Five Quarts_ A Personal and Natural History of Blood - Bill Hayes [92]
Richard’s whole demeanor said, Ah, good question! “Well, you’re right, HIV does only infect white cells,” he replied. But when you’re “manipulating” blood products, it’s not so cut-and-dried. He then motioned to the centrifuge. “Centrifugation is a pretty crude separation technique. You’re artificially causing trauma. White cells are very fragile; they can rupture and release the virus.” Free virus, he called it, which can then turn up in the wrong blood “zone.” In test studies with HIV-infected blood, he noted, “All of the blood products have been shown to contain virus”—red cells and platelets, as well as plasma.
As for my hypothetical, as it turns out, people with HIV do on rare occasion donate blood, although they’re typically unaware at the time of their positive status. “We get about two or three HIV positives a year out of 125,000 donations, which means the donor history and medical screening we’re conducting is actually quite effective.”
By way of explaining to me the many layers of safeguards in place, he suggested we jump ahead thirty-six hours in the processing of newly donated blood. At this point the Arizona test results have just arrived by computer. The red cells have remained refrigerated, the plasma kept frozen, and the platelets have never stopped undulating in their metal beds. Richard and I now stood in the Label & Release room, where a technician sat before a computer monitor, a box to her right filled with rock-hard plasma units. The technician swiped the bar code on the first frosty unit of plasma, calling up its results, pass or fail. (The red cells and platelets would also undergo this inspection today.) An A-OK was followed by a search of national, state, and internal databases to quadruple-check the donor’s information. Has the individual ever been deferred in the past because of, say, foreign travel or short-term illness? Did the donor make his or her donation before the mandatory fifty-six-day wait? (This waiting period allows hemoglobin levels to return to normal.) An approval label only generates if no flags go up. The rejection rate is “very low,” Richard noted. “Far less than 1 percent.”
The new label was smoothed over the old, then the unit was scanned again and officially validated. “Now this unit is, by definition, ‘Finished Goods,’ ” Richard announced, framing it with his hands.
Along with the seal of approval, each bag at this moment acquires an important quality: monetary value. The not-for-profit Blood Centers of the Pacific does, after all, have to survive financially. In the Bay Area this translates into a unit of fresh frozen plasma selling for $70; red cells for $180; and platelets for $600. (The national average price tags are roughly 20 percent lower, Richard noted.) Yearly, the center sells to forty local hospitals approximately 125,000 units of red cells, 50,000 of plasma, and 15,000 of platelets. The organization wholesales an additional 75,000 units of plasma to pharmaceutical companies for further processing, such as the making of factor VIII concentrate. (Only a small percentage of the center’s total output is whole blood, a fact I found surprising. TV medical dramas, as it turns out, vastly overplay the call for whole-blood transfusions.) At any given time about 10,000 units of special red cells remain here on the premises, 99 percent of which are kept frozen in long-term storage. In this capacity, the bank is most bank-like. Some of this store is autologous blood—donated and reserved for an individual’s own future use, such as for an upcoming surgery—but most of it is blood of the rarest types, the Château Lafittes of the blood world. To keep these red cells viable for as long as possible, each unit is infused with a preservative, Richard explained, “not unlike the antifreeze