Large Granular Lymphocytic Leukemia
New large granular lymphocytic leukemia research, summarized each month in plain language.
2026 so far: So far in 2026 (January-September), real-world reports added treatment signals (immunosuppression, golidocitinib, bendamustine), while expert and lab studies aimed to standardize LGLL diagnosis and reduce confusion with reactive mimics. Read the 2026 review
We also cover clinical trials.
Yearly update
2026 so far
- Newer drug signals. Treatment evidence broadened beyond immunosuppression into newer agents.
- Immunosuppression in practice. Routine-care cohorts reinforced immunosuppression responses and tolerability limits.
- Plasma cell overlap. Overlap with plasma cell disorders gained clearer frequency and subgroup signals.
- Standardizing diagnosis. Expert guidance converged on shared definitions and fewer diagnostic pitfalls.
- Avoiding mimics. More studies highlighted infection/reactive patterns that resemble LGLL.
New
September 2026
- Treatment response reports. Two small reports found responses with golidocitinib or bendamustine.
- Blood count changes. Blood counts improved quickly with golidocitinib, with short follow-up.
- NK-cell test pitfalls. Reactive NK cells can look like leukemia on flow tests.
August 2026
- Diagnosis criteria. Experts proposed shared criteria for T-LGLL diagnosis and response.
- Plasma cell overlap. Data suggest LGLL often occurs with plasma cell disorders.
- Subgroup treatment signal. In one overlap subgroup, B-cell therapy outperformed immunosuppression.
- Unusual aggressive case. One fast-progressing T-LGLL case lacked common driver mutations.
July 2026
- First-line immune suppression. First treatments like cyclosporine or cyclophosphamide often led to remission.
- Sirolimus after prior therapy. Sirolimus often worked after earlier NK-LGLL treatments.
- Switches from side effects. Some people switched drugs because side effects were hard to tolerate.
- Blood smear screening. Blood smear counts closely matched flow testing and suggested a 24% cutoff.
June 2026
- Low blood counts. Very low blood counts can make T-LGLL harder to spot.
- Bone marrow overlap. Some cases occurred with aplastic anemia and a small PNH clone.
- Cell and gene signs. Rare cell findings and a STAT3 mutation were reported.
- Sildenafil observation. One case improved during sildenafil use, but cause is unclear.
May 2026
- Common CD8 pattern on flow. On blood flow cytometry, T-LGLL cells often looked like very mature CD8 T cells.
- Markers seen more often. CD57, CD16, and HLA-DR were reported more often in T-LGLL than in reactive T-LGL expansions.
- Some cases look different. Some T-LGLL cases showed CD8 subset patterns that did not match the most common “very mature” profile.
April 2026
- Response to first treatment. In one small real‑world series, many people improved after their first immunosuppressive treatment.
- Symptoms at diagnosis. In that same series, fatigue and low blood counts were common at diagnosis.
- What gene panels add. Gene panel testing often found mutations and was used mainly to inform prognosis rather than to change the diagnosis.
- Rare immune overlap. One case report described LGLL occurring alongside other immune‑related bone marrow problems in the same person.
March 2026
- Infection can look like LGL. In some infections, activated NK cells can look similar to patterns seen in LGL leukemia.
- NKG2C marker on flow test. Adding NKG2C to blood flow cytometry may help suggest a CMV-related reactive NK-cell expansion in this setting.
- Severe neutropenia case. One reported HIV case linked severe neutropenia to T-cell LGL leukemia found during a diagnostic workup.
February 2026
- T‑cell clonality testing. T‑cell receptor (TCR) gene rearrangement testing was often positive in T‑LGLL and was uncommon in several comparison groups, which can help support the diagnosis when other findings are hard to interpret.
- NK‑like test patterns. Some T‑cell disorders, including T‑LGLL, can look like NK‑cell disorders on routine marker tests, and added lineage evidence (including clonal TCR findings) helped clarify these cases.
- Reticulocytes and PRCA. In one center’s comparison, a lower reticulocyte count best separated T‑LGLL with pure red cell aplasia (PRCA) from T‑LGLL without PRCA, consistent with reduced red‑cell production in the PRCA group.
January 2026
- Low neutrophils. Low neutrophils were common, often with autoimmune histories.
- Single-case treatment. One report noted neutrophil recovery after oral fludarabine plus pegfilgrastim.
- Muscle disease overlap. Inclusion body myositis was the main muscle condition reported.
- Common gene changes. STAT3 and STAT2 changes were most common, without outcome links.
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