(BQ) Part 1 book Wallach''s interpretation of diagnostic tests presents the following contents: Autoimmune diseases, cardiovascular disorders, central nervous system disorders, digestive diseases, endocrine diseases, genitourinary system disorders, gynecologic and obstetric disorders, hematologic disorders,...
Wallach’s Interpretation of Diagnostic Tests Pathways to Arriving at a Clinical Diagnosis TENTH EDITION Wallach’s Interpretation of Diagnostic Tests Pathways to Arriving at a Clinical Diagnosis TENTH EDITION Edited by Mary A Williamson, MT (ASCP), PhD Vice President, Scientific Affairs & Laboratory Operations ACM Medical Laboratory Rochester, New York Former Assistant Professor Department of Pathology University of Massachusetts Medical School Worcester, Massachusetts L Michael Snyder, MD Professor Department of Medicine and Pathology University of Massachusetts Medical School UMass Memorial Medical Center Worcester, Massachusetts Chief Medical Officer Quest Diagnostics MA, LLC Marlborough, Massachusetts Executive Editor: Rebecca Gaertner Senior Product Development Editor: Kristina Oberle Production Project Manager: Alicia Jackson Design Coordinator: Joan Wendt Senior Manufacturing Coordinator: Beth Welsh Marketing Manager: Stephanie Manzo Prepress Vendor: SPi Global Printed in China Copyright © 2015 Wolters Kluwer © 2011, 2007 by LIPPINCOTT WILLIAMS & WILKINS, a Wolters Kluwer Business, © 2000 by Lippincott Williams & Wilkins, © 1996, 1992 and 1986 by Jacques Wallach, MD, © 1978, 1974 and 1970 by Little, Brown and Company Two Commerce Square 2001 Market Street Philadelphia, PA 19103 USA LWW.com All rights reserved This book is protected by copyright No part of this book may be reproduced or transmitted in any form or by any means, including as photocopies or scanned-in or other electronic copies, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotations embodied in critical articles and reviews Materials appearing in this book prepared by individuals as part of their official duties as U.S government employees are not covered by the above-mentioned copyright To request permission, please contact Lippincott Williams & Wilkins at Two Commerce Square, 2001 Market Street, Philadelphia, PA 19103, via email at permissions@lww.com, or via our website at lww.com (products and services) Library of Congress Cataloging-in-Publication Data Wallach's interpretation of diagnostic tests — Tenth edition / edited by Mary A Williamson, L Michael Snyder p ; cm Includes bibliographical references and index ISBN 978-1-4511-9176-9 (paperback : alk paper) I Williamson, Mary A., editor II Snyder, L Michael, editor [DNLM: Clinical Laboratory Techniques Diagnostic Techniques and Procedures QY 25] RB38.2 616.07'56—dc23 2014012353 Care has been taken to confirm the accuracy of the information presented and to describe generally accepted practices However, the authors, editors, and publisher are not responsible for errors or omissions or for any consequences from application of the information in this book and make no warranty, expressed or implied, with respect to the currency, completeness, or accuracy of the contents of the publication Application of this information in a particular situation remains the professional responsibility of the practitioner; the clinical treatments described and recommended may not be considered absolute and universal recommendations The authors, editors, and publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accordance with the current recommendations and practice at the time of publication However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any change in indications and dosage and for added warnings and precautions This is particularly important when the recommended agent is a new or infrequently employed drug Some drugs and medical devices presented in this publication have Food and Drug Administration (FDA) clearance for limited use in restricted research settings It is the responsibility of the health care provider to ascertain the FDA status of each drug or device planned for use in his or her clinical practice 987654321 I am deeply grateful to my parents Priscilla and Thomas Williamson for their unconditional love Sincere thanks to Joanne Saksa for her gracious hospitality and warmest gratitude to Brenda DeMay, for her unconditional love and continually encouraging me to challenge myself I am most indebted to Dr L Michael Snyder, a true mentor throughout the years who has taught me that anything is possible— even the Boston Red Sox can win the World Series! Special thanks to all of the authors for their hard work and commitment, especially Liberto Pechet, a true gentleman Mary A Williamson, MT(ASCP), PhD To my wife Barbara, and children Cathe, Lizzy, and John for their tireless understanding and support throughout the years To my assistant Suzanne O’Brien for her dedication and help with the textbook I would also like to acknowledge Dr Mary Williamson, for without her commitment, dedication and hard work, we would not have met the target date for completion of the tenth edition L Michael Snyder, MD Contributors M Rabie Al-Turkmani, BPharm, PhD Assistant Professor Department of Pathology University of Massachusetts Medical School Associate Director, Immunology, Immunoassay & Hematology Laboratories UMass Memorial Medical Center Worcester, Massachusetts Scientific Director, Quest Diagnostics MA, LLC Marlborough, Massachusetts Vishesh Chhibber Medical Director, Transfusion Medicine North Shore University Hospital Hofstra North Shore-LIJ School of Medicine North Shore-LIJ Health System Manhasset, New York Marzena M Galdzicka, PhD, MP(ASCP)CM , DABCC Clinical Assistant Professor Department of Pathology University of Massachusetts Medical School Shrewsbury, Massachusetts Scientific Director, Quest Diagnostics MA, LLC Marlborough, Massachusetts Edward I Ginns, MD, PhD, DABCC Professor of Neurology, Pathology, Pediatrics and Psychiatry Director, Lysosomal Disorders Treatment and Research Program University of Massachusetts Medical School Shrewsbury, Massachusetts Scientific Director, Quest Diagnostics MA, LLC Marlborough, Massachusetts Amanda J Jenkins, PhD Associate Professor Department of Pathology University of Massachusetts Medical School Director, Toxicology UMass Memorial Medical Center Worcester, Massachusetts Scientific Director, Quest Diagnostics MA, LLC Marlborough, Massachusetts Charles R Kiefer, PhD Associate Professor Department of Pathology University of Massachusetts Medical School Director, Andrology Laboratory Director, Clinical Assay Research UMass Memorial Medical Center Worcester, Massachusetts Patricia Minehart Miron, PhD Clinical Associate Professor of Pathology and Pediatrics University of Massachusetts Medical School Director, Cytogenetics UMass Memorial Medical Center Worcester, Massachusetts Scientific Director, Quest Diagnostics MA, LLC Marlborough, Massachusetts Michael J Mitchell, MD Clinical Associate Professor Department of Pathology University of Massachusetts Medical School Director, Microbiology UMass Memorial Medical Center Worcester, Massachusetts Scientific Director, Quest Diagnostics MA, LLC Marlborough, Massachusetts Liberto Pechet, MD Professor Emeritus Departments of Pathology and Medicine University of Massachusetts Medical School Worcester, Massachusetts Lokinendi V Rao, PhD Clinical Associate Professor Department of Pathology University of Massachusetts Medical School Laboratory Director, UMass Memorial Clinical Laboratories UMass Memorial Medical Center Worcester, Massachusetts Scientific Director, Quest Diagnostics MA, LLC Marlborough, Massachusetts Craig S Smith, MD Assistant Professor Department of Medicine University of Massachusetts Medical School Director, Cardiac Intensive Care Division of Cardiology UMass Memorial Medical Center Worcester, Massachusetts L Michael Snyder, MD Professor Department of Medicine and Pathology University of Massachusetts Medical School UMass Memorial Medical Center Worcester, Massachusetts Chief Medical Officer, Quest Diagnostics MA, LLC Marlborough, Massachusetts Juliana G Szakacs, MD, MSW Director of Pathology and Laboratory Medicine Harvard Vanguard Medical Associates Boston, Massachusetts Mary A Williamson, MT (ASCP), PhD Vice President, Scientific Affairs & Laboratory Operations ACM Medical Laboratory Rochester, New York Former Assistant Professor Department of Pathology University of Massachusetts Medical School Worcester, Massachusetts Hongbo Yu, MD, PhD Associate Professor Department of Pathology University of Massachusetts Medical School Director, Hematopathology and Hematopathology Fellowship Program Director, Flow Cytometry Laboratory UMass Memorial Medical Center Worcester, Massachusetts antibodies to D, C, E, c, e, S, s, K, k, Fya, Fyb, Jka, Jkb Reagent red cells must be able to detect these antibodies as well as antibodies to M, N, P1, Lea, Leb CROSSMATCH After a type and screen is completed, an appropriate blood product can be selected to transfuse the patient Ideally, ABO identical blood products should be transfused, but due to inventory management constraints, often ABO compatible (but not ABO identical) products are issued for transfusion Table 15-2 reviews the type of red cells and plasma that are compatible with each of the ABO blood groups TABLE 15–2 Blood Products That are Compatible with Each ABO Blood Group Plasma, platelets, and cryoprecipitate can be transfused without a crossmatch However, for RBC transfusion, each unit of red cells should be crossmatched with the recipient’s plasma prior to transfusion The type of crossmatch necessary depends on whether the patient’s antibody screen is positive or negative If the patient’s antibody screen is negative, generally an immediate spin crossmatch is performed by simply mixing the red cells selected for transfusion with the patient’s plasma and checking for agglutination after centrifugation An immediate spin crossmatch is essentially a second check of the donor and recipient’s ABO compatibility as agglutination will be seen if the patient’s plasma has ABO antibodies to cognate antigens on the red cells selected for transfusion In some institutions, patients who have a negative antibody screen may be eligible for an “electronic crossmatch” if the institution has validated the blood bank information/computer system to not allow an incompatible blood product to be issued to the patient If the patient had a positive antibody screen, a complete crossmatch using AHG is appropriate Many clinically significant non-ABO alloantibodies are IgG antibodies and will not result in agglutination unless AHG is added to the suspension of red cells and plasma Thus, patients who have a positive antibody screen should have the crossmatch performed by incubating the patient’s plasma and donor red cells at body temperature followed by addition of AHG The sample of blood used to perform the crossmatch (as well as the type and screen) must be recently acquired from the patient if the patient has been recently transfused or pregnant This is necessary because the patient may produce an antibody to a RBC antigen within a few days after being exposed to allogeneic red cells Generally, a sample should not be more than days old if the patient has been recently transfused or pregnant, but a sample drawn up to weeks prior to transfusion is acceptable if the patient has not had any recent exposure to blood It is also important to review the blood bank history to prevent the transfusion of RBCs that may have antigens that the patient previously had antibodies to In these patients, the antibody titer may decrease in strength to below detectable levels, but subsequent exposure to the antigen can result in brisk antibody production and a delayed hemolytic transfusion reaction Unlike RBC transfusion, transfusion of other blood products does not require a recent sample because selection is based on the patient’s blood type, and a crossmatch does not need to be performed TRANSFUSION OF BLOOD PRODUCTS Transfusion of blood products carries significant risks Thus, prior to any transfusions, the risks and benefits should be carefully assessed and blood products should be provided to the patient only if the benefits outweigh the risks Today, transfusion of whole blood is exceedingly rare in the United States Patients are usually transfused with the specific blood component that is required (e.g., packed red cells, plasma, platelets, or cryoprecipitate) RED CELL TRANSFUSION The goal of red cell transfusion is to increase oxygen delivery to tissues when necessary Red cell transfusion is appropriate for the treatment of anemia if it will ameliorate symptoms of anemia or aid in correcting or preventing the adverse physiologic consequences of anemia Most patients will tolerate a loss of approximately 50% of their circulating hemoglobin before they start to experience significant consequences due to acute anemia In acute blood loss, symptoms due to hypovolemia are usually seen before symptoms due to anemia In chronically anemic patients (patients who become anemic over weeks or months), compensatory mechanisms allow patients to tolerate lower hemoglobin levels than patients who become acutely anemic Considering the many variables involved, it is often challenging to determine whether tissue ischemia exists and whether it will be alleviated with red cell transfusion Who Should Be Suspected? There is a significant variation in RBC transfusion practices between institutions Most studies that have audited transfusion of blood products have reported that there was unnecessary transfusion of patients and there is a trend toward more conservative hemoglobin transfusion triggers Authorities in TM agree that most patients with a hemoglobin of 10 g/dL will not require red cell transfusion There is also general agreement that within this range, the transfusion of blood products needs to be individualized to the patient At the author’s institution, a trigger of a hemoglobin of g/dL is used for most hospitalized patients with the notable exception of patients with unstable cardiac disease (see Table 15-3) TABLE 15–3 Common Indications for Blood Product Transfusion and Special Processing PLASMA TRANSFUSION The previous practice of using plasma as a volume expander has largely become extinct Today, plasma is almost always transfused to patients due to a deficiency of one or more proteins present in normal plasma The proteins that are most commonly repleted are coagulation factors Other deficient proteins that may be repleted with plasma transfusion include ADAMTS 13 in patients with TTP and complement factors in patients with HUS Who Should Be Suspected? Despite the most common indication for plasma transfusion being the treatment of coagulopathy, there are no clear guidelines for the appropriate use of plasma in this setting Thus, very often plasma is transfused unnecessarily to patients who not benefit from it A more proactive approach in regard to plasma transfusion is appropriate in bleeding patients who require massive transfusion of blood products In such patients, if coagulopathy develops, it may result in excessive bleeding that can be life threatening and it may be extremely difficult to correct a severe coagulopathy These patients have multiple factors contributing to the coagulopathy including dysfunction of the enzymes of the coagulation cascade (due to hypothermia and acidosis) and consumption of coagulation factors due to DIC Considerations Several types of plasma products are available for transfusion These include fresh frozen plasma (FFP), frozen plasma 24 (FP24), and thawed plasma (TP) FFP is plasma that has been separated from a whole blood collection and put into a freezer within hours of collection FP 24 is plasma that has been placed in the freezer within 24 hours of collection Both of these products can be kept frozen up to year; however, once thawed, they must be used within 24 hours Thawed plasma is FFP or FP24 that has been relabeled as “thawed plasma” and now can be used for up to days after thawing The concentration of the majority of coagulation factors does not vary significantly among FFP, FP24, and TP with the exception of factor V and factor VIII FP24 and TP have lower concentrations of factor V and factor VIII as these two factors have the shortest in vitro half-life However, factor deficiency is rare, and factor is an acute-phase reactant that is often elevated in patients requiring plasma transfusion Most often, the vitamin K–dependent factors (II, VII, IX, and X) are the factors that need to be replaced in order to correct coagulopathy These factors are stable at refrigerator temperatures and not significantly decreased in FP24 or TP Laboratory Findings When assessing a patient for coagulopathy (usually an acquired coagulopathy), the most common laboratory tests ordered are a prothrombin time (PT)/international normalized ratio (INR) and an activated partial thromboplastin time (aPTT) The PT is very sensitive and will be abnormal before coagulopathy will result in bleeding Generally, an increase in bleeding is not usually seen until the PT is >1.3 times the upper limit of the normal range (which usually corresponds to an INR of approximately 2) In nonbleeding patients with an elevated INR due to warfarin use, vitamin K can be used to correct the coagulopathy (over 6–24 hours) without plasma transfusion It is also important to note that plasma transfusion is significantly more effective in decreasing a patient’s INR when the INR is significantly elevated As the patient’s INR gets closer to or below 2, a large amount of plasma will result in a much smaller decrease in the INR than the same volume of plasma given to the same patient at a higher INR Another important consideration when transfusing plasma, especially prior to an invasive/surgical intervention, is that the plasma should be transfused within a few hours of the intervention The in vivo half-life of some of the coagulation factors that need correction (such as factor 7) is a few hours and correcting the coagulopathy with plasma transfusion >8 hours prior to transfusion will likely be of little benefit Additionally, the use of plasma for warfarin reversal will likely decrease significantly with the recent approval of four factor prothrombin complex concentrate (PCC) in the United States CRYOPRECIPITATED AHF TRANSFUSION A unit of cryoprecipitated AHF (also known as cryoprecipitate) is prepared from a unit of plasma When frozen plasma is placed in a refrigerator and starts to thaw, there is precipitation of some proteins This precipitate contains a significant proportion of the factor VIII, von Willebrand factor, fibrinogen, fibronectin, and factor XIII that is present in the unit of plasma Subsequently, the unit is centrifuged to separate the precipitate from the supernatant plasma The cryoprecipitate is then frozen until it is necessary to transfuse Who Should Be Suspected? In the past, cryoprecipitate was used to treat patients who had hemophilia A But due to safer alternatives, cryoprecipitate is no longer used for this purpose in the United States The primary use for cryoprecipitate today is to replete fibrinogen in patients with hypofibrinogenemia or disfibrinogenemia (e.g., patients with DIC, patients requiring massive transfusion) Laboratory Findings Fibrinogen levels between 50 and 100 mg/dL are generally adequate in patients to achieve hemostasis However, levels 30 mL If the rosette test is negative, one vial of RhIg is administered to cover the small amount of fetal blood in the maternal circulation that may be present If the rosette test is positive, the amount of fetal red cells in the maternal circulation can be quantitated using flow cytometry or the Kleihauer-Betke (acid/elution) test The Kleihauer-Betke is performed by treating maternal red cells on a thin slide smear with acid and then counterstaining the slide Fetal hemoglobin is resistant to acid treatment so maternal cells will appear as “ghosts” while fetal cells will be pink Usually, 2,000 cells are counted, and the percentage of fetal red cells is determined and multiplied by the maternal blood volume to determine the volume of fetal blood in the maternal circulation The maternal blood volume can be calculated using the mother’s height and weight or alternatively 5,000 mL is occasionally used as an estimate of the blood volume of postpartum women Alternatively, flow cytometry can also be used to determine the amount of fetal–maternal hemorrhage The amount of RhIg to be given to the mother is then determined using the estimated volume of fetal blood in circulation that must be covered by RhIg The volume of fetal–maternal hemorrhage is then divided by 30 mL (that each 300 μg vial of RhIg will cover) to determine the number of vials necessary The result of the calculation is rounded to the closest whole number and then one additional vial is added to allow for an error in the estimation/calculation Additional doses of RhIg may also be necessary in Rh-negative women if the patient has any events that may have introduced fetal blood into the maternal circulation such as trauma, version, abortion, or amniocentesis (please refer to the suggested reading for additional discussion) CONCLUSION Over the last 100 years, there have been significant advances in the field of transfusion medicine All of the major blood groups have been identified and techniques for serologic testing have been developed Today, almost all hospitals have blood banks that are able to provide blood products to patients who require them Although transfusion can be life saving, there are significant risks associated with blood product transfusion Thus, blood products should only be transfused if necessary Suggested Readings Roback J, Grossman B, Harris T, et al., eds Technical Manual, 17th ed Bethesda, MD: AABB Press; 2011 Simon T, Snyder E, Solheim B, et al., eds Rossi’s Principles of Transfusion Medicine, 4th ed Bethesda, MD: Blackwell Publishing; 2009 ... Wallach’s Interpretation of Diagnostic Tests Pathways to Arriving at a Clinical Diagnosis TENTH EDITION Wallach’s Interpretation of Diagnostic Tests Pathways to Arriving at... Assistant Professor Department of Pathology University of Massachusetts Medical School Worcester, Massachusetts L Michael Snyder, MD Professor Department of Medicine and Pathology University of Massachusetts... 2 015 Wolters Kluwer © 2 011 , 2007 by LIPPINCOTT WILLIAMS & WILKINS, a Wolters Kluwer Business, © 2000 by Lippincott Williams & Wilkins, © 19 96, 19 92 and 19 86 by Jacques Wallach, MD, © 19 78, 19 74