Naslov
The Impact of The "New Normal" On Stem Cell Laboratory Practices

Autori
Mazić, Sanja ; Bojanić, Ines ; Liker, Milica ; Burnać Iva Lucija ; Golemovic, Mirna ; Gojčeta, Koraljka ; Skific, Marijana, Škifić ; Rimac, Vladimira ; Cepulic, Ćepulić Golubić, Branka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, stručni

Izvornik
BONE MARROW TRANSPLANTATION, Volume 56, SUPPL 1 / - , 2021, 328-328

Skup
47th Annual Meeting of the EBMT

Mjesto i datum
Online ; Pariz, Francuska, 14.03.2021. - 17.03.2021

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
stem cell ; COVID

Sažetak
The Impact of The "New Normal" On Stem Cell Laboratory Practices

Izvorni jezik
Engleski

Napomena
Background: Covid-19 pandemic put before us new
challenges regarding the procurement and
organization of allogeneic hematopoetic progenitor
cell (HPC) transplantation. Therefore, securing
the cryopreserved graft before start of patient
conditioning is recommended to reduce risks due to
donor or recipient infection or transport
disturbances. Quality control (QC) standards for
autologous grafts are well established and
translated to allogenic setting but the impact of
factors such as prolonged storage and cell
concentration during transport on cryopreservation
and grafts recovery is not clear. Practice is to
begin conditioning immediately after the graft is
cryopreserved which opens up new questions
regarding QC. New measures created extra workload
for the stem cell laboratory and QC unit.

Methods: We investigated the impact of
cryopreservation on work load of the stem cell lab
and graft QC issues.

Data on allogenic mobilized peripheral blood HPC
received, cryopreserved and infused during 2019.
Were compared to the first 11 months of 2020.

Results: in 2019. we received 25 HPC products for
25 patients which were infused fresh except one
which was cryopreserved due to organisational
issues of pediatric recipient conditioning. We
cryopreserved 82 bags intended for donor
lymphocyte infusions (DLI). In the first 3
quarters of 2020. we cryopreserved 129 bags (34
products, 33 patients) for the purpose of
transplantation and DLI which is 1,5 times more
than previously. By December number of
cryopreserved bags went up to 189 (49 patients, 50
products) which is more than twofold higher along
with 90 bags thawed and infused. Mean time from
collection to cryopreservation was 51 hours
(26,5h-67h).

Our standard QC for cryopreserved HPC products
includes viability assessment using 7-AAD and
colony forming unit assay (CFU). with the start of
pandemic, the decision on quality of cryopreserved
products relies on acceptable results of flow
cytometry analysis of cryovial sample thawed 48
hours after freezing. After informing the
transplant unit (TU) of acceptable QC results
conditioning is started.

The median of CD45/7AAD viability of 98% (61-100)
in native product dropped to 71,5% (30-93) in
thawed cryovial sample whilst CD34/7AAD native
viability of median 100% (97-100) held at median
96% (2-98) post thaw and the results of CFU assay
were in accordance. One product with poor
viability and recovery in all cryovials tests was
further investigated, transplant bags were
analysed only to confirm the total loss of cell
viability (CD45/7-AAD 30%, CD34/7-AAD 0,3%). This
raised questions of factors that could have
contributed such as prolonged time from collection
to cryopreservation (>67 hours) and inadequate
dilution of fresh cells (>250x109/L WBC). Patient
was postponed and haplo transplant was initiated
which was complicated with Covid-19 infection of
the donor starting GCSF.

Conclusions: Recommended cryopreservation of HPC
products is a substantial financial and workload
burden for the stem cell laboratory and QC unit.
Cryopreservation tends to triple in 2020. and
additional thawing procedures take considerable
amount of time of overstretched staff working in
epidemiologically acceptable shifts. Additional QC
results need to be timely and clearly communicated
to the TU so that deviations can be resolved
before the start of conditioning.

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