Internal Medicine Commons^™

Two Years Of Ocrelizumab Treatment In Black And Hispanic People With Multiple Sclerosis In Chimes: A Single-Arm Clinical Trial, Lilyana Amezcua, Anthony Reder, Evanthia Bernitsas, Nancy Monson, Timothy Vartanian, Gregory Wu, Mansoor Saleh, Annette Okai, Ahmed Obeidat, Dilraj Sokhi

Haematology and Oncology, East Africa

Objective To evaluate the effectiveness and safety of ocrelizumab in self-identified black and Hispanic people with relapsing multiple sclerosis.

Methods The Characterization of Ocrelizumab in Minorities with Multiple Sclerosis (CHIMES) trial, a prospective, open-label, single-arm, phase 4 study, intentionally recruited underrepresented populations in the US, Puerto Rico, and Kenya. Black and Hispanic people with relapsing multiple sclerosis aged 18–65 years with Expanded Disability Status Scale score 0–5.5 received ocrelizumab for 2 years. The primary endpoint was the proportion of participants with no evidence of disease activity in 3 components at week 48: protocol-defined relapse, 24-week confirmed disability progression, and disease …

Severe Cold Agglutinin Hemolytic Anemia Secondary To Mycoplasma Pneumoniae And Epstein-Barr Virus Co-Infection In An Elderly Patient, Aura Mc Calderon, Jose Loayza, Luis Salcedo, Ivan Mogollon, Asmik Asatrian

Research Symposium

Introduction: Cold autoimmune hemolytic anemia (AIHA) is an uncommon, complement-mediated hemolysis typically driven by IgM autoantibodies; secondary forms are often infection-related. Severe, transfusion-refractory presentations are rare in older adults. We present an elderly patient with Mycoplasma pneumoniae and Epstein–Barr virus co-infection complicated by life-threatening cold agglutinin hemolysis.

Case report: Upon admission, a 79-year-old male patient presented with a one-week history of fatigue, pyrexia, nasal congestion, and dyspnea; examination findings revealed pallor, bibasilar crackles, and mild splenomegaly. Laboratory investigations indicated the presence of severe hemolytic anemia accompanied by compensatory reticulocytosis and thrombocytosis (hemoglobin 5.5 g/dL, hematocrit 17.2%, MCV 100 fL, reticulocytes …

Iptacopan-Responsive Pnh With Pancytopenia: Hematologic Normalization And Dose Adjustment For Transaminitis, Aura Mc Calderon, Jose Loayza, Francisco Arias, Catherine Matos, Bharat Peddinani, Diane Nguyen

Research Symposium

Introduction: Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal hematopoietic stem-cell disorder driven by loss of GPI-anchored complement regulators (CD55, CD59), leading to complement-mediated intravascular hemolysis, cytopenias, and thrombosis. We report a new PNH diagnosis in a young woman with severe pancytopenia who achieved hematologic improvement on oral iptacopan, requiring dose adjustments for mild liver enzyme elevation.

Case Report: On February 27, 2025, a 38-year-old female patient exhibited symptoms of progressive fatigue, dyspnea, and jaundice. Initial laboratory assessments indicated the presence of severe hemolytic anemia accompanied by pancytopenia, hemoglobin level recorded at 4.7 g/dL, white blood cell count at 1.6×10³/µL (absolute …

Assessing Aflatoxin Knowledge, Perceptions, And Related Practices, In A Rural Coastal Community: A Population-Based Cross-Sectional Survey, Rosebella Iseme, Joseph Abuodha, Anthony Ngugi, Innocent Abayo, Mansoor Saleh

Population Health, East Africa

Background

Aflatoxin contamination is a significant yet under-addressed food safety challenge in low-resource settings, driven by a complex interplay of environmental, agricultural, and socio-economic factors. Limited access to agricultural inputs, inadequate post-harvest handling and storage, and weak regulatory enforcement alongside food scarcity and climate change heighten the risk of contamination and exposure. Human exposure is associated with serious health consequences, including hepatocellular carcinoma, immune suppression, and childhood stunting. Although aflatoxin is increasingly recognized as a global food safety concern, little is known about community-level knowledge, risk perceptions, and preventive practices. This study examined household heads’ awareness, perceptions, and behaviours related …

Renal Adverse Effects Of Antiangiogenic Agents In A Tertiary Hospital In Kenya, Joan Wambugu, Joyce Bwombengi, Jasmit Shah, Manel Haj Mansour

Internal Medicine, East Africa

Introduction Anti-angiogenic therapies, including vascular endothelial growth factor (VEGF) inhibitors and tyrosine kinase inhibitors (TKIs), have transformed cancer management by targeting tumor vasculature and suppressing metastasis. However, these agents can induce renal toxicities such as hypertension, proteinuria, and acute kidney injury (AKI), which may affect treatment continuity and outcomes. Data from sub-Saharan Africa on these adverse effects remains scarce.

Methods This was a retrospective cross-sectional study conducted at the Aga Khan University Hospital, Nairobi, oncology clinic. Medical records of adult patients receiving anti-angiogenic therapy between January 2020 and December 2024 were reviewed. Demographic data, comorbidities, treatment regimens, renal parameters, and …

A Stroke That Wasn’T: Thrombotic Thrombocytopenic Purpura Presenting With Isolated Neurologic Deficits, Renuka Mahatara, Sahil N. Parikh, Amelia Piccone, Merid Moqattash, Nicole Ryan, Dmitri Zbarsky

South Atlantic Division GME Research Days 2026

No abstract provided.

Cefazolin: A Rare Etiology Of Induced Coagulopathy, Ahmed Ismail, Anam Habib, Cayleigh Blumrick

Department of Medicine Faculty Publications

Cefazolin, a first-generation cephalosporin, is commonly used to treat methicillin-susceptible Staphylococcus aureus (MSSA) infections. Although generally well tolerated, coagulation abnormalities have rarely been reported during therapy. We describe the case of an 81-year-old man treated with prolonged cefazolin for MSSA endocarditis who developed severe coagulopathy characterized by marked elevation of both the international normalized ratio (INR) and activated partial thromboplastin time (aPTT). The abnormalities occurred after initiation of cefazolin and worsened despite cessation of other anticoagulants. Following discontinuation of cefazolin and administration of vitamin K, coagulation parameters rapidly improved and subsequently normalized. This case highlights a rare but clinically significant …

Accidental Daily Dosing: Severe Methotrexate Toxicity In A Patient With Rheumatoid Arthritis, Sidra Memon, Kavitha Vemuri, Syed Uzair Mahmood, Darshit Patel

Advances in Clinical Medical Research and Healthcare Delivery

This case highlights a crucial complication of oral methotrexate therapy: toxicity due to dosing errors. A patient’s daily dosing regimen, instead of the intended weekly schedule, led to a significantly excessive cumulative dose of methotrexate over a short period, resulting in severe hematologic and mucosal toxicity. This underscores the importance of clear patient education and vigilant prescription practices to prevent such errors.

Lymphoma Imaging In Hiv And Non-Hiv Patients: A Retrospective Cross-Sectional Study With Clinical And Pathological Correlation, Poonamjeet Loyal, Edward Chege, Jasmit Shah, Anne Mwirigi, Samuel Gitau

Imaging & Diagnostic Radiology, East Africa

Background: Patients with Human Immunodeficiency Virus (HIV)have an atypical imaging pattern of lymphoma. There is paucity of literature on differences in tumor volume or burden of disease amongst HIV positive patients compared with HIV negative patients and how this correlates with clinicopathological parameters of aggressiveness and prognosis.

Methods: This was a retrospective cross-sectional study of patients with non-Hodgkin lymphoma which were categorized into HIV positive and HIV negative. The tumor burden, disease sites, international prognostic score and Ki-67 index were recorded. Continuous variables were analyzed using the Kruskal Wallis test and categorical variables with Fisher’s Exact test.

Results …

Upper Respiratory Tract Infection Leading To A New Diagnosis Of Sweet Syndrome And Monoclonal Gammopathy Of Unknown Significance, Nidhi Rawat, Meron Gebrehiwot, Jason Raw, Jeyaprakash Ramachandran

HCA Healthcare Journal of Medicine

Background

We present a rare case of Sweet syndrome with underlying monoclonal gammopathy of unknown significance (MGUS) which initially presented as upper respiratory tract infection.

Case Presentation

A 52-year-old woman presented with a complaint of sore throat for 6 days, productive cough and fever for 5 days, and red, pruritic, circular, tender rashes on face, arms and trunk for 2 days. There was a past history of similar self-limiting rashes presenting intermittently for 1.5 years. She also reported to be taking tablet ibuprofen, as required for the past 1-2 years, for cervical spondylosis. On integumentary examination, widespread, red, tender, annular …

Effect Of Valemetostat On The Pharmacokinetics Of Midazolam And Digoxin: A Phase 1 Drug-Drug Interaction Study In Patients With Non-Hodgkin Lymphoma, Masaya Tachibana, Steven Horwitz, Eric Jacobsen, Francine Foss, Pamela Allen, Pierluigi Porcu, Tatyana Feldman, Jia Ruan, Jonathan Brammer, Jie Wang, Shinichi Inaba, Yuka Iko, Keiko Nakajima, Yasuyuki Kakurai, Noriaki Kitami, Yang Chen, Yvonne Lau

Department of Medicine Faculty Papers

Valemetostat tosylate (valemetostat) is an oral, potent, dual inhibitor of enhancer of zeste homolog (EZH)2/1, under investigation in non-Hodgkin lymphomas (NHLs) and solid tumors. In vitro, it inhibits cytochrome P450 3A (CYP3A) and P-glycoprotein (P-gp) when combined with sensitive CYP3A or P-gp substrates. This drug–drug interaction (DDI) sub-study is part of the phase 1 trial of valemetostat monotherapy (DS3201-A-J101; NCT02732275), assessing the effect of valemetostat on the pharmacokinetics (PK) of sensitive CYP3A and P-gp substrates midazolam and digoxin, respectively, in patients with relapsed or refractory NHL, and its safety and efficacy. Patients received two simultaneous single doses of midazolam and …

Outcomes And Microbiological Patterns Of Bacteremia In Chemotherapy-Related Febrile Neutropenia At A Tertiary Facility In Kenya, Abhijit Ghose, Jasmit Shah, Anne Mwirigi, Charles Makasa, Felix Riunga

Internal Medicine, East Africa

Introduction: Febrile neutropenia (FN) is a major cause of mortality and morbidity in patients with malignancy post-chmotherapy. Current guidelines for managing FN recommend starting empiric antibiotic therapy (EAT) promptly. The choice of antibiotic is based on the patient’s condition, local data on common microorganisms isolated, and their resistance patterns. Of note, there is a growing trend of isolating multi-drug–resistant gram-negative bacteria in these patients. In sub-Saharan Africa, there are insufficient data on the mortality rates of FN. There is also a lack of local epidemiologic data on the frequently isolated microorganisms and their antibiotic resistance patterns. This makes it challenging …

Clinico-Epidemiological Characteristics Of Cerebral Venous Sinus Thrombosis In Kenya: A Retrospective Case Series, Taby Siika, Jaskirat Sokhi, Juzar Hooker, Sheila Waa, Anne Mwirigi, Jasmit Shah, Dilraj Sokhi

Internal Medicine, East Africa

Background: Cerebral venous sinus thrombosis (CVST) is a rare cause of stroke that is more common in young, especially female, adults and can be challenging to diagnose due to its frequently non-specific presentation and diverse risk factors. Most cases are idiopathic, and international guidelines do not recommend routine investigations for underlying thrombophilia. Timely diagnosis, with prompt neuroimaging and guideline-based treatment, leads to good outcomes. However, in the literature on CVST from sub-Saharan Africa, the gap is substantial, with the few cases described as being related to systemic and/or brain infections. We describe here the largest cohort of CVST from the …

Complications And Management Of Idiopathic Multicentric Castleman Disease, Kavanya Feustel, Jacob W. Keeling, Olivia Makos, Dmitriy Scherbak

HCA Healthcare Journal of Medicine

Background

The pathophysiology of idiopathic multicentric Castleman disease (iMCD) is poorly understood compared to the other subtypes of MCD, which has contributed to limited treatment options and poor prognosis for iMCD patients. The pathogenesis of iMCD is thought to be mediated in part by dysregulation of interleukin (IL)-6.

Case Presentation

We present a case report of a 39-year-old Caucasian man with siltuximab-refractory iMCD. He presented with severe lower extremity lymphedema and wounds. His disease progressed through standard-of-care siltuximab. Due to his severe disease-related morbidity, he contracted recurrent infections, often complicated by sepsis. Ultimately, he required a left lower extremity amputation. …

Immune Thrombocytopenic Purpura Association With Epstein-Barr Virus, Amer Aldamouk, Bachr Masri, Ali Khan, Pulkita Uppal

Graduate Medical Education Research Journal

Immune thrombocytopenia (ITP), also referred to as idiopathic thrombocytopenic purpura, is an acquired form of thrombocytopenia caused by antibodies directed against platelet glycoproteins, particularly anti-GpIIb/IIIa antibodies. Epstein-Barr virus (EBV), a herpes virus infecting a large majority of the population before adulthood, has been implicated in various immune-mediated disorders, including ITP. In this report, we present a case of a young adult female with a history of thrombocytopenia who was found to have severe thrombocytopenia attributed to chronic EBV infection. Despite initial treatment with corticosteroids and intravenous immunoglobulin (IVIG), the patient's condition necessitated second-line therapies, including rituximab and thrombopoietin receptor agonists. …

Can Anemia Be A Prognostic Indicator To Scope For Gastroesophageal Junction Adenocarcinoma?, Ryan Tam, Neha Narayanan, Evan Basha, Joel Thompson

Advances in Clinical Medical Research and Healthcare Delivery

Gastroesophageal junction adenocarcinoma is a rapidly progressive disease that has a poor prognosis with a 5-year survival rate of 20%. It commonly presents with major symptoms of dysphagia and weight loss in addition to a long-standing history of reflux. As of now, screening for esophageal adenocarcinoma (EAC) is dependent on identifying risk factors which include a family history of Barrett’s esophagus and esophageal adenocarcinoma or patients with gastroesophageal reflux disease and at least one other risk factory for EAC such as age greater than 50 years, obesity or central adiposity, history of smoking, or male gender. Here, we present a …

Mystery Of Maha: Hypertension’S Twist Over Cancer’S Shadow, Andrew Takla, Gabriel Vachon, John Hix, Nagesh Jadhav

Advances in Clinical Medical Research and Healthcare Delivery

Microangiopathic hemolytic anemia (MAHA) refers to nonimmune hemolysis resulting from the intravascular fragmentation of red blood cells. The etiology of such disorders can range from primary thrombotic microangiopathic syndromes (TMA) to various systemic conditions, posing a diagnostic challenge. Prompt identification requires a sharp clinical assessment to improve outcomes.

Iron Deficiency—More Than Just Anemia: A Literature Review, Arianna S Moss, Zahra Pakbaz

Journal of Community Hospital Internal Medicine Perspectives

Iron deficiency (ID) is a global public health concern, as it can be a prodrome of gastrointestinal (GI) malignancies, exacerbate chronic conditions, and lead to an overall decreased quality of life. Despite being the most prevalent nutritional deficiency, it remains underdiagnosed by many healthcare professionals. Misconceptions regarding the clinical and laboratory manifestations of ID lead to delayed or missed diagnoses, contributing to poor patient outcomes. Though anemia is a commonly known consequence of ID, there are additional consequences that remain underrecognized by the medical community, including vague signs and symptoms, such as fatigue, depression, and abnormalities in white blood cell …

A Rare Case Of Lenalidomide Associated B Cell Lymphoblastic Leukemia, Yagnapriya Ammakola, Nitya Batra, Ashbita Pokharel, Ishmael Jaiyesimi

Conference Presentation Abstracts

Introduction Autologous stem cell transplantation followed by maintenance with Lenalidomide has improved the overall survival and progression free survival in patients with Multiple Myeloma. However, maintenance therapy with Lenalidomide can increase the risk of several hematological adverse events including secondary B cell lymphoblastic leukemia. We present a case of 61 year old female who was previously treated for multiple myeloma and on maintenance Lenalidomide developed B lymphoblastic leukemia/lymphoma. Case presentation A 61 year old female initially presented with left sided hip pain and lower back pain in 2018.Chest X ray revealed mass like opacity in the left upper lobe and …

Atypical Dengue Fever With Severe Hematological Manifestations: A Case From The Rio Grande Valley, Elias Arellano Villanueva, Alhasan Asaad, Jose Campo Maldonado

Research Symposium

Background: Dengue fever, a mosquito-borne viral illness, is endemic in tropical regions, including border regions like the Rio Grande Valley while often self-limited, severe presentations such as dengue hemorrhagic fever and dengue shock syndrome highlight its challenges and complexities. This report describes an atypical dengue case with severe hematological manifestations, underscoring the diagnostic challenges and the importance of early recognition, multidisciplinary evaluation, and evidence-based management.

Case Presentation: A 22-year-old Hispanic female with no significant past medical history presented to the ED with hematemesis and fever following her travel to Monterrey, Mexico. Initial symptoms included high fever (107.6°F), chills, diarrhea, vomiting, …

A Peculiar Pancreatitis: Investigating The Adverse Effects Of Mesalamine, Elias Arellano Villanueva, Miguel Lopez, Alhasan Asaad, Jose Campo Maldonado

Research Symposium

Background: Acute pancreatitis (AP) is a leading cause of gastrointestinal-related hospitalizations in the United States, accounting for approximately 300,000 emergency department visits annually. It is characterized by parenchymal and peripancreatic fat necrosis accompanied by inflammation. The clinical diagnosis of AP is based on elevated serum amylase and lipase levels, characteristic imaging findings, and epigastric pain often radiating to the back. While gallstones and alcohol use are the most common causes of AP, drug-induced pancreatitis (DIP) is a rare but increasingly recognized etiology, contributing to 0.1–5% of cases. DIP is typically diagnosed by excluding other causes and is often associated with …

Case Series On Prosthetic Valve Thromboses Treated With Intravenous Thrombolysis At A Tertiary Teaching Hospital In Nairobi – Kenya, John Odhiambo, Salim Abdallah, Mzee Ngunga

Internal Medicine, East Africa

Valvular heart disease is a significant global health issue, particularly in developing countries where Rheumatic Heart Disease (RHD) is the leading cause. Valve replacement surgeries have increased, with mechanical prostheses favored for their durability. However, thromboembolism remains a critical complication post-surgery, with prosthetic valve thrombosis rates of 0.03% for bioprosthetic valves and between 0.5% to 8% for mechanical valves in the aortic and mitral position. This report details two cases of heart failure following valve replacement due to rheumatic heart disease. The first case involves a 42-year-old female who developed prosthetic valve thrombosis after discontinuing warfarin for menorrhagia postmechanical mitral …

When Two Doses Make All The Difference: The Case Of Factor V Leiden In A Young Hispanic Male, Alberto Pena, Janetly Reinoso, Liza Salloum, Khiem D. Ngo, Sobia Memon, Johanna Mora

Research Symposium

Background: Recurrent venous thromboembolism (VTE) causes a substantial burden, particularly when the cause is unclear. Traditionally VTE risks include older age, immobilization, obesity, and malignancy. When VTE recurs in a young patient without these traditional factors, genetics must be considered. Of the inherited thrombophilias, Factor V Leiden (FVL) is the most common. Normally, activated factor V combines with factor X to produce thrombin, leading to clot formation. This process is regulated by activated protein C (APC), which inactivates factor V to stop coagulation. FVL is a single-base point mutation at one of the APC cleavage sites on Factor Va and …

A Literary Review Of Physician Approach To Patient Care: Implications In Cancer Care, Daniel Ramirez, Kinsley Batson

Annual Research Symposium

No abstract provided.

Recombinant Factor Viia: New Insights Into The Mechanism Of Action Through Product Innovation, Miguel A Escobar, Maureane Hoffman, Giancarlo Castaman, Cedric Hermans, Johnny Mahlangu, Johannes Oldenburg, Charles L Percy, Mark T Reding, Amy D Shapiro, Steven W Pipe

Faculty, Staff and Student Publications

Management of bleeding in persons with hemophilia and inhibitors involves treatment with bypassing agents, including recombinant activated factor VII (rFVIIa). Two rFVIIa products are commercially approved for use in the United States and the European Union. Eptacog alfa and eptacog beta share the same amino acid sequence but differ in posttranslational modifications. Although rFVIIa has been used to manage bleeding in persons with hemophilia and inhibitors for over 30 years, its mechanisms of action is still being studied. In vitro and in vivo studies have suggested that rFVIIa could promote hemostasis by (1) increasing tissue factor-dependent activation of factor (F)X …

Hemophagocytic Lymphohistiocytosis Due To Ehrlichiosis: A Case Series, Ajay Iyer, Mattias D'Anna, Shruti Verma, Thomas Pritchard, Vladimir Begilman, Himal Bajracharya, Kaveh Naemi

HCA Healthcare Journal of Medicine

Background

Hemophagocytic lymphohistiocytosis (HLH) is an immunologic syndrome characterized by excessive inflammation and tissue injury due to uncontrolled activation of the phagocytic system. The underlying mechanism is a lack of downregulation of activated macrophages and lymphocytes by natural killer and T cells. Unfortunately, the diagnosis is often delayed or missed due to the rarity of the disease, decreased awareness, and clinical picture variability. Ehrlichiosis is becoming a more prevalent tick-borne illness in endemic regions and a relatively uncommon but increasingly considered cause of HLH.

Case Presentation

We describe the cases of 2 patients diagnosed with secondary HLH as per the …

Real-World Impact Of Emicizumab And Immunosuppression On Acquired Hemophilia A: A Multicenter Us Cohort, Jacqueline N Poston, Cassandra Bryan, Annette Von Drygalski, Kadhim Al Banaa, Jenny Y Zhou, Aric Parnes, Evan C Chen, Osman Khan, Patrick Ellsworth, Lorraine Cafuir, Christopher Walsh, Miguel A Escobar, James F Wu, Lynn M Malec, Craig M Kessler, Maissaa Janbain, Rebecca Kruse-Jarres

Faculty, Staff and Student Publications

Acquired hemophilia A (AHA) is an autoimmune bleeding disorder that is caused by factor VIII (FVIII) autoantibodies with high morbidity and mortality due to bleeding and complications from immunosuppression (IST). To address the real-world implications of the FVIII mimetic antibody, emicizumab, and the role of IST, we retrospectively collected de-identified data on 62 patients with AHA who were treated off-label with emicizumab for a median of 10 weeks at 12 US-based hemophilia treatment centers. Most patients (95.2%) had acute bleeding at diagnosis, and 62.9% had partial or no control of bleeds despite the use of hemostatic agents at the time …

Assessing The Impact Of Obesity On Postoperative Outcomes In Rcc Using Machine Learning, Atulya A. Khosla, Manas Pustake, Sufal Chhabra, Yanjia Zhang, Mukesh Roy, Muni Rubens, Venkataraghavan Ramamoorthy, Anshul Saxena, Ishmael A. Jaiyesimi

Conference Presentation Abstracts

Introduction Obesity is associated with an increased risk of developing renal cell carcinoma (RCC) but paradoxically correlates with improved outcomes in metastatic cases. Moreover, the data on the relationship between obesity and postoperative outcomes following nephrectomy are inconsistent. Accurate prediction of postoperative outcomes, including complications, 30-day readmissions, and mortality, is essential for improving patient outcomes in surgical procedures. In this study, we utilized ML models to predict such outcomes in RCC patients undergoing nephroureterectomy, radical nephrectomy, partial nephrectomy, and other excision procedures on the kidney using data from the National Surgical Quality Improvement Program (NSQIP; 2016- 2021). Methods A gradient-boosted …

Nosebleed No More: Recognizing And Diagnosing Factor Viii Inhibitor, Salam Harb, Leidy Huie Martinez Md, Jose Alvarado Md, Ajit Koli Do, Hazem Nasef Ms4

HCA-NSU MD Research Day

Acquired hemophilia is a condition characterized by the unexpected onset of severe bleeding due to an issue with coagulation factors. Typically, this disorder results from the production of autoantibodies against the Factor VIII coagulation factor. Although acquired hemophilia is an extremely rare condition, with an annual incidence of just 1.5 cases per million, it is crucial to recognize and understand it. This is because diagnosing this disorder is intricate, and if left undiagnosed and untreated, it can lead to high levels of morbidity and mortality. This case stands out as the condition typically targets older adults, with around 80% of …

How Did Dat Happen? A Coombs Negative Delayed Hemolytic Transfusion Reaction In A Patient With Myelodysplastic Syndrome: A Case Report, Aniket Vijay Rao Dr, Aditya Sanjeevi, Daniel Jose Idoate, Nagesh Jadhav, Basil Verghese, Himal Kharel

Advances in Clinical Medical Research and Healthcare Delivery

Delayed hemolytic transfusion reactions (DHTRs) present significant challenges in diagnosis and management despite advancements in pre-transfusion testing. We report a case of a 76-year-old female with myelodysplastic syndrome (MDS) who developed severe hemolytic anemia following a seemingly compatible blood transfusion and appropriate pretransfusion testing. Evaluation revealed characteristics consistent with DHTR. Diagnostic uncertainty arose due to a negative Direct Antiglobulin Test (DAT) in the setting of a concomitant Vitamin B-12 deficiency. She was supported with prednisone and B12 supplementation. We discuss challenges in diagnosis, including the limitation of DAT, and propose strategies for comprehensive antibody identification. The case underscores the importance …