Characteristics and outcome of a territory-wide cohort study of patients with acquired hemophilia A in Hong Kong.

INTRODUCTION: Acquired hemophilia A (AHA) is a rare bleeding disorder with destruction of factor VIII by autoantibodies. Comprehensive data for Chinese patients are lacking. Predictors of hospital stay have not been investigated. METHODS: A territory-wide review of patients diagnosed with AHA from January 1, 2012, to December 31, 2021 was performed by retrieving patients' information from an electronic database system in Hong Kong. RESULTS: Overall, 165 patients were included in this 10-year study, and the estimated incidence was 2.4 per million/year, which was higher than those reported from Caucasian cohorts. The median age of diagnosis was 80 years old. Patients had a long hospital stay (median: 25 days) and high mortality (55.2 %). The majority of deaths were caused by immunosuppression-related sepsis (49.5 %). Age was an independent predictor of overall survival (Hazard ratio: 1.065, 95 % CI: 1.037-1.093, p < 0.001), complete remission (CR) status (odd ratios (OR): 0.948, 95 % CI: 0.921-0.976, p < 0.001) and time to achieve CR (OR: 1.043, 95 % CI: 1.019-1.067, p < 0.001). Higher hemoglobin level on presentation was associated with shorter time to achieve CR (OR: 0.888, 95 % CI: 0.795-0.993, p = 0.037). Factor VIII level < 1 % normal, high inhibitor titer and intensive immunosuppressive regimen predicted long hospital stay. CONCLUSION: We presented comprehensive data of Chinese patients with AHA which comprised predominantly frail elderly who required long hospital stay and had high sepsis-related mortality. This posed challenges in managing AHA in such patients. Individualized immunosuppressive therapy is needed to balance the benefits and risk of septic complications.

A specific early eluting peak in Bio-Rad Variant II cation-exchange high-performance liquid chromatography (CE-HPLC) for the screening of alpha-thalassaemia in a Chinese population.

The early eluting peaks in the first minute of cation-exchange high-performance liquid chromatography (CE-HPLC) are often not analysed in haemoglobin pattern studies, except for haemoglobin (Hb) Bart's and Hb H peaks. In this study, we described the presence of a specific α-thalassaemia early eluting peak (αEEP) at the retention time of 0.24 min generated by Variant II CE-HPLC (ß-Thalassaemia Short Program; Bio-Rad Laboratories). We have evaluated the utility of αEEP for the screening of α-thalassaemia trait in our local Chinese population in comparison to the Hb H inclusion body test. A total of 303 blood samples presenting with microcytosis were sent for haemoglobin pattern study and were analysed for the presence or absence of αEEP and Hb H inclusions. Twenty cases with a normal mean corpuscular volume were assessed as a control. Discordant results between the αEEP and the Hb H inclusion test were reviewed with the α-globin genotyping test performed. The concordance rate of the αEEP and the Hb H inclusion body test was 96.0% (κ=0.921, p<0.001). Eight of 303 cases (2.6%) were initially negative for the Hb H inclusion test but positive for the αEEP. All eight cases were found to have occasional Hb H inclusion bodies upon review. Four of 303 cases (1.3%) were negative for the αEEP but positive for the Hb H inclusion test. Of these four cases, two (50%) showed heterozygous Southeast Asian (SEA) type deletion, one (25%) showed Hb Quong Sze mutation, and one (25%) showed no mutation detected upon molecular testing. All the Hb E trait cases with no Hb H inclusions and the negative control group showed the absence of the αEEP. The sensitivity and specificity of αEEP for detecting SEA deletion were 93.8% and 100% respectively, which is superior to the Hb H inclusion test (sensitivity 81.3%, specificity 95.2%). The αEEP is found to be a more sensitive method than the Hb H inclusion body test in the screening of α-thalassaemia trait in our Chinese population, in which SEA type deletion is prevalent. Further study is needed to explore the utility of the αEEP in the screening of α-thalassaemia traits in other populations. The exact nature of the αEEP is yet to be defined.

Resolution of platelet count interference due to cytoplasmic fragments of leukaemic cells by flow cytometry in acute myeloid leukaemia.

BACKGROUND: Platelet count interference could lead to problems in clinical decisions especially in the cases of thrombocytopenia. Here we report a case of platelet count interference in Beckman Coulter DxH800 haematology analyser due to cytoplasmic fragments of leukaemic cells in acute myeloid leukaemia. A 19-year-old female patient presented to the emergency department with bruises and anaemic symptoms. A machine platelet count (by impedance method) was 40 × 109 /L. There was a flag on platelet count interference by debris. Peripheral blood smear showed some bluish cytoplasmic fragments are seen mimicking platelets. METHOD: Immunological platelet counting by flow cytometry using fluorochrome-labeled antibodies against platelet markers CD41 and CD61 was attempted by adopting and modifying from the ICSH reference method for platelet counting. Events with low forward scatter and positive CD41 and/or CD61 expression were identified as platelets, and events with high forward scatter and negative CD41 and CD61 expression were identified as red cells. RESULTS: The platelet count was derived from the formula: Platelet count = RBC count (Haematology analyser) × PLT event (flow cytometry)/RBC events (flow cytometry). The immunological platelet count was determined to be 2 × 109 /L, which is much lower than the original machine count and platelet transfusion was warranted.

Diagnostic and treatment hurdles in plasma cell myeloma with t(11;14) translocation: A case report.

t(11;14) translocation is one of the most common chromosomal abnormalities in plasma cell myeloma. The present case report presented a case of plasma cell myeloma with t(11;14) translocation, in which the plasma cells were small lymphoplasmacytoids in morphology with positive cluster of differentiation-20 and Cyclin D1 expression. These results led to initial diagnostic difficulties. The patient was refractory to bortezomib-based therapy, and responsive to vincristine, doxorubicin and dexamethasone. However, the prognostic value of t(11;14) in plasma cell myeloma remains to be determined. With recent advances in treatment options, physicians should be aware of the clinical and pathological characteristics of this translocation in plasma cell myeloma.

Reirradiation of nasopharyngeal carcinoma with intracavitary mold brachytherapy: an effective means of local salvage.

PURPOSE: To assess the role of intracavitary mold brachytherapy in salvaging local failure of nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS: The outcomes of 118 consecutive NPC patients with local failure treated with mold brachytherapy between 1989 and 1996 were retrospectively reviewed. Eleven patients received additional external radiotherapy. RESULTS: All molds were tailor-made, and the whole procedure was performed under local anesthesia. Pharyngeal recess dissection was routinely performed to allow direct contact of the radioactive source with the pharyngeal recess, a common site of local failure. Initially, the molds were preloaded with 192Ir wires, but since 1992, the sources have been manually afterloaded; the mold has also been redesigned for better conformity, ease of insertion, and radiation safety. Using brachytherapy alone, 50-55 Gy was given for recurrence in 4-7 days; for persistence, 40 Gy was administered. The overall complete remission rate was 97%. The rates of 5-year local control, relapse-free survival, disease-specific survival, overall survival, and major complication were 85%, 68.3%, 74.8%, 61.3%, and 46.9%, respectively. Major complications included nasopharyngeal necrosis with headache, necrosis of cervical vertebrae with atlantoaxial instability, temporal lobe necrosis, and palsy of the cranial nerves. The afterloaded mold was as effective as the preloaded version, but with fewer complications. CONCLUSIONS: Intracavitary mold brachytherapy was effective in salvaging NPC with early-stage local persistence or first recurrence.