Aplastic Anaemia
Aplastic anaemia is a rare but serious condition in which the bone marrow stops making enough blood cells of any kind. It's not a cancer — but it needs cancer-clinic-level care, and the good news is that today, with the right treatment, most patients do well.
What aplastic anaemia is — in plain words
Despite the name, aplastic anaemia is not just an anaemia. It's a failure of the bone marrow to produce all three blood cell types — red cells, white cells and platelets. This combined deficiency is called pancytopenia. In most adult cases, the cause is the immune system mistakenly attacking and destroying the stem cells from which all blood is made.
The marrow itself, on biopsy, looks strikingly empty — replaced largely by fat. That image, distressing as it sounds, is what gives us the diagnosis and also the route to treatment: if we can stop the immune attack, the few remaining stem cells can recover and refill the marrow.
What causes it
In around 70-80% of adult cases we never identify a specific trigger — this is called idiopathic aplastic anaemia. The rest may follow:
- Certain viral infections — particularly seronegative hepatitis, EBV, parvovirus B19, HIV.
- Certain drugs — chloramphenicol, some anti-thyroid drugs, certain anti-epileptics, gold compounds, NSAIDs (rarely).
- Toxins — benzene, some agricultural chemicals.
- Inherited bone marrow failure syndromes — Fanconi anaemia, dyskeratosis congenita, others — particularly in younger patients.
- Pregnancy — rarely.
How aplastic anaemia presents
The symptoms reflect what's missing from the blood:
- Fatigue, breathlessness, palpitations, pale skin — from severe anaemia.
- Bruising easily, prolonged nosebleeds, gum bleeding, small red skin spots (petechiae), heavy periods — from very low platelets, often the most striking initial feature.
- Mouth ulcers and frequent or severe infections, sometimes with fever — from very low neutrophils.
Unlike leukemia, there's typically no enlarged spleen, no swollen lymph nodes, no abnormal cells circulating. That contrast is a clue.
"When the platelets are 5 and the haemoglobin is 5, it's terrifying for the family. But aplastic anaemia is one of the conditions where modern treatment has changed everything. The job in the first weeks is keeping you safe while the longer-term plan takes hold."
How we diagnose it
- CBC with reticulocyte count — pancytopenia with a low reticulocyte count (the marrow isn't responding).
- Peripheral blood smear — to rule out abnormal cells that would point to leukemia or MDS.
- B12, folate, iron studies, thyroid, liver and kidney function, viral screen — looking for reversible or contributing causes.
- Bone marrow aspirate and biopsy — the definitive test. We expect a strikingly hypocellular marrow (less than 25% cellularity), without abnormal infiltration. What the procedure is like →
- Cytogenetics and flow cytometry — to exclude MDS and detect a paroxysmal nocturnal haemoglobinuria (PNH) clone (commonly coexists).
- Chromosomal fragility testing (for Fanconi anaemia) — particularly in younger patients.
- HLA typing — done early, even before treatment is decided, so transplant can move quickly if needed.
Severity classification
We grade aplastic anaemia by how low the counts are, because severity guides treatment.
Non-severe
Counts low but not in the dangerous range. May be managed with observation and supportive care.
Severe (SAA)
Two of three: neutrophils < 0.5, platelets < 20, reticulocytes < 60 × 10⁹/L, on a hypocellular marrow. Needs urgent definitive treatment.
Very Severe (VSAA)
As above but with neutrophils < 0.2. Highest infection risk; treat urgently.
PNH-overlap
A PNH clone is detected alongside the aplastic anaemia — flagged and monitored over time.
Treatment — two main paths
Allogeneic stem cell transplant
For younger patients (broadly under 40-50) with severe disease and a fully-matched sibling donor, transplant is the first choice. It offers genuine cure — replacing the failed marrow with a healthy donor marrow. Outcomes in this setting are excellent, with long-term survival above 80%.
For patients without a matched sibling, a matched unrelated donor transplant is increasingly considered upfront, particularly in younger patients. Read more about transplant →
Immunosuppressive therapy (IST)
For adults without an immediate transplant option — typically older patients, or those without a suitable donor — the standard treatment is ATG (anti-thymocyte globulin) plus ciclosporin, often now combined with eltrombopag. ATG is a course of intravenous infusions given over four days, in hospital, with careful monitoring; ciclosporin is then continued for many months. Response takes time — three to six months — so the early phase is one of supportive care while the immune system is reset and the marrow recovers.
Roughly two-thirds of patients respond to first-line IST, and the addition of eltrombopag has improved both response rate and depth. Relapses can occur; some patients respond to a second course; others ultimately go to transplant.
Supportive care — what keeps you safe in the meantime
- Red cell transfusions for symptomatic anaemia — typically irradiated, leucodepleted, and CMV-safe if transplant is on the horizon.
- Platelet transfusions for bleeding, or prophylactically when platelets are very low.
- Antibiotic, antifungal and antiviral prophylaxis when neutrophils are severely low.
- Iron chelation for patients receiving repeated red cell transfusions, to prevent iron overload.
- Vaccinations — kept up to date, particularly before transplant.
What outcomes look like — honestly
Aplastic anaemia, untreated, is dangerous. Treated promptly with modern protocols, outcomes are now very good. Sibling-donor transplant in young patients produces long-term survival above 80%. Immunosuppressive therapy with ATG, ciclosporin and eltrombopag produces meaningful responses in around two-thirds of patients, with many achieving normal counts and a normal life. Late events — clonal evolution to MDS, PNH or AML — occur in a minority and are watched for with periodic monitoring.
Daily life during and after treatment
The first months are the hardest — frequent clinic visits, transfusions, infection precautions. As counts recover, life expands again. Patients on long-term ciclosporin need regular blood tests for levels and kidney function. Most patients return to work, school, and family life. We'll plan around critical events together and be honest about what's safe at each stage.
What to bring to your first visit
- Every CBC you've ever had — trends are revealing.
- Any bone marrow report, plus cytogenetics, flow cytometry, viral screen, and PNH testing if done.
- A complete medication list, including any drugs taken in the months before counts dropped.
- Family history — relevant for inherited bone marrow failure syndromes in younger patients.
- A close family member, ideally a potential sibling donor's details if HLA typing is being considered.
A new diagnosis, or unexplained pancytopenia?
Send the reports first. We'll classify, plan, and coordinate transplant referral where it makes sense.
Medically reviewed by
Dr. Rehan Abdullah
Dr. Rehan Abdullah is a dual-trained clinical and radiation oncologist with over a decade of experience treating both solid tumours and hematologic malignancies. He serves as Consultant Oncologist at INMOL Hospital and sees patients at Farooq Hospital and Healthnox Medical Center, Lahore. Read full profile →
This page is patient education, not a substitute for an in-person consultation. Cancer care must be individualised. Read our medical disclaimer →