Potential role of intravenous immunoglobulin in the management of peripartum maternal thrombocytopenia due to various causes

Society for Maternal-Fetal Medicine Consult Series #64: Systemic lupus erythematosus in pregnancy

Systemic lupus erythematosus (SLE) is a chronic, multisystem, inflammatory autoimmune disease characterized by relapses (commonly called "flares") and remission. Many organs may be involved, and although the manifestations are highly variable, the kidneys, joints, and skin are commonly affected. Immunologic abnormalities, including the production of antinuclear antibodies, are also characteristic of the disease. Maternal morbidity and mortality are substantially increased in patients with systemic lupus erythematosus, and an initial diagnosis of systemic lupus erythematosus during pregnancy is associated with increased morbidity. Common complications of systemic lupus erythematosus include nephritis, hematologic complications such as thrombocytopenia, and a variety of neurologic abnormalities. The purpose of this document is to examine potential pregnancy complications and to provide recommendations on treatment and management of systemic lupus erythematosus during pregnancy. The following are the Society for Maternal-Fetal Medicine recommendations: (1) we recommend low-dose aspirin beginning at 12 weeks of gestation until delivery in patients with systemic lupus erythematosus to decrease the occurrence of preeclampsia (GRADE 1B); (2) we recommend that all patients with systemic lupus erythematosus, other than those with quiescent disease, either continue or initiate hydroxychloroquine (HCQ) in pregnancy (GRADE 1B); (3) we suggest that for all other patients with quiescent disease activity who are not taking HCQ or other medications, it is reasonable to engage in shared decision-making regarding whether to initiate new therapy with this medication in consultation with the patient's rheumatologist (GRADE 2B); (4) we recommend that prolonged use (>48 hours) of nonsteroidal antiinflammatory drugs (NSAIDs) generally be avoided during pregnancy (GRADE 1A); (5) we recommend that COX-2 inhibitors and full-dose aspirin be avoided during pregnancy (GRADE 1B); (6) we recommend discontinuing methotrexate 1-3 months and mycophenolate mofetil/mycophenolic acid at least 6 weeks before attempting pregnancy (GRADE 1A); (7) we suggest the decision to initiate, continue, or discontinue biologics in pregnancy be made in collaboration with a rheumatologist and be individualized to the patient (GRADE 2C); (8) we suggest treatment with a combination of prophylactic unfractionated or low-molecular-weight heparin and low-dose aspirin for patients without a previous thrombotic event who meet obstetrical criteria for antiphospholipid syndrome (APS) (GRADE 2B); (9) we recommend therapeutic unfractionated or low-molecular-weight heparin for patients with a history of thrombosis and antiphospholipid (aPL) antibodies (GRADE 1B); (10) we suggest treatment with low-dose aspirin alone in patients with systemic lupus erythematosus and antiphospholipid antibodies without clinical events meeting criteria for antiphospholipid syndrome (GRADE 2C); (11) we recommend that steroids not be routinely used for the treatment of fetal heart block due to anti-Sjögren's-syndrome-related antigen A or B (anti-SSA/SSB) antibodies given their unproven benefit and the known risks for both the pregnant patient and fetus (GRADE 1C); (12) we recommend that serial fetal echocardiograms for assessment of the PR interval not be routinely performed in patients with anti-SSA/SSB antibodies outside of a clinical trial setting (GRADE 1B); (13) we recommend that patients with systemic lupus erythematosus undergo prepregnancy counseling with both maternal-fetal medicine and rheumatology specialists that includes a discussion regarding maternal and fetal risks (GRADE 1C); (14) we recommend that pregnancy be generally discouraged in patients with severe maternal risk, including patients with active nephritis; severe pulmonary, cardiac, renal, or neurologic disease; recent stroke; or pulmonary hypertension (GRADE 1C); (15) we recommend antenatal testing and serial growth scans in pregnant patients with systemic lupus erythematosus because of the increased risk of fetal growth restriction (FGR) and stillbirth (GRADE 1B); and (16) we recommend adherence to the Centers for Disease Control and Prevention medical eligibility criteria for contraceptive use in patients with systemic lupus erythematosus (GRADE 1B).

Treatment of severe thrombocytopenia associated with systemic lupus erythematosus in pregnancy with eltrombopag: A case report and literature review

WHAT IS KNOWN AND OBJECTIVE

Severe thrombocytopenia associated with systemic lupus erythematosus (SLE) in pregnancy is infrequent. Its occurrence can lead to serious adverse pregnancy consequences and perinatal complications. The thrombopoietin (TPO) analogue eltrombopag has been successfully used in the treatment of autoimmune thrombocytopenia, but its safety and efficacy in severe thrombocytopenia during pregnancy remain unclear.

CASE SUMMARY

We report a 33-year-old woman with SLE at 29 + 3 weeks gestational age who developed severe thrombocytopenia with complaints of epistaxis, gum bleeding and haematuresis. Most conventional treatments including glucocorticoids, intravenous immunoglobulin (IVIG) and cyclosporine did not elevate her platelets, but eltrombopag worked well and her platelet count gradually recovered, allowing her to deliver a healthy baby at 36 + 3 weeks gestational age.

WHAT IS NEW AND CONCLUSION

This suggests that eltrombopag in combination with glucocorticoids has a good safety and efficacy profile in pregnant patients with SLE complicated by severe thrombocytopenia.

Intravenous Immune Globulin (IVIG) for Treatment of Autoimmune Heparin-Induced Thrombocytopenia: A Systematic Review

OBJECTIVE

To evaluate intravenous immune globulin (IVIG) for autoimmune heparin-induced thrombocytopenia (aHIT), including platelet recovery, IVIG dose, dosing weight, IVIG product used, and complications reported.

DATA SOURCES

PubMed and EMBASE were searched from inception through June 21, 2020. Search terms included heparin-induced thrombocytopenia, HIT, intravenous immune globulin, IVIG, autoimmune HIT, aHIT, and immune globulin.

STUDY SELECTION AND DATA EXTRACTION

Patients administered IVIG for HIT and diagnosed by immunoassay (optical density ≥2) or positive activation assay were included.

DATA SYNTHESIS

Twenty-four cases were reviewed; 92% had persistent aHIT. Time to IVIG administration post-nonheparin anticoagulant initiation was 9 days (median). Most common IVIG cumulative dose was 2 g/kg (dosed as 1 g/kg/d for 2 consecutive days); 75% had a favorable platelet increase (≥50 × 10⁹/L) within 5 days of initial IVIG dosing.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

aHIT is characterized by critically low platelets, thrombosis, and a persistent delay in platelet recovery despite treatment with a nonheparin anticoagulant. An immunoassay and subsequent confirmatory activation assay (at low, high, and 0 IU/mL unfractionated heparin levels) is recommended to confirm diagnosis. Patients nonresponsive to nonheparin anticoagulants within 5 days of initiation should be evaluated for IVIG treatment (2 g/kg cumulative dose). More data are needed to clarify appropriate IVIG dosing weight, although based on current published literature, it is recommended to use actual body weight.

CONCLUSIONS

Data reported support use of IVIG as adjunctive therapy for patients with aHIT. Judicious IVIG use based on key clinical and laboratory findings is critical.

Autoimmune heparin-induced thrombocytopenia and venous limb gangrene after aortic dissection repair: in vitro and in vivo effects of intravenous immunoglobulin

BACKGROUND

Heparin-induced thrombocytopenia (HIT) is a prothrombotic disorder characterized by heparin-dependent antibodies that activate platelets (PLTs) via PLT FcγIIa receptors. "Autoimmune" HIT (aHIT) indicates a HIT subset where thrombocytopenia progresses or persists despite stopping heparin; aHIT sera activate PLTs strongly even in the absence of heparin (heparin-independent PLT-activating properties). Affected patients are at risk of severe complications, including dual macro- and microvascular thrombosis leading to venous limb gangrene. High-dose intravenous immunoglobulin (IVIG) offers an approach to interrupt heparin-independent PLT-activating effects of aHIT antibodies.

CASE REPORT

A 78-year-old male who underwent cardiopulmonary bypass for aortic dissection developed aHIT, disseminated intravascular coagulation, and deep vein thrombosis; progression to venous limb gangrene occurred during partial thromboplastin time (PTT)-adjusted bivalirudin infusion (underdosing from "PTT confounding"). Thrombocytopenia recovered with high-dose IVIG, although the PLT count increase began only after the third dose of a 5-day IVIG regimen (0.4 g/kg/day × 5 days). We reviewed case reports and case series of IVIG for treating HIT, focusing on various IVIG dosing regimens used.

RESULTS

Patient serum-induced PLT activation was inhibited in vitro by IVIG in a dose-dependent fashion; inhibition of PLT activation by IVIG was much more marked in the absence of heparin versus the presence of heparin (0.2 U/mL). Our literature review indicated 1 g/kg × 2 IVIG dosing as most common for treating HIT, usually associated with rapid PLT count recovery.

CONCLUSION

Our clinical and laboratory observations support dose-dependent efficacy of IVIG for decreasing PLT activation and thus correcting thrombocytopenia in aHIT. Our case experience and literature review suggests dosing of 1 g/kg IVIG × 2 for patients with severe aHIT.

Intravenous immunoglobulin as an adjunct therapy in persisting heparin-induced thrombocytopenia

Heparin induced thrombocytopenia (HIT) is a serious adverse drug reaction caused by transient antibodies against platelet factor 4 (PF4)/heparin complexes, resulting in platelet activation and potentially fatal arterial and/or venous thrombosis. Most cases of HIT respond to cessation of heparin and administration of an alternative non-heparin anticoagulant, but there are cases of persisting HIT, defined as thrombocytopenia due to platelet activation/consumption for greater than seven days despite standard therapy. These patients remain at high risk for thrombotic events, which may result in limb-loss and mortality. Intravenous immunoglobulin (IVIg) has been proposed as an adjunct therapy for these refractory cases based on its ability to saturate FcγRIIa receptors on platelets, thus preventing HIT antibody binding and platelet activation. We describe 2 cases of persisting HIT (strongly positive antigen and functional assays, and persisting thrombocytopenia >7 days) with rapid clinical response to IVIg. We performed in-vitro experiments to support IVIg response. Healthy donor platelets (1 × 10e6) were treated with PF4 (3.75 μg/mL) for 20 min followed by 1-hour incubation with patients' sera. Platelet activation with and without addition of IVIg (levels equivalent to those reached in a patient after treatment with 2 gm/Kg) was evaluated in the PF4-dependent P-selectin expression assay (PEA). A significantly decreased platelet activation was demonstrated after the addition of IVIg to both patient samples, which correlated well with the rapid clinical response that each patient experienced. Thus, our study supports the use of IVIg as an adjunct therapy for persisting HIT.

IVIg for Treatment of Severe Refractory Heparin-Induced Thrombocytopenia

BACKGROUND

Heparin-induced thrombocytopenia (HIT) complicated by severe thrombocytopenia and thrombosis can pose significant treatment challenges. Use of alternative anticoagulants in this setting may increase bleeding risks, especially in patients who have a protracted disease course. Additional therapies are lacking in this severely affected patient population.

METHODS

We describe three patients with HIT who had severe thromboembolism and prolonged thrombocytopenia refractory to standard treatment but who achieved an immediate and sustained response to IVIg therapy. The mechanism of action of IVIg was evaluated in these patients and in five additional patients with severe HIT. The impact of a common polymorphism (H/R 131) in the platelet IgG receptor FcγRIIa on IVIg-mediated inhibition of platelet activation was also examined.

RESULTS

At levels attained in vivo, IVIg inhibits HIT antibody-mediated platelet activation. The constant domain of IgG (Fc) but not the antigen-binding portion (Fab) is required for this effect. Consistent with this finding, IVIg had no effect on HIT antibody binding in a solid-phase HIT immunoassay (platelet factor 4 enzyme-linked immunoassay). The H/R131 polymorphism in FcγRIIa influences the susceptibility of platelets to IVIg treatment, with the HH131 genotype being most susceptible to IVIg-mediated inhibition of antibody-induced activation. However, at high doses of IVIg, activation of platelets of all FcγRIIa genotypes was significantly inhibited. All three patients did well on long-term anticoagulation therapy with direct oral anticoagulants.

CONCLUSIONS

These studies suggest that IVIg treatment should be considered in patients with HIT who have severe disease that is refractory to standard therapies.