immunological diseases in pregnancy

IMMUNOLOGICAL DISEASES IN PREGNANCY

Presented by: Nandinii Ramasenderan & Mohd Amir Ghani

Overview:• Introduction

• Antiphospholipid syndrome

• Systemic Lupus Erythematosus

• Idiopathic thrombocytopenic purpura

Introduction:Maintain pregnancy

Maternal host bypass/ compensate for usual immunological process

To ensure recognition & elimination of non-self molecules

Bidirectional interaction btwn maternal & feto-placental unit

Redirection of maternal immunology away from cell med. towards humoral responsiveness

Conceptus protect: secreting TH2 cytokine & down regulates TH1 (IL2, INF γ, TNF) -harmful to the maintenance of pregnancy-

Course of autoimmune disease is attended

Imm adaptation facilitate intrauterine implantation of the blastocyst & maintenance of the fetal semi-allograft

Normal preg: Not associated with increase in autoantibody production

A preexisting autoimmune disease in the mother may influence the outcome of pregnancy

Source: Buyon, JP., The effects of pregnancy on autoimmune diseases, 1998. Journal of Leucocyte Biology, 63, 281-283.

1. ANTIPHOSPHOLIPID SYNDROME (APS)

A multisystemic disease, characterized by venous or arterial thromboses, or certain obstetric complications, & the presence of antiphospholipid antibodies (APAs)

APAs are a heterogeneous group of autoantibodies that bind to negatively charged phospholipids, phospholipid-binding protein, or a combination of the two.

Lupus anticoagulant (LA), anticardiolipin antibodies (aCL) & anti-beta 2 glycoprotein 1 (anti-β2GP1) antibodies are the main types.

occurs in isolation as a primary APS in > 50% of the cases, or associated with other autoimmune diseases, most often with systemic lupus erythemathosus (SLE).

occurs > in young women of fertile age (rarely in children, and only 12% of all APS occur after 50 years of age)

Source: Haram, K., Jacobsen, EM., Sandset, PM., Antiphospholipid Syndrome : Chapter 10: APS in Pregnancy. 2012. inTech, Norway, 161-173.

Antiphospholipid Antibodies in Pregnancy

IUGRRecurrent miscarriag

e

Preeclampsia

Placental abruption

In addition: Arterial / Venous

thrombosis

Premature delivery or

fetal death


Pathogenesis of APS


Antiphospholipid antibodies

Pregnancy loss

Impair both trophoblast invasion in the decidua &the spiral arteries &the placental hormone production uteroplacental insufficiency and fetal loss

Mechanism:

Interfere with the normal in vivo fx of phospholipids

or phospholipid binding proteins that are crucial to regulation of coagulation

β2GP1, induce expression of TF

(major cellular initiator of the coagulation protease cascade, plays important

roles in both thrombosis and inflammation)

APAs: Dysregulate the fibrinolytic system by cross-

linking with annexin II (profibrinolytic endothelial

cell surface receptor) on the endothelial cell surface

inducing TF

APAs bind directly to trophoblasts cells and cause cellular injury,

defective extravillous cytotrophoblast (EVT) invasion (in the decidua and spiral arteries),

and induce a localinflammatory response as a result

of activation of complement

TF acting as an pro inflammatory

molecule enhances neutrophil activity which may cause

trophoblast injury, placentaldysfunction and damage to

the embryo


Diagnosis of APS-Both on clinical criteria and persistent positivity for APA. Laboratory testing for APA (ELISA) is used to confirm or refute the diagnosis

-Essential that a positive test for APA is repeated after at least 12 weeks to confirm diagnostic criteria.

• Clinically based on:

1) one or more unexplained deaths of normal fetuses at or beyond the 10th week of gestation, or

2) one or more premature births before the 34th week of gestation because of eclampsia, severe preeclampsia, or placental insufficiency, or

3) three or more unexplained consecutive spontaneous abortions before the 10th gestational week. Pregnant women with such complications should have laboratory testing.

(Source: Miyakis, S., Lockshin, MD,. Atsumi, T., Branch, DW., Brey, RL., Cervera, R., et al. International consensus statement on an update of the classification criteria for definite antiphospholipid syndrome (APS), 2006. J Thromb Haemost, 4(2):295-306.)


Outcome of pregnancy in APS

• There is increasing evidence that the outcome of pregnancy in APS is influenced by the underlying phenotype.

• Women with obstetric APS have better pregnancy outcomes than women with thrombotic APS.

Source: Soh, MC., Pregnancy: Antiphospholipid Syndrome : Five-year View, 2010. MedScape MultiSpeciality Article, http://www.medscape.org/ viewarticle/732034_11 [Accessed on: 23-08-2013]

http://www.medscape.org/viewarticle/732034_11



Current management of APSHeparin combined with aspirin. LMWHs are at least as effective as unfractioned

heparin and are safer.

MOA: Aspirin inhibit APA med. hypercoagulopathy in the intervillous space of the placenta

Heparin prevent APA from interfering with cytotrophoblast migration & promote blastocyst implantation in addition to prevention of venous thrombosis

Prolonged heparin treatment may induce osteoporosis. (Better to use LMWH)

The pregnancy- associated prothrombotic changes in the coagulation system are maximal immediately after delivery.

It is well accepted that persistent APA-positive women require post-partum anticoagulation.

Therefore, it is desirable to continue LMWH during labor or delivery in women receiving antenatal thromboprophylaxis.

The duration of recommendations range from 3-5 days(RCOG), to 6-8 weeks(Derksen, et al.) and up to 12 weeks(Erkan, D.,).


Use of anticoagulant during pregnancy

• Warfarin crosses the placenta and is teratogenic in the first trimester.

• Women, who are on long- term warfarin treatment because of previous thrombosis, should switch to heparin when trying to conceive or when pregnancy is confirmed.

• In high risk groups, such as women with mechanical heart valves, warfarin may be used in pregnancy, but only after organogenesis (6th-12th week) because of high risk of fetal malformations.

• Warfarin treatment is however, also associated with spontaneous abortions, prematurity and CNS abnormalities.

• As warfarin cross the placenta and subsequently affect fetal coagulation, there is a risk for bleeding complications in the fetus and during birth.


Use of anti-coagulants in lactating women

• Heparin and LMWHs are not secreted into breast milk and can be safely given to nursing mothers.

• Warfarin is safe after delivery & for breast feeding, but requires close monitoring, frequent visits to an anticoagulant clinic & carries an increased risk of postpartum hemorrhage and perineal hematoma compared with LMWH.

• In women with APA antibodies, and a history of severe preeclampsia, at least low dose aspirin (75-80 mg once a day) is recommended.

• Glucocorticoids, cytotoxic agents, and intravenous immunoglobulin have no confirmed benefit and should not be used to treat pregnant women with APS.


Contraception after birth

• Oral estrogen coating contraceptives increase the maternal thrombotic risk of women with APAs and SLE.

• Intrauterine devices are more appropriate.

• However, progesterone-only contraceptives do not increase the risk of thrombosis.

• If a woman with APS wants to be pregnant again, pre-conceptional treatment deserves consideration.

• Some women with APS may need life-long warfarin treatment.


CATASTROPHIC ANTIPHOSPHOLIPID SYNDROME (CAPS)

CAPS

A very severe variant of the classic APS.Life threatening condition

CH: clinical evidence of multiple organ involvement developing over a very short period of time, histopathological evid. of multiple small vessel occlusions and laboratory confirmation of the presence of aPL

usually in high titre

Common trigger: InfectionOthers: anticoagulation withdrawal or low INR, medications (e.g., oral

contraceptive), obstetric complications, neoplasia, SLE flares, trauma and surgery

Source: Sciascia, S., Pedrera, CL., Roccatello, D. & Cuadrada, MJ., Catastrophic Antiphospholipid Syndrome (CAPS), 2012. Best Practice & Research Rheumatology, 26, 535-537.

Management:• Current treatment guidelines suggest, in addition to early diagnosis, aggressive

therapies to avoid the potentially fatal outcome.

• The combination of:

- high doses of intravenous (i.v.) heparin,

- i.v. steroids,

- i.v. immunoglobulins and/or

- Repeated plasma exchanges

are the basic treatment of choice for all patients with this severe condition

(Evidence Level II)

Source: Sciascia, S., Pedrera, CL., Roccatello, D. & Cuadrada, MJ., Catastrophic Antiphospholipid Syndrome (CAPS), 2012. Best Practice & Research Rheumatology, 26, 535-537.

2. IDIOPATHIC THROMBOCYTOPENIC

PURPURA (ITP)

IDIOPATHIC TROMBOCYTOPENIc PURPURA (ITP)

Thrombocytopenia in pregnancy is

relatively common, occurring in 7 to

10% of unselected pregnancies.

ITP only accounts for approximately 3% of these cases

as compared to gestational or

incidental thrombocytopaenia of pregnancy (74%) and hypertensive

disorders of pregnancy (21%)

Source: Ministry of Health Malaysia, Management of immune thrombocytopenic purpura (ITP), 2006. Clinical Practice Guidelines, 24-29.

PATHOPHYSIOLOGY

Platelet destruction secondary to a circulating immunoglobulin

(IgG) antiplatelet antibody that crosses the placenta and may

affect fetal platelets

Clinical Manifestation:• Abnormally heavy menstruation

• Bleeding into the skin causes a characteristic skin rash that looks

like pinpoint red spots (petechial rash)

• Easy bruising

• Nosebleed or bleeding in the mouth

Diagnosis:• a. Clinical

• The diagnosis of ITP in pregnancy remains one of exclusion as there is no confirmatory laboratory test.

• Important to obtain a detailed history and physical examination to exclude other secondary causes and to assess the clinical severity of haemostatic defects.

• b. Laboratory

• The aim of investigation is to confirm thrombocytopenia and to exclude secondary causes. If gestational thrombocytopenia is suspected, only regular monitoring of platelet counts is required without further investigations


Differential Diagnosis

HELLP syndro

me TTP

DIC

APS

Folate deficiencyViral:

Dengue, HIV, HCV

Spurious due to

platelet clumping or macrothromb-ocytes

Drug-related

Gestational or incidental

thrombocytopenia of

pregnancy

Pre-eclampsi

a

Modified from British Committee for Standards in Haematology GeneralHaematology Task Force

(2003)


Investigations:1) Full blood count

2) Peripheral blood film: to exclude platelet clumping and red cell fragmentation (in TTP, pre-eclampsia, HELLP or DIC)

3) Coagulation screen (PT, APTT, BT, fibrinogen, D-dimer)

4) Liver function tests

5) HIV screening

6) ANA

7) Lupus anticoagulant/ anticardiolipin antibody

~for patients with past history of unexplained pregnancy losses/ thrombosis (Grade C)

~Bone marrow examination is unnecessary unless there is suspicionof myelodysplastic syndrome, leukaemia or lymphoma(Grade C)


Management:• Close collaboration between haematologist, obstetrician,

neonatologist and anaesthetist is needed to ensure a good pregnancy outcome.

• Platelet counts in women with ITP may decrease as pregnancy progresses and need to be monitored closely as follows:

-1st to 2nd trimester : monthly

-3rd trimester : 2 weekly

-at term : weekly

• The principal of management in ITP during pregnancy is to do least harm to both the mother and the foetus. The decision to treat is based on assessment of the risk of significant haemorrhage.


Modalities of treatment of ITP in pregnancy• Corticosteroids and IVIG are effective and safe in pregnancy and are

used as first line therapy. (Grade B)

• Androgen analogs such as danazol and cytotoxic agents are contraindicated in the treatment of ITP in pregnancy due to its teratogenecity. (Grade C)

• Splenectomy is considered only if above measures fail to elevate the platelet counts and patient has serious bleeding. This is best deferred until the second trimester to prevent miscarriage.


Recommendations : When to treat?• Platelet count < 20 x 109/L before 36 weeks• Symptomatic bleeding at any trimester• Platelet count < 30 x 109/L after 36 weeks

Management before 36 weeks:• Management can be divided into 3 groups based on clinical presentation & platelet count.

1) Asymptomatic patients with mild to moderate thrombocytopenia (platelet count >20 x 109/L)

a. No treatment is required

b. To expect further drop of platelet during 3rd trimester

2) Symptomatic patients or those with moderate to severe thrombocytopenia (platelet count <20 x 109/L)

a. Corticosteroid prednisolone 1mg/kg/day with rapid taper to keep <30mg/day (safe from adverse foetal effects)

AND/ OR

b. IVIG 1g/kg (according to pre-pregnant weight) every month


3) Severe thrombocytopaenia (platelet count <10 x 109/L)

• The approach in managing these groups of patients is to deliver the minimum amount of therapy necessary.

a. high dose corticosteroid (methylprednisolone/dexamethasone)

AND

b. periodic high dose IVIG 1g/kg x 2 days

~Splenectomy during 2nd trimester is considered if above measures fail to elevate the platelet count.~

Management after 36 weeks:

• The mother should be assessed at 36 weeks by both the haematologistand the obstetrician.

• platelet count >30 x 109/L

- safe for normal vaginal delivery in patients with otherwise normal coagulation

• platelet count <30 x 109/L

- admit for pulsed IVIG and close monitoring

• The mode of delivery in a mother with ITP is based on obstetric indications.

• Caesarian section is only for obstetric indications and the patient will require:

i. iv corticosteroids if platelet count between 30-50 x 109/L

ii. IVIG and iv corticosteroids if platelet count <30 x 109/L

iii. IVIG and iv corticosteroids plus platelet transfusion if platelet count<10 x 109/L


Management during labor:• Platelet count above 50 x 109/L is safe for caesarian section under general

anaesthesia but not epidural anaesthesia.

• Epidural anaesthesia is best avoided because of the risk of epidural haematoma and cord compression.

• However, patients who prefer epidural analgesia need to be admitted earlier for IVIG infusion in order to raise the platelet counts to a safe level >80 x 109/L.

• If platelet counts are less than 50 x 109/L and patient requires immediate caesarian delivery, administer IVIG and methylprednisolone.

• Give platelet transfusion just prior to surgery.


‘Safe’ Platelet Thresholds for delivery• vaginal delivery: > 30 x 109/L• caesarean section: > 50 x 109/L• epidural anaesthesia: > 80 x 109/L (Grade C)

immunological diseases in pregnancy

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