A Fatal Case of Immune Hyperhemolysis with Bone Marrow Necrosis in a Patient with Sickle Cell Disease

Hyperhaemolytic Syndrome in Sickle Cell Disease: Clearing the Cobwebs

Sickle cell disease (SCD) presents with a dynamic background of haemolysis and deepening anaemia. This increases the demand for transfusion if any additional strain on haemopoiesis is encountered due to any other physiological or pathological causes. Patients with cerebrovascular accidents are placed on chronic blood transfusion; those with acute sequestration and acute chest syndrome are likewise managed with blood transfusion. These patients are prone to develop complications of blood transfusion including alloimmunization and hyperhaemolytic syndrome (HHS). This term is used to describe haemolysis of both transfused and "own" red cells occurring during or post-transfusion in sickle cell patients. Hyperhaemolysis results in worsening post-transfusion haemoglobin due attendant haemolysis of both transfused and autologous red cells. The mechanism underlying this rare and usually fatal complication of SCD has been thought to be secondary to changes in the red cell membrane with associated immunological reactions against exposed cell membrane phospholipids. The predisposition to HHS in sickle cell is also varied and the search for a prediction pattern or value has been evasive. This review discusses the pathogenesis, risk factors and treatment of HHS, elaborating on what is known of this rare condition.

Analysis and Clinical Characteristics of 23 Cases of Bone Marrow Necrosis

BACKGROUND

Bone marrow necrosis (BMN) is a rare secondary disorder of many discrepant neoplastic processes. The etiology is diverse, and malignancy is the most common background disease.

PATIENTS AND METHODS

Between 2005 and 2019, a total of 23 cases of BMN were detected and analyzed at Zhujiang Hospital and Nanfang Hospital.

RESULTS

In our study, the 40-60-year-old age group was the one with the highest incidence of BMN (n = 12, 52.2%). The background diseases of patients with BMN varied. Eighteen (78.3%) of 23 patients were diagnosed with hematologic diseases at the same time, most of which were acute B lymphocytic leukemia (n = 8, 34.8%). The complete blood count of these 23 patients noted a decrease in hemoglobin (100%), a decrease or increase in white blood cells and neutrophils, and thrombocytopenia (78.3%). The levels of lactate dehydrogenase (> 300 U/L) and serum ferritin (> 500 μg/L) were elevated in all patients, and 16 (94.1%) of 17 patients presented with increased d-dimer levels. The 2-week cumulative survival and 2-year cumulative survival of patients with BMN were 56.5% and 47.4%, respectively. The mortality probability within 2 weeks was 43.5%, and the adjusted mortality probability was 26.7% within 2 weeks to 2 years, indicating that patients with BMN had the greatest risk of death within 2 weeks.

CONCLUSION

BMN patients with B lymphocytic leukemia as the background disease had a better prognosis than those with other background diseases. BMN of unknown etiology may have an extremely poor prognosis. Therefore, diagnosing the background disease plays an important role in the treatment of BMN.

Can we better predict delayed hemolytic transfusion reactions and hyperhemolysis in sickle cell disease?

Delayed hemolytic transfusion reactions (DHTR) occurring in individuals with sickle cell disease (SCD) are usually indolent but may rarely progress to life-threatening hemolysis known as hyperhemolysis syndrome (HHS), which can be difficult to diagnose and manage. We evaluate a predictive model for DHTR proposed by Drs. Pirenne and Yazdanbakhsh. A scoring system and nomogram were utilized in three individuals with SCD and delayed hemolysis, with one likely having HHS. The scoring system is based on identified risk factors for developing hemolysis from patient transfusion history, while the nomogram utilizes persistence of hemoglobin A (HbA) which is not innate to SCD patients. We propose a novel method for HbA estimation to facilitate application of the nomogram. Application of the recently published predictive scoring system revealed a low risk of developing DHTR in one patient and an intermediate risk in two patients. As serial HbA values are not routinely assessed, HbA measurements were only available in one of the three patients, though use of the nomogram predicted a high likelihood of DHTR. The recently published predictive score and nomogram yielded mixed results and should be interpreted with caution when predicting the risk of developing DHTR in individuals with SCD. Management of DHTR/HHS continues to be a challenge for transfusion medicine and hematology services standardized methods to facilitate their early diagnosis and treatment are warranted to improve the safety of blood transfusions in individuals with SCD.

Delayed haemolytic and serologic transfusion reactions: pathophysiology, treatment and prevention

PURPOSE OF REVIEW

The aim of this study was to summarize the basic epidemiology, pathophysiology and management of delayed serologic and delayed haemolytic transfusion reactions (DHTRs), as well as recent developments in our understanding of these adverse events.

RECENT FINDINGS

Several studies have identified risk factors for DHTRs, including high alloantibody evanescence rates among both general patient groups and those with sickle cell disease (SCD). Antibody detection is also hampered by the phenomenon of transfusion record fragmentation. There have also been enhancements in understanding of what may contribute to the more severe, hyperhaemolytic nature of DHTRs in SCD, including data regarding 'suicidal red blood cell death' and immune dysregulation amongst transfusion recipients with SCD. With growing recognition and study of hyperhaemolytic DHTRs, there have been improvements in management strategies for this entity, including a multitude of reports on using novel immunosuppressive agents for preventing or treating such reactions.

SUMMARY

Delayed serologic and haemolytic reactions remain important and highly relevant transfusion-associated adverse events. Future directions include further unravelling the basic mechanisms, which underlie DHTRs and developing evidence-based approaches for treating these reactions. Implementing practical preventive strategies is also a priority.