Chapter 195

Episode 195 Me? I’m a Detective (3)

"Get a brain MRI?"

With my brow furrowed deeply, I updated the comments.

Korean Slave 1: I’m talking to the pediatric hem-onc professor right now, and they’re planning to start the HLH protocol using Etoposide.

Not even a second passed before comments screaming in panic began flooding the window.

Pediatric Ghost 77: FUCK NO!!!!!! NO!!!!! Block it no matter what!!!!!!

Pediatric Ghost 77: If you give that, the kid will literally die!!! Tell them to cancel the meds right now!!!

They're reacting this violently?

A sudden chill ran down my spine. Etoposide is a powerful cytotoxic chemotherapy drug. If this drug were pumped into the veins of a six-year-old child under a mistaken diagnosis, it would completely obliterate an already shattered immune system, crossing a point of no return.

Korean Slave 1: What is it? Give me some explanation. Why the hell can't we use it? I need to know the reason to stop them.

Pediatric Ghost 77: It looks like DADA2, so tell them to stop!!!!!!

"..."

A giant question mark floated in my head.

What?!?!

DADA2?!?!?!

What the hell is that? DADA Two? DADA I? Is it the name of some new idol group?

Through six years of medical school, one year of internship, and rolling through three years as an emergency medicine resident, it was a combination of letters and numbers I had never heard even once.

Korean Slave 1: What is that?

Rheumatology Old Woman: It’s a rare disease, my little quack. Adenosine Deaminase 2 Deficiency is the full name. It’s a very nasty vasculitis caused by a genetic mutation. You need to give a TNF-alpha inhibitor. If you give Etoposide, the bone marrow will completely melt and the kid will die.

A rare genetic disease?

Thanks to the Rheumatology Old Woman's kind explanation, a cold sweat rolled down my forehead. Even for university hospital professors, it isn't easy to instantly think of such an ultra-rare genetic disease based solely on unexplained inflammatory markers and MAS findings. That’s why everyone was racking their brains and ultimately trying to go with the standard HLH chemotherapy protocol.

However, the Pediatric Ghost 77's god-tier reasoning was only just beginning.

Pediatric Ghost 77: Think about it, you idiot! Look at the chart from earlier—pneumonia two years ago! You probably thought it was just a passing cold, but that's evidence of an immunodeficiency!

Pediatric Ghost 77: And the gallbladder is swollen, but the culture is normal. Why would a gallbladder rot when there are no bacteria? Yet, the high fever and CRP are spiking like crazy.

Pediatric Ghost 77: If so, it means the microvessels supplying blood to the gallbladder got blocked, causing ischemic necrosis! Because of vasculitis!

The ghost's typing speed was getting faster and faster. The patient's symptoms, which had been fragmented throughout the printout sheet, were coming together to form one massive diagnosis inside the Pediatric Ghost's head.

Pediatric Ghost 77: And there’s a quack here who suspects the pancytopenia is cancer.

Hematoma is Hell: Hey, you bastard. Why the hell are you talking like that?

Pediatric Ghost 77: (Ignoring emoticon) The autoimmune panels like ANA, RF, ANCA, and Lupus Anticoagulant all came back normal, yet MAS and immunodeficiency hit at the same time. On top of that, there are vasculitis symptoms on the legs. Do you think all of this is just cancer happening to overlap by coincidence? What else could it be!

Possessed, I left a comment.

Korean Slave 1: Um... a rare disease?

Pediatric Ghost 77: Yes, you shit!!! Thrombotic cutaneous vasculitis + young child + purple mottling + cytopenia/MAS + immunodeficiency!!! The intersection of all these crazy symptoms is exactly = DADA2!!!!!

To think someone who claimed to be stuck in a neonatal intensive care unit knew the mechanism of such a crazy, ultra-rare disease perfectly.

Pediatric Ghost 77: (Picture)

With that, the Pediatric Ghost sent a picture explaining the mechanism in detail.

Ah, the reason they told me to get an MRI earlier was because if it's a vasculitis like DADA2, it can be accompanied by multiple cerebral microinfarctions, and they wanted to check for that.

"Phew."

Letting out a deep sigh, I brushed my hand against the void to turn off the floating gallery window.

To be completely honest? I didn't fully understand it. Why a deficiency in adenosine deaminase or whatever makes macrophages go wild and causes vasculitis—my brain couldn't completely follow the molecular biological mechanism. I was just a resident whose job was to hold onto a patient's life in the ER and send them off to the corresponding department.

But that kind of stuff didn't matter. What mattered was that the ghost's words were the absolute truth, and the fact was that the moment the chemotherapy drug entered the child's body right now, everything would be over.

So, let's do what I'm an expert at.

Leave the difficult paper analysis to those genius ghosts. I just need to do what I do best.

Stirring up trouble. Act like the mad dog of the emergency room, flipping the table and slamming on the brakes first.

Son Jong-un had just finished his phone call with Professor Jeong Yu-jin and was about to click on Etoposide after searching for it in the prescription window. I turned toward Son Jong-un, who was about to order the medication.

"Jong-un! Don't bring out the chemo drug!!! Stop!!"

At that bombshell shout, not only Son Jong-un, who was holding the mouse, but also the residents looking at charts and the ward nurses guarding the station—everyone turned their heads to look at me simultaneously, as if by design.

A brief silence fell over the room. Son Jong-un rolled his neck to stretch, then immediately began to manage the situation again.

"Hyo-eun, keep doing what you were doing. Stabilize Do-yoon as much as possible for now and get him ready so we can transfer him to the PICU right away."

"Yes! Understood!"

Kim Hyo-eun gave a short nod, hurriedly packed the supplies needed for treatment, and ran toward the patient's room.

"Right... sigh."

Son Jong-un wiped his face with both hands and let out a deep sigh.

"Shit. I feel like a crazy bastard, but let's at least hear your reason. At least you're my peer and my friend. Even if it's crazy talk, I'll listen."

It was the voice of a doctor who had cast aside everything—whether it was pediatrics or emergency medicine—and purely wanted to save the patient.

I pointed my finger at Do-yoon's disastrous lab values displayed on the monitor and began to speak.

"This is MAS."

"I know. That's why I'm trying to use Etoposide right now. To stop him from dying of multiple organ failure." Son Jong-un replied, sounding frustrated.

"But there’s a different underlying cause."

Son Jong-un tilted his head at my words.

"This isn't MAS triggered by Kawasaki disease or a typical rheumatologic condition. But if that cause is right... if this deduction is correct..."

"If it's correct?" Son Jong-un swallowed hard.

"The moment you use Etoposide, Do-yoon dies."

At my words, what little color was left in Son Jong-un's face completely vanished. I caught a glimpse of Kim Hyo-eun and the nurses hurriedly heading toward the patient's room with IV fluids and medications, and I continued speaking.

"Let's get a brain MRI first."

"What?"

"As soon as Do-yoon stabilizes even a little, let's push him into the imaging room as an emergency and just take a 30-minute scan."

A deep frown etched into Son Jong-un's brow.

"An MRI? The brain? All of a sudden? The brain?"

In this situation where systemic inflammation, blood vessels, and liver enzymes were exploding, to suddenly take a picture of his head—from the perspective of the pediatrics chief, it couldn't help but sound completely out of left field.

"Because..."

It was right when I was about to voice the flawless logic the ghosts had pointed out.

"That's an interesting story."

A cool, sharp female voice.

The door inside the station burst open, and a young professor revealed herself.

Assistant Professor Jeong Yu-jin from the Department of Pediatric Hematology-Oncology. She was one of the children's hospital professors in charge of pediatric cancer and blood diseases, the one who had just approved the Etoposide prescription over the phone with Son Jong-un.

"Ah, Professor. Hello."

Startled, Son Jong-un jumped out of his seat and bowed.

At the same time, I cursed Son Jong-un with my mouth.

Did that door connect to the professor's office? Shit.

Son Jong-un also contorted his facial muscles to mouth back, looking wronged.

I obviously thought you knew!

What the hell. Without knowing the professor was listening to everything from behind, I had been shouting about how the kid would die if they used the chemo drug.

"Ahem."

Professor Jeong Yu-jin cleared her throat lightly as she walked up to us.

"Ah, yes. Professor. To explain..."

Son Jong-un hurriedly tried to fix the situation, but Jeong Yu-jin raised her hand to lightly cut him off.

"Before that, who are you?"

At that cold question, I swallowed my spit and answered as politely as possible.

"I am Han Hyeonjae, a 3rd-year resident in Emergency Medicine."

"..."

I could see Jeong Yu-jin's expression souring in real-time.

Absurdity, disbelief, and anger. A resident from another department—and an emergency medicine resident at that, whose job is to just stabilize initial vitals and dump the patient upstairs—had just thrown a wrench into her final order as a pediatric hem-onc professor and shouted for them to stop?

"Uh, Professor! I mean, Hyeonjae here is a bit unique! No, it's not that, but last time, Professor Hwang Jun from Neonatology...!" Son Jong-un turned pale and began rambling nonsense.

"Son Jong-un. Get a hold of yourself!"

Jeong Yu-jin's fierce reprimand froze the station.

"You're the head of the doctor's office! Do you not know what the ferritin levels are right now? The child is melting away, and you're bringing in a resident from another department to chat and block a prescription?!"

"Professor."

Before Son Jong-un could get chewed out any further, and before more time was wasted, I took a step forward.

"If Etoposide goes in now, the patient will die. Please, just listen to me once."

At my bold shout, Jeong Yu-jin glared at me as if she couldn't believe my audacity. Her expression looked like she wanted to call security to drag me out this instant, but my overly confident gaze made her hesitate for a moment.

"Sigh..."

She checked her wristwatch checked aggressively.

"Five minutes. Finish it within five minutes."

Summoning all the knowledge from the Pediatric Ghost and the Rheumatology Old Woman inside my head, I opened my mouth.

"The child is currently in an immunodeficient state. If you use Etoposide, a cytotoxic chemotherapy drug, on top of that, even a single mold spore floating in the air entering his lungs will lead to systemic sepsis—"

"I know. I know, but..." Jeong Yu-jin began to counter. "It's better than dying from multiple organ failure. If we leave him like this, he'll die within a day or two. It's a 100 percent chance of death versus a 50 percent chance of sepsis."

But that wasn't the only card I held.

"That's not all. The disease I suspect is one that targets the endothelial cells of the blood vessels. In this case, if Etoposide goes in, the platelet count will plummet due to bone marrow suppression, causing the risk of cerebral hemorrhage to skyrocket beyond control."

At the words that left my mouth, Jeong Yu-jin's pupils trembled minutely. She was a doctor too. There was no way she didn't know what kind of catastrophe would occur if you stripped away platelets from a patient whose blood vessels were already ruined.

However, before that, the premise itself that the vessel walls were damaged had to be established.

"...So what do you suspect?"

The question finally came out. I took a deep breath and spat out the damn disease name the Pediatric Ghost had told me.

"Yes. The fundamental cause of Do-yoon's MAS flare-up is DADA2."

"DADA2?"

A look of unfamiliarity briefly flashed across Jeong Yu-jin's face, before her expression stiffened as if she recalled something. On the other hand, Son Jong-un, who was standing next to me, was staring at me with a look that screamed, What the fuck kind of disease is that?

Deliberately ignoring Son Jong-un's expression, I continued.

"First, think about a simple case of MAS triggered by a typical viral infection or Kawasaki disease. In that case, how do the cutaneous manifestations of vasculitis present?"

"Petechiae or systemic erythema appear."

"Exactly. However, Do-yoon showed livedo reticularis, which is a mottled purplish discoloration." I emphasized the 'Skin' section written on the progress printout sheet. "This is a finding that microvessels are being blocked by thrombi, not just simple inflammation. If it's DADA2, where there is a genetic deficiency in Adenosine Deaminase 2 which protects the vascular endothelial cells, this unique skin lesion is perfectly explained."

"But you can't overturn a diagnosis based on livedo reticularis alone—"

"It might not be convincing enough. That's why there's a second reason." I naturally packaged the ghost's knowledge as if it were my own and threw it out. "In typical MAS patients—meaning when macrophages are activated—immunoglobulin levels are normal or even elevated because the immune system is hyper-excited."

I pointed to Heo Do-yoon's immune panel numbers that I had checked earlier.

"But Do-yoon is in a significantly low, immunodeficient state. If he is a patient with a congenital immunodeficiency who couldn't make antibodies properly since birth, and if that disease is DADA2, then these abnormal lab values make perfect sense."

"Then the reason we need to get a brain MRI is..."

"If the brain was affected by simple MAS, an MRI would show findings of diffuse edema due to macrophage activation syndrome-induced encephalopathy." I paused to catch my breath. "But if it's DADA2, as per my deduction, the microvessels in the brain will be blocked in multiple areas due to vasculitis, showing a very characteristic finding of lacunar infarction."

"..."

The pediatric hematology-oncology professor, the pediatrics chief, and the emergency medicine resident.

Professor Jeong Yu-jin stared at me blankly, as if she had seen a ghost. It was understandable, considering the pathophysiology and radiological differentiation points of an ultra-rare disease—which she herself might have only glanced at in the corner of a journal—were pouring out of an emergency medicine resident's mouth.

Pitter-patter!

Breaking the silence, Kim Hyo-eun came running breathlessly from the other end of the hallway.

"Dr. Son! After switching the steroid to Dexa, the child's breathing status improved a bit... Oh, Professor Jeong?"

The moment Jeong Yu-jin heard Kim Hyo-eun's report, she turned her head toward her and spoke.

"Let's push him for an emergency MRI right now."

"What?"

Son Jong-un and Kim Hyo-eun questioned back simultaneously.

"Quickly."