Outcomes in Mild to Moderate Isolated Thrombocytopenia

Clinical Laboratory Investigations and Antivenom Administration after Malayan Pit Viper (Calloselasma rhodostoma) Envenoming: A Retrospective Study from Southernmost Thailand

The Malayan pit viper (MPV: Calloselasma rhodostoma) is a medically important venomous snake causing numerous envenomations in Thailand. Administration of specific snake antivenom is the only effective treatment for MPV-envenomed patients. However, inappropriate administration or misuse of snake antivenom is problematic in some remote areas of tropical countries where the snakebite envenoming rate is notable. Currently, the indications for administration of MPV antivenom are focused mainly on hematological factors. These include 1) venous clotting time > 20 min, 2) unclotted 20-minute whole-blood clotting time, 3) international normalized ratio > 1.2, 4) platelet count < 50 × 103/μL, 5) systemic bleeding, and 6) impending compartment syndrome. We aimed to determine the association between laboratory data and antivenom administration in MPV-envenomed patients. A retrospective study of data from 2016 to 2021 in Narathiwat Province, the southernmost province in Thailand, was conducted. A total of 838 MPV-bitten patients were included in this study. Local effects and systemic effects were observed in 58.8% and 27.7% of patients, respectively. Coagulopathies, which range from abnormal blood clotting to systemic bleeding, represented the majority of systemic effects. Acute kidney injury developed in 2.5% of patients. In this study, 57.3% of patients were considered appropriate antivenom recipients. Interestingly, the present study revealed that local bleeding and mild to moderate thrombocytopenia became the independent factors for inappropriate use of MPV antivenom. Reeducation and supervision regarding the rational use of snake antivenom are needed to minimize the misuse of antivenom.

Malaria parasitaemia and its impact on biological parameters among children <16 years old attending the Nkwen District Hospital, Cameroon

Introduction

Malaria remains a major public health problem in children in endemic areas. This study aimed to determine its prevalence, intensity, and assess how biological parameters like RBC count, haemoglobin, haematocrit, glycaemia, platelet count and WBC count vary with respect to parasitaemia in children <16 years attending the Nkwen District Hospital, northwest Cameroon.

Materials and Methods

The study was a hospital-based cross-sectional study conducted between March-May 2023. Structured, closed-ended questionnaires were administered to obtain information. Patients' temperature was measured using an infrared forehead digital thermometer. Malaria was diagnosed by RDT and positive samples Giemsa-stained for parasitaemia. Full blood count was performed using a haemolyser and glycaemia measured using a glucometer.

Results

In total, 321 children were examined. Overall prevalence of malaria (all P. falciparum) was 22.7% (73/321), with 24.7% (18/73), 34.2% (25/73) and 41.1% (30/73) having low, moderate and high parasitaemias, respectively. Overall GMPD was 2.670.8±179.9/μL; children aged 6-10 years were hit hardest (5.377.7 ± 3.2/μL). Malaria-positive children had significantly lower RBC count, Hb concentration, Hct, blood sugar, WBC and platelet counts (p<0.05) compared to those that were negative. Among positive children, RBC count, Hct, Hb, lymphocyte and platelet count each showed a significant (p<0.05) decrease while total WBC and granulocyte count each showed a significant (p<0.05) increase with increasing levels of parasitaemia.

Conclusions

Changes in biological parameters during malaria are sensitive but poor specific indicators of malaria because they may overlap with symptoms of other infections. More attention should be given to children aged 6-10 years during strategic planning and design of malaria control programmes.

γ-Secretase inhibitor in combination with BCMA chimeric antigen receptor T-cell immunotherapy for individuals with relapsed or refractory multiple myeloma: a phase 1, first-in-human trial

BACKGROUND

γ-Secretase inhibitors (GSIs) increase B cell maturation antigen (BCMA) density on malignant plasma cells and enhance antitumour activity of BCMA chimeric antigen receptor (CAR) T cells in preclinical models. We aimed to evaluate the safety and identify the recommended phase 2 dose of BCMA CAR T cells in combination with crenigacestat (LY3039478) for individuals with relapsed or refractory multiple myeloma.

METHODS

We conducted a phase 1, first-in-human trial combining crenigacestat with BCMA CAR T-cells at a single cancer centre in Seattle, WA, USA. We included individuals aged 21 years or older with relapsed or refractory multiple myeloma, previous autologous stem-cell transplant or persistent disease after more than four cycles of induction therapy, and Eastern Cooperative Oncology Group performance status of 0-2, regardless of previous BCMA-targeted therapy. To assess the effect of the GSI on BCMA surface density on bone marrow plasma cells, participants received GSI during a pretreatment run-in, consisting of three doses administered 48 h apart. BCMA CAR T cells were infused at doses of 50 × 106 CAR T cells, 150 × 106 CAR T cells, 300 × 106 CAR T cells, and 450 × 106 CAR T cells (total cell dose), in combination with the 25 mg crenigacestat dosed three times a week for up to nine doses. The primary endpoints were the safety and recommended phase 2 dose of BCMA CAR T cells in combination with crenigacestat, an oral GSI. This study is registered with ClinicalTrials.gov, NCT03502577, and has met accrual goals.

FINDINGS

19 participants were enrolled between June 1, 2018, and March 1, 2021, and one participant did not proceed with BCMA CAR T-cell infusion. 18 participants (eight [44%] men and ten [56%] women) with multiple myeloma received treatment between July 11, 2018, and April 14, 2021, with a median follow up of 36 months (95% CI 26 to not reached). The most common non-haematological adverse events of grade 3 or higher were hypophosphataemia in 14 (78%) participants, fatigue in 11 (61%), hypocalcaemia in nine (50%), and hypertension in seven (39%). Two deaths reported outside of the 28-day adverse event collection window were related to treatment. Participants were treated at doses up to 450 × 106 CAR+ cells, and the recommended phase 2 dose was not reached.

INTERPRETATIONS

Combining a GSI with BCMA CAR T cells appears to be well tolerated, and crenigacestat increases target antigen density. Deep responses were observed among heavily pretreated participants with multiple myeloma who had previously received BCMA-targeted therapy and those who were naive to previous BCMA-targeted therapy. Further study of GSIs given with BCMA-targeted therapeutics is warranted in clinical trials.

FUNDING

Juno Therapeutics-a Bristol Myers Squibb company and the National Institutes of Health.

Molecular mechanisms of hematological and biochemical alterations in malaria: A review

Malaria is a dangerous disease that contributes to millions of hospital visits and hundreds of thousands of deaths, especially in children residing in sub-Saharan Africa. Although several interventions such as vector control, case detection, and treatment are already in place, there is no substantive reduction in the disease burden. Several studies in the past have reported the emergence of resistant strains of malaria parasites (MPs) and mosquitoes, and poor adherence and inaccessibility to effective antimalarial drugs as the major factors for this persistent menace of malaria infections. Moreover, victory against MP infections for many years has been hampered by an incomplete understanding of the complex nature of malaria pathogenesis. Very recent studies have identified different complex interactions and hematological alterations induced by malaria parasites. However, no studies have hybridized these alterations for a better understanding of Malaria pathogenesis. Hence, this review thoroughly discusses the molecular mechanisms of all reported hematological and biochemical alterations induced by MPs infections. Specifically, the mechanisms in which MP-infection induces anemia, thrombocytopenia, leukopenia, dyslipidemia, hypoglycemia, oxidative stress, and liver and kidney malfunctions were presented. The study also discussed how MPs evade the host's immune response and suggested strategies to limit evasion of the host's immune response to combat malaria and its complications.

Outcomes of patients with thrombocytopenia evaluated at hematology subspecialty clinics

BACKGROUND

Thrombocytopenia is a frequently encountered laboratory abnormality and a common reason for hematology referrals. Workup for thrombocytopenia is not standardized and frequently does not follow an evidence-based algorithm. We conducted a systematic analysis to evaluate the laboratory testing and outcomes of patients evaluated for thrombocytopenia at hematology clinics in a tertiary referral center between 2013 and 2016.

PATIENT AND METHODS

We performed a comprehensive chart review for patients evaluated for thrombocytopenia during the study period. Patients were followed for 1 year from the initial hematology evaluation and assessed for the development of a hematologic malignancy, rheumatologic, or infectious diseases among other clinical outcomes.

RESULTS

We evaluated 472 patients with a median (range) age of 61 (17-94) years. The majority (63.8%) had mild thrombocytopenia. Within 1 year of follow-up, 14 patients (3.0%) were diagnosed with a hematologic malignancy. A higher likelihood of developing a hematologic malignancy was noted in patients with concurrent leukopenia (hazard ratio [HR] 9.97, 95% confidence interval [CI] 3.28-30.32, p < .01) and increasing age (HR per 10-year deciles 1.52, 95% CI 1.03-2.25, p = .03). In patients with asymptomatic isolated mild thrombocytopenia, laboratory testing did not reveal any significant positive findings and patients did not receive any new major diagnosis during the follow-up period.

CONCLUSION

Our findings provide basis and call for development of an evidence-based algorithmic approach for evaluation of patients with thrombocytopenia, testing, and referrals. It also supports a conservative approach mainly driven by physical exam signs, symptoms, and other laboratory findings for patients with isolated mild thrombocytopenia.

Platelet Disorders

After vascular injury and exposure of subendothelial matrix proteins to the intravascular space, mediators of hemostasis are triggered and allow for clot formation and restoration of vascular integrity. Platelets are the mediators of primary hemostasis, creating a platelet plug and allowing for initial cessation of bleeding. Platelet disorders, qualitative and quantitative, may result in bleeding signs and symptoms, particularly mucocutaneous bleeding such as epistaxis, bruising, petechiae, and heavy menstrual bleeding. Increasing evidence suggests that platelets have functional capabilities beyond hemostasis, but this review focuses solely on platelet hemostatic properties. Herein, normal platelet function as well as the effects of abnormal function and thrombocytopenia are reviewed.