(EP162) 간이식 후 평생 먹는 면역억제제의 종류와 부작용 총정리 feat.거부반응 | 서울대병원 간담췌외과 이광웅 교수, 김민섭 전임의

Main Ideas & Lessons

• Why rejection happens

  • The immune system attacks foreign material entering the body.
  • After a liver transplant, rejection is driven primarily by immune cells, especially T cells.
  • B cells mainly produce antibodies, so their role is comparatively less central in T-cell–mediated rejection.

• What immunosuppressants do

  • Immunosuppressants inhibit T-cell activity to prevent the immune system from attacking the transplanted liver.
  • B-cell (antibody) function is relatively preserved, because the goal is specifically to suppress T-cell–mediated rejection.

• Typical dosing/intensity pattern over time

  • Immunosuppression is strongest immediately after dosing, then is gradually reduced.
  • The talk uses an FK (tacrolimus) blood level as the main measurable indicator (including examples of target ranges).
  • Core concept: use higher early suppression to prevent rejection, then lower later to reduce long-term side effects.

• Combination (“principle of immunosuppression”)

  • Instead of relying on one extremely strong drug, the approach is to use ~4 drug types initially to avoid unacceptable side effects.
  • Later, the regimen is typically reduced to 2 or even 1 drug for maintenance.

• Main immunosuppressant types mentioned (and their roles)

  • Tacrolimus (FK): described as the most important backbone drug
    • A historical name/version is contrasted with a newer equivalent, stated as fully replaced.
    • Practical theme: start at an adequate level, then taper without fully stopping.
  • MMF (Mycophenolate mofetil) (“MMF” as shown in subtitles)
    • Supports immunosuppression, often at higher early doses.
    • Side effects can include lowering white blood cells, leading to complications; dosage may be reduced or stopped.
  • Steroids
    • Strong early dosing with a gradual taper.
    • Given at high doses initially, then reduced to stopping/lower maintenance.
  • CSA (Cyclosporine) (“csa” in subtitles)
    • Mentioned as an additional component in the combination strategy.
  • Certican (Everolimus)
    • Mentioned as an immunosuppressant with anticancer effects.
    • Used selectively for patients at higher risk of hepatocellular carcinoma recurrence, or when other cancers develop (e.g., stomach, skin, lung).
    • Side effects can include wound loosening / ventral hernia risk; not used for all patients.
    • Dosing differs by constitution/region; subtitles state Koreans often need higher doses to achieve comparable blood concentrations.

• How strength is measured (and why dose isn’t the same for everyone)

  • The video emphasizes that blood levels (FK levels) determine immunosuppression strength, not just the pill dose.
  • Example described:
    • If one patient has an FK concentration of 6 and later reaches 8.8 after taking the same dose, 8.8 is ~30–40% stronger than 6 (as described).

• Target ranges (conceptual targets mentioned)

  • About ~8 during the first month
  • ~6–8 up to ~3 months
  • ~5–6 after ~3 months
  • Often ~4–5 after ~1 year

• Why you shouldn’t keep immunosuppression “too high”

  • Higher-than-necessary levels increase risk of:
    • Infections
    • Kidney/organ or heart function decline (subtitles mention heart function decline)
    • Diabetes
    • Hair loss
    • Elevated potassium (subtitles wording unclear, described as “potassium dextrin levels”)
    • Seizures
  • Core rule: maintain the minimum effective concentration that prevents rejection, using the lowest effective immunosuppressant amount.

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Medication Adherence & Causes of Rejection (“What Leads to Rejection”)

Two broad reasons rejection occurs

1. Rejection even when medication is taken properly

   • The minimum protective level may not be reached.
   • Effective level can be affected by food/drug interactions, which can cause major fluctuations, destabilizing immunosuppression:
     • Grapefruit
     • Antifungal agents
     • Tuberculosis medications

2. Medication nonadherence (more common)

   • Examples mentioned:
     • Not taking meds at all (subtitles emphasize alcohol use disorder often correlates with skipping meds)
     • Interruptions, such as running out for about a week, or skipping for 3 days, then taking “whenever remembered”
   • Consequences timeline described:
     • At first, it may seem “fine,” but later rejection intensifies.
     • Possible signs:
       • Jaundice
       • Itching
       • Worsening lab results (subtitles mention “GLT” rising; wording uncertain)

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Symptoms to Watch & When to Go to the Hospital

• Key symptoms mentioned
  • Itching
    • Can occur due to bile duct problems and also due to rejection.
  • Jaundice
    • Suggested as a more advanced sign.
    • Subtitles state jaundice can result from:
      • ~70% bile duct issues
      • ~30% rejection reactions
  • Itching + jaundice together
    • If a patient is taking immunosuppressants consistently and suddenly develops both itching and jaundice, the likelihood of rejection is described as high → go to the hospital immediately.

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Hospital Workup & Treatment Once Rejection is Suspected (Step-by-Step)

Step 1: Diagnose the cause (don’t assume it’s rejection)

• Because itching and mild jaundice can come from bile duct strictures, doctors first evaluate bile ducts and rule out other causes.

Step 2: Imaging first

• CT scan to check whether the bile duct is dilated.

Step 3: Decide on procedure vs biopsy

• If bile duct findings aren’t clearly consistent and there are no definitive visible bile duct problems, and adherence is reported, doctors may:
  • Perform a biopsy to confirm whether it is truly rejection.

Step 4: Treatment if rejection is confirmed

• Steroid therapy
  • 500 mg steroid (subtitles refer to “Solo Medley”) at the highest transplant-time dose level
  • Given for 3 days
• Goal: reverse rejection and restore liver function.

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Likelihood of Recovery & Risk of Repeat Rejection

• Most patients recover if treated early
  • Subtitles state ~8 out of 10 recover.
• Steroid failure can occur
  • For the subset where steroids don’t work:
    • Steroids may be tried again, but success drops to less than 50%.
• If the liver recovers, it can return near baseline
  • Even after damage from rejection, liver function may rebound if recovery is successful.
• Repeated rejection episodes reduce recovery potential
  • If rejection recurs (example given: drinking again + skipping meds):
    • Recovery becomes progressively harder.
    • By 2–3 recurrences, the liver may develop fibrosis or cirrhosis-related scarring (subtitles mention “melanosis,” wording unclear).

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Sources / Speakers Featured

• Professor Lee Kang-hoon — Seoul National University Hospital, Department of Hepato-Patient Remission (as stated in subtitles)
• (Second guest/context name in video title) Kim Min-seop — Formerly (전임의) (speaker not clearly identified in subtitles beyond the title)