Thymus rejuvenation

[qBx123Yk]

Growth hormone enhances thymic function in HIV-1–infected adults

AI summary :

Study Design
​Participants: 22 HIV-1-infected adults who were already on stable antiretroviral therapy (cART).
​The Problem: HIV accelerates “thymic involution” (the shrinking of the thymus), leaving patients with low levels of new, “naïve” T-cells, even if the virus is controlled.
​The Intervention: Participants were randomized to receive either recombinant human growth hormone (rhGH) or no hormone (observational control) for one year.

Key Findings: Physical Regrowth
​The researchers used CT scans to measure the density and mass of the thymus.
​Reversing Fat Replacement: At the start, most participants’ thymuses were almost entirely replaced by fat (adipose tissue).
​Significant Mass Gain: After 6 months of GH treatment, there was a robust increase in thymic density (up to +50 Hounsfield units compared to +1 in the control group).
​Visible Architecture: The scans showed the reappearance of dense “cellular” thymic tissue, indicating the organ was structurally rebuilding itself.

Key Findings: Functional Immune Output
​Regrowing the organ is only useful if it produces “working” immune cells. The study confirmed this using two biomarkers:
​TRECs (T-cell Receptor Rearrangement Excision Circles): These are tiny loops of DNA found only in “newborn” T-cells. The GH group saw a significant increase in TREC frequency, proving the thymus was producing de novo T-cells from scratch.
​Naïve CD4+ T-cell Counts: The number of circulating naïve CD4+ T-cells (the “infantry” of the immune system) increased by 96.4% in the GH group, compared to only 17.6% in the control group.

[julianj1]

There was this one article about Red Light Therapy potentially rejuvenating the thymus, but the abstract doesn’t tell you very much and I don’t have the full text.

Photobiomodulation and Thymus rejuvenation

One experiment in mice (?) isn’t much.

How would you measure if the thymus is regenerating in humans?

[qBx123Yk]

@julianj1

How would you measure if the thymus is regenerating in humans?

CT scan to estimate the size, preferably before and after. And you need someone to interpret the result.

[Cole]

Aging of lymphoid organs_ Can photobiomodulation reverse age‐associated thymic involution via stimulation of extrapineal melaton.pdf (1.3 MB)

The full text has been uploaded for you. I took a brief look, and the quality is very low, there is no need for any research.

[Cole]

Many professors have questioned this low-quality study. TRIIM did not provide histopathological evidence from thymus biopsies. Their main basis for determining thymic regeneration was magnetic resonance imaging (MRI). Without a biopsy, it is impossible to confirm whether the cells that reoccupy the space are genuine thymic epithelial cells capable of producing T cells, or merely edema, connective tissue proliferation, or other non‑functional cells. MRI simply cannot determine thymic regeneration.

[julianj1]

Thanks Cole. Much appreciated.

[qBx123Yk]

@Cole

did not provide histopathological evidence from thymus biopsies.

My sense is that the study wouldn’t have been authorized if surgery was required (that’s what biopsy of the thymus requires : surgery ).

I’m comfortable with the evidence given, which is: mri image showing size change, and measured immune system changes like increase T-cell production, and TREC levels.

[julianj1]

It seems to me that there isn’t a particular standardised CT scan test or software that would be able to generate reliable results that the longevity community could study and respond to.

Perhaps there might be in the future.

[julianj1]

Proboost Thymic A has been around for an awful long time. 1990s ish.

There haven’t been any tests or updated knowledge about it since it’s release, which I find a bit odd.