Atypical chronic myeloid leukemia (aCML) is a rare disease that is currently classified under the myelodysplastic (MDS)/myeloproliferative neoplasm (MPN) disease spectrum. MDS/MPN diseases are characterized by the absence of the Philadelphia (Ph) chromosome and the overlap between bone marrow fibrosis and dysplastic features. The Ph chromosome, resulting from BCR-ABL1 translocation, helps to distinguish aCML from chronic myeloid leukemia (CML). The currently reported incidence of aCML is imprecise because aCML is diagnosed primarily based on morphological features and other unspecified laboratory findings, and there is an especially high chance of under-diagnosis of aCML and other MDS/MPN diseases. Recent advances in next-generation sequencing (NGS) have allowed a greater understanding of the nature of aCML, providing better opportunities to achieve higher diagnostic accuracy and for the use of more targeted treatment to achieve better outcomes. Herein, we present a case of a 68-year-old woman who came to our hospital complaining of shortness of breath, fatigue, and weakness, who was found to have significantly increased leukocytosis, hepatosplenomegaly, and was negative for the Ph chromosome. Further investigations with NGS revealed mutations in ASXL1, GATA2, NRAS, and SRSF2 but not CSF3R. In addition to this, peripheral smear and bone marrow aspiration findings were suggestive of aCML based on specific morphological findings. Since the patient was ineligible for a stem cell transplant (SCT), symptomatic treatment was started with cell transfusion; however, the patient continued to have symptomatic anemia that required multiple transfusions. A trial with trametinib, a mitogen-activated protein kinase kinase (MEK) inhibitor, was later started as a targeted therapy based on one of her genetic mutations. Interestingly, the patient's blood counts stabilized, she reported feeling better, and she did not need any blood transfusions for four consecutive months during treatment with trametinib. Unfortunately, our patient later died from sepsis resulting from secondary infections. In light of the significant advancements in NGS, clinicians should always consider utilizing it as a helpful tool to not only establish a rare diagnosis of aCML but also to offer the best available targeted therapy when applicable. This might alleviate the burden associated with the poor prognosis of aCML.

The bite of a brown recluse spider ( Loxosceles reclusa ) is usually associated with skin necrosis; however, it can lead to more significant morbidity including acute hemolytic anemia, rhabdomyolysis, disseminated intravascular coagulopathy and death. Here we highlight a case using plasmapheresis as treatment for acute hemolytic anemia caused by the bite of a brown recluse spider. A 49-year-old male presented to the emergency room 5 days after suffering a spider bite due to worsening symptoms. He had worsening pain at the site of the bite, diffuse body myalgias, darkening of his urine, chills, and shortness of breath. Hematology was consulted to assist in the management of hemolytic anemia refractory to multiple blood transfusions, worsening acute kidney failure requiring hemodialysis, and concern for impending death. After a literature review suggesting plasmapheresis may be beneficial in this scenario, the case was discussed with the local blood bank, and plasmapheresis was initiated. The patient underwent plasmapheresis with albumin for 2 days and the patient’s hemoglobin improved and stabilized. Therapy of loxoscelism is directed at limiting the dermatonecrosis at the site of the envenomation and in cases of systemic illness supportive care is recommended. Therapeutic plasma exchange has been shown efficacious in treating snake envenomation, but there are limited data detailing its use for brown recluse spider envenomation. Here we present a case to highlight the benefit of plasmapheresis in a patient with acute hemolytic anemia secondary to a brown recluse spider bite.

Patient: Female, 46Final Diagnosis: Rituximab induced acute thrombocytopeniaSymptoms: Abdominal discomfortMedication: —Clinical Procedure: —Specialty: HematologyObjective:Adverse events of drug therapyBackground:Rituximab is a chimeric monoclonal antibody to CD20 that is used to treat vasculitis, B-cell lymphoproliferative disorders, and B-cell non-Hodgkin lymphoma (NHL). A report is presented of a case of rituximab-induced acute thrombocytopenia (RIAT) in a woman with splenic marginal zone lymphoma (SMZL) and chronic hepatitis C virus (HCV) infection.Case Report:A 46-year-old woman with SMZL complicated by chronic HCV infection presented with worsening B symptoms of fever, night sweats, and loss of weight. The patient had a history of recreational drug use. Intravenous treatment with rituximab (dose, 375 mg/m2) commenced with close monitoring in hospital. On the following day, the complete blood count (CBC) showed that her platelet count had dropped from her admission level of 167,000/μl to 7,000/μl, with no change in hemoglobin or white blood cell (WBC) levels. A diagnosis of RIAT was made. The patient was managed conservatively and monitored for the development of potential clinical complications.Conclusions:RIAT is a rare complication of treatment with rituximab and may be poorly recognized. Further studies are needed to determine the incidence and causes of thrombocytopenia in patients treated with rituximab and the possible association with chronic viral infections, including HCV.

Serum iPTH was measured i n 160 AGA f u l l -t e r m and premature normocalcemic and hypocalcemic i n f a n t s during the f i r s t 96 hours o f l i f e . I n normal f u l l -t e r m i n f a n t s , iPTH was low i n cord blood and remained low during the f i r s t 12 hours o f l i f e as serum Ca declined. Thereafter the serum iPTH rose t o the midnormal range. Consistent w i t h our previous studies, i n only 20% o f serum samples from hypocalcemic f u l l -t e r m i n f a n t s was iPTH elevated; i n the remainder, iPTH was inappropriately low. though usually i n the normal d e t e c t i b l e range. By contrast. serum iPTH was elevated i n 75% o f samples o f hypocalcemic prematures. Moreover, elevated iPTH was found i n approximately 15% and 35% serum samples o f n o m c a l c e m i c f u l l -t e r m and premature i n f a n t s , respectively. At any given Ca l e v e l the serum iPTH appeared t o vary inversely w i t h gestational age. The r e s u l t s sug- --gest 1) That parathyroid responsiveness i s greater i n premature at 32 days). These data indicate lj exposure to PTU or LID rethan f u l l -t e r m i n f a n t s , possibly r e l a t e d to lesser period o f exsults in a marked aberration of the maturationofthehypothalamoposure t o hypercalcemia i n utero and 2) That a f a c t o r ( s ) other pituitary thyroid axia in the neonatal rat 2) the decreased hythan parathyroid i n s u f f i c i e n c y acts i n the newborn t o reduce pothalamic TRH concentration is compatible with an increased plasma Ca; i n some i n f a n t s , compensatory increases i n parathyturnover of TRH and 3) the normal thyroid hormone concentrations r o i d a c t i v i t y may be s u f f i c i e n t t o maintain n o m c a l c e m i a , whilein the LID group suggest that TSH may play a predominant role in i n others there i s e i t h e r no compensatory increase o r the innegative feedback at the hypothalamic level. crease i s i n s u f f i c i e n t and hypocalcemia r e s u l t s . It i s possible t h a t metabolic clearance o f iPTH varies w i t h gestation and accounts, i n p a r t , f o r our findings.ONTOGENESIS OF THYROID HORMONE PRODUCTION IN THE NEO-NATAL RAT. J.D. Dubois and J.H. Dussault. D6parte-ment dlEndocrinologie-bl6tabolisme. CHUL. Qu6bec. P.Q. This study was undertaken to examine the ontogenesis of thyroid hormone production in the neonatal rat (from 5 days to adulthood) by measuring C~~~I I -T~ and c~~~I I -T~ kinetic parameters b y single-compartmental analysis. Tq and Tj serum concentrations were measured by specific radioimmunoassay. The volume of distribution (VD) and the metabolic clearance rate (MCR) of T4, high at 5 days, increase to a peak at 22-26 days and decline to adult values.The T& production rate (PR) low st 5 days, increases to peak values at 14 to 32 days and declines toward adult values. The TI, fractional removal rate (K) is similar from birth to adulthood. No difference is observed for K. VD and MCR of T3 during the life of the rat. The Tj PR from minimal values at 5 days attains adult values ...

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