8% of pregnant patients) succeeded in having one or more live births.

APS – AETIOLOGY

Thrombotic events occur only occasionally in spite of the persistent presence of aPL: a two-hit hypothesis.

The aPL (‘‘first hit’’) increases the thrombophilic risk and the clotting takes place in the presence of another thrombophilic condition (‘‘second hit’’)

Second hit: - infectious processes

- genetic background: polymorphism of genes encoding for signalling pathways of proinflammatory mediators (ie, the tlr4 gene), platelet glycoproteins

- thrombophilic conditions (protein C resistance due to factor V defect, protein C/protein S deficiency, factor II deficiency)

- sex hormones

- thrombotic risk factors: hypertension, smoking, hypercholesterolemia, OC/HRT use

APS – PATOGENESI

Anti-fosfolipidi trombosi e aborti

Molti antigeni riconosciuti dagli aPL sono coinvolti nellatrombosi e nell’emostasi.

I livelli degli anticorpi correlano con il rischio di manifestazionicliniche.

L’immunizzazione passiva di animali da laboratorio conimmunoglobuline umane provenienti da pazienti con APSinduce la comparsa di trombosi e abortività.

Harris EN et a l. Arch Intern Med 1986Blank M et a l. Prod Natl Acad Sci USA 1991Pierangeli SS et a l. Thromb Haemost 1995

1. Interferenza degli autoanticorpi con le reazioniemostatiche che si verificano sulle superficicellulari

2. Legame degli autoanticorpi con gli antigenipresenti sulle superfici cellulari e conseguentetrasduzione di segnali intracitoplasmatici ealterazione dell’attività cellulare

APS – PATOGENESI 2

Thrombosis a) soluble coagulation

factors:-protein C/S pathway inhibition;-fibrinolysis inhibition

b) coagulation cells:-induction of a pro-inflammatory and pro-coagulant endothelial and monocytephenotype;

Miscarriage

a) throphoblast cells:

-reduction of proliferation and differentiation; -gonadotrophin secretion impairment;-complement-mediated inflammatory process

PRINCIPAL PATHOGENIC MECHANISMS MEDIATED BY aPL

Nel 1990 tre laboratori dimostrarono che il legame tra

aCL e l’antigene richiede la presenza di un cofattore

proteico identificato nella bbbb2–glicoproteina I (bbbb2-GPI)

Mc Neil HD et a l. Proc Natl Acad Sci USA 1990

Galli M et a l. Lancet 1990

Matsuura H et a l. Lancet 1990

Cofattori Proteici e Sindrome da Anticorpi Antifosfolipidi

• bbbb2-GPI• protrombina• annessina V• proteina C, proteina C attivata • proteina S• fattore V • fattore X• trombomodulina• chininogeni ad alto o basso peso molecolare

aPLs represent a heterogeneous family of autoantibodies directed to several antigens.

Several findings suggest β2-glycoprotein I and prothrombin as the most relevant antigens in APS.

Nevertheless, new target antigens, such as lyso(bis)phosphatidic acid and sulfatides, have recently been described.

aPLs represent a heterogeneous family of autoantibodies directed to several antigens.

Several findings suggest β2-glycoprotein I and prothrombin as the most relevant antigens in APS.

Nevertheless, new target antigens, such as lyso(bis)phosphatidic acid and sulfatides, have recently been described.

a-PTh

a-CL

a-PEa-LBPA

a-PS a-annexin-2

a-factor-XII

???LAC

a-sulfatides

aa--ββ22--GPIGPI

Valesini G & Alessandri C. Ann NY Acad Sci 2005

bbbb2-glicoproteina I

bbbb2-GPI, apolipoproteina H, è una glicoproteina di 50 kDa, 326 aa, concentrazione plasmatica di circa 200 mmmmg/ml

bbbb2-glicoproteina I

bbbb 2 - GPI presenta in vitro un effetto inibitorio sui meccanismi della coagulazione

inibisce l’attività della protrombinasi,

la via intrinseca della coagulazione,

l’aggregazione piastrinica ADP-mediata

l’attivazione del fattore X da parte delle piastrine

Anti-bbbb2-glicoproteina I

Anti-bbbb2-GPI associati alle trombosi in maniera più significativa degli aCL

Balestrieri G et al. Lupus 1995

Sorice M et al. Thromb Haemost 1996

Anti-bbbb2-GPI inducono una tipica APS in vivo nei modelli murini in seguito ad immunizzazione passiva

George J et al. Circulation 1998

Immunoreactivity by the a β 2 - GPI MoAb1A4 with:

• astrocytoma line T67

• glioma line T70

• neuroblastoma line LAN5

Anti-bbbb2-GPI attivano le cellule endotelialiinducendo un fenotipo pro-infiammatorio e pro-coagulante.

Aumentata espressione di molecole di adesione (ICAM 1, VCAM 1, E- Selectin)

Aumentata secrezione di IL- 6 e IL- 1 β

Del Papa N et al. Clin Exp Rheumatol 1995

Del Papa N et al. J Immunol 1998

Simantov R et al. J Clin Invest 1995

MONOCITI E APS

I monociti dei pazienti con APS e trombosipresentano un’aumentata espressione sullasuperficie cellulare di Tissue Factor (TF).

RUOLO PATOGENETICO DEL TISSUE FACTOR

•1994: anticorpi monoclonali aCL stimolanol’espressione del TF da parte dei monociti

Kornberg A et a l. J Immunol. 1994; 153: 1328- 32

•1997: l’espressione di TF monocitario è significativamente aumentata nei pazienti con APS e pregressi episodi trombotici

Cuadraro MJ et al. Arhritis Rheum. 1997; 40: 834- 41

• 2000: anticorpi anti-bbbb2GPI ottenuti da pazienti con APSsono in grado di indurre l’espressione di TF sullecellule endoteliali

Kornberg A et a l. IMAJ 2000; 2 (suppl): 27- 32

Espressione di mRNA per la β2-GPI RT-PCR

LineaLinea 11:: DNADNA ladderladder

LineaLinea 22:: bbbbbbbb22--GPIGPI mRNAmRNA dada HEpGLHEpGL22

LineaLinea 33:: bbbbbbbb22--GPIGPI mRNAmRNA dada monocitimonociti

LineaLinea 44:: bbbbbbbb--actinaactina mRNAmRNA dada HEpGLHEpGL22

LineaLinea 55:: bbbbbbbb--actinaactina mRNAmRNA dada monocitimonociti

Espressione della β2-GPI sulla superficie monocitaria

Analisi citofluorimetrica della bbbb2-GPI e Tissue Factor

APS SLE NHS

Acute thrombotic event: heparin followed by warfarin treatment.

Because of the documented increased risk of recurrences, patientswith venous thrombosis and aPL should be treated with an oralanticoagulation longer than the usual schedule. Treatment shouldbe prolonged for life if aPL positivity persists.

Intermediate-intensity warfarin treatment (INR range from 2.0 to 3)or high-intensity treatment (INR >3.0): is still a matter for debate.

ANTI-PHOSPHOLIPID SYNDROME THERAPY -THROMBOSIS

Rosove MH et al. Ann Intern Med 1992Khamashta MA et al. NEJM 1995Krnic- Barrie S et al. Arch Intern Med 1997Schulman S et al Am J Med 1998 Luzzana C et al. J Nephrol 2002

Paziente filippina, 39 aa; Fumatrice da circa 20 aa; Tireopatia autoimmune; Morte fetale 5° mese

Catastrophic antiphospholipid syndrome

ANTI-PHOSPHOLIPID SYNDROME THERAPY -THROMBOSIS

Forma catastrofica:

occlusioni vascolari multiple che rapidamente determinano gravi danni d’organo dovute ad uno stato procoagulante continuo e spesso irreversibile.

Terapie immunosoppressive quali ciclofosfamide, immunoglobuline per via endovenosa, plasmaferesi, anti-CD20.

Valesini G & Pittoni V. Ann Med 2000

APS is now recognised as the commonest treatable cause of recurrentmiscarriage. The success rate of aPL+ pregnancies has risen from aprevious 15% to over 75%.

The reasons for the success are:

• treatment in pregnancy with aspirin and low molecular weight heparin,

• careful obstetric care, a failing Doppler is an indication for early delivery.

Alternative therapy in refractory cases: intravenous immunoglobulins(IVIG) in addition to LDASA and heparin

Thromboprophylaxis during the postpartum period (6 weeks)

ANTI-PHOSPHOLIPID SYNDROME THERAPY -obstetrical aspects

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