Time is Blood: The Impact of Diagnostic Delays on Acquired Hemophilia A

Lipopolysaccharide-binding protein functions as factor VIII inhibitor in bullous pemphigoid associated with acquired hemophilia A

Bullous pemphigoid (BP) represents an autoimmune blistering disorder that may coexist with acquired hemophilia A (AHA), a rare autoimmune condition arising from the formation of circulating autoantibodies directed against factor VIII (FVIII). The underlying pathomechanisms of BP-AHA remain elusive. This study conducted a retrospective analysis of data from 196 BP patients admitted to our hospital. We have collected serum samples from a recently admitted BP-AHA patient and healthy controls to isolate, screen and identify the potential FVIII inhibitors. The expression and function of lipopolysaccharide-binding protein (LBP) in BP-AHA were further validated by a series of biochemical experiments. The retrospective analysis showed that the activated partial thromboplastin time (APTT) values of seven patients exceeded 33.8 s (normal value) in 196 BP patients. FVIII: C (%) and FVIII inhibitors in the plasma of partial prolonged-APTT patients were significantly altered compared with control group or non-prolonged-APTT group. LBP was identified as a potential inhibitory protein of FVIII. Consistently, a notable alteration in LBP expression was observed in the plasma of BP patients with prolonged-APTT. Moreover, the amount of LBP bound to FVIII in the BP-AHA patient was notably higher than that in control group, which was also markedly reversed after treatment. In vitro experiments finally confirmed that exogenous LBP directly bound to FVIII and significantly inhibited FVIII activity. In conclusion, the incidence of AHA in BP patients may be substantially underestimated, which needs more vigilance towards indicators such as APTT, LBP, and FVIII. LBP emerges as an inhibitory protein of FVIII, indicating the potential involvement in the progression of BP-AHA.

Prognostic factors for recurrence in acquired hemophilia A-results from a long-term observational study

Objectives

Acquired hemophilia A (AHA) is a rare autoimmune disease caused by autoantibodies against factor (F)VIII (FVIII), potentially leading to life-threatening bleeding. While predictors for remission have been analyzed, data on recurrence is lacking.

Methods

This study investigated predictors of AHA recurrence in 41 patients. Patients were divided into 2 groups: those with recurrence (n = 18) and those in stable long-term remission (n = 23) with at least 1 year of follow-up.

Results

All relapses occurred within 1 year of initial remission. The median follow-up period was 3.8 years (IQR, 1.8-6.4) for all included patients. Multivariate Cox regression analysis revealed that initial FVIII activity <1 IU/dL and failure to achieve initial complete remission (CR) were significant predictors of relapse. Kaplan-Meier curves showed significantly different relapse-free survival rates for patients with initial FVIII activity <1 IU/dL vs ≥1 IU/dL (χ2[1] = 5.950, P = .015), and for those achieving initial CR vs partial remission (χ2[1] = 6.570, P = .010).Other factors such as inhibitor titer, gender, age, World Health Organization scale, underlying disorder, controlled disorder, initial immunosuppressive therapy, immunosuppressive therapy escalation, and partial remission at day 21 showed no significant relation to recurrences. Overall survival did not differ significantly between relapsing and nonrelapsing patients (χ2[1] = .896, P = .344).

Conclusion

Initial FVIII <1 IU/dL and failure to achieve initial CR are identified as risk factors for recurrence in AHA. Patients with these characteristics should be closely monitored for at least 1 year after initial remission due to increased recurrence risk.

Bleeding After Central Venous Catheter Placement in a Patient With Undiagnosed Acquired Hemophilia A: A Case Report

Acquired hemophilia A is a rare condition caused by autoantibodies against endogenous coagulation factor VIII, which results in spontaneous bleeding. Workup of a patient with difficult hemostasis after removing and placing a central venous catheter led to the diagnosis of acquired hemophilia A. A 64-year-old man was transferred with an intramuscular right thigh mass. Initial biopsy at an outside facility showed degenerated muscle and coagula and he was transferred for incisional biopsy and definitive treatment. The patient had difficult venous access, and a right internal jugular venous catheter was placed. The catheter insertion site showed slow continuous bleeding. Achieving adequate hemostasis after removing the catheter was difficult, and a hematoma formed after the placement of an infraclavicular axillary venous catheter under ultrasound guidance. Coagulation studies revealed a prolonged activated partial thromboplastin time at 96 seconds. The patient was then diagnosed with acquired hemophilia A by enzyme-linked immunosorbent assay using anti-factor VIII antibodies. Even if ultrasound-guided central venous catheterization is performed carefully, bleeding may occur in some patients, suggesting the possibility of coagulopathy. Decision-making for performing central venous catheterization requires extensive knowledge of coagulopathies to understand the causes of bleeding complications.