Are You Positive?

by Stephen Davis

  Chapter Nineteen

  Court started promptly at ten, but the lawyers had been at the sidebar arguing for about fifteen minutes. Apparently, Armand was objecting to Campbell asking more questions of Dr. Tanner, since he had said the previous day that he had no more questions and closed out his direct examination of the witness.

  “Your Honor, while that’s true, I also did not have all the results back from the defendant’s Western Blot tests, which I want to ask Dr. Tanner about. I can either ask him now, before Mr. Armand cross-examines, or I can ask on re-direct, in which case Mr. Armand will not have the chance to cross-examine Dr. Tanner at all on these results.”

  “And if I object to you bringing these test results up in re-direct, since they were not part of your direct?” Armand argues.

  “Then I will simply ask to recall Dr. Tanner later and go into them at that time,” Campbell replies.

  Armand’s not giving in, just on general principle. “And if I object to recalling this witness?...”

  “Stop it,” the judge interrupts. “That’s enough. We’re not going to waste time on a lot of technicalities. Mr. Armand, I feel confident that Mr. Campbell will find a way to get these test results into the record. I suggest you let him do it now, and then you will have the opportunity to ask Dr. Tanner about them.”

  “But, Your Honor….”

  The judge isn’t interested in any more discussion on the matter. “Objection overruled. Mr. Campbell, you may start off by asking the witness about these test results, but only about these test results and nothing else. You did, in fact, close out your direct yesterday, and I won’t open it back up to just anything. Now, step back, both of you.”

  “Thank you, Your Honor,” both attorneys say in unison. They were trained to do that, whether or not they agreed with the decision.

  Campbell takes his place at the lectern. Both video cameras in the courtroom are operational, and Dr. Tanner’s face appears on the big video screen looking exactly the way it did twenty-four hours ago. “Good morning, Dr. Tanner.”

  Tanner looks at his watch. “Good evening, Mr. Campbell.”

  “Dr. Tanner, did you have time to look over the results I emailed you from the ten different laboratory HIV Western Blot tests for the defendant in this trial?” Campbell holds up the ten lab reports in his hand.

  “Yes, I did, and I have them here.” Tanner holds up his copies in the same fashion.

  “And did you reach any conclusions?”

  “Well, Mr. Campbell, may I remind you that there are five different criteria in the United States that could have been used to interpret the test results. Although a couple of the laboratories specified which criteria they had used, most didn’t. So what I did was to take the actual protein reactive bands from each laboratory and apply all five of the different criteria to them – which means that there were a total of fifty different possible outcomes… five criteria for each of the ten labs. Is that clear?”

  Campbell looks at the jury and is satisfied. “Yes, I think that’s clear.”

  “Okay. So here’s what I came up with. Thirty-one times out of the fifty possibilities, the defendant was confirmed HIV-Positive on this Western Blot. That’s sixty-two percent. The other nineteen times, the defendant is Indeterminate. He is never Negative, because there is at least one protein lighting up in each lab.”

  Campbell writes something down on his legal pad. Of course, he had already done this exercise a number of times last night, so he knew exactly what to expect. Fortunately, Tanner’s results matched his precisely.

  “To say it another way, Dr. Tanner, the defendant would not have tested Positive 38% of the time.”

  “That is correct.”

  “38 percent. That’s kind of a lot, isn’t it?”

  “I would say so, yes.”

  Wonder if I can slip this in? “Dr. Tanner, in your mind, does that create a reasonable doubt that the defendant is actually HIV-Positive?”

  “Objection. This witness is not qualified to make that kind of determination.” The tone of Armand’s voice is getting a lot more angry, and rough, and accusative, Sarah notices. Maybe he isn’t as confident with the way the trial is going now, she thinks. I’d be worried, too, if I were him.

  Campbell, on the other hand, is keeping his composure. “Your Honor, I disagree. This witness is holding in his hands the results of ten HIV Western Blots tests for the defendant. He has been accepted as an expert witness on the Western Blot test itself. Surely that qualifies him to express his opinion on whether those test results constitute a reasonable doubt about the defendant’s HIV-Positive status.”

  The judge deals Armand another blow. “Overruled. The witness may answer the question.”

  Tanner has been waiting patiently, both for the judge’s decision and this particular question. “Do I have a reasonable doubt the defendant is really HIV-Positive? You bet, Mr. Campbell. More than a reasonable doubt, I can assure you. And I should point out that the results submitted by these labs confirm that as well.”

  “Could you explain what you mean by that?”

  Tanner can be seen leafing through the ten sheets of lab results. “I mean the final result sent back by these ten labs is: six Positive, and four Indeterminate. That’s 40% Indeterminate. Yesterday I said 38%, so that’s pretty damn close.”

  That was about as emotional as Campbell had ever heard Tanner, and probably ever would. “Just to be clear, Dr. Tanner, each of these ten labs included their interpretation of the test results, even though most of them didn’t say which set of criteria they were using?”

  “Correct.”

  “And six of them said the result was Positive, and four said it was Indeterminate.”

  “Correct.”

  “So if the defendant’s blood had been sent to one of these labs that found it to be Indeterminate…”

  “…we wouldn’t be sitting here today, Mr. Campbell. Most likely, the defendant would have to take two more Western Blot tests over the next six months, and if both of them came back Indeterminate as well, he would be deemed to be HIV-Negative.”

  “And there would be no murder weapon - HIV.”

  “No, sir.

  Campbell wants this repeated for the jury. “So we are here today simply because one particular set of criteria was used to interpret a Western Blot test that found him Positive, but there was a 40% chance that result would have been different at a different lab. Is that accurate to say?”

  “Entirely accurate, yes. And to save you some time, Mr. Campbell, 40% is much more than a reasonable doubt that the defendant is HIV-Positive.”

  “Objection.” Armand just yells it out from his chair.

  Campbell doesn’t care. “No more questions. Thank you, Dr. Tanner. Mr. Armand, your witness.”

  Armand sits for a minute, clearly trying to regain his composure and decide what tack to take with this witness. Eventually he makes his way to the lectern. “Dr. Tanner, you claimed in your testimony that the Western Blot test would produce a lot of false positives if it was given to someone who had not had an ELISA test. Are you aware that the Western Blot is not supposed to be given to anyone who has not had at least two Positive ELISA tests?”

  “I am aware of that, sir, and I think it’s very clear why not. But I don’t see how that changes the accuracy of the test, other than covering up all those false positives it would produce if it were given by itself.”

  Armand’s frustration makes its way to the surface again. “But you agreed that the Western Blot was designed to confirm two prior Positive ELISAs, did you not?”

  Tanner is too sharp to fall into that trap. “I did not, no sir. In fact, I said it was designed to expose the false positives the ELISAs were producing and not to confirm the positives the ELISAs were getting.”

  “But what’s the difference, Dr. Tanner. In either case, the Western Blot is confirming the ELISA results, whether they were false positives or true positives.”

  “That’s not true, Mr. A
rmand. There’s a big difference. Let me try to explain it to you, since you clearly don’t understand. Imagine if you gave a written math test to a classroom of students, and you thought some of them cheated on it. You could design a couple more questions to give verbally to the students you thought cheated at the end of the test that would clearly demonstrate whether they had the ability to get the kind of grade they did, or proved that they cheated and got a false grade. Anyone who got a high score on the written test but flunked the verbal questions would obviously have cheated.”

  Armand jumps in quickly. “But conversely, anyone who got a high score on the verbal questions as well as the written test would not have cheated.”

  “Not true. It’s entirely possible that some of those who cheated could guess right on the verbal questions and never be detected. So you’re not going to find all the cheaters, but you’ll probably catch a lot of them. On the other hand, if you wanted to confirm all of those who had not cheated, you would design the test very differently.”

  Armand throws his hands up in the air in disgust. “What are we talking about? None of this makes any difference. The Centers for Disease Control and Prevention has clearly stated that anyone who has two Positive ELISA tests and a Positive Western Blot test is HIV-Positive, end of story.”

  But Tanner is not giving in. “It’s not the end of story, Mr. Armand, because there is no scientific basis for them to make that decision.”

  Armand storms over to his table and picks up a piece of paper. Arriving back at the lectern so Tanner could see him, he waves the paper in the air, as if shaking his fist. “Dr. Tanner, you can’t see this, but I will read to you what the CDC actually says. They say, and I quote: ‘the combined accuracy of the ELISA plus either the WB or IFA is greater than 99%.’ This is the premier health organization in the world, not just the United States. Are you suggesting they are lying to everyone?”

  Tanner smiles, which aggravates Armand even more. “I actually called the CDC and asked them what grounds they had to make that statement, and what scientific studies supported their conclusions. They said that it was the result of a book edited by Gerald Schochetman and J. Richard George called AIDS Testing: A Comprehensive Guide to Technical, Medical, Social, Legal, and Management Issues, the second edition, published in November of 2005. So I read that book, and I will repeat that there is no scientific evidence in that book that would allow them to make the statement that the combined accuracy of the ELISA plus either the WB or IFA is greater than 99%. Now, maybe they aren’t intentionally lying to us, Mr. Armand, but what they are saying simply cannot be true, for several reasons.”

  Armand doesn’t know what to do with this. “I’m not going to argue with you, Dr. Tanner. We have the CDC’s statement. I brought forward expert witnesses that said the same thing. We have viral load tests that confirm HIV infection on these people as well. So why should anyone believe you when you say it isn’t true?”

  Campbell is on his feet before Armand can finish. “Objection. Your Honor, once again, neither I nor this witness has mentioned the HIV viral load tests, and Mr. Armand has no basis in my direct to include those in his cross-examination. In addition, the CDC has not included the viral load test as a confirmation test for HIV infection in the statement Mr. Armand is referring to.”

  The judge agrees. “Mr. Armand, leave out the viral load tests and focus on the ELISA and Western Blot tests.”

  Armand is beside himself. “Your Honor, this is outrageous. Mr. Campbell brings in one emergency room doctor from halfway around the world – one out of hundreds of thousands of highly respected doctors and scientists and researchers who can’t all be out of their minds – and just because he says the CDC is wrong, we’re supposed to believe him?” Armand stares at the judge for a minute, but gets no response. Finally, he gives up. “I have no further questions of this witness.”

  Everyone can see the judge’s eyebrows go up, but his voice remains steady. “Re-direct, Mr. Campbell?”

  “Absolutely, Your Honor.” Campbell rises and makes his way back to the lectern. “Dr. Tanner, you said that the CDC’s statement that the combined accuracy of the ELISA plus either the WB or IFA is greater than 99% is not accurate for several reasons. What are they?”

  Tanner visibly relaxes now that Campbell is asking the questions again. “Well, first and foremost, there are no scientific studies to verify it. The book that they say gives them the proof doesn’t actually prove anything at all; because in order to make that statement, you have to have found actual HIV by culture in 99% of the people who tested Positive after both an ELISA and a Western Blot. That kind of validation study has never been done and is therefore not mentioned in the book; and actual validation is the only way you could make that statement.”

  “What you’re saying is that not only have the ELISA tests and the Western Blot tests not been validated individually, the combined test results have never been validated either, even though they’re claiming they have?”

  “Correct.”

  Tanner knows he’s dealing a heavy blow to the AIDS industry with this testimony, and he seems to be enjoying it immensely. But the best is yet to come. “Secondly, you cannot verify the results of one test with the results of another test, when the two tests are virtually identical. I said yesterday that the only difference between the HIV ELISA test and the HIV Western Blot test was that the proteins in the test kit are in one big soup in the ELISA and separated into ten separate bands in the Western Blot. But both tests still use exactly the same proteins.”

  “And what’s the problem with that?”

  “Think about it. In that example of the math quiz I made up a few minutes ago, it would be like using exactly the same questions for the verbal confirmation test that were asked on the written test. Most cheaters could get them right the second time just a few minutes later, don’t you think?”

  Campbell hopes the jury gets the analogy. “It would stand to reason….”

  Tanner interrupts. “But what won’t stand to reason, to use your words, is using a Western Blot test to confirm a Positive ELISA test. The whole thing is completely illogical. It’s called ‘Begging the Question,” and it…”

  This time it’s Campbell who interrupts. “Dr. Tanner, I’m going to stop you there, because I have another witness who is an expert in logic who is prepared to testify about begging the question.”

  Tanner seems a little disappointed, as if he had looked forward to being the one who delivered the knock-out punch. “Oh, alright.”

  “But I want to get back to the book that supposedly serves as the basis for the CDC’s statement that the combined ELISA and Western Blot tests are 99% accurate. What does it actually say?”

  Tanner holds up the book in range of the video camera so Campbell and the rest of the court can see it on their screen. “I have the book right here, Mr. Campbell, and I’m starting on page 89 where they claim that…” Tanner puts on his glasses and reads, ‘…the licensed tests for HIV antibody are highly sensitive (greater than 99.8 percent) and specific (greater than 99.8 percent).’ Now let’s be clear: they’re talking about the individual ELISA and Western Blot tests at this point – not the combined tests. But my first question would be: How did they arrive at these sensitivity and specificity percentages if they’ve never done validation studies to find actual HIV infection in the people who test Positive, which is the only accepted way I know of to establish true sensitivity and specificity? So I admit I start with some skepticism about the accuracy of their numbers.”

  I wonder whether I’ve opened a can of worms with too much detail. “Can we just take them for their word for now and accept their numbers?”

  Tanner peers into the camera over the glasses he never took off, realizes that, takes them off, and relents. “Okay. I can do that. Although I should tell you that even the CDC, in this book, admits that the ELISA test will produce 335 false positives out of every 1000 positive results on the ELISA test, based on .4 percent of the population bei
ng HIV-Positive.”

  Oh, God. This was a mistake. How do I get out of it now? “Dr. Tanner, maybe we should just focus on how they come up with the statement that the combined HIV tests will be 99% accurate.”

  “Alright. Well, on pages 91 and 92,” and Tanner puts his glasses back on, “there is a complex mathematical formula they use to determine what’s called the Positive Predictive Value of four combined HIV tests.”

  Campbell interrupts. “Four? I thought that only two Positive ELISAs and one Western Blot was required.”

  “That’s true,” Tanner agrees, taking his glasses off again. “But all their calculations are based on three ELISAs and one Western Blot, so right there they’ve got a problem.”

  “Can we overlook that problem as well?” and let’s get to the meat of the matter, please.

  “Well, okay. But please understand that using four tests makes their math even more wrong.”

  Campbell is getting impatient. “So what is wrong with their math?”

  “First of all, it’s math. It’s all theoretical. It’s all on paper with no relevance to reality. You know that you can prove mathematically that two plus two is five, don’t you – on paper, anyway. But in reality, two plus two is four, and we all know that to be true.”

  Campbell looks at the jury and nods his head. “I’m sure we’d all agree with that.”

  “But the biggest problem with their math is that they use a wrong formula to determine the specificity of the combined four tests. Basically, they multiply the four test specificities together, which is not what would happen in real life. Here’s what I mean….”

  Campbell can’t let this go on. It’s way too much. “Dr. Tanner, I don’t think we can go there. I think we’re going to have to settle for your expert opinion about the formula.”

  Tanner seems almost insulted that he was cut off. “Well… my expert opinion is that the formula is wrong and produces an accuracy that cannot be substantiated in either the math or in the real world.”

  Campbell hates to do it, because he knows Tanner has a very good point. But there is no way he is going to risk losing the jury in a bunch of numbers and getting them sidetracked on some complicated technical issues, when the most critical and simple point of all is just waiting to be heard: they can’t use one test to confirm another, even if the math were right! “Thank you, Dr. Tanner. I have no further questions for this witness, Your Honor.”

  The judge wants to give Armand time to settle down; so even though it’s early, he announces, “Court is in recess until two p.m. this afternoon.”