What is HSCT?

Haematopoietic stem cell transplantation (HSCT) is a treatment for multiple sclerosis that involves intense chemotherapy. The primary ain is to halt the damage MS causes by destroying your immune system before then regrowing it, using your stem cells.

Essentially, it is to ctrl, alt +del your immune system before rebooting it.

Autologous hematopoietic stem cell transplantation (ASHCT) is a type of transplantation that uses the person's own stem cells, particularly from peripheral blood. HSCT sometimes has the "A" at the beginning: this just means it's your own stem cells that are put back in, not someone else's. These cells are collected in advance, stored at sub-zero temperatures, and returned at a later stage, after high dose chemotherapy or immunosupressive therapy.

This has been an established treatment for more than 3 decades and is clinically approved for hematological malignancies/cancers (such as lymphoma, leukaemia, etc.). Due to haemopoietic stem cell transplantation, the majority of the patients suffering from tumor blood diseases, who earlier were condemned to rapid death, obtained significantly increased chances for recovery. This treatment, so common for cancers, was used, then, to treat autoimmune diseases such as MS. As fundamental investigations have shown, the cause for development of autoimmune diseases is impairment of the cells of the immune system. It is not surprising that therapeutic methods, saving hematological patients, proved to also be effective in multiple sclerosis.

It has up to a 95% success rate for people with RRMS, and 75%-85% success rates for people, like me, with PPMS.

The procedure that I had in Russia uses a form of chemo called non-myeloablative chemotherapy as opposed to myeloablative chemotherapy, the former being far less intensive and risky than the latter. "Ablative" here means destructive, from to destroy. The mortality rates for the type they give in Russia are far, far lower than for the more destructive variety.

In technical terms (this is taken from the Russian HSCT Facebook forum Files section), the difference is:

Hematopoietic Stem Cell Transplantation (HSCT) - All HSCT protocols for the treatment of autoimmune disorders, and MS specifically, ablate self-intolerant autoreactive lymphocytes in the body that are responsible for the underlying nerve damage / destruction. HSCT protocols run a spectrum from complete in-vivo lympocyte ablation (the myeloablative protocols) to partial in-vivo lymphoablation (non-myeloablative protocols also sometime referred to as "Reduced Intensity Conditioning" (RIC) regimens).

• Myeloablative HSCT

The myeloablative protocol for treatment of hematologically-rooted autoimmune conditions most commonly incorporates a BEAM (Carmustine, Cytarabine, Etoposide, Melphalan) chemotherapy protocol which is administered over a period of six days plus often the addition of ATG for a couple of days as adjunct lymphoablation. It results in the near-complete ablation of both the body's (autoreactive) lymphocytes that are the cause of MS, as well as the bone marrow. Once the re-infused stem cells engraft to form new functional bone marrow, the lymphocyte population is replenished with naive non-reactive cells resulting in a halting of underlying disease activity.

• Non-Myeloablative (or RIC) HSCT

The non-myeloablative protocols vary in administration schedule (based upon doctor discretion) and strongly links the mobilization and conditioning phases (they are time-dependant to each other whereas for the myeloablative protocol they are not max-time-linked). Most non-myeloablative protocols utlize a chemical subset of Cyclophosphamide, Carmustine, Fludarabine, Alemtuzemaub and Anti-Thymocyte Globulin (ATG)). Because the non-myeloablative HSCT protocols are preferrentially lymphoablative (and incompletely myeloablative), the in-vivo plasma autoreactive lymphocyte population is not entirely eliminated but instead "diminished" to a threshold level below which autoimmune-mediated damage occurs. The bone marrow is not completely ablated which creates a greater treatment safety margin and allows the patient to more promptly recover from the chemotherapy following conditioning. Although a "gentler" chemotherapy and lower Treatment Related Mortality (TRM) as compared to the myeloablative HSCT protocol, there is unfortunately a proporation of non-myeloablative-treated-patients (20-25%) that results in an insufficient diminishment of autoreactive lymphocytes that necessitates post-transplantation cyclophosphamide infusion retreatments to bring a treated MS patient into remission. The more complete in-vivo lymphocyte ablation of the myeloablative HSCT protocol does not have this same issue.