RESULTS
In the pandemic year 2020, the donation program in Slovakia dropped by
28.6% (P<0.0001) compared to 2019 which was the most
successful year for organ transplants in the history of Slovakia. The
number of kidney transplantations decreased by 33.5%
(P<0.0001), kidney transplantations from living donors were at
a comparable level (P=0.0767). Compared to 2018, kidney transplantations
decreased by 10.3% (P=0.0001) during the COVID-19 crisis in Slovakia
(Figure 1).
A total of 305 patients (210 men, 68.8%) with confirmed SARS-CoV-2
positivity between March 6, 2020 and March 31, 2021 were included in our
analysis. Basic characteristics of the group are shown in Table 1. The
median age was 54 years (52.7 ± 12), the median body mass index was 29
kg/m2 (29.6 ± 18.3), 291 recipients (95.4%) suffered
from hypertension and 109 (35.7%) from diabetes mellitus. Patients who
were longer after the kidney transplantation became ill more frequently,
with a median of 68 months (84.8 ± 64.3). Excellent graft function
(eGFR; CKD-EPI ≥ 1.5 mL/s/1.73 m2) at the time of the
first positive test was found in 27 cases (8.9%), 121 patients (39.7%)
were in the second stage of chronic kidney disease (eGFR; CKD-EPI 1.49
– 1.0 mL/s/1.73 m2), 120 (39.3%) in the third stage
(eGFR; CKD-EPI 0.99 – 0.5 mL/s/1.73 m2), and 37
(12.1%) with advanced graft dysfunction (eGFR; CKD-EPI < 0.5
mL/s/1.73 m2).
In the first wave of COVID-19 crisis only three positively tested
patients (1%) for SARS-CoV-2 were identified in Slovakia, the course of
the disease was asymptomatic/moderate. During the second wave, the
COVID-19 morbidity rose significantly, SARS-CoV-2 was identified in 302
KTRs (99%), of which, in the first period of the second wave, it was
147 KTRs (48.2%), followed by 155 (50.8%) positively tested KTRs in
the second period of the second pandemic wave (Tab. 1).
Criteria for the asymptomatic/moderate course of the disease were met by
206 patients (67.5%), admission to the hospital was indicated in 99
KTRs (32.5%) (Tab. 1). 192 positively tested patiens (63%) called the
transplant centers and consulted the symptoms and the treatment (Tab.
1), more frequently during the second period of the second wave (54.9%vs 71.6%; P=0.0028), more commonly with asymptomatic/moderate
course of the disease (72.1% vs 46.9%); P<0.0001)
(Tab. 2). In 92 hospitalized patients (92.9%), the physicians from the
hospitals/COVID-19 departments to which the patients were admitted
consulted the treatment with experienced nephrologists from the
transplant centers, especially discontinuation of immunosuppressants,
doses of steroids, and supportive antimicrobial treatment and prevention
of thrombosis (Tab. 2). There were no deaths recorded during the first
wave, thirty patients (9.8%) died during the second wave of COVID-19
pandemic, there was no significant difference between both periods of
the second wave (Tab. 1). Elderly patients were hospitalized more
frequently (P=0.0059); for the whole set, in both univariate and
multivariate analysis (Tab. 3), the age over 59 years was a risk factor
for a more severe course and death. Another risk factor for
hospitalization and death in the whole set, according to the univariate
analysis, was diabetes mellitus, while in the multivariate analysis
(Tab. 3), diabetes mellitus was only associated with a more severe
course of the disease (OR [95% CI]: 2.0433 [1.1812-3.5346];
P=0.0106). Patients with advanced graft dysfunction defined by eGFR
< 0.5 mL/s (Tab. 3), OR [95% CI] had a worse prognosis
associated with the risk of death: 4.8668 [1.7182-13.7849];
P=0.0029). In contrast, better graft function was more common in
patients with a mild course (45.9% vs 27.6%, P=0.0028).
We did not find any effect of arterial hypertension, BMI, time since
transplantation, CNI, MMF/MPA, mTOR-I and ACE-I on the incidence and
clinical course of COVID-19 in KTRs during the first and second waves of
the pandemic (Tab. 2). At the time of finding of the infection, patients
with a more severe course and need for hospitalization (93.9 vs85.8; P=0.0419) were more frequently treated with corticosteroids at a
higher mean dose than the mild course group (7.3±5.3 vs 5.9±3.1;
P=0.0056). While according to a univariate analysis, a lower dose of
prednisolone (<10mg) was a protective factor at the onset of
infection, the protective effect of low doses of corticosteroids was not
confirmed by the multivariate analysis (Tab. 3).
We focused our interest in whether the proliferation of the alpha
variant of the SARS-CoV-2 virus affected the course and risk factors of
COVID-19 in kidney transplant patients. By comparing subgroup 2 (09/2020
- 12/2020) and subgroup 3 (01/2021 - 03/2021), we did not find any
significant differences in the screened parameters depending on the
period when patients became ill or tested positive for SARS-CoV-2 virus
(Tab. 2, Tab. 4, Tab. 5).
Finally, we compared COVID-19 morbidity and mortality rates between KTRs
and patients on hemodialysis (HD).
While among the patients after kidney transplantation, 14% tested
positive, in the hemodialysis cohort, there was up to 52% positivity
(P<0.0001). Mortality among the infected kidney recipients was
9.8% vs 30% (P <0.0001) in HD patients. Of the total
set of KTRs in dispensary, a total of 1.4% died in Slovakia during the
COVID-19 pandemic by the end of March 2021, while in the population of
HD patients it was up to 15.6% (P<0.0001).