Allogeneic bone marrow transplantation is one of the important means to treat certain types of leukemia. This treatment process mainly uses bone marrow mobilizers to promote the donor's hematopoietic stem cells into the bloodstream. Approximately 10ml of hematopoietic stem cell solution is then extracted through blood collection and centrifuge separation, which is less than normal blood donation, and then injected into the recipient's body through an intravenous injection. And this hematopoietic stem cell solution is actually a blood product. And blood products, of course, have the potential to transmit various diseases.

"As a general rule......," Dr. Pascal thought for a long time, frowning. "Bone marrow transplantation should be non-contagious. ”

A general allogeneic bone marrow transplant generally occurs in relatives of the recipient. And most of them are immediate family members. Some patients who are not very lucky may not be able to match with relatives. At this time, hematopoietic stem cell donation is needed to treat the disease. Bone marrow mobilizers require a minimum of four days of continuous injections. From the moment the donor is confirmed, he or she undergoes a considerable number of disease tests to ensure that the hematopoietic stem cells he donates do not cause disease transmission. Moreover, even if there is a newly infected disease, the donor will show some clues during the four-day mobilization injection.

"What about the general principle?" Sun Lien also knows that the pre-donation inspection is very important and very strict. But that doesn't mean there won't be some non-human oversights – after all, the unexpected is the unexpected.

"Could there be some pathogen transmission from an unconventional test item?" said Dr. Pascal, who wasn't so sure. He just relied on his own research experience and research direction, and probably made a guess. "There may be some viruses that have no specific antibodies and no specific symptoms, right?"

Sun Lien rolled his eyes, there were no specific antibodies, and there were no specific symptoms. If there is such an infectious disease, and it can be behaving like Yang Jianqiang, then all doctors and medical scientists can wash their necks and wait for death - how excited doctors are when they encounter rare cases, just look at the medical records and reports in the journals published every month.

However, there really is nothing wrong with Dr. Pascal's reasoning. In the absence of specific antibodies, it is possible to bypass pre-donation testing. Without specific manifestations, it is possible for both the donor and the physician to ignore the manifestations. If Lin Jianqiang's current cause comes from donated bone marrow, then only pathogens that meet both conditions can do it.

"The MRI results are in. The two of them were staring at the door, and Liu Pingchuan walked out of the room with the newly released MRI images, his brows furrowed deeply, and some of his gray eyebrows were furrowed in the middle. "Xiao Sun, come and see this. ”

The eight areas of edema were evident on MRI, but the most striking was the area of edema near the basal layer, which looked a little blurry, but it was indeed an almost circular gray spot.

"MRS showed an increase in Cho metabolic levels and a decrease in NAA metabolic levels. Liu Pingchuan estimated that Sun Lien could only watch the excitement, but he couldn't see the specific doorway. He explained, "Cho represents the degradation product of myelin, which is related to maintaining the integrity of myelination. The decrease in NAA metabolism indicates damage to brain cells. ”

"From early to now, there has been such a big change...... Sun Lien asked with a frown, "Could it be herpes simplex encephalitis?"

Herpes simplex encephalitis is a relatively common type of viral encephalitis, and its biggest feature is its rapid progression. But this conjecture was denied by Dr. Pascal, "Herpes simplex encephalitis is the first temporal lobe, and this patient is multiple. There were no signs of gyrus edema. ”

"What about cryptococcal infections?" asked Dr. Pascal, after a moment of silence, "the onset of this infection is insidious......

"There are no soap bubble cysts. Liu Pingchuan also joined the discussion. "And cryptococcus isn't invisible – the morning test doesn't change so quickly. ”

"So, there are three things that we need to figure out now. Sun Lien made a statement and concluded, "First of all, why does the disease progress so quickly. Second, what is the cause of his present symptoms. Third, whether the damage to brain cells and multiple edema are direct manifestations of his disease. ”

Pascal nodded thoughtfully. The first two questions raised by Sun Lien are very simple and straightforward, while the third question has some deep meaning. If we think blindly in terms of infectious diseases, it is possible to misdiagnose some autoimmune diseases with less obvious characteristics as infectious diseases. This possibility also needs to be taken into account, given that the patient's condition changes after adjustment of the immunosuppressive regimen.

"Start with mannitol and lower the brain pressure. Sun Lien shook his head. He originally thought that this imaging examination could provide some direct clues to assist in the diagnosis, but he did not expect that after going around in a circle, the diagnostic idea returned to the original point.

Today's plan...... The patient's condition can only be stabilized first. Sun Lien looked at Yang Jianqiang, who was pushed back to the emergency department, and suddenly felt a little irritable in his heart.

That's all there is to being a doctor. The salary is not high, and I am tired to death. Being misunderstood and wronged by patients is commonplace. And what makes doctors feel that their work is meaningful...... In fact, it is to diagnose the incurable diseases in the patient and cure the fatal diseases.

Saved a life, and then gained self-satisfaction. This is the main motivation that supports the tiring work of most doctors every day.

And now...... It seems that this motivation has become more difficult to obtain. Sun Lien was not only a little irritable, but even a little angry.

"What's next?" After a moment of calm, Sun Lien turned to Dr. Pascal and asked, "Do you have any suggestions?"

"I think ......," Dr. Pascal thought for a moment and offered his own idea, "let's do a PCR test of blood and cerebrospinal fluid." ”

"What project are you looking for?" asked Sun Lien with a frown. PCR testing is generally used to verify pathogen conjecture. Conducting a PCR test without even a reliable conjecture is purely a provocative means of preparing to find fault with the laboratory department.

"Let's start by checking out the infections that are more common after bone marrow transplantation. Dr. Pascal spread his hands, "The parasites that cause central nervous system symptoms are, strongyloidiasis fecal, toxoplasmosis. As for the virus, VZV (herpes zoster virus) we have just ruled out. The course of EBV (Epstein-Barr virus) is also not so fast. JCpolyomavirus (JC polyomavirus) is currently looking the most likely. ”

"Progressive multifocal leukoencephalopathy?" Liu Pingchuan understood the direction of Dr. Pascal's conjecture. "It's a rare disease. ”

"But it is possible to change the metabolites on Cho, and it is also subacute onset. Dr. Pascal seemed confident in this speculation. But then his slightly excited expression cooled down again, "But...... The prognosis for this disease is not very good. ”

It's not just not good, it's just bad. Until now, there is no effective treatment for progressive multifocal leukoencephalopathy caused by JC polyomavirus. Ordinary antiviral therapy is very ineffective against JC polyomavirus, and the only way to improve symptoms is to strengthen immunity.

For Yang Jianqiang, if he is really infected with JC polyomavirus, it is basically equivalent to a death sentence. Boost immunity, it will trigger an inflammatory storm, and then he will die. If immunity is not enhanced, the JC polyoma virus will continue to develop, and more and more white matter will be damaged, and he will still die.

"This ......" Sun Lien held his breath in his chest, he really didn't expect this to be the result. After holding it for a long time, he sighed and proposed, "Let's check them all." I hope it's not JC. ”

Liu Pingchuan wanted to go to the rescue room to talk to Zhou Jun, and the matter of explaining the patient's situation to Zhou Jun was naturally taken over by Vice President Liu. Dr. Pascal returned to the clinic with a melancholy expression. Sun Lien stood alone at the door of the imaging department, holding his hands on his chest and pondering.

Dr. Pascal's diagnosis was clear, and he narrowed his initial suspicions to two parasites and a virus. Experienced veteran doctors are indeed much stronger than stunned young people like Sun Lien. But stunned Qing vaguely felt that there was something wrong in the narrative just now.

According to Dr. Pascal, the JC polyomavirus mainly affects the brain, but the onset is mostly chronic or acute. If Yang Jianqiang's onset time is calculated from the beginning of blurred vision, there is no problem with subacute onset. Imaging tests proved that Yang Jianqiang's condition only began to accelerate suddenly. If we speculate according to this logic, the diagnosis of JC polyomavirus seems somewhat untenable.

Also, the imaging features do not seem to match. Sun Lien thought of the imaging test results he had just seen. The location of the eight edematous areas is relatively scattered. But most of them are at the junction of gray matter and white matter. Since the disease caused by JC polyomavirus is called "progressive multifocal leukoencephalopathy", it is thought that the main site of involvement should be the white matter of the brain, not the junction area.

But if it's not JC...... Sun Lien's eyes widened suddenly.

"Before I knew each other...... Lao Yang should have had a dog. "He said his grandmother used to have a white cat. A big white cat with blue eyes, very beautiful. It's just that it was almost 30 years ago. ”

The patient has a history of close contact with cats and dogs! He was suddenly full of gratitude for his trip to the capital. If it weren't for the level of case writing of Tongxie, he would definitely not have discovered the connection so easily. Only by recording all the information in detail can it be possible to find the basis and answer for the diagnosis from it!

Sun Lien's diagnosis was that Yang Jianqiang had cerebral toxoplasmosis. But his toxoplasmosis did not come from bone marrow donation, but eggs that had been latent in his body for a long time. He is a recessive patient with toxoplasmosis!8)