[Novel treatment strategies for acquired hemophilia A].

Acquired hemophilia A (AHA) is a bleeding disorder caused by autoantibody (inhibitor) production targeting blood coagulation factor VIII (FVIII). It is characterized by sudden onset, and often causes extensive and severe bleeding in soft tissue. Acquired hemophilia A is diagnosed when coagulation tests show normal PT, prolonged APTT, decreased FVIII activity, normal VWF activity, and positive FVIII inhibitor. Hemostatic therapy mainly consists of bypass therapy, which activates the extrinsic coagulation pathway, bypassing the need for FVIII or factor IX. Emicizumab, a bispecific antibody that substitutes for FVIII function, can be used to prevent bleeding. Immunosuppressive therapy is necessary to suppress or eradicate inhibitors. The majority of patients go into remission with treatment, but some die from bleeding symptoms or infections associated with immunosuppressive therapy.

Cases of acquired hemophilia A following COVID-19 vaccines: Cogent safety signal or possible reporting/detection bias? Preliminary evidence from Tuscany, Italy.

PURPOSE: Several case reports of acquired hemophilia A (AHA) following COVID-19 vaccines were recently published. A possible increased incidence of AHA during the COVID-19 vaccination campaign was also suggested. We aimed at generating evidence for the preliminary assessment of the association between AHA and COVID-19 vaccination through an ecological study in one Italian region, Tuscany. METHODS: An ecological study was performed using the population-based administrative data source of Tuscany. Per each year between 2017 and 2021, we included patients aged 5+ and active into the database as of January 1. Temporal patterns of annual incidence of possible AHA cases and AHA-tested patients were respectively observed. The rates of possible AHA cases per AHA-tested patients were calculated in 2021 and 2017-2019, respectively (calendar year 2020 was excluded because non-representative of the pre-pandemic era). Age-sex standardization was applied. Poisson's 95% confidence intervals (95% CI) were estimated. Statically significant differences were defined as absence of 95% CI overlap. RESULTS: In 2021, standardized incidence of both possible AHA cases (5.6/million subjects/year; 95% CI = 3.4-8.7) and AHA-tested patients (60.7/1000 subjects/year; 95% CI = 60.4-60.9) showed the lowest point estimates, though only the latter was statistically different compared to previous calendar years. The standardized rate of possible AHA cases per AHA-tested patients was 9.2/100000 (95% CI = 5.6-14.3) in 2021 and 12.5/100000 (95% CI = 8.2-18.1) during 2017-2019. CONCLUSIONS: These preliminary findings do not support the hypothesis of an increased incidence of AHA cases during the COVID-19 vaccination campaign. However, in 2021, the still ongoing healthcare access restrictions might have contributed to the low incidence of AHA and laboratory tests observed. Therefore, large-scale multi-database studies are warranted.

Acquired hemophilia A following COVID-19 vaccination - The importance of prompt diagnosis: A case report.

Acquired hemophilia A (AHA) is a rare coagulopathy characterized by hemorrhagic manifestations. It has been linked to various conditions, including autoimmune disorders, drugs, tumors, lymphoproliferative disorders, and infections. We present a case of AHA in a 71-year-old male patient with cutaneous hematoma occurring 8 days after vaccination for COVID-19. This report aims to highlight the risk of FVIII inhibitor development following an immune stimulus, thus improving our knowledge regarding possible vaccination-related adverse events. Furthermore, we underline how the potential risk of not recognizing disease manifestations promptly, together with specific coagulation alterations, could significantly affect the patient's outcome. Adequate management plans and the diffusion of shared guidelines are of fundamental importance in order to prevent the development of life-threatening complications and initiate appropriate treatment as soon as possible. DATA AVAILABILITY: All data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author.

Sudden-onset gallbladder rupture due to Ceftriaxone-associated pseudolithiasis in a patient with acquired hemophilia A.

We herein report a 76-year-old man with acquired hemophilia A (AHA) who developed gallbladder rupture due to Ceftriaxone (CTRX)-associated pseudolithiasis. The patient was admitted for an examination of systemic subcutaneous bleeding. A blood test showed a prolonged activated partial thromboplastin time and sequentially revealed low factor VIII activity (<1%) and a high factor VIII inhibitor level of 143 BU/mL. The patient was thus diagnosed with AHA. After admission, he developed a high-grade fever and was administered intravenous CTRX, considering the possibility of psoas abscess or cellulitis. Although his high-grade fever was improved, computed tomography incidentally showed a high-density lesion in the gallbladder, suggestive of CTRX-associated pseudolithiasis without clinical symptoms. Despite cessation of CTRX, the pseudolithiasis never disappeared, and the patient suddenly died after rapid progression of abdominal bloating. An autopsy revealed that the gallbladder was severely swollen and had ruptured with hemorrhaging because of hemorrhagic cholecystitis, caused by CTRX-associated pseudolithiasis with AHA. Our case demonstrated that CTRX-associated pseudocholelithiasis can unexpectedly induce gallbladder hemorrhaging and rupture in a patient with a bleeding diathesis, including AHA. CTRX-associated pseudocholelithiasis can cause a fatal outcome in patients with a bleeding disorder, even if CTRX is ceased as soon as pseudocholelithiasis is detected.

Key Genes of the Immune System and Predisposition to Acquired Hemophilia A: Evidence from a Spanish Cohort of 49 Patients Using Next-Generation Sequencing.

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by the presence of autoantibodies against factor VIII (FVIII). As with other autoimmune diseases, its etiology is complex and its genetic basis is unknown. The aim of this study was to identify the immunogenetic background that predisposes individuals to AHA. HLA and KIR gene clusters, as well as KLRK1, were sequenced using next-generation sequencing in 49 AHA patients. Associations between candidate genes involved in innate and adaptive immune responses and AHA were addressed by comparing the alleles, genotypes, haplotypes, and gene frequencies in the AHA cohort with those in the donors' samples or Spanish population cohort. Two genes of the HLA cluster, as well as rs1049174 in KLRK1, which tags the natural killer (NK) cytotoxic activity haplotype, were found to be linked to AHA. Specifically, A*03:01 (p = 0.024; odds ratio (OR) = 0.26[0.06-0.85]) and DRB1*13:03 (p = 6.8 × 103, OR = 7.56[1.64-51.40]), as well as rs1049174 (p = 0.012), were significantly associated with AHA. In addition, two AHA patients were found to carry one copy each of the low-frequency allele DQB1*03:09 (nallele = 2, 2.04%), which was completely absent in the donors. To the best of our knowledge, this is the first time that the involvement of these specific alleles in the predisposition to AHA has been proposed. Further molecular and functional studies will be needed to unravel their specific contributions. We believe our findings expand the current knowledge on the genetic factors involved in susceptibility to AHA, which will contribute to improving the diagnosis and prognosis of AHA patients.

[Utility of thromboelastography in the treatment of acquired hemophilia A].

Acquired hemophilia A (AHA) is a bleeding disorder caused by the spontaneous development of inhibitory autoantibodies to factor VIII. Thromboelastography (TEG) is a clinical examination that assesses clot formation in the whole blood. However, its utility in the hemostatic management of AHA is unexplored. A 35-year-old man who developed AHA after abdominal surgery was treated for hemostasis with bypassing agents. The TEG R value, which was prolonged as bleeding worsened, was improved by switching to bypassing agents. We report this impressive case, which suggests that TEG can monitor hemostatic effects and is useful for the management of a bypassing agent regimen in addition to its previously acknowledged utility in clinical evaluation.

[Acquired hemophilia A following BNT162b2 mRNA COVID-19 vaccination].

Acquired hemophilia A (AHA) is a rare disease characteized by bleeding symptoms caused by decreased factor VIII activity due to the appearance of inhibitors to factor VIII triggered by malignancy or collagen disease. An 86-year-old woman developed purpura on her extremities after the first dose of the BNT162b2 mRNA COVID-19 vaccine. This symptom subsided after a few days. After the second dose of the BNT162b2 mRNA COVID-19 vaccine, purpura appeared again, and the patient was referred to our hospital Her APTT was remarkably prolonged to 110 seconds, and a cross-mixing test revealed an inhibitor pattern. Since FVIII activity was <1% and FVIII inhibitor was 51.6 BU, she was diagnosed with AHA. Prednisolone therapy was started, and coagulative complete remission was achieved. Because acquired hemophilia can develop after mRNA COVID-19 vaccination, as in this case, it is critical to monitor the appearance of bleeding symptom.

[Acquired hemophilia A that developed after BNT162b2 mRNA COVID-19 vaccination and worsened following re-vaccination].

An 86-year-old Japanese male patient visited a nearby hospital with painful swelling in his left upper and lower limbs 35 days after the second dose of the BNT162b2 mRNA coronavirus disease-2019 (COVID-19) vaccine. He was referred to our hematological department due to a prolonged activated partial thromboplastin time and was urgently admitted. He was diagnosed with acquired hemophilia A (AHA) based on factor VIII (FVIII) activity of 1.7%, FVIII inhibitor of 152.3 BU/ml, and FVIII-binding antibodies detected by enzyme-linked immunosorbent assay. Immunosuppressive therapy with prednisolone (PSL) at 0.5 mg/kg/day was started owing to the risk of infection due to old age and poor activities of daily living. Hemostasis treatment with bypass hemostatic preparations (rFVIIa preparation, FVIIa/FX) was administered for each bleeding event, such as intramuscular and knee joint bleeding, resulting in good hemostatic effects. Coagulative complete remission was achieved on day 69 with PSL treatment; however, FVIII activity decreased with PSL tapering. AHA relapse with rectus abdominis muscle hematoma was observed after the third vaccination. This is the first Japanese report of AHA after COVID-19 vaccination and the world's first case, in which the presence of anti-FVIII-binding antibodies were observed.

[Coagulative complete remission following early gastric cancer resection in a patient with steroid-resistant acquired hemophilia A and nephrotic syndrome].

During laparoscopic cholecystectomy, an 89-year-old man was discovered to have a prolonged APTT. He was transferred to our hospital for a thorough examination because wound bleeding necessitated a reoperation. Based on coagulation factor VIII activity (FVIII:C) of 3.6% and FVIII inhibitor levels of 48.5 BU/ml, he was diagnosed with acquired hemophilia A (AHA). Due to concerns about his advanced age and postoperative infection, immunosuppressive therapy with prednisolone 0.5 mg/kg/day was initiated. His clinical course was favorable, except hemorrhagic shock caused by intramuscular hemorrhage on the right back, although low FVIII inhibitor levels persisted for more than a month; additionally, lower leg edema and increased urinary protein were also observed. He was diagnosed as with AHA and secondary nephrotic syndrome, possibly because of early gastric cancer. As a result, radical endoscopic submucosal dissection (ESD) was performed while a recombinant coagulation factor VIIa preparation was administered. AHA improved rapidly following ESD, and coagulative remission was achieved. Simultaneously, the nephrotic syndrome improved. Because the control of malignant tumors may improve the status of AHA, the timing of malignant tumor intervention must be considered considering the risk of bleeding and infection associated with immunosuppression.

Acute-type acquired hemophilia A after COVID-19 mRNA vaccine administration: A new disease entity?

Acquired hemophilia A (AHA) is a rare autoimmune bleeding disorder. Various autoimmune diseases, including AHA, have been reported to occur after the administration of mRNA COVID-19 vaccines. However, the characteristics of these AHA cases remain unclear. We report a case in which AHA arose in a young patient after the administration of an mRNA COVID-19 vaccine, but improved rapidly. The patient's factor VIII (FVIII) inhibitor titer spontaneously decreased to less than half of that seen at diagnosis. One week after the initial immunosuppressive therapy, the FVIII inhibitor had disappeared. Our case suggests that AHA that arises in young patients after COVID-19 vaccination may resolve spontaneously, and the levels of FVIII inhibitors may decrease more rapidly in such cases than in idiopathic AHA. Unlike for immune thrombocytopenic purpura (ITP), no acute type of AHA has been recognized. This case suggests that just as there is an acute type of ITP that develops in children/after vaccination, there may be an acute type of AHA that arises in young patients that receive mRNA COVID-19 vaccines.

Usefulness of anti-factor VIII IgG ELISA in acquired hemophilia A follow-up.

Acquired hemophilia A (AHA) is a rare autoimmune bleeding disorder due to the presence of neutralizing autoantibodies directed against the coagulation factor VIII (FVIII). The reference method to detect and quantify anti-FVIII antibodies is the Bethesda assay (BA), but it presents some limitations such as a lack of sensitivity for low titers of inhibitor and the need for experienced laboratory. A commercially available ELISA detecting anti-FVIII antibodies has demonstrated excellent sensitivity and specificity. The aim of our study was to assess the performance of this ELISA for the detection of anti-FVIII IgG in AHA patients during the follow-up. In total, 11 acquired hemophilia A patients were recruited, and anti-FVIII antibody levels were monitored by BA and ELISA. Anti-FVIII IgG ELISA showed 100% sensitivity and 100% specificity, and it correlated with the BA. Discrepancies observed in 13.3% of cases were consistent with patients' biological evolution. All these data suggest the possible use of anti-FVIII IgG ELISA for both diagnosis and follow-up of AHA patients.

Use of thromboelastography before the administration of hemostatic agents to safely taper recombinant activated factor VII in acquired hemophilia A: a report of three cases.

BACKGROUND: Acquired hemophilia A (AHA) is a rare autoimmune disease characterized by bleeding events. Recombinant activated factor VII (rFVIIa) is a first-line bypassing agent, which is effective against clinically significant bleeding. However, there is no standard way of tapering and discontinuing rFVIIa, mainly because there is no established method for monitoring rFVIIa therapy for AHA. CASE PRESENTATION: Here, we report three AHA cases, in which we adjusted the rFVIIa dosing interval based on the results of thromboelastography (TEG) performed just before the administration of the next dose of rFVIIa. The dosing interval of rFVIIa was prolonged based on the reaction rate time (R) according to TEG, which is correlated with coagulation factor activity. The R-value reference range reported by the manufacturer of the TEG system was used as a threshold for making decisions. In these three cases, there was no rebleeding, and the patients' ability to perform activities of daily living did not decline. CONCLUSION: Our cases suggest that conducting TEG-based monitoring just before the administration of the next dose of rFVIIa may be useful for guiding increases in the rFVIIa dosing interval without causing rebleeding events. Further investigations are warranted to examine how TEG could be used to determine the most appropriate rFVIIa dosing interval, e.g., through regular TEG-based monitoring, and the optimal TEG-derived threshold for indicating changes to the rFVIIa dosing interval.

Acquired Hemophilia A associated with bullous pemphigoid: A rare combination.

Acquired Hemophilia A (AHA) is a rare autoimmune disorder, caused by the development of circulating autoantibodies against coagulation factor VIII (FVIII). AHA is associated with bullous pemphigoid in 2% of patients. We report a case of a 74-year-old man admitted with anemia and a tense subcutaneous and muscular hematoma in the right thigh. Blood analysis confirmed AHA. The patient had a recent diagnosis of bullous pemphigoid. Response to bypass agents and corticosteroids was good with bleeding control and normalization of FVIII and negative autoantibodies, respectively. In a 3-month follow-up period after tapering and stopping prednisolone, a relapse occurred, and immunosuppression was reinitiated. An early diagnosis and effective treatment in AHA are essential to reduce morbimortality. A careful tapering of immunosuppression is important to minimize FVIII inhibitor recurrence, as observed in this case.

Acquired hemophilia A and delta storage pool deficiency in a patient with indolent non-Hodgkin lymphoma.

B-cell lymphoproliferative diseases may be associated with acquired hemostasis disorders, such as acquired hemophilia A (AHA) caused by autoantibodies that neutralize factor VIII activity, and δ-storage pool deficiency, an abnormality of platelet function due to defective dense granules and impaired secretion. We describe the case of a 67-year-old man in whom these two acquired bleeding disorders were concomitantly present as the first clinical manifestation of an indolent non-Hodgkin lymphoma. Immunosuppressive therapy with prednisone was initially started to eradicate anti-FVIII antibodies, subsequently boosted with cyclophosphamide and rituximab, these medications being also chosen to treat the associated indolent lymphoma. Bleeding symptoms were first tackled with limited benefit by using rFVIIa and then rescued using recombinant porcine FVIII. After a 6 month's follow-up lymphoma and AHA were in remission and platelet function was improved. This case underlines the need of multiple and complex diagnostic and therapeutic approaches to rare acquired bleeding disorders associated with lymphoproliferative diseases.

Corpus luteum hemorrhage with acquired hemophilia A: a case report and literature review.

BACKGROUND: The rupture of the corpus luteum (CL) may occur at all stages of a woman's reproductive life. Bleeding of the ruptured CL varies from self-limiting hemorrhage to massive hemoperitoneum, causing the shock and subsequent emergency surgery. But hemoperitoneum secondary to ruptured CL is a rare complication and situation for women with bleeding disorders. CASE PRESENTATION: We here describe a case of severe CL hemorrhage with factor VIII deficiency. We chose conservative management instead of surgery for the abnormal hemostatic condition. With blood product and factor concentrate support, conservative management was successful in avoiding surgery in the episode of bleeding. CONCLUSION: Gynecologist should be alert for the patients with abnormal hemostatic condition. Selective patients presenting with CL hemoperitoneum association with bleeding disorders may undergo conservative management and avoid the risk of surgery.

A case of acquired hemophilia A and bullous pemphigoid following SARS-CoV-2 mRNA vaccination.

Acquired hemophilia is a rare disease resulting from autoantibodies against endogenous factor VIII (FVIII), which associates with bleeding and a high mortality rate. The pathophysiology is still unclear. Recent studies suggest genetic and environmental factors trigger the breakdown of immune tolerance. We report a 77-year-old Taiwanese man presented with multiple ecchymoses and some hemorrhagic blisters three weeks after SARS-CoV-2 mRNA (Moderna) vaccination. Isolated activated partial thromboplastin time (aPTT) prolongation was found. Acquired hemophilia A (AHA) was confirmed by low factor VIII (FVIII) activity and high titer of FVIII inhibitor. The pathohistology of skin biopsy further supported the concomitant diagnosis of bullous pemphigoid. To date, 6 cases of acquired hemophilia A following SARS-CoV-2 mRNA vaccination were reported worldwide. We reviewed and summarized the characteristics of these cases. We also discussed the rare finding of concomitant acquired hemophilia A and bullous pemphigoid. Bullous pemphigoid results from autoantibody against epithelial basement membrane zone of skin. In this article, we proposed possibility of SARS-CoV-2 mRNA vaccine associated autoimmunity against FVIII and epithelial basement membrane zone.

[Examination of the effect of immunosuppressive therapy on acquired hemophilia A in elderly patients with bloodstream infections].

AIM: Acquired hemophilia A (AHA) is an acquired autoantibody (inhibitor) against blood coagulation factor VIII (FVIII) that significantly reduces FVIII activity and causes a bleeding tendency. Immune acquired coagulation factor deficiency. The peak age of onset is in the 70s. In Japan, which has an aging society, the number of reports has recently been increasing, and it should be noted that AHA is a bleeding disease that can occur in the elderly. Examined 5 cases of AHA that were experienced in our hospital. The FVIII inhibitor level, APTT, underlying disease, treatment history, and outcome were retrospectively examined using medical records. RESULTS: The age of onset was 76-93 years. At the time of diagnosis, the Hb (mg/dL) value was 6.1-10.3, the APTT was 75.6-203.2 seconds, the FVIII inhibitor value (BU/mL) was 18-686, and the platelet count was within the normal range in all cases. Bleeding control was possible using a bypass hemostatic agent in 4 patients. All patients underwent immunosuppressive therapy. Two patients were discharged alive and 3 patients died. The cause of death was infectious disease in all cases. The total prednisolone-equivalent dose of the deceased patients was 1,240-3,206 mg; one patient was treated with cyclophosphamide and was treated with dexamethasone. CONCLUSION: Long-term immunosuppressive therapy is expected to increase the risk of infection in elderly patients. The risk assessment of AHA treatment-related bloodstream infections is insufficient, and it will be necessary to accumulate data and consider appropriate assessments and countermeasures.

A Unique Case of Acquired Hemophilia A Presenting with Transient Ischemic Attack.

Acquired hemophilia A (AHA) is a rare but serious condition, usually associated with significant spontaneous or traumatic bleeding and a high mortality rate. In this report, we describe the case of an elderly patient presenting a transient ischemic attack concurrently with AHA. A thrombotic event in AHA is occasionally associated with the use of bypassing agents for treatment, but a spontaneous thrombotic event has not ever been described.

Successful management of acquired hemophilia A onset during pregnancy: A case report.

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by autoantibodies that inhibit coagulation factor VIII. Pregnancy could be associated with AHA in younger women. Because of its rarity, the optimal management for pregnancy-related AHA has not yet been established. Herein, we present the case of a 32-year-old woman with AHA diagnosed during pregnancy because of elevated activated partial prothrombin time, decreased factor VIII activity, and the presence of a factor VIII inhibitor. She was treated with immunosuppressive therapy consisting of corticosteroid and cyclosporine administration. Although complete remission could not be induced in the peripartum period, she gave birth safely by cesarean delivery in combination with prophylactic bypass hemostatic therapy. This work would provide helpful information to guide better recognition and treatment of pregnancy-related AHA cases.

[Acquired hemophilia A with reappearance of inhibitor 10 years after the completion of immunosuppressive therapy].

Acquired hemophilia A (AHA) is a disease that causes severe bleeding with the appearance of an inhibitor (INH) against blood coagulation factor VIII (FVIII). The prevalence of this condition is low; it occurs in only one in one to four million people per year; however, the number of diagnosed cases has increased in recent years owing to the greater awareness of the disease. It is noteworthy that this is a hemorrhagic disease that suddenly develops in the elderly. AHA treatment is divided into hemostatic treatment for bleeding and immunosuppressive therapy (IST) for removing FVIII-INH. As long as FVIII-INH remains, there is a risk of fatal bleeding; therefore, it is desirable to start IST soon after diagnosis. However, the use of immunosuppressive drugs for the elderly is often challenging due to concerns about adverse events, such as infectious diseases that have a considerable impact on prognosis. Ten years after the end of IST, we managed the case of a patient with AHA who had a relapse of FVIII-INH at the age of 84 years. In this case, relapse was detected early when there was no bleeding symptom, and remission was rapidly achieved with a small amount of IST without any adverse effects. There are few reports on AHA relapse; we believe that the present report will contribute meaningfully to the literature on this subject and would be useful when considering the long-term management of AHA.