Autoimmune Hepatitis: Diagnosis, Steroids, and Azathioprine Explained

Autoimmune hepatitis isn't something you catch from someone else. It’s not caused by alcohol, viruses, or poor diet. It happens when your immune system-designed to protect you-turns on your own liver. This rare but serious condition causes chronic inflammation that, if left untreated, can lead to scarring, liver failure, or even the need for a transplant. The good news? We know how to treat it. And for most people, the right combination of medications can stop the damage and even reverse it.

How Do Doctors Diagnose Autoimmune Hepatitis?

There’s no single blood test that says, "Yes, you have autoimmune hepatitis." Instead, doctors put together pieces of a puzzle: symptoms, blood work, imaging, and a liver biopsy. Many people don’t feel sick at first. Some notice fatigue or joint pain. Others get jaundice-yellow skin or eyes-or have unexplained abdominal swelling. But often, it’s found by accident during routine blood work when ALT and AST liver enzymes are way above normal-sometimes five to ten times higher than they should be.

Blood tests look for two key markers: high levels of immunoglobulin G (IgG), and specific autoantibodies. The most common are antinuclear antibodies (ANA) and smooth muscle antibodies (SMA). These are found in about 80% of cases, called Type 1 AIH. A smaller group has LKM1 antibodies, known as Type 2, which is more common in children. But here’s the big update from the 2025 European Association for the Study of the Liver guidelines: these antibody types don’t change how you’re treated. Doctors used to split patients into groups based on them. Now, they don’t bother. The treatment is the same regardless.

The real gold standard for diagnosis is a liver biopsy. A thin needle, guided by ultrasound, takes a tiny sample of liver tissue. Under the microscope, pathologists look for something called interface hepatitis-where immune cells attack the border between liver tissue and blood vessels. If this pattern shows up in at least 20 portal tracts, and other causes like hepatitis B or C are ruled out, the diagnosis is clear. A scoring system called the Revised IAIHG helps confirm it. A score above 15 means probable AIH. Above 20? Definite.

Why Steroids Are the First Line of Defense

Once diagnosed, treatment starts fast. The goal isn’t just to lower enzyme levels-it’s to stop the immune system from destroying your liver. That’s where steroids come in. Prednisone (or its active form, prednisolone) is the go-to drug. It’s powerful, fast-acting, and suppresses the immune response almost immediately.

Most patients start with 0.5 to 1 mg per kilogram of body weight daily-up to 60 mg a day. Within two weeks, you’ll often see ALT and AST levels drop by half. That’s a strong clue the diagnosis is right. But steroids come with a price. Weight gain, moon face, mood swings, insomnia, high blood sugar, and bone thinning are common. About 70% of people on steroid-only treatment develop side effects within a year.

That’s why steroids are never used alone for long. They’re paired with azathioprine.

Azathioprine: The Steroid-Sparing Partner

Azathioprine (brand name Imuran, or generic azathioprine) is an immunosuppressant that’s been used since the 1970s. It doesn’t work fast. It takes weeks to months to kick in. But it’s the key to reducing steroid doses. When used together, azathioprine allows doctors to cut prednisone by 70-80% within six months. That slashes side effects from 70% down to about 30%.

The typical starting dose is 50 mg a day, then increased to 1-2 mg per kg daily (up to 150 mg). But here’s the critical step: before you even start azathioprine, you need a TPMT enzyme test. About 0.3% of people have a genetic variation that makes them unable to break down the drug. For them, azathioprine can cause life-threatening drops in white blood cells. Testing for this costs $250-$400 in the U.S., and while 89% of academic centers do it now, only 45% of community clinics still skip it. Don’t let that happen to you.

Side effects of azathioprine include nausea, fatigue, and occasional pancreatitis. About 12% of patients develop low blood counts. Regular blood tests every 2-4 weeks in the first few months catch these early.

How Long Do You Need to Take These Drugs?

This is the question most patients ask: "Will I be on this forever?" The answer is: probably.

Complete biochemical response-meaning normal ALT, AST, and IgG levels-takes 18 to 24 months. But that’s just the start. The real goal is histological remission: no more liver inflammation seen on biopsy. That happens in 50-70% of people after two to three years of treatment.

Some patients try to stop meds after remission. But here’s the hard truth: 50-90% relapse within a year of stopping. That’s why 60-80% of people stay on low-dose maintenance therapy long-term. If you do try to stop, it has to be slow-over six to twelve months-with monthly blood tests. Most relapses happen in the first three months after stopping.

What If the First Treatment Doesn’t Work?

About 10-15% of people don’t respond well after 12-18 months. That’s called treatment failure. It doesn’t mean you’re out of options. Mycophenolate mofetil (CellCept) is now the most common second-line drug. It’s taken twice daily and works well for people who can’t tolerate azathioprine. Calcineurin inhibitors like tacrolimus are another option.

New drugs are coming fast. JAK inhibitors like tofacitinib showed 55% response in early trials. Monoclonal antibodies targeting interleukin-6 are in phase 2 testing. And obeticholic acid, already approved for other liver diseases, got FDA breakthrough status in 2024 for AIH. Early results show it outperforms standard therapy.

What You Need to Do Before and During Treatment

Before starting any immunosuppressant, you must be tested for hepatitis B. About 15-20% of people carry the virus silently. If you start steroids or azathioprine without treating it, your hepatitis B can flare up dangerously. If you’re positive, you’ll need antivirals like tenofovir before starting AIH treatment.

You should also get vaccinated for hepatitis A and B-before you start immunosuppression. Once you’re on these drugs, vaccines don’t work as well. You’ll only get 40-60% protection instead of the 90% healthy people get.

Monitoring is non-negotiable. Blood tests every 2-4 weeks at first. Then every 3 months. Liver biopsies are recommended after 18-24 months to check for true remission. And don’t ignore your mental health. Studies show 47% of patients on steroids report mood changes. Support groups, like those run by the American Liver Foundation, help more than you’d think.

Real Stories, Real Outcomes

One Reddit user, "HepBWarrior87," described gaining 30 pounds of fluid in three weeks and feeling like a stranger in the mirror. Another, "AutoimmuneFighter," had pancreatitis from azathioprine and switched to mycophenolate-only to see liver enzymes finally stabilize after 18 months.

But there’s hope. "LiverSurvivor99" on HealthUnlocked shared that after two years on low-dose steroids and azathioprine, a repeat biopsy showed her liver fibrosis had reversed from stage F3 to F0-no scarring left. That’s not rare. The National Institute of Diabetes and Digestive and Kidney Diseases confirms: treatment can reverse liver damage.

The Bottom Line

Autoimmune hepatitis is serious, but it’s manageable. Diagnosis takes time, but it’s precise. Treatment with steroids and azathioprine works for most people. Side effects are real, but they’re manageable with the right monitoring. And for many, the goal isn’t just survival-it’s healing. With consistent care, your liver can recover. The key is starting early, sticking with the plan, and never skipping follow-ups.