Tocilizumab induced acquired factor XIII deficiency in patients with rheumatoid arthritis

Tocilizumab-induced hypofibrinogenemia in patients with systemic-onset juvenile idiopathic arthritis

Systemic juvenile idiopathic arthritis (SJIA) is a chronic inflammatory disease of childhood with elevated serum IL-6 levels. As an inhibitor of IL-6R, tocilizumab (TCZ) has been approved to treat SJIA patients. TCZ-induced hypofibrinogenemia has been only reported in adult cases and limited small case series with rheumatoid arthritis or giant cell arteritis. Here, we describe the incidence of TCZ-induced hypofibrinogenemia in SJIA patients and its possible influence on bleeding risk. SJIA patients with TCZ treatment in Shenzhen Children's hospital were retrospectively reviewed. Only those with the data on serum fibrinogen levels were included. Data on clinical manifestations, laboratory parameters, management, and sJADAS10-ESR score were collected. Laboratory data were extracted following the start of TCZ therapy at 2, 4, 8, 12, and 24 weeks thereafter. Seventeen SJIA patients with TCZ treatment were included. Thirteen (76.47%, 13/17) had hypofibrinogenemia. The lowest serum fibrinogen levels were even below 1.5 g/L in seven (41.17%, 7/17) patients. Among four patients without MTX treatment, two had obvious hypofibrinogenemia. Although five patients had already stopped steroid treatment 24 weeks after TCZ treatment, three of them still had hypofibrinogenemia. Only P14 had mild nasal mucosal bleeding occasionally. Coagulation tests were regularly performed in eight patients, of these, six had hypofibrinogenemia, which occurred following one to four doses of TCZ; continuation of TCZ treatment hadn't further aggravated hypofibrinogenemia. Serum fibrinogen levels were not decreased consistently with the improvement of sJADAS10-ESR score in more than half of these eight patients. Factor XIII was detected in six patients and none was identified with Factor XIII deficiency. TCZ alone may induce hypofibrinogenemia in SJIA patients. Continuation of TCZ treatment may be safe for most SJIA patients. But for SJIA patients with indications of surgery or complicated with MAS, the risk of hemorrhage should be regularly evaluated during TCZ treatment. The association between TCZ-induced hypofibrinogenemia and factor XIII deficiency remains uncertain.Trial registration: Not applicable; this was a retrospective study.

Expression of factor XIII originating from synovial fibroblasts and macrophages induced by interleukin-6 signaling

BACKGROUND

Blood coagulation factor XIII (FXIII) promotes cross-linking between fibrin molecules at the final stage of the blood coagulation cascade. However, its expression in cells or tissues and function, particularly factor XIII subunit B (FXIII-B), remains controversial. Hemorrhagic FXIII deficiency following anti-interleukin-6 (IL-6) receptor antibody treatment has been reported in patients with rheumatoid arthritis (RA). Patients receiving this biologics have reduced FXIII activity when compared to the activity in those treated with other biologics. The relationship between pro-inflammatory cytokines and FXIII expression remains unknown.

METHODS

To investigate the expression pattern of FXIII in synovial tissues, immunohistochemistry, RT-qPCR, and western blotting were performed. FXIII-A expressed monocyte-derived macrophages were treated with recombinant IL-6 and anti-IL-6 receptor antibody. RNA sequencing of FXIII-B-overexpressing cells was performed to clarify the function of FXIII-B.

RESULTS

The immunohistochemical analysis of synovial tissues revealed that factor XIII subunit A (FXIII-A) was expressed in M2 macrophages, and FXIII-B was expressed in fibroblast-like synoviocytes. IL-6 stimulation upregulated FXIII-A expression in IL-4-induced monocyte-derived macrophages, and the anti-IL-6 receptor antibody suppressed FXIII-A expression. FXIII-B was more abundantly secreted in the supernatant of fibroblast-like synoviocytes compared with that of other cells. RNA sequencing showed that FXIII-B elevated the expression of genes associated with anti-apoptotic molecules and chemokines.

CONCLUSIONS

Our findings highlight that synovial tissue is one of the sources of FXIII production. We also have demonstrated IL-6-dependent FXIII-A expression and the novel potential functions of FXIII-B.

Is Real-World Evidence Used in P&T Monographs and Therapeutic Class Reviews?

BACKGROUND

Payers are faced with making coverage and reimbursement decisions based on the best available evidence. Often these decisions apply to patient populations, provider networks, and care settings not typically studied in clinical trials. Treatment effectiveness evidence is increasingly available from electronic health records, registries, and administrative claims. However, little is known about when and what types of real-world evidence (RWE) studies inform pharmacy and therapeutic (P&T) committee decisions.

OBJECTIVE

To evaluate evidence sources cited in P&T committee monographs and therapeutic class reviews and assess the design features and quality of cited RWE studies.

METHODS

A convenience sample of representatives from pharmacy benefit management, health system, and health plan organizations provided recent P&T monographs and therapeutic class reviews (or references from such documents). Two investigators examined and grouped references into major categories (published studies, unpublished studies, and other/unknown) and multiple subcategories (e.g., product label, clinical trials, RWE, systematic reviews). Cited comparative RWE was reviewed to assess design features (e.g., population, data source, comparators) and quality using the Good ReseArch for Comparative Effectiveness (GRACE) Checklist.

RESULTS

Investigators evaluated 565 references cited in 27 monographs/therapeutic class reviews from 6 managed care organizations. Therapeutic class reviews mostly cited published clinical trials (35.3%, 155/439), while single-product monographs relied most on manufacturer-supplied information (42.1%, 53/126). Published RWE comprised 4.8% (21/439) of therapeutic class review references, and none (0/126) of the monograph references. Of the 21 RWE studies, 12 were comparative and assessed patient care settings and outcomes typically not included in clinical trials (community ambulatory settings [10], long-term safety [8]). RWE studies most frequently were based on registry data (6), conducted in the United States (6), and funded by the pharmaceutical industry (5). GRACE Checklist ratings suggested the data and methods of these comparative RWE studies were of high quality.

CONCLUSIONS

RWE was infrequently cited in P&T materials, even among therapeutic class reviews where RWE is more readily available. Although few P&T materials cited RWE, the comparative RWE studies were generally high quality. More research is needed to understand when and what types of real-world studies can more routinely inform coverage and reimbursement decisions.

DISCLOSURES

This project was funded by the National Pharmaceutical Council. Hurwitz, Brown, Peters, and Malone have nothing to disclose. Graff is employed by the National Pharmaceutical Council Part of this study was presented as a poster presentation at the AMCP Managed Care & Specialty Pharmacy 2016 Annual Meeting; April 19-22, 2016; San Francisco, CA. Study concept and design were primarily contributed by Malone and Graff, along with Hurwitz and Brown. All authors participated in data collection, and data interpretation was performed by Malone, Hurwitz, and Graff, with assistance from Brown and Peters. The manuscript was written primarily by Hurwitz and Malone, along with Graff, Brown, and Peters, and revised by Malone, Brown, Peters, Hurwitz, and Graff.

Spontaneous Intraparenchymal Hepatic Hemorrhage as a Sequela of COVID-19

Patients with coronavirus disease 2019 (COVID-19) have been presenting with varying signs and symptoms. The medical community is being updated with new knowledge about this disease daily. We present a case of intrahepatic hemorrhage in a patient diagnosed with C0VID-19 which we believe was caused by endothelialitis, which is a characteristic feature of COVID-19. Nevertheless, further continued studies are required to validate this point. We aim to educate the medical community about the possible complications by COVID-19 in the liver and highlight that N-acetylcysteine (NAC) may be a useful option in these cases.

Spontaneous Spinal Epidural Hematoma During Simultaneous Tocilizumab and Warfarin Use in a Patient With Rheumatoid Arthritis: Is There a Drug Interaction Between Tocilizumab and Oral Anticoagulants?

Interleukin 6 (IL-6) plays a main role in the immunopathogenesis of rheumatoid arthritis (RA). Tocilizumab (TCZ) is a humanized immunoglobulin G1 monoclonal antibody against the human IL-6. Warfarin sodium is an oral anticoagulant that is primarily metabolized by cytochrome P450 2C9 (CYP2C9). Impaired metabolism of this low therapeutic index drug is important as it may result in serious bleeding. In this article, we present a 56-year-old female patient with RA, treated with TCZ and warfarin sodium and presented spontaneous spinal epidural hematoma (SSEH) of thoracic spine although international normalized ratio levels were in normal ranges. One week after decompressive surgery for hematoma, a cervical spine abscess developed which resulted in her death. To the best of our knowledge, this is the first case of RA developing SSEH while taking TCZ and warfarin sodium together. Although it is difficult to attribute the severe bleeding to TCZ treatment, clinicians should be aware that concomitant use of oral anticoagulants and TCZ might result in potentially fatal complications in patients with RA.

Tocilizumab Effects on Coagulation Factor XIII in Patients with Rheumatoid Arthritis

Introduction

Rheumatoid arthritis (RA) is a chronic systemic auto-immune disease associated with a prothrombotic state. Tocilizumab, an interleukin-6 receptor inhibitor, is highly effective in controlling disease activity and thrombotic risk. Factor XIII (FXIII), involved in thrombotic complications, has been reported to be reduced in RA patients during maintenance treatment with tocilizumab, but no data are available before and after the drug administration. Thus, we investigated the effects of tocilizumab on FXIII, thrombin generation and inflammation in patients with RA naïve for the drug.

Methods

We studied 15 consecutive adult patients with RA at baseline and 4 weeks after the onset of parenteral administration of tocilizumab, measuring disease activity and plasma levels of C-reactive protein (CRP), FXIII, and prothrombin fragments F1+2 by immunoenzymatic methods. Fifteen healthy subjects, sex-and age-matched with patients, served as normal controls for laboratory measurements.

Results

At baseline, patients with established RA had a median DAS28 of 4.8 (3.2–8.3) and, compared to healthy controls, had higher plasma levels of CRP (p < 0.0001), FXIII (p = 0.017) and F1+2 (p < 0.0001). Four weeks after starting treatment with tocilizumab, based on the EULAR response criteria, eight patients were classifiable as responders and seven as non-responders. In responders, we observed a statistically significant reduction not only of the values of DAS28 and CRP (p = 0.012 for both), ut also of plasma levels of FXIII (p = 0.05) and F1+2 (p = 0.025). In non-responders, all the studied parameters were unchanged.

Conclusion

The decrease of FXIII and F1+2 levels after tocilizumab treatment observed only in those patients who responded to the drug indicates that the effect of tocilizumab on the prothrombotic state is linked to the control of inflammation and disease activity and not to a direct effect of the drug, thus contributing to the reduction of the cardiovascular risk.

Acquired factor XIII deficiency: A review

Acquired factor XIII (FXIII) deficiency is a rare bleeding disorder that can manifest with spontaneous or delayed life-threatening hemorrhage. Causes of acquired deficiency include immune-mediated inhibition, as well as non-immune FXIII hyperconsumption or hyposynthesis. The occurrence of acquired FXIII deficiency can be idiopathic or may be associated with comorbidities, such as malignancies or autoimmune disorders. Recognition of acquired FXIII deficiency and its underlying cause is imperative, as treatment options vary depending on the etiology. Diagnosis requires quantitative FXIII testing in addition to supplemental inhibitor studies if the clinical situation suggests an immune-mediated pathophysiology. Treatment may involve FXIII replacement, antifibrinolytic administration, and/or inhibitor eradication. However, treatment targets and thresholds are undefined in acquired FXIII deficiency. This review will focus on the clinical characteristics, diagnostic issues and therapeutic options for both immune and non-immune acquired FXIII deficiency. Cases are described to illustrate the clinical features of acquired FXIII deficiency.

Tocilizumab treatment in patients with rheumatoid arthritis is associated with reduced fibrinogen levels and increased blood loss after total knee arthroplasty

OBJECTIVE

Since IL-6 has been associated with activation of the coagulation cascade and upregulation of fibrinogen transcription, we retrospectively tested the hypothesis that patients with rheumatoid arthritis (RA) treated with tocilizumab (TCZ) may lose more blood when undergoing total knee arthroplasty (TKA).

METHODS

This study included 115 RA patients who underwent primary TKA and were preoperatively tested for fibrinogen levels. The blood volume of each patient was calculated using the Nadler formula, and estimated blood loss after TKA was calculated as the change between pre-operative and post-operative hematocrits. If salvaged blood was reinfused, the volume was measured and added to the volume of the estimated blood loss.

RESULTS

We observed that patients treated with TCZ had significantly lower pre-operative fibrinogen levels than those not treated with TCZ (190.0 mg/dL versus 347.0 mg/dL, respectively; p = .00018). We also observed a statistically significant increase in mean total volume of estimated blood loss after TKA in RA patients who had been treated with TCZ compared with those not treated with TCZ (797.1 mL versus 511.4 mL, respectively; p = .0039).

CONCLUSION

TCZ treatment in patients with RA may increase the risk of blood loss after TKA because of decreased fibrinogen levels.

Is Real-World Evidence Used in P&T Monographs and Therapeutic Class Reviews?

BACKGROUND

Payers are faced with making coverage and reimbursement decisions based on the best available evidence. Often these decisions apply to patient populations, provider networks, and care settings not typically studied in clinical trials. Treatment effectiveness evidence is increasingly available from electronic health records, registries, and administrative claims. However, little is known about when and what types of real-world evidence (RWE) studies inform pharmacy and therapeutic (P&T) committee decisions.

OBJECTIVE

To evaluate evidence sources cited in P&T committee monographs and therapeutic class reviews and assess the design features and quality of cited RWE studies.

METHODS

A convenience sample of representatives from pharmacy benefit management, health system, and health plan organizations provided recent P&T monographs and therapeutic class reviews (or references from such documents). Two investigators examined and grouped references into major categories (published studies, unpublished studies, and other/unknown) and multiple subcategories (e.g., product label, clinical trials, RWE, systematic reviews). Cited comparative RWE was reviewed to assess design features (e.g., population, data source, comparators) and quality using the Good ReseArch for Comparative Effectiveness (GRACE) Checklist.

RESULTS

Investigators evaluated 565 references cited in 27 monographs/therapeutic class reviews from 6 managed care organizations. Therapeutic class reviews mostly cited published clinical trials (35.3%, 155/439), while single-product monographs relied most on manufacturer-supplied information (42.1%, 53/126). Published RWE comprised 4.8% (21/439) of therapeutic class review references, and none (0/126) of the monograph references. Of the 21 RWE studies, 12 were comparative and assessed patient care settings and outcomes typically not included in clinical trials (community ambulatory settings [10], long-term safety [8]). RWE studies most frequently were based on registry data (6), conducted in the United States (6), and funded by the pharmaceutical industry (5). GRACE Checklist ratings suggested the data and methods of these comparative RWE studies were of high quality.

CONCLUSIONS

RWE was infrequently cited in P&T materials, even among therapeutic class reviews where RWE is more readily available. Although few P&T materials cited RWE, the comparative RWE studies were generally high quality. More research is needed to understand when and what types of real-world studies can more routinely inform coverage and reimbursement decisions.

DISCLOSURES

This project was funded by the National Pharmaceutical Council. Hurwitz, Brown, Peters, and Malone have nothing to disclose. Graff is employed by the National Pharmaceutical Council Part of this study was presented as a poster presentation at the AMCP Managed Care & Specialty Pharmacy 2016 Annual Meeting; April 19-22, 2016; San Francisco, CA. Study concept and design were primarily contributed by Malone and Graff, along with Hurwitz and Brown. All authors participated in data collection, and data interpretation was performed by Malone, Hurwitz, and Graff, with assistance from Brown and Peters. The manuscript was written primarily by Hurwitz and Malone, along with Graff, Brown, and Peters, and revised by Malone, Brown, Peters, Hurwitz, and Graff.

Effects of Factor XIII Deficiency on Thromboelastography. Thromboelastography with Calcium and Streptokinase Addition is more Sensitive than Solubility Tests

Background

Homozygous or double heterozygous factor XIII (FXIII) deficiency is characterized by soft tissue hematomas, intracranial and delayed spontaneous bleeding. Alterations of thromboelastography (TEG) parameters in these patients have been reported. The aim of the study was to show results of TEG, TEG Lysis (Lys 60) induced by subthreshold concentrations of streptokinase (SK), and to compare them to the clot solubility studies results in samples of a 1-year-old girl with homozygous or double heterozygous FXIII deficiency.

Case

A year one girl with a history of bleeding from the umbilical cord. During her first year of life, several hematomas appeared in soft upper limb tissue after punctures for vaccination and a gluteal hematoma. One additional sample of a heterozygous patient and three samples of acquired FXIII deficiency were also evaluated.

Materials and Methods

Clotting tests, von Willebrand factor (vWF) antigen and activity, plasma FXIII-A subunit (pFXIII-A) were measured by an immunoturbidimetric assay in a photo-optical coagulometer. Solubility tests were performed with Ca²⁺-5 M urea and thrombin-2% acetic acid. Basal and post-FXIII concentrate infusion samples were studied. TEG was performed with CaCl₂ or CaCl₂ + SK (3.2 U/mL) in a Thromboelastograph.

Results

Prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time, fibrinogen, factor VIIIc, vWF, and platelet aggregation were normal. Antigenic pFXIII-A subunit was < 2%. TEG, evaluated at diagnosis and post FXIII concentrate infusion (pFXIII-A= 37%), presented a normal reaction time (R), 8 min, prolonged k (14 and 11min respectively), a low Maximum-Amplitude (MA) ( 39 and 52 mm respectively), and Clot Lysis (Lys60) slightly increased (23 and 30% respectively). In the sample at diagnosis, clot solubility was abnormal, 50 and 45 min with Ca-Urea and thrombin-acetic acid, respectively, but normal (>16 hours) 1-day post-FXIII infusion. Analysis of FXIII deficient and normal plasma mixtures (< 2–102% of pFXIII-A), showed that Ca-urea solubility was abnormal at pFXIII-A < 9%, thrombin-acetic acid at pFXIII-A<18%, but TEG MA and elasticity at 23% and Lys60 with SK at pFXIII-A< 40%.

Conclusions

TEG parameters MA and elasticity, and Lys 60 in TEG either with Ca²⁺ or Ca²⁺ and SK are more sensitive to low levels of pFXIII than solubility tests. The increased Lys60 induced by a subthreshold concentration of SK could probably reflect the clot characteristics “in vivo” in many patients with pFXIII levels between 5–40% and could be potentially considered as screening test.