November 2010
Feature Story

Anne Paxton

Humble urinalysis, the oldest but most overlooked laboratory test, gets a massive infusion of four-color glamour in the latest textbook produced by five members of the CAP Hematology and Clinical Microscopy Resource Committee: the Color Atlas of the Urinary Sediment: An Illustrated Field Guide Based on Proficiency Testing.

“I feel we now have the most comprehensive urinalysis atlas ever published. It’s the best peer-reviewed educational publication available for teaching urinalysis to medical students, physicians, and medical technologists,” says co-author Meryl Haber, MD, of Scottsdale, Ariz., who edited the atlas’ sections on history and normal anatomy, and on casts.

Everything similar is out of print, except for one textbook on wet urinalysis that takes a different slant, says fellow author Eric F. Glassy, MD, of Affiliated Pathologists Medical Group in Torrance, Calif., who was in charge of graphics for the atlas. “There are a few urinalysis atlases or textbooks out there, but there really isn’t anything else that has the scope of this text, or the richness, or the number of illustrations and photographs.”

The Color Atlas of the Urinary Sediment is the fourth and last in a series of reference works sponsored by the CAP Hematology and Clinical Microscopy Resource Committee—all intended as teaching tools and ongoing references for laboratories, primary care physicians, and advanced practice nurse training programs.

Several target audiences will be interested in the publication, Dr. Glassy says. “The main focus is the clinical lab and bench technologist wanting to identify urinary sediment elements. Secondly, it’s geared to medical schools and physicians who perform urinalysis in their office and might be interested in how to identify these various elements. The third audience will be pathologists, who are often asked for help in identification.”

The book’s format follows that of the previous atlases by including photomicrographs of the urinary sediment, a discussion of the morphologic features of each element, and results of the CAP Surveys in which participants were asked to identify the element. Containing nearly 550 photomicrographs and more than 250 illustrations, the Color Atlas also has a foldout three-page spread to illustrate the section Dr. Haber wrote on the history of urinalysis.

With engravings, paintings, drawings, and charts included on nearly every one of its 400-plus pages, the book, slated for release in December, has already chalked some pre-publication sales, and the authors believe it will be another best-seller for the CAP Press.

Typically, the publications available to pathologists doing uroscopy, internal medicine physicians specializing in nephrology, and surgeons who specialize in kidney disease are limited to textbooks and the manuals that companies making testing equipment send out, Dr. Haber notes.

This atlas, by contrast, “is distinguished not only by its comprehensiveness, but also by the fact that it’s all in color, there is a written explanation of the reason for diagnosis of each element, and each major part—cells, casts, and crystals—includes an introductory section explaining how the elements seen microscopically develop in the urine and how they change.”

“We started working on the urine Color Atlas about three years ago,” says Katherine A. Galagan, MD, who wrote the sections on organisms and exogenous materials, and some items in the normal urinalysis and diagnostic issues section. “But we started talking about it 15 years ago.”

“Every laboratory, even small ones, does urinalysis, and everyone thinks of it as a no-brainer test using reagent strips,” says Dr. Galagan, director of the clinical laboratory at Virginia Mason Medical Center, Seattle. “And although dipstick testing is fairly straightforward, urinary sediment evaluation is actually quite difficult. Even a good medical technologist can have trouble identifying various elements, yet it’s really important data; it may be telling you a person has serious kidney disease, vasculitis, or other serious conditions, and you want to be able to recognize them.”

In the case of the Color Atlas of the Urinary Sediment, one co-author, Dr. Haber, has been a well-known expert on urinalysis for many years and has produced previous atlases on the subject, Dr. Galagan says. “But this is going to be the most complete text on the market.” With the material drawn from the impressive private collections of Dr. Haber and co-author Patrick Ward, MB, BCh, she adds, “there’s information in here you would be hard-pressed to find anywhere else.”

One example is the chapter on crystals. “There is a lot of confusion in the field because the analysis of kidney stones and the identification of urinary sediment crystals are two separate areas of testing. If one uses infrared spectroscopy or crystallography to analyze kidney stones, they are called by geologic names, such as struvite, brushite, or weddellite—whereas in uroscopy they have chemical names like magnesium ammonium phosphate, or calcium hydrogen phosphate, or even a common name like ‘triple phosphate.’ So it’s terribly confusing.”

“The wonderful thing about the chapter Dr. Ward has written is that he pulls all of this information together. His introduction clarifies which urinary crystals are associated with stone formation, and which are not, and includes two tables that show the geologic names, the chemical formulas, and the common name,” Dr. Galagan says. Also included in the atlas’ crystal section is material about infectious stones and how they are formed. “There is also fascinating information about clinical syndromes such as hyperoxaluria and cystinuria that are of interest to urologists and nephrologists as well.”

Many earlier atlases of urinalysis have primarily just discussed the foreign elements of urine and pretty briefly at that, says co-author David Blomberg, MD, of Arrowhead Pathologists, Duluth, Minn. By contrast, the Color Atlas contains special topics such as proteinuria, critical values, proficiency testing, competency testing, and dysmorphic red cells. On microscopy of crystals, he notes, Dr. Ward wrote not from the standpoint of identifying crystals, but from the relation of crystals to stones, “because stones are what create problems such as infection, blockage, bleeding, or renal failure.”

Pathologists in training actually spend very little time in urology, and urinalysis is often referred to as the stepchild of the lab, Dr. Blomberg notes. “There’s a lot of information there, but it’s fairly unglamourous when you compare it to the molecular tests today, or to immunohistochemistry or some of the exotic chemistry tests or flow cytometry.”

As Dr. Haber’s history section illustrates, however, a couple of centuries ago urine was the linchpin of the lab. “You did urinalysis or you didn’t do anything,” Dr. Blomberg says.

Dr. Haber’s fascination with urinalysis goes back to the 1960s when he was a professor at the University of Hawaii. “We had a class of medical students and medical technologists, and part of the curriculum dealt with renal disease and urinalysis. I didn’t feel that the ones available were adequate, and I decided the only way to get around that was to write something.”

This Color Atlas contains a chapter on the colorful history of urine as a means of prognostication. Drawing on his private collection of artworks as well as those from London’s Wellcome Medical Library and other museums’ collections of medical paraphernalia, Dr. Haber outlines the history of “Pisse Prophecy”—the art of using the physical appearance of urine to diagnose disease and develop a prognosis—as reflected in texts dating back to the ancient Egyptians, and numerous paintings from the 14th to the 19th century.

“I’ve taken it upon myself to amplify the historical aspect because I find it such an interesting part of medical history,” Dr. Haber says. Among other insights, he reveals that the yellow flask that the distinguished chemist is holding intently up to the light in so many familiar paintings by the old European masters is really a flask of urine being studied by a physician.

The authors collaborated with Dr. Glassy on the components of the atlas that needed illustrations. “Basically one of the authors would send me a chapter, I’d read through and suggest what deserves an illustration, or we would decide to expand some section and pull a chunk of text out and give it its own treatment,” Dr. Glassy says. The book is peppered with vignettes or highlights called “A Closer Look” that focus on areas such as cystinuria, candida infections, lipids in urine, decoy cells, or muddy casts.

All the illustrations are his original work. “We would do Web searches and there were some old-time texts you could consult to see how they conceptualized some of these urinary sediment elements. So we drew concepts from the body of literature out there. But these are all drawings that we did on our own,” he says.

That the series of atlases or field guides are based on the College’s findings from proficiency testing makes them unique, and Dr. Galagan credits Dr. Glassy with the suggestion to produce a series of atlases that could maximize the value of all the proficiency testing data the College has acquired.

“The whole idea of proficiency testing, of course, is to improve laboratory performance over a period of time,” Dr. Haber explains, “and the way to determine that is to send out samples, in this case urinary sediment photomicrographs, and see how accurately laboratories could recognize sedimentary elements that relate directly to patient care.” Dr. Haber has been involved in proficiency testing since the formation of the hematology microscopy committee in the mid-1980s.

Statistics over the decades since then show that, over time, labs involved in proficiency testing evaluations improved their performance. “We selected a five-year period, 2002–2007, and we confirmed that labs subscribing to PT improved by reading and studying and using this material on urinalysis,” Dr. Haber says.

“When you look at an example on a photograph of a cell or a cast or some other element,” Dr. Glassy says, “it’s important to know not only what it is, but also what it is not. What the differential might be, and how other folks identified it, rightly or wrongly, are important. That’s what the book is all about.” Once the College started proficiency testing, “each year the number of folks that have done well or improved has increased, so that means somebody’s learning something.”

With the Color Atlas, “now we’ve pulled all these PT examples together, so people can look at the statistics and see 50 percent thought this, 20 percent thought that, and if I read the text associated with the photograph, I can see why some identifications are not correct,” Dr. Glassy says. It’s only because of the College’s archives of proficiency testing that the authors were able to dive in and provide that kind of focus. “Otherwise it’s just a book of pictures with short titles and minimal subtext.”

Often textbooks will say “here’s an example of a crystal,” but not say what’s specific about it that helps make a correct diagnosis, Dr. Glassy points out. The Color Atlas’ approach, however, “really fine-tunes your eye, so that you can appreciate truth and separate it from something that’s near-truth.”

In the previous atlases, the committee used examples only from proficiency testing. “But in this case we wanted to show much more than what the College has produced over the last 20 or 30 years of PT, so a lot more images and examples are included to make the book as complete as possible.”

The authors didn’t select every proficiency testing sample in urinalysis because there are multiple examples of any given subject, Dr. Blomberg says. “Out of perhaps 20 or 30 samples for urine, we chose a representative number based on the quality of images and how a group of images would fit together. PT is based on the master list, but some conditions are vanishingly rare, so for a few situations we would go to private collections, mostly Dr. Ward’s and Dr. Haber’s, to get things that weren’t available anywhere else.” Melanin casts in urine were one example, he says.

Dr. Glassy started doing graphic design many years ago when he was preparing page layouts for hospital and laboratory newsletters. Then as the tools got better, he found he was able to practice more and more. While he doesn’t consider himself a freehand artist, “I think my skill set is maybe taking a complex subject and breaking it down into something more understandable by creating an illustration that is visually arresting and also tells a story.”

There is a huge gap to fill, Dr. Glassy says. “There are just not enough books out there on urinary sediment to help technologists identify these elements. Urologists probably don’t underestimate the importance of these elements, but labs and individual physicians do. Certainly those taking care of patients may not appreciate what these differently formed elements and casts are and how they are tied into disease. Because all these other tests are going on, they may not remember that urine may provide an up-front diagnosis, or confirm a diagnosis.”

Dr. Glassy hopes the Color Atlas will encourage more interest in and awareness of the importance of urinary sediments. “I think you have two of the world’s experts in co-authors Dr. Ward and Dr. Haber, and they were willing to open up the extensive archives of slides and photographs they’ve taken over the years, and include that material in the book, along with their wonderful treatises about the history of urinalysis and how to make diagnoses.”

Clinical laboratories in the U.S. are not the only ones that will be interested in the book, Dr. Blomberg says. “We absolutely believe there is a fairly large international market for this, and that’s one of the reasons we put some items in, such as material on schistosomiasis, which you wouldn’t see in the U.S. except among overseas travelers.”

Still, the authors weren’t able to make the atlas an exhaustive encyclopedia. “There are examples of formed elements described in the urinary sediment for which we could provide no examples either through private collection or the CAP archives,” Dr. Blomberg says. He urges all laboratorians who encounter these unusual elements in their practice to consider submitting the material or images to the committee for potential inclusion in future Surveys.

In the medical textbook arena, a book that sells 5,000 copies has done very well, he says, and sales of the previous atlases have been very healthy. “The hemoglobinopathy atlas has probably sold about 2,000 copies, which is a lot for such a specialized area. The body fluids atlas released in 2006 has sold about 5,000 copies, and the hematology atlas, our best-selling book, has sold more than twice as many copies over the 10 years since it was published.”

Dr. Blomberg regards the Color Atlas of the Urinary Sediment as a definitive text on urinalysis and he expects it will also sell well. “Bailey and Scott for diagnostic microbiology, Mollison for transfusion medicine, Tietz for clinical chemistry, Baselt for toxicology ... I see this book as a classic text that belongs in that company.”