January 2026 Research Update

This month added a more practical picture of how people with LAM are doing on treatment and how everyday testing may relate to longer-term outcomes. In a large registry study, a shorter 6-minute walk distance separated people into groups with different survival outcomes, even though it did not forecast how quickly breathing test numbers would fall. In a separate cohort, people maintained at lower sirolimus blood levels had similar lung function changes to those kept at conventional levels, suggesting that the exact target range may not always change lung function results in this setting. [1] [2]

A single-center retrospective comparison of sirolimus trough concentrations reported no meaningful difference in FEV1 change between a low-level group (below 5 ug/L) and a conventional-level group (5 ug/L or higher) at 1 year, and the groups still looked similar at 3 years. This study focused on lung function change, and it did not report safety differences between the dosing targets in the provided summary. The main message is that, in this cohort, lower measured sirolimus levels were not linked to worse FEV1 outcomes compared with conventional targets. [2]

A separate registry analysis found that the 6-minute walk test carried different information than a standard breathing test trend. People who walked less than 425.5 meters had worse baseline measures (including more oxygen drop during the walk and worse quality-of-life scores) and had a higher risk of death or lung transplant during follow-up, but the walk distance did not predict the future rate of FEV1 decline. Put simply, this study suggests that how far someone can walk in 6 minutes may reflect overall risk and daily impact, even when it does not track the speed of lung function change. [1]

For patients, these studies mainly add context about monitoring rather than introducing a new therapy. The sirolimus study is based on real-world records and suggests that lower measured drug levels may sometimes be linked with similar breathing-test outcomes, but it does not prove that any specific target is best for an individual. The 6-minute walk study suggests that a simple walking test may capture day-to-day functional limits and may relate to long-term outlook, even if it does not tell you how quickly breathing tests will change. [2] [1]

What remains uncertain is how well these results apply outside the single centers studied, and whether changing sirolimus targets would change side effects or long-term outcomes, since that was not clearly reported here. Still, this month makes it clearer that LAM follow-up is not just one number: drug levels, breathing tests, and a walking test may each reflect different parts of the disease experience. These findings may matter now for understanding how clinicians interpret tests, and they may matter later if confirmed across more diverse groups. [2] [1]

This month, studies measuring many proteins in blood moved LAM biomarker research in two directions at once: better ways to tell LAM from non-LAM, and better ways to estimate who may worsen over time. One study built a multi-protein blood score that very accurately separated women with LAM from healthy controls, including people with low VEGF-D. Another study focused on a single protein, CCL14, and found that higher baseline levels tracked with more severe lung damage on imaging and with later progression in a clinical follow-up cohort. [3] [4]

For diagnosis, researchers reported that PMEL was higher in LAM than in controls, and they combined PMEL with five other proteins to create a 6-protein LAMScore with near-perfect diagnostic accuracy in their cohorts. The same work also reported higher levels of multiple neutrophil-related proteins (including MMP8), which the authors interpreted as supporting a role for neutrophil activity in LAM biology. The practical point is that blood-based diagnosis may eventually become more reliable for people whose VEGF-D is low, but the summary does not indicate that this score is already used in routine care. [3]

For prognosis, the CCL14 study reported that this blood marker was higher in LAM than in healthy controls and was highest in people with more advanced CT grades and angiomyolipomas. Baseline CCL14 was higher in people who later progressed than in those who stayed stable, and it correlated with an increase in CT-measured cystic lung burden over time; VEGF-D was less predictive in that dataset. The same project used tissue and lab experiments to suggest CCL14 is made mainly by lymphatic and blood vessel lining cells and may activate mTOR-related signaling in those cells, offering a possible biological explanation for why it might track with progression. [4]

For patients and caregivers, these studies mainly add information about where blood testing might be headed, rather than changing what testing is standard today. The PMEL-based approach and the multi-protein LAMScore could matter in the future for people who have unclear cases or low VEGF-D, because the study reported very strong separation between LAM and controls. CCL14 could matter later as a way to estimate progression risk, since higher levels at baseline were linked to later worsening in the study group and to more cystic change on CT scans. [3] [4]

What remains uncertain is how these tests would perform across many hospitals, different populations, and over longer follow-up, and whether results would be consistent enough for routine decision-making. Even with those gaps, this month makes it clearer that LAM may have measurable blood signals that reflect both diagnosis (who has LAM) and trajectory (who may worsen), and that different markers may serve different purposes rather than one test answering everything. [3] [4]

This month linked immune biology and kidney involvement to LAM in two very different ways: one study used genetics to ask which blood immune cell traits might sit upstream of LAM risk, and two case reports described real-world procedures for kidney angiomyolipomas. The genetic results give an early, research-level signal that basophil-related traits may play a role in sporadic LAM risk, but they do not tell us how symptoms will behave or how to treat an individual. The case reports show that kidney angiomyolipomas can be managed with different approaches depending on resources and clinical situation, but single cases cannot predict what will happen for most patients. [5] [6] [7]

In a Mendelian randomization analysis using European-ancestry genetic data, higher basophil count and basophil percentage were linked to higher odds of sporadic LAM, while higher lymphocyte count was linked to lower odds. The study also estimated that part of the basophil effect might work through transitional B cells, and it highlighted several immune-cell-related genes as possible upstream drivers. Because this is a genetic inference approach, it is best understood as pointing to possible biological pathways rather than as a test or predictor ready for clinical use. [5]

Two case reports focused on large kidney angiomyolipomas, which are benign tumors that can cause pain or bleeding risk. In one patient with sporadic LAM, a selective embolization procedure blocked the tumor-feeding arteries while preserving normal kidney blood flow, and imaging 15 weeks later showed shrinkage from 56 mm to 39 mm. In another patient with tuberous sclerosis complex, a large fat-poor kidney mass was treated with nephrectomy, and the report emphasized the challenges of multidisciplinary care and long-term surveillance in a resource-limited setting. [6] [7]

For patients, the genetic immune-cell study is mainly early research that may help explain why LAM develops, but it does not provide a new blood test to diagnose LAM or guide treatment decisions right now. The angiomyolipoma case reports may feel more immediately relatable because they describe procedures people may hear about, but they are still single-patient experiences and cannot define what is typical. Together, these studies add to understanding that LAM involves immune pathways and that kidney angiomyolipomas can require individualized procedural planning. [5] [6] [7]

What remains uncertain is whether the basophil signal will hold up in larger and more diverse genetic datasets, and whether it connects to measurable disease activity in people already diagnosed with LAM. For angiomyolipomas, the case reports do not compare procedures or show long-term outcomes, but they do clarify practical goals that clinicians often balance, such as controlling the tumor while preserving kidney function when possible. These findings may matter later by guiding future research priorities and by documenting options used in real clinical situations. [5] [6] [7]