Impact of COVID-19 After Autologous Hematopoietic Stem Cell Transplantation in Sweden

This retrospective observational cohort study aims to describe the impact of COVID-19 in patients treated with autologous stem cell transplantation (ASCT) for malignant disease in terms of risk factors, morbidity, need for supportive care and mortality. All patients treated with ASCT in Sweden from 1st January 2020 until 31st December 2020 are eligible for this study. Patients who also has tested positive for SARS-CoV-2 from start of conditioning or later will be identified through the national registry of the Public Health Agency of Sweden and a systematic analysis of their medical records will be performed.

Research question How does infection with SARS-CoV-2 affect patients with hematological malignancies who are treated with autologous hematopoietic stem cell transplantation?

Study population All Swedish citizens treated with ASCT for malignant disease in Sweden from 1st January 2020 until 31st December 2020 are eligible for this study. There will be a minimum follow-up time of one month for all patients.

Data collection and storage Patients will be identified using local ASCT registers at the seven university hospitals, as there is no national register for ASCT-patients in Sweden. These seven university hospitals are the only sights to perform ASCT in Sweden. The Public Health Agency of Sweden (Folkhälsomyndigheten - FHM) has the national responsibility to surveil and control communicable disease. The FHM uses several different surveillance systems to monitor the spread of COVID-19. Since COVID-19 is subject to mandatory reporting under the Communicable Diseases Act, physicians and laboratories continuously supply data to be analyzed daily by the FHM. The coverage of this database is estimated to be very high, close to 100%. For this study the investigators will link the patients identified through the ASCT-centers with the register of SARS-Cov-2 positive patients (SmiNet) held by the FHM. Patients who has tested positive for SARS-CoV-2 on the day of start of conditioning or at any given time thereafter will be included in the study. Inclusion of positive SARS-CoV-2 tests will start from 1st January 2020 until 31st March 2021 to allow for 3 months of follow-up after transplantation. For every ASCT-patient that has tested positive for COVID-19 after ASCT a systematic analysis of their medical records will be performed to describe the circumstances, impact and outcome of the COVID-19.

All data collected will be stored in a deidentified data set on a secure server held by Dalarna Country Council where name and social security number have been erased and given a coded study number. Each patient will only be identified using a separately stored code key. All storage, correspondence and analysis with the code key and pseudonymized data set will adhere to current European General Data Protection Regulation (GDPR) guidelines. The code key will be destroyed as soon as data collection is completed, data quality is secured and the final report is published. The data set will be stored for 10 years and then be destroyed.

Eligibility Criteria:
Inclusion Criteria:

* Diagnosis of hematological cancer (C81-C96 according to the International Classification of Diseases 10th revision (ICD-10).
* Autologous hematopoietic stem cell transplantation performed 1 January 2020 until 31st December 2020 at a Swedish transplantation center.
* Positive RT-PCR test for SARS-CoV-2 performed in Sweden

Exclusion Criteria:

- Age below 18 years and 0 months at the time of transplantation