About

Bremansu OSA-ANDREWS, PhD, is the Medical Director of Clinical Chemistry and serves as a Clinical Assistant Professor in the Department of Pathology, Immunology and Laboratory Medicine at the University of Florida College of Medicine. He is actively involved in clinical laboratory operations, overseeing the Core Lab's Chemistry, Urinalysis, and Immunology sections, as well as the Endocrinology Lab section at UFPath Labs. Dr. Osa-Andrews has a teaching profile that includes courses such as Fund Micro and Immuno, General Pathology, and Foundations of Medicine, reflecting his commitment to medical education. His research focuses on understanding the clinical dynamics of pathological conditions, nutrition, assay validation, and improving laboratory testing quality to enhance patient diagnosis and treatment. His active projects include investigating the effects of lipemia on blood gas assessments, comparing serum immunoglobulin assays for multiple myeloma diagnosis, and exploring the relationship between blood folate levels and cancer risk. Dr. Osa-Andrews emphasizes integrating scientific rigor with clinical relevance in his teaching philosophy, fostering an environment that supports diversity, equity, and inclusion, and mentoring future healthcare professionals. His professional background includes a PhD in Biochemistry from South Dakota State University and a fellowship in Clinical Chemistry from the University of Texas Southwestern Medical Center.

Research topics

• Biology
• Medicine
• Internal medicine
• Bioinformatics
• Animal science
• Genetics
• Pathology
• Molecular biology
• Chromatography
• Biochemistry
• Food science
• Chemistry
• Pediatrics

Selected publications

• Emerging Technologies and Advanced Strategies in Hemoglobin Defect Screening

  Journal of Clinical Medicine · 2025-08-12 · 3 citations

  reviewOpen accessCorresponding

  Hemoglobin (Hb) defects, or hemoglobinopathies such as thalassemia and structural Hb variants, are among the most prevalent inherited diseases and are associated with significant mortality and morbidity worldwide. Screening for hemoglobinopathies in the primary care setting plays a critical role in enhancing patient outcomes and advancing population health. It promotes awareness, enables early diagnosis and treatment, supports informed reproductive decisions through genetic counseling, and facilitates access to novel therapies such as genetic modifications. Screening approaches for hemoglobinopathies have evolved to reflect regional prevalence, healthcare infrastructure, and ethical considerations. Varying strategies underscore the necessity of tailoring to local contexts, balancing cost, accuracy, accessibility, and social impact. As global migration reshapes population genetics, flexible and equitable screening frameworks are increasingly essential. This review focuses on practical techniques suitable for the screening of Hb defects in primary care. Recent advances and findings in high-performance liquid chromatography, capillary zone electrophoresis, mass spectrometry, point of care testing, and molecular methodologies are covered. In addition, strategies and approaches in multiple regions in the world are reviewed.

  PublisherOA PDFDOI

• A Case of Myelodysplastic Syndrome-Induced Acquired Sideroblastic Anemia.

  PubMed · 2025-10-01

  articleOpen access1st authorCorresponding

  Hematological disorders are frequently encountered at the doctor's office and in the emergency room. Sideroblastic anemia, a rare hematological malady, is characterized by ring sideroblasts in the red blood cells due to accumulation of poorly transported and underutilized iron. Unlike primary sideroblastic anemia which can be conclusively diagnosed through genetic testing, the more common secondary form of the disease requires intricate cascading of several preliminary and confirmatory laboratory testing to determine the accurate etiology and provide the appropriate management regimen. The scope of laboratory medicine is broadening; clinical chemists and other laboratorians are tasked with directing broader clinical pathology sections, including Core lab hematology. Understanding the testing dynamics, diagnostic criteria and management of hematological diseases is fundamental to attaining success in consulting with providers to manage diseases such as sideroblastic anemia. Via a relevant case study, we explore the etiology, workup, symptoms, and treatment of myelodysplastic syndrome-induced sideroblastic anemia.

  PublisherOA PDF

• An Introduction to the Complete Blood Count for Clinical Chemists: White Blood Cells

  The Journal of Applied Laboratory Medicine · 2025-01-28 · 4 citations

  review1st authorCorresponding

  BACKGROUND: The most frequently ordered laboratory test worldwide is the complete blood count (CBC). As clinical chemists are increasingly assigned to assist or direct laboratories outside of the traditional clinical chemistry sections, such as the automated hematology section, expertise must be established. This review article is a dedication to that ongoing effort. CONTENT: In this primer, the white blood cell (WBC) test components of the CBC are introduced, followed by a discussion of the laboratory evaluation of leukopenia and leukocytosis. SUMMARY: The laboratorian's approach to consult cases should be guided by the patient's clinical history and presentation while being able to provide key laboratory-based insights to assist in resolving result discrepancies that may otherwise go unnoticed.

  PublisherDOI

• B-355 Utility of Quantitative immunoglobulins assay as auxiliary test for the diagnosis of monoclonal gammopathy

  Clinical Chemistry · 2025-10-01

  articleOpen accessSenior author

  Abstract Background In clinical practice, several serum protein electrophoresis (SPE) are ordered without a preliminary order of serum quantitative immunoglobulins (QIgs) but pathologists can order the test for comparison. There is not enough correlative data for SPE and QIg, making the need for evidenced-based system of test-ordering for the laboratory investigation of the presence of monoclonal protein essential. Objective: The goal of the project is to expand the original data to improve the comparative analysis of QIgs assay and SPE for concordance determination, establish the utility of QIgs.? Methods In this second phase of the project, additional results from the past 1-year of SPEs, IFEs, free light chains, QIgs were retrieved from the electronic medical records. Consistent with the clinical indication of CRABs symptoms of multiple myeloma, results of calcium, red blood cell count, and creatinine were also pooled and analyzed. Results of free light chain assay (FLC) and associated kappa-lambda ratios (K/L) were also obtained. Excel spreadsheet was used to filter the retrieved data and GraphPad prism was employed to analyze the data. Results Of the 134 tests that include at least two of the tests of interest, there were 34 normal and 29 abnormal SPEs; 28 normal and 50 abnormal QIgs; 30 normal and 34 abnormal K/Ls; and 28 normal and 27 abnormal IFEs. 19 elevated QIgs corresponded with positive SPEs, compared to 5 normal QIgs that synchronized with normal SPEs, whereas 21 QIgs results were discrepant with SPEs. 15 normal and 13 abnormal K/L were concordant with respective SPEs, while 23 K/L results were discordant with SPEs. 11 positive QIgs corresponded with IFEs but 19 disagreed. 14 positive K/L correlated with IFEs and 12 disagreed. 17, 12 and 10 SPEs were ordered without QIgs, K/L or IFEs respectively. 13%, 55%, 36% and 60% of respectively elevated calcium (Ca), hemoglobin (Hb), Creatinine (Cr) and red blood cells (RBC) agreed with SPEs. 7%, 27%, 31% and 26% of respectively normal Ca, Hb, Cr and RBC were discrepant with SPEs. 78%, 33%, 39% and 33% of respectively normal Ca, Hb, Cr and RBC were compared with SPEs. Conclusion All together, our results demonstrate that abnormal QIgs show a stronger correlation with SPEs than normal QIgs do and represent 54% overall concordance of QIgs. Compared to 50% concordance of FLC with SPEs, there’s a strong case of the utility of QIgs in the assessment of monoclonal gammopathies. The story is slightly deviant with IFEs, as K/L shows a minimally higher correlation than QIgs does. Hypogammaglobulinemia may have been partly responsible for the nonconformities in the case of QIgs, as protein fractions are generally low regardless of the presence of M-protein. The low discrepancies of Ca, Hb, Cr, and RBC; in addition to normal Ca and elevated Hb correlating best with SPEs, highlights the importance of the CRAB symptoms in the pathophysiology of monoclonality. The present research will have a direct impact on the auxiliary utilization of QIgs for interpreting SPEs and evaluating multiple myeloma.

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• ATP-Binding Cassette Transporter of Clinical Significance: Sideroblastic Anemia

  Journal of Personalized Medicine · 2024 · 2 citations

  Senior authorCorresponding
  • Biology
  • Medicine
  • Bioinformatics

  The ATP-binding cassette (ABC) transporters are a vast group of 48 membrane proteins, some of which are of notable physiological and clinical importance. Some ABC transporters are involved in functions such as the transport of chloride ions, bilirubin, reproductive hormones, cholesterol, and iron. Consequently, genetic or physiological disruption in these functions is manifested in various disease processes like cystic fibrosis, Tangier disease, and sideroblastic anemia. Among other etiologies, primary sideroblastic anemia results from a genetic mutation in the ATP-binding cassette-7 (ABCB7), a member of the ABC transporter family. There are not many articles specifically tackling the disease processes caused by ABC transporters in detail. Some testing methodologies previously reported in the available literature for investigating sideroblastic anemia need updating. Here, we expound on the relevance of ABCB7 as a clinically important ABC transporter and a rare participant in the disease process of Sideroblastic anemia. The other genetic and secondary etiologies of sideroblastic anemia, which do not involve mutations in the ABCB7 protein, are also described. We review the pathophysiology, clinical course, symptoms, diagnosis, and treatment of sideroblastic anemia with a focus on modern technologies for laboratory testing.

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• A Hemoglobinopathy That Produces an Array of Different Hemoglobin A1c Values

  Journal of Hematology · 2024-06-01 · 3 citations

  articleOpen access

  Hemoglobin A1c (HbA1c) refers to non-enzymatically glycated hemoglobin and reflects the patient's glycemic status over approximately 3 months. An elevated HbA1c over 6.5% National Glycohemoglobin Standardization Program (NGSP) (48 mmol/mol the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC)) can be used to diagnose diabetes mellitus. In our laboratory, HbA1c is determined by ion-exchange chromatography which has the advantage of detecting common Hb variants such as Hb S, C, E and D without adversely affecting the HbA1c determination. Certain homozygous or compound heterozygous hemoglobinopathies such as homozygous sickle disease and Hb SC disease can significantly lower the HbA1c by reducing red cell lifespan. Occasionally however, rare and mostly benign hemoglobinopathies can interfere with this technique resulting in an apparent elevation of HbA1c in an otherwise non-diabetic patient. In this report, we describe such a hemoglobinopathy termed Hb Wayne that resulted in a significant HbA1c elevation in a normoglycemic individual. HbA1c was determined by multiple methods including immunoassay, a modified capillary electrophoresis and an alternative ion-exchange system. These techniques yielded significantly lower A1c results, more in keeping with the patient's clinical background. The alternative ion-exchange system resulted in a low A1c that was qualified by warning flags on the chromatogram that indicated the result was not reportable. The hemoglobinopathy in question, Hb Wayne, is a frameshift mutation in the alpha globin gene that results in an extended alpha globin polypeptide that can form two variants Hb Wayne I and Wayne II. Hb Wayne is a clinically silent asymptomatic disorder with no hematologic consequences. The artifactual elevation of HbA1c is, in contrast, very significant because it may result in a misdiagnosis of diabetes mellitus leading to unnecessary treatment. In this report, we compare our findings with other descriptions of Hb Wayne in the literature and corroborate a number of previous observations and conclusions.

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• Screening for hemoglobinopathy with capillary electrophoresis in adult patients

  American Journal of Clinical Pathology · 2021 · 2 citations

  1st authorCorresponding
  • Medicine
  • Pediatrics
  • Internal medicine

  Abstract Hemoglobinopathy screening is frequently needed in adult patients, including prenatal carrier screen, workup of unexplained anemia, and bone marrow donor and recipient screening. However, the preferred test method for screening of hemoglobinopathy is not well established due to limited guidance from professional societies. American College of Obstetricians and Gynecologists’ Committee on Genetics recommended hemoglobin electrophoresis as the screening method of hemoglobinopathy in pregnancy; nevertheless, electrophoresis employs various methodologies, including acid gel electrophoresis, alkaline gel electrophoresis, and capillary electrophoresis (CE) with alkaline buffer. For other adult patient populations who need hemoglobinopathy screening, no clear guidelines dictate the method of choice. A previous study has shown that CE captures major hemoglobinopathies with comparable performance to high-performance liquid chromatography (HPLC) in pediatric patients but no study has investigated using CE alone in adult patient screening. In this retrospective study, we evaluated the utility of CE as a screening method to rule out clinically significant hemoglobin variants. During eight months, 312 adult patients without previously identified hemoglobin variants had hemoglobinopathy screening performed using a comprehensive testing algorithm. This cascade algorithm screens for hemoglobinopathy using both CE (Capillarys, Sebia, Paris, France) and HPLC (laboratory-developed test) with reflex to more advanced variant identification such as mass spectrometry and genetic analyses. Categories of abnormal findings were reviewed to determine if hemoglobinopathy can be identified by using CE only. The patient population mainly consists of pregnant women and anemic patients with hematologic malignancies with an average age of 42. Out of the 312 screened patients, 47 had abnormal results. The most frequent condition was elevated hemoglobin F (N=25) ranging 2-5% seen in leukemia patients on chemotherapy attributed to bone marrow stress. Eight cases of beta plus thalassemia (featuring hemoglobin A2 >4%) and 3 cases of hemoglobin C trait were identified in patients with little to mild clinical manifestations (red blood cell indices suggesting anemia). Decreased hemoglobin A2 fraction was observed in 7 patients, and potential causes were alpha thalassemia or iron deficiency. Other less common hemoglobinopathies included heterozygote A2 prime (N=3, a benign delta chain variant that migrates separately from hemoglobin A2 on CE) and hemoglobin G-Philadelphia (N=1). All of the abnormal results are identifiable by CE alone, although HPLC and more advanced methods help confirm the diagnosis. Our study shows that CE as the first line of screening method would rule out major hemoglobinopathies in adults. There have been reports that rare but clinically significant hemoglobin variants like hemoglobin Malmo may not be detected by CE, and therefore, certain pre-test probability factors need to be considered when testing for hemoglobinopathies, such as race/ethnicity background, family history, red blood cell indices, and iron deficiency status.

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• Plasma Carboxyl-Metabolome Is Associated with Average Daily Gain Divergence in Beef Steers

  Animals · 2021 · 6 citations

  • Chemistry
  • Biochemistry
  • Biology

  = 8), and blood samples were obtained from the two groups for plasma preparation. Relative quantification of carboxylic-acid-containing metabolites in the plasma samples was determined using a metabolomics technique based on chemical isotope labeling liquid chromatography mass spectrometry. Metabolites that differed (fold change (FC) ≥ 1.2 or ≤ 0.83 and FDR ≤ 0.05) between LF and HF were identified using a volcano plot. Metabolite set enrichment analysis (MSEA) of the differential metabolites was done to determine the metabolic pathways or enzymes that were potentially altered. In total, 328 metabolites were identified. Volcano plot analysis revealed 43 differentially abundant metabolites; several short chain fatty acids and ketone bodies had greater abundance in HF steers. Conversely, several long chain fatty acids were greater in LF steers. Five enzymatic pathways, such as fatty acyl CoA elongation and fatty-acid CoA ligase were altered based on MSEA. This study demonstrated that beef steers with divergent ADG had altered plasma carboxyl-metabolome, which is possibly caused by altered abundances and/or activities of enzymes involved in fatty acid oxidation and biosynthesis in the liver.

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• Calcitriol and Calcipotriol Modulate Transport Activity of ABC Transporters and Exhibit Selective Cytotoxicity in MRP1-overexpressing Cells

  Drug Metabolism and Disposition · 2018-09-19 · 25 citations

  articleOpen access
  PublisherOA PDFDOI

• Development of Novel Intramolecular FRET-Based ABC Transporter Biosensors to Identify New Substrates and Modulators

  Pharmaceutics · 2018-10-13 · 8 citations

  articleOpen access1st author

  Multidrug resistance protein 1 (MRP1) can efflux a wide variety of molecules including toxic chemicals, drugs, and their derivatives out of cells. Substrates of MRP1 include anti-cancer agents, antibiotics, anti-virals, anti-human immunodeficiency virus (HIV), and many other drugs. To identify novel substrates and modulators of MRP1 by exploiting intramolecular fluorescence resonance energy transfer (FRET), we genetically engineered six different two-color MRP1 proteins by changing green fluorescent protein (GFP) insertion sites, while keeping the red fluorescent protein (RFP) at the C-terminal of MRP1. Four of six recombinant proteins showed normal expression, localization, and transport activity. We quantified intramolecular FRET using ensemble fluorescence spectroscopy in response to binding of known substrate or ATP alone, substrate/ATP, and trapping of the transporter in closed conformation by vanadate. Recombinant MRP1 proteins GR-881, GR-888, and GR-905 exhibited reproducible and higher FRET changes under all tested conditions and are very promising for use as MRP1 biosensors. Furthermore, we used GR-881 to screen 40 novel anti-cancer drugs and identified 10 hits that potentially directly interact with MRP1 and could be substrates or modulators. Profiling of drug libraries for interaction with MRP1 can provide very useful information to improve the efficacy and reduce the toxicity of various therapies.

  PublisherOA PDFDOI

Frequent coauthors

• Neil Harris

  University of Florida

  5 shared

• Clive Wasserfall

  University of Florida

  4 shared

• William E. Winter

  4 shared

• Maximo J. Marin

  University of Florida

  4 shared

• Ashraf B. Muzwagi

  University of Florida

  4 shared

• Patrick A. Maher

  University of Florida

  4 shared

• Kee W. Tan

  3 shared

• Surtaj H. Iram

  Wrightington, Wigan and Leigh NHS Foundation Trust

  3 shared

Labs

• OSA LabPI

Education

• Ph.D. BIOCHEMISTRY, CHEMISTRY/BIOCHEMISTRY

  South Dakota State University

  2018

• Mphil. CHEMICAL PATHOLOGY, CHEMICAL PATHOLOGY

  University of Ghana Medical School

  2010

• Bsc. BIOCHEMISTRY, BIOCHEMISTRY

  Kwame Nkrumah University of Science and Technology College of Science

  2005

Awards & honors

• Academic Article: THE FOLATE CONUNDRUM: DEFICIENCY, TOXICITY…
• National / Invited Speech: THE FOLATE CONUNDRUM: DEFICIENCY,…
• National / Other Poster: The Effect of Lipemia on the Labora…
• Grants: Data Coordinating Center for Type 1 Diabetes TrialNe…
• Funding: UNIV OF SOUTH FLORIDA via NATL INST OF HLTH NIDDK