American Journal of Hematology

COVID-19 is a systemic infection with a significant impact on the hematopoietic system and hemostasis. Lymphopenia may be considered as a cardinal laboratory finding, with prognostic potential. Neutrophil/lymphocyte ratio and peak platelet/lymphocyte ratio may also have prognostic value in determining severe cases. During the disease course, longitudinal evaluation of lymphocyte count dynamics and inflammatory indices, including LDH, CRP and IL-6 may help to identify cases with dismal prognosis and prompt intervention in order to improve outcomes. Biomarkers, such high serum procalcitonin and ferritin have also emerged as poor prognostic factors. Furthermore, blood hypercoagulability is common among hospitalized COVID-19 patients. Elevated D-Dimer levels are consistently reported, whereas their gradual increase during disease course is particularly associated with disease worsening. Other coagulation abnormalities such as PT and aPTT prolongation, fibrin degradation products increase, with severe thrombocytopenia lead to life-threatening disseminated intravascular coagulation (DIC), which necessitates continuous vigilance and prompt intervention. So, COVID-19 infected patients, whether hospitalized or ambulatory, are at high risk for venous thromboembolism, and an early and prolonged pharmacological thromboprophylaxis with low molecular weight heparin is highly recommended. Last but not least, the need for assuring blood donations during the pandemic is also highlighted.

We undertook this study to develop uniformly accepted criteria for the definition of organ involvement and response for patients on treatment protocols for immunoglobulin light-chain amyloidosis (AL). A consensus panel was convened comprising 13 specialists actively involved in the treatment of patients with amyloidosis. Institutional criteria were submitted from each, and a consensus was developed defining each organ involved and the criteria for response. Specific criteria have been developed with agreed on definitions of organ and hematologic response as a result of discussions at the 10th International Symposium on Amyloid and Amyloidosis held in Tours, France, April 2004. These criteria now form the working definition of involvement and response for the purposes of future data collection and reporting. We report criteria that centers can now use to define organ involvement and uniform response criteria for reporting outcomes in patients with light-chain AL.

DISEASE OVERVIEW: Multiple myeloma accounts for approximately 10% of hematologic malignancies. DIAGNOSIS: The diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy-proven plasmacytoma plus evidence of one or more multiple myeloma defining events (MDE): CRAB (hypercalcemia, renal failure, anemia, or lytic bone lesions) attributable to the plasma cell disorder, bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain (FLC) ratio ≥ 100 (provided involved FLC is ≥100 mg/L), or >1 focal lesion on magnetic resonance imaging. RISK STRATIFICATION: The presence of del(17p), t(4;14), t(14;16), t(14;20), gain 1q, or p53 mutation is considered high-risk multiple myeloma. The presence of any two high risk factors is considered double-hit myeloma, and three or more high risk factors is triple-hit myeloma. RISK-ADAPTED INITIAL THERAPY: In patients who are candidates for autologous stem cell transplantation, induction therapy consists of bortezomib, lenalidomide, dexamethasone (VRd) given for approximately 3-4 cycles followed by autologous stem cell transplantation (ASCT). In high-risk patients, daratumumab, bortezomib, lenalidomide, dexamethasone (Dara-VRd) is an alternative to VRd. Selected standard-risk patients can collect stem cells, get additional cycles of induction therapy, and delay transplant until first relapse. Patients who are not candidates for transplant are treated with VRd for approximately 8-12 cycles followed by maintenance or alternatively with daratumumab, lenalidomide, dexamethasone (DRd) until progression. MAINTENANCE THERAPY: Standard-risk patients need lenalidomide maintenance, while bortezomib plus lenalidomide maintenance is needed for high-risk myeloma. MANAGEMENT OF RELAPSED DISEASE: A triplet regimen is usually needed at relapse, with the choice of regimen varying with each successive relapse.

DISEASE OVERVIEW: Multiple myeloma accounts for approximately 10% of hematologic malignancies. DIAGNOSIS: The diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy proven plasmacytoma plus evidence of one or more multiple myeloma defining events (MDE) namely CRAB (hypercalcemia, renal failure, anemia, or lytic bone lesions) features felt related to the plasma cell disorder, bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain (FLC) ratio ≥100 (provided involved FLC is ≥100 mg/L), or >1 focal lesion on magnetic resonance imaging (MRI). RISK STRATIFICATION: The presence of del(17p), t(4;14), t(14;16), t(14;20), gain 1q, or p53 mutation is considered high-risk multiple myeloma. Presence of any two high risk factors is considered double-hit myeloma; three or more high risk factors is triple-hit myeloma. RISK-ADAPTED INITIAL THERAPY: In transplant eligible patients, induction therapy consists of bortezomib, lenalidomide, dexamethasone (VRd) given for approximately 3-4 cycles followed by autologous stem cell transplantation (ASCT). In high-risk patients, daratumumab, bortezomib, lenalidomide, dexamethasone (Dara-VRd) is an alternative to VRd. Selected standard risk patients can get additional cycles of induction, and delay transplant until first relapse. Patients not candidates for transplant are typically treated with VRd for approximately 8-12 cycles followed by lenalidomide; alternatively these patients can be treated with daratumumab, lenalidomide, dexamethasone (DRd). MAINTENANCE THERAPY: After ASCT, standard risk patients need lenalidomide maintenance, while bortezomib-based maintenance is needed for patients with high-risk myeloma. MANAGEMENT OF REFRACTORY DISEASE: Most patients require a triplet regimen at relapse, with the choice of regimen varying with each successive relapse.

To the Editor: A cluster of unexplained pneumonia cases was reported by the People's Republic of China to the World Health Organization (WHO) on 31 December, 2019. The etiology for this outbreak was a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was responsible for the Corona Virus Disease 2019 (COVID-19).1 Singapore confirmed its first imported case on 23 January 2020 and local transmission was detected on 4 February, 2020. As of 28 February, 2020, Singapore had 96 confirmed cases of COVID-19 infection. SARS-CoV-2 was confirmed by real time reverse transcriptase-polymerase chain reaction (RT-PCR), performed on respiratory samples of these patients. A majority of 69 out of these 96 patients were treated at the National Centre for Infectious Diseases (NCID). We herein present a detailed analysis of the hematological parameters of the COVID-19 patients at the NCID (see Table 1). Of the 69 patients that had been admitted to the NCID, 26 patients were still hospitalized, and 43 patients had been discharged as of 28 February 2020. Also, 67 patients had at least one complete blood count (CBC) performed during inpatient stay; 65 patients had CBC performed on day of admission. We analyzed the hematological indices of all COVID-19 infected patients from day 1 of admission until 28 February 2020. We obtained data from the Laboratory Information System (LIS) exclusively which provided information on the age, gender, ethnicity and location of each patient. We divided the patients into two groups; ICU and non-ICU patients. Additionally, flow cytometry on lymphocyte subsets was performed from 24 to 28 February 2020, on a subgroup of nine COVID-19 patients; five ICU patients and four non-ICU patients (with six normal individual blood samples as controls). Immunophenotyping was performed using a Becton Dickinson FACSCanto II Flow analyzer. Most patients were of Chinese ethnicity (89.5%), while the minority were of Malay (4.5%), Indian (1.5%) and other ethnicities (4.5%). Just 9 out of the 67 (13.4%) patients required ICU care. Notably, ICU patients were about a decade older than the non-ICU patients; the median age of ICU patients was 54 years old while the median age of non-ICU patients was 42 years old (P = .02). On admission, leukopenia was observed in 19 patients (29.2%) with only one patient presenting with severe leukopenia (WBC < 2 × 109/L). Lymphopenia featured in 24 patients (36.9%) with 19 having moderate lymphopenia (absolute lymphocyte count [ALC] 0.5-1 × 109/L), and five with severe lymphopenia (ALC < 0.5 × 109/L). Most patients had normal platelet counts, with 13 patients (20.0%) having mild thrombocytopenia (platelet count 100-150 × 109/L). Peripheral blood film review showed that a higher number of patients (69%) who were lymphopenic had the presence of a few reactive lymphocytes, of which a subset appeared lymphoplasmacytoid. This contrasts with the severe acute respiratory syndrome (SARS) outbreak in 2003 where reactive lymphocytes were not observed in a study on Haematologic parameters in SARS in Singapore2 and only in 15.2% of cases in a similar Hong Kong study.3 Our analysis revealed that on admission, most patients had a normal CBC (normal Hb, WBC and platelet count) and lactate dehydrogenase (LDH). And, no patient presented with moderate or severe thrombocytopenia that is frequently observed in other viral illnesses such as dengue fever which is endemic in our region. However, 28% of all patients presented with lymphopenia (ALC < 1 × 109/L). This number is significantly smaller compared to 63% of patients in Wuhan, China, and 42% of patients outside of Wuhan who presented with lymphopenia.4, 5 This disparity in numbers may in part be reflective of the extent of epidemiological data available within the surveillance pyramid in those regions. Those requiring ICU care had a lower ALC and higher LDH. These were findings also reported by Huang et al on the characteristics of COVID-19 patients in Wuhan, China.4 Lymphopenia has been well described in retrospective analysis of patients in Hong Kong and Singapore afflicted with SARS-CoV in 2003, and was associated with adverse outcomes and ICU stay.2, 3, 6 Lymphopenia featured prominently in our COVID-19 ICU group with a median nadir ALC of 0.4 × 109/L, compared to 1.2 × 109/L in the non-ICU group. Monitoring of such hematologic parameters may help to identify patients who may need ICU care. An ALC approaching severe lymphopenia of <0.6 × 109/L may possibly be considered as one of the indicators for early admission for supportive care in the ICU. Between the ICU (n = 9) and non-ICU (n = 58) patients, using Fisher's exact tests, we found that admission ALC and LDH stood out as discriminating laboratory indices with a P value of <.001 and .005 respectively. The ICU patients in general presented with more profound lymphopenia with seven out of nine being lymphopenic; four of whom had severe lymphopenia. Note, LDH was performed for 4 out of the 9 ICU patients on admission, and all four cases had a raised LDH with a median value of 1684 U/L (reference range 270-550 U/L). Comparatively non-ICU patients tend to present with a normal LDH, median value 401 U/L; with only five out of 26 non-ICU patients presenting with a raised LDH above 550 U/L. During their stay in ICU, those patients developed more profound, statistically significant decrements in their hemoglobin levels, with ALC and absolute monocyte count (AMC) levels compared to the non-ICU group. The median nadir ALC was 0.4 × 109/L in the ICU group compared to 1.2 × 109/L in the non-ICU group (P value <.001), while the median nadir AMC was 0.2 × 109/L in the ICU group, compared to 0.4 × 109/L in the non-ICU group (P value <.001). Notably, ICU patients tend to develop neutrophilia during the hospitalization with a median peak Absolute Neutrophil Count (ANC) of 11.6 × 109/L, compared to 3.5 × 109/L in the non-ICU group (P value < .001). The ICU group also had a peak LDH which was significantly higher than the non-ICU group. The median nadir platelet count remained in the normal range (above 150 × 109/L) for both groups and was not a discriminating test on admission or during the hospitalization. To date, three out of the nine ICU patients have been discharged from ICU care. We noted increasing values in their WBC, ALC, AMC, and down trending LDH as their clinical condition improved. Flow cytometry performed on peripheral blood lymphocytes demonstrate prominent lymphopenia in the ICU patients as compared to the non-ICU patients and normal controls. The ICU patients have significantly lower CD45+, CD3+, CD4+, CD8+, CD19+ and CD16/56+ counts. The CD4/CD8 ratio was not inverted in all groups of patients, unlike other viral infections such as human immunodeficiency virus (HIV) and cytomegalovirus (CMV) infections where the CD4/8 ratio is usually inverted. The limitation of our study is missing data as laboratory investigations were not performed daily on all patients especially those who were minimally symptomatic in the general isolation ward. We also recognize that correlating onset of symptoms (days of illness) with hematological parameters is important and would require a case note review which was not done in this study. However, this review is a reflection of real-life clinical setting wherein a proportion of asymptomatic patients (admitted from positive RT-PCR results during contact tracing) may not have significant anomalies on their CBC at presentation. Lastly, admission laboratory results for ICU patients transferred from other institutions were not reflected in our data set. This may result in lower hematological indices on admission as those patients were already in critical condition. Further studies should be conducted comparing patients' onset of symptoms and correlating their clinical condition to laboratory findings. In conclusion, our study showed that on admission, older age, lymphopenia and raised LDH were associated with ICU admissions. Patients who were transferred to the ICU had a deeper nadir ALC, nadir AMC and nadir hemoglobin, and higher peak ANC and peak LDH levels as compared to patients who did not require ICU stay. We thank the Department of Haematology and the Department of Laboratory Medicine, Tan Tock Seng Hospital for the full support in the laboratory investigations. We also greatly appreciate the efforts of healthcare workers and the support of their families during this outbreak. Special thanks to Lim Shu Ping and Wong Lai Har for their assistance with specimen collection and processing; and Lin Yihao Clement for his assistance with the DSRB application. All authors declare no competing interests. This study was approved by the National Healthcare Group Domain Specific Review Board (DSRB). No patient identifiers were collected and approval of exemption for informed consent was obtained.

Initially described in 1948 by Hertert thromboelastography (TEG) provides a real-time assessment of viscoelastic clot strength in whole blood. Rotational thromboelastometry (ROTEM) evolved from TEG technology and both devices generate output by transducing changes in the viscoelastic strength of a small sample of clotting blood (300 µl) to which a constant rotational force is applied. These point of care devices allow visual assessment of blood coagulation from clot formation, through propagation, and stabilization, until clot dissolution. Computer analysis of the output allows sophisticated clot formation/dissolution kinetics and clot strength data to be generated. Activation of clot formation can be initiated with both intrinsic (kaolin, ellagic acid) and extrinsic (tissue factor) activators. In addition, the independent contributions of platelets and fibrinogen to final clot strength can be assessed using added platelet inhibitors (abciximab and cytochalasin D). Increasingly, ROTEM and TEG analysis is being incorporated in vertical algorithms to diagnose and treat bleeding in high-risk populations such as those undergoing cardiac surgery or suffering from blunt trauma. Some evidence suggests these algorithms might reduce transfusions, but further study is needed to assess patient outcomes.

Red blood cell (RBC) autoantibodies are a relatively uncommon cause of anemia. However, autoimmune hemolytic anemia (AIHA) must be considered in the differential diagnosis of hemolytic anemias, especially if the patient has a concomitant lymphoproliferative disorder, autoimmune disease, or viral or mycoplasmal infection. Classifications of AIHA include warm AIHA, cold agglutinin syndrome, paroxysmal cold hemoglobinuria, mixed-type AIHA, and drug-induced AIHA. Characteristics of the autoantibodies are responsible for the various clinical entities. As a result, diagnosis is based on the clinical presentation and a serologic work-up. For each classification of AIHA, this review discusses the demographics, etiology, clinical presentation, laboratory evaluation, and treatment options.

Chimeric antigen receptor (CAR) T-cell therapy represents a major advancement in personalized cancer treatment. In this strategy, a patient's own T cells are genetically engineered to express a synthetic receptor that binds a tumor antigen. CAR T cells are then expanded for clinical use and infused back into the patient's body to attack and destroy chemotherapy-resistant cancer. Dramatic clinical responses and high rates of complete remission have been observed in the setting of CAR T-cell therapy of B-cell malignancies. This resulted in two recent FDA approvals of CAR T cells directed against the CD19 protein for treatment of acute lymphoblastic leukemia and diffuse large B-cell lymphoma. Thus, CAR T cells are arguably one of the first successful examples of synthetic biology and personalized cellular cancer therapy to become commercially available. In this review, we introduce the concept of using CAR T cells to break immunological tolerance to tumors, highlight several challenges in the field, discuss the utility of biomarkers in the context of predicting clinical responses, and offer prospects for developing next-generation CAR T cell-based approaches that will improve outcome.

DISEASE OVERVIEW: Multiple myeloma accounts for approximately 10% of hematologic malignancies. DIAGNOSIS: The diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy proven plasmacytoma plus evidence of one or more multiple myeloma defining events (MDE): CRAB (hypercalcemia, renal failure, anemia, or lytic bone lesions) attributable to the plasma cell disorder, bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain (FLC) ratio ≥100 (provided involved FLC is ≥100 mg/L and urine monoclonal protein is ≥200 mg/24 h), or >1 focal lesion on magnetic resonance imaging. RISK STRATIFICATION: The presence of del(17p), t(4;14), t(14;16), t(14;20), gain 1q, del 1p, or p53 mutation is considered high-risk multiple myeloma. Presence of any two high risk factors is considered double-hit myeloma; three or more high risk factors is triple-hit myeloma. RISK-ADAPTED INITIAL THERAPY: In patients who are candidates for autologous stem cell transplantation, induction therapy consists of anti-CD38 monoclonal antibody plus bortezomib, lenalidomide, dexamethasone (VRd) followed by autologous stem cell transplantation (ASCT). Selected standard risk patients can delay transplant until first relapse. Frail patients who not candidates for transplant are treated with VRd for approximately 8-12 cycles followed by maintenance or alternatively with daratumumab, lenalidomide, dexamethasone (DRd) until progression. MAINTENANCE THERAPY: Standard risk patients need lenalidomide maintenance, while bortezomib plus lenalidomide maintenance is needed for high-risk myeloma. MANAGEMENT OF RELAPSED DISEASE: A triplet regimen is usually needed at relapse, with the choice of regimen varying with each successive relapse. Chimeric antigen receptor T (CAR-T) cell therapy and bispecific antibodies are additional options.

DISEASE OVERVIEW: Chronic lymphocytic leukemia (CLL) is the commonest leukemia in western countries. The disease typically occurs in elderly patients and has a highly variable clinical course. Leukemic transformation is initiated by specific genomic alterations that impair apoptosis of clonal B-cells. DIAGNOSIS: The diagnosis is established by blood counts, blood smears, and immunophenotyping of circulating B-lymphocytes, which identify a clonal B-cell population carrying the CD5 antigen, as well as typical B-cell markers. PROGNOSIS: The two similar clinical staging systems, Rai and Binet, create prognostic information by using results of physical examination and blood counts. Various biological and genetic markers also have prognostic value. Deletions of the short arm of chromosome 17 (del [17p]) and/or mutations of the TP53 gene, predict resistance to chemoimmunotherapy and a shorter time to progression, with most targeted therapies. A comprehensive, international prognostic score (CLL-IPI) integrates genetic, biological and clinical variables to identify distinct risk groups of CLL patients. THERAPY: Only patients with active or symptomatic disease, or with advanced Binet or Rai stages require therapy. When treatment is indicated, several options exist for most CLL patients: a combination of venetoclax with obinutuzumab, ibrutinib monotherapy, or chemoimmunotherapy. For physically fit patients younger than 65 (in particular when presenting with a mutated IGVH gene), chemoimmunotherapy with fludarabine, cyclophosphamide and rituximab remains a standard therapy, since it may have curative potential. At relapse, the initial treatment may be repeated, if the treatment-free interval exceeds 3 years. If the disease relapses earlier, therapy should be changed using an alternative regimen. Patients with a del (17p) or TP53 mutation are a different, high-risk category and should be treated with targeted agents. An allogeneic SCT may be considered in relapsing patients with TP53 mutations or del (17p), or patients that are refractory to inhibitor therapy. FUTURE CHALLENGES: Targeted agents (ibrutinib, idelalisib, venetoclax, obinutuzumab) will be increasingly used in combination to allow for short, but potentially definitive therapies of CLL. It remains to be proven that they generate a superior outcome when compared to monotherapies with inhibitors of Bruton tyrosine kinase, which can also yield long-lasting remissions. Moreover, the optimal sequencing of drug combinations is unknown. Therefore, CLL patients should be treated in clinical trials whenever possible.

ABSTRACT In AL amyloidosis, advanced renal disease can impact treatment options and cause significant morbidity. Patients with ESRD requiring dialysis are a group with currently unmet needs. In this collaborative study, we identified 362 patients from three European centers who initiated dialysis during the course of the disease. Median survival after the initiation of dialysis was 40 months. Heart involvement, higher BMPC infiltration at diagnosis, and lambda light chain type were associated with inferior survival. At the time of dialysis initiation, cardiac biomarkers were prognostic for postdialysis outcome, but they did not perform the same as in patients not on dialysis. Higher FLCs levels at dialysis initiation were also prognostic, independently of cardiac biomarkers and other adverse factors. After starting dialysis, 151 patients received further treatment; median postdialysis survival for those that achieved CR/VGPR was significantly improved with 63.8 vs. 42 months for patients who achieved PR or less. In conclusion, patients with AL amyloidosis that require dialysis still represent a group of patients with poor outcomes, although, they can have prolonged postdialysis survival if they achieve deep hematologic response and have limited cardiac and clonal disease; such patients could also be considered for renal transplantation.

The sickle cell disease (SCD) community was taken by surprise by the 2024 withdrawal of voxelotor from the global market.A drug that had been embraced as the first disease-modifying, oral, once-daily therapy to increase hemoglobin (Hb) and reduce hemolysis in patients as young as 4 years old had its dosing paused and was ultimately withdrawn after a signal of excess mortality emerged across the voxelotor development program, including in RESOLVE (NCT05561140) and in the trial reported in this issue, HOPE Kids 2 [1].For clinicians who had started using voxelotor in adolescents with conditional transcranial Doppler (TCD) velocities, or who were awaiting its extension to younger children with elevated stroke risk, the timing was difficult and the results were conflicting: a well-conducted, randomized, placebo-controlled trial had met its primary efficacy endpoint while also showing more vaso-occlusive crises (VOCs) and more deaths in the active arm.HOPE Kids 2 is therefore an unusually important paper, a rare instance of a modern pediatric SCD trial that is simultaneously positive and sobering, and one that deserves careful reflection.Here, we discuss what the trial shows about efficacy, the safety signals for VOC and for mortality, an underexplored hypothesis linking voxelotor's mechanism to malaria susceptibility, and what these findings mean for clinical practice in Africa (Table 1).

Rusfertide mechanism of action and clinical trial results in polycythemia vera.