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New hemoglobin disorders atlas one for the books

May 2003
Karen Southwick

A new Color Atlas of Hemoglobin Disorders, available soon from the CAP, may replace a dog-eared textbook more than 20 years old upon which many laboratories still rely.

“The standards [on hemoglobin disorders and diagnosis] were old books out of print for years,” says Steven H. Kroft, MD, associate professor of pathology, Division of Hematopathology, University of Texas Southwestern Medical Center, Dallas. In fact, he says, many labs depend on photocopies of an out-of-print 1980 publication by Virgil F. Fairbanks, MD, called Hemoglobinopathies and Thalassemias, Laboratory Methods and Clinical Cases.

It was Dr. Fairbanks himself, retired from the Mayo Clinic, who urged the CAP Hematology and Clinical Microscopy Resource Committee to create a new reference on hemoglobin disorders. Dr. Fairbanks also initiated the CAP Hemoglobinopathy Survey.

“This whole process [to publish the atlas] started out about five years ago at Dr. Fairbanks’ suggestion,” says James D. Hoyer, MD, a hematopathology consultant at the Mayo Clinic and an advisor to the CAP’s hematology committee. Dr. Hoyer is co-editor of the atlas.

The same committee produced an earlier book, the Color Atlas of Hematology, in 1998. That atlas was so well received that committee members decided to undertake another, this one on hemoglobin disorders. This atlas was largely compiled and edited over the past two years, says Dr. Kroft, another co-editor. It is similar in style and format to the hematology atlas, with full-color electrophoretic scans, illustrations, diagrams, peripheral blood smears, and numerous tables.

The lack of up-to-date material on hemoglobinopathies supported the need for a hemoglobin atlas. “The idea was an educational and practical reference that would cover everything you’re likely to see in practice,” Dr. Kroft says. The CAP had a wealth of information in its Surveys to meet the need, he notes.

The CAP Surveys identify the cases laboratories may have difficulty with, so the atlas addresses those in depth, says Linda M. Sandhaus, MD, associate professor of pathology, Case Western Reserve University School of Medicine and University Hospitals of Cleveland. “The Surveys are intended to be a teaching tool,” she adds. “The atlas is intended to capture that same purpose.” Dr. Sandhaus, a member of the hematology committee, helped edit the atlas.

The atlas presents various disorders as they would appear on electrophoresis and, in some cases, on high-performance liquid chromatography, or HPLC. The atlas also contains photomicrographs and isoelectric focusing images. And it presents a case-study discussion of the results, including issues such as how to diagnose, what to rule out, and what the differential diagnoses might be. The discussion also covers confirmatory tests.

“You can use this with students to present an unknown case,” says Dr. Sandhaus. “They can approach it as they would a real clinical situation and turn the page over to see what the results were.”

The 315-page atlas encompasses wet lab and dry lab results for disorders ranging from common to rare. It uses a format similar to that of the Survey. The discussion includes a report of how labs fared on identifying the disorder in the CAP Surveys.

“This is not meant to say that labs aren’t doing a good job,” says Dr. Hoyer. “A lot of these [disorders] were very challenging, and we expected labs to have a difficult time identifying them, especially small labs.” The atlas helps laboratories recognize some of the rare, complex disorders so, if necessary, the lab can send them out for additional testing.

Many of the electrophoresis and HPLC illustrations came from the Mayo Clinic and, as such, present a wide variety of cases. “There are almost 70 examples of different hemoglobin disorders,” says Dr. Hoyer. “If there’s something you don’t recognize, you can probably find it here.” He singles out the focuses on groups of disorders, such as alpha and beta thalassemias and Hb E, as particularly useful in compiling information. “A lot of this is fairly standard stuff, but it’s just not put into book form very often,” he adds.

The case-study format was chosen because the CAP’s Surveys lent themselves to that and because “what people liked about Dr. Fairbanks’ book were the illustrative cases of abnormal hemoglobin,” says Dr. Kroft. “Our idea was to produce a new version of illustrative cases, an update of Dr. Fairbanks’ in a sense.”

The CAP’s atlas, however, is unique because the information from the Surveys “isn’t available anywhere else,” Dr. Kroft adds. “We were able to update information and incorporate the results of newer studies and methods to diagnose hemoglobin disorders,” including HPLC.

Many labs are moving to HPLC from routine electrophoresis and “are using HPLC as a primary screening modality,” he says. The CAP atlas is valuable because it contains extensive examples of the newer technology.

Dr. Sandhaus’ laboratory at the University Hospitals of Cleveland moved to HPLC about two years ago. “It’s faster, it’s cheaper, and it requires much less technologist time,” she says. Committee members “felt it was very important to include HPLC diagrams in the atlas, even though we didn’t have that data to send out for proficiency testing.”

Dr. Sandhaus has already used an early version of the atlas in clinical practice at Case Western. “I saw an abnormality on an HPLC result from a newborn infant that might have been hemoglobin-Bart’s,” she says. She turned to the relevant section in the atlas and found an HPLC tracing for the condition.

The atlas is geared toward medical technologists and technicians, pathologists, residents, and clinicians interested in hemoglobin disorders. Dr. Kroft expects the hematologists at his medical center to quickly snag a couple of the atlases for themselves.

“The atlas will be a great reference for labs that do hemoglobin identification,” says Dr. Sandhaus. “It presents a very comprehensive collection of cases,” all of which are cross-referenced.

The committee’s next project is an atlas on body fluids that, too, will incorporate CAP Surveys data. After that may come a second edition of the hematology atlas and an atlas of urine sediment.

At CAP TODAY press time, the Color Atlas of Hemoglobin Disorders was slated for release in May. Sample pages will be available on the CAP web site. The atlas is $125 for CAP members and $150 for non-members. To order, call the CAP at 800-323-4040 and press option 1#.

Karen Southwick is a writer in San Francisco.