Discussion:
This study aims to share our experiences in transplant and hemodialysis patients since the time 11 March 2020 when the first case of COVID-19 was observed. The mortality rate was found to be high in both HD and kidney transplant patients as expected.(2,3,10) However, there are also studies claiming that mortality in solid organ transplantation (SOT) cases is not different from other patients. Rinaldi et al. in their study including 885 (SOT: 24, non-SOT: 861) patients, they found 30-day mortality in SOT and non-SOT cases, respectively, 19% (n: 4) and 22.1% (n: 186).(11) However, in this study, the mean age of patients was lower than in our study.
Four groups were included in the multicentric retrospective and observational study in which 47 centers in Turkey participated with 1210 patients: control (n: 450), HD (n: 390), RT (n: 81), and stage 3-5 chronic kidney patients (CKD, n: 289). The mortality rate was 4%, 16.2%, 11.1% and 28.4% in the control, HD, RT, and CKD groups respectively. Although the mortality was statistically higher in HD and CKD groups compared to the control group. There was no difference between the RT and control groups.(12) There was no control group in our study. And the mortality rate was found to be 20.8% (15/72) and 15.5% (9/58) in the HD and RT groups respectively. This difference was not statistically significant. (p:646). However, in the RT group, the patients were younger (p: 0.001) and none of the transplant cases had a post-transplant time <6 months.
Villanego et al. in their study divided patients into four groups according to posttransplant RT age and post-transplant time in their study: age <65 years and posttransplant time >6 months, age <65 and time ≤6, age ≥65 and time >6 and age ≥65 and time ≤6; and the mortality rate was 11.3%, 24.5%, 35.4%, and 54.5% respectively. The first six months of intensive immunosuppression following the transplant and age >65 years were predictors for mortality in this study.(13)
One of the interesting data of our study is that mortality was found to be lower in univariate analyzes in RT cases whose post-transplant outpatient follow-up was performed in our center (p: 0.02). The mortality rate was %7.5 (n: 3) out of 40 patients treated in our center. One of these patients, who had a history of Coronary artery disease without obvious involvement in the lung, died of myocardial infarction. It was suspected that it might be myocardial infarction (MI) caused by a COVID-19 infection.(14) The low mortality in cases followed up by our center may be due to close contact with the patients by transplant doctor and earlier admission to the hospital. In addition, the symptoms, laboratory findings, and imaging of the patients who were not hospitalized were followed.
Alberici et al evaluated 20 transplant patients admitted to the hospital in their study. The mean time between the onset of symptoms and admission to the hospital was 5.5 (3.3-8) days. All immunosuppressions of the patients, except steroids, were discontinued after hospitalization. Five (25%) of the patients died. Hemodialysis was performed on a patient.(15) Forty patients were hospitalized in our study. The mean time between the onset of symptoms and admission to the hospital was 3 (2-5) days. The mortality rate was %22.5 in the hospitalized patients. There was a significant difference between the patients followed up in our center and patients followed up in external centers in terms of the time before the admission to the hospital. It was 2 (2-3) and 5 (4-5.75) days and the mortality rate was 7.5% and 33.3% respectively. One of our patients was taken to the HD program due to worsening graft functions.
1073 cases were included in the study in which European Renal Association COVID-19 Database (ERACODA) data were evaluated. There were 305 (28%) RT patients and 768 (72%) HD patients and mortality was 21% and 25% respectively. The mean age was 60±13 ve 67±14 years respectively. The advanced age was found to be related to mortality in the RT patients. And fragility and advanced age were found to be related to mortality in HD patients.(16) Although an increase in CRP, ferritin, D-dimer levels, lymphopenia, dyspnea, and bilateral involvement in CT images was statistically significant in the univariate analysis, no single factor was found to be related to mortality in multivariate analysis.
The mortality rate in our patient HD group was 20.8%. In other studies on hemodialysis patients with COVID-19 infection, mortality rates range from 10% to 31%.(4,17) Our results are consistent with these studies. The overall mortality rate of COVID‐19 in the general population has been reported by about 3.2%.(18) Hence, although the data are limited, the studies on HD patients strongly suggest that the mortality rate is much higher in these patients. The presence of comorbid diseases accompanied by chronic renal failure patients and immunosuppression caused by uremia are likely to be contributors to this higher mortality rate.
The main risk factor for in-hospital mortality in due to COVID-19 is advanced age. In patients with comorbidities such as chronic kidney disease, hypertension, chronic obstructive pulmonary disease, diabetes mellitus, malignancy, and obesity, advanced age was the strongest predictor of a poor outcome under infectious diseases.(19) In our study, the mean age of HD patients was 57.5 median (43-65) years. Half of our patients were women and half were men. In the in-hospital mortality group, the mean age was found to be 72 medians (63-79) years. Multivariable logistic regression analysis was showed that advanced age and dyspnea as admission symptoms were statistically significant associated with in-hospital mortality. A meta-analysis included 19 articles and 39 case reports; D-dimer (2-fold), CRP (7-fold), and procalcitonin (2-fold) values were observed in patients with severe disease compared to those with mild forms; It has been shown that high erythrocyte sedimentation rate (ESR) and c-reactive protein (CRP) values are predictive for sepsis and mortality, and lymphopenia and high LDH values are significantly associated with intensive care unit( ICU) admission.(20) In the HD-specific COVID-19 studies, the mortality rate has been reported to be related to lymphopenia, elevated CRP, dialysis treatment length, elevated D-dimer and cardiovascular comorbidities so far.(21-23) In our study, we did not find a statistically significant relationship between in-hospital mortality and the predictors mentioned above, but advanced age and dyspnea (possibly result of hypoxemia) were more common in the in-hospital mortality group. The small sample size is likely to limit the significance of our statistical results. Therefore, it is necessary to clarify the clinical course of COVID-19 infection and predictors determining the need for intensive care and mortality in hemodialysis patients, which are a group of patients with comorbid diseases frequently.