ABSTRACT
BACKGROUND AND AIMS: As COVID-19 related mortality is higher in haemodialysis patients than in the general population, proper vaccination strategies against the SARS-CoV-2 virus have utmost importance. It has been previously shown that mRNA vaccines (e.g. BNT162b2) can generate >95% of seropositivity in haemodialysis patients [1]. On the other hand, the seropositivity rate reached by the inactivated vaccine (CoronaVac ® ) was around 80%. In this study, we aimed to analyse the persistence of SARS-CoV-2 antibodies in haemodialysis patients for 6 months and compare it with the healthy controls. METHOD: Haemodialysis patients who were vaccinated either by BNT162b2 or CoronaVac ® and who continued their regular controls for 6 months were involved in the study. Those who had previous or active SARS-CoV-2 infection, who had malignancies and those who had received immunosuppressive drugs in the previous 12 month were excluded from the study. SARS-CoV-2 IgG levels were measured by a commercial test after the first doses of the vaccines and at the end of the sixth month. Healthy healthcare workers who were vaccinated with similar vaccine schemes were taken as the control group. RESULTS: We recruited 85 haemodialysis patients who had received their first doses of either vaccine. Of them, 4 patients died;3 patients were hospitalized because of COVID-19 infection during the follow-up;9 patients missed at least one of their regular controls;and 2 patients were diagnosed with malignancy. A total of 26 patients experienced asymptomatic or mild COVID-19 infection during the follow-up period. SARS-CoV-2 IgG levels were measured at the end of the sixth month for the remaining 41 patients. Sero-positivity significantly decreased at the end of the sixth month for both vaccines, but the BNT162b2 group (n = 22) still had better seropositivity than CoronaVac ® (n = 19) group (81% versus 50%;P = .03). In contrast, the seropositivity of healthy controls, even with the inactivated vaccine, was 96%. When one booster dose was applied, 90% of seropositivity could be maintained in the BNT162b2 group at the sixth month. CONCLUSION: BNT162b2 vaccine generates more persistent antibodies than inactivated vaccines in haemodialysis patients. However, when compared with the healthy controls at the end of the sixth month, antibody titers decrease more profoundly in haemodialysis patients. The booster dose can maintain the antibody levels and should be applied at least every 6 months.
ABSTRACT
BACKGROUND AND AIMS: Kidneys are among the affected organs in COVID-19 and there may be different etiologies resulting in acute kidney injury (AKI) in different stages of the disease. There have been previous studies focusing on incidence and mortality of AKI in COVID-19 but none has made in depth analysis in relation to the background pathophysiology. Based on previous observations, we hypothesized that all AKIs seen in COVID-19 are not uniform and we aimed to analyze the etiologies and prognosis of AKI among hospitalized COVID-19 patients in relation to the time of AKI during different phases of the disease. METHOD: A total of 1056 patients were admitted to the designated COVID-19 clinics from March to July in 2020. 77 Patients who were younger than 18 years old and 7 kidney transplant patients were excluded from the study. 427 of the remaining patients were confirmed by real time polymerase chain reaction (RT-PCR) test.). As eGFR below 60 mL/min/1,73 m2 was already shown to be related to mortality, these patients (44) were also excluded. As immunologic response is generally accepted to start with the second week of COVID-19 course, patients were classified into three groups, those who had AKI on admission, those who developed AKI in the first week and those who developed AKI starting from 7th day. Initial lymphocyte counts, creatinine levels, electrolytes, acid-base status and changes in the inflammatory markers were compared between the groups. A comparison between patients who survived and who died was also performed. RESULTS: 89 of the 383 included COVID-19 patients developed AKI. 24% of those who developed AKI died. Patients who developed AKI later had higher peak CRP and D-dimer levels with lower nadir lymphocyte counts (p=0,000, 0,004 and 0,003 respectively). Additionally, patients who died had higher initial inflammatory marker levels and lower lymphocyte counts than those who survived. Mortality of patients who had AKI on hospital admission (13%) was similar to the overall COVID-19 mortality for inpatients, however it was as high as 44% for those who developed AKI after 7th day. Early AKI was related to pre-renal causes and had a milder course. However, later AKIs were more related to immunologic response and had significantly higher mortality. Patients who died had significantly higher ferritin and d-dimer levels upon their hospital admissions (p=0,000). Electrolyte disturbances, metabolic acidosis and mortality were also higher in patients who developed AKI later. Hypernatremia (OR: 6,5, 95% CI: 3 - 13,9) and phosphorus disturbances (both hyperphosphatemia (OR: 3,3;95%CI: 1,6 - 6,9) and hypophosphatemia (OR: 3,9;95% CI: 2,0-7,9)) were related to mortality. CONCLUSION: Findings of this study suggest that AKI in COVID-19 is not of one kind. When developed, AKI should be evaluated in conjunction with the disease stage and possible etiologies.