A pneumonia associated with acute respiratory syndrome coronavirus 2 (SARS-CoV2) emerged in Wuhan, China. The SARS-CoV-2 infection spread rapidly all over the world. As of June 12, the total number of SARS-CoV-2 cases reported by the world health organization (WHO) reached 7.553.182 and 423.349 deaths. There are currently no proven treatment for Coronavirus disease 2019 (Covid-19).
There is no effective antiviral drug in the treatment of Covid-19 disease. It is an urgent need to seek an alternative strategy, especially in the treatment of serious patients. Convalescent Plasma (CP) therapy can be used for this disease. CP is the administration of antibodies collected from recently infected and recovered Covid-19 patients to Covid-19 patients for therapeutic purposes.
CP was used during the 1918 flu epidemic and reduced mortality among plasma recipients. CP treatment is a reliable treatment option for the prevention and treatment of infectious diseases for more than a hundred years. However, the benefit of CP treatment to mortality in Ebola virus disease has not been showed. Recently, CP was used as a effective and reliable treatment option in SARS CoV-1 and Middle East respiratory syndrome (MERS) epidemics. Therefore, it suggested that the use of CP transfusion may be beneficial in patients infected with SARS-CoV-2.
Materials and Method
CP treatment was applied to 26 Covid-19 patients in intensive care unit who had quantitative reverse transcriptase–polymerase chain reaction (qRT-PCR) positive Sars-Cov-2 infection. Plasma was collected at least 14 days after complete recovery from patients who had mild or moderate infection with Sars-Cov-2 infection.
500-600 cc plasma was collected from the donors with a therapeutic apheresis device for 60-90 minutes considering age and comorbidity. Donors were selected from those who could be blood donors between the ages of 18-60. All tests (Eliza, etc.) before donation to the donors were done before the procedure. Antibody titer was checked before donating to the donors.
Plasma was collected from donors with antibody positivity. Before starting the procedure, PCR was confirmed to be negative for Covid-19 in both the swab and serum of the donor. Informed consent was obtained from both the donor and the patients. After the CPs were collected, they were prepared and frozen in 200 cc packages with a sterile combining set. The collected CPs were applied to severe Covid-19 patients. Laboratory values of patients just before CP and after 1 week were compared. This study was approved by the local ethical committee of Inonu University, Medical Faculty on 26 May, 2020 under the number 2020/77.
PCR positive Covid-19 patients who received CP treatment were included in the study. Patients with no PCR positivity and strongly suspected Covid-19 disease were excluded from the study. In addition to supportive treatment, hydroxychloroquine and azithromycin were administered to all patients and then favipravir.
Statistical analyses were performed using SPSS 25.0 software package. Shapiro-Wilk test was used to test the normality of distribution of the categorical variables. We used the Wilcoxon test to detect differences between parameters before and after CP. The relationship between disease severity and mortality was analyzed with Fisher’s exact test. Mann-Whitney U test was used to compare clinical and laboratory parameters between the alive and dead patients. p<0,05 was considered statistically significant.
A total of twenty-six Covid-19 patients (8 females and 18 males) with a mean age of 67.4 ± 15.5 years were included in the study. Pneumonic infiltration was present in the chest computerized tomography of all patients. Twenty six patients were given only one session of CP. Laboratory values of patients just before CP and after 1 week.
There were no statistically significant differences in leukocyte, neutrophil, lymphocyte, platelet, CRP, ferritin, LDH, ALT, AST, sO2 and total bilirubin values just before and after 1 week of CP. The hemoglobin level in our patients treated with CP was statistically significantly lower than before CP. The reason for this was thought to be dilutional anemia due to hydration applied to patients. No severe adverse reactions were observed after CP transfusion.
The time from admission to patients to CP administration was 13.87 ± 6.5 days. While 6 of 17 patients who needed mechanical ventilation were dead, none of 9 patients who did not need mechanical ventilation died. Of the 26 Covid-19 patients included in the study, 20 were alive and 6 died. Laboratory values and clinical parameters of patients living and dying at the time of admission were compared. A statistically significant difference was found between age and lymphocyte values of living and dying patients. The patients who died were determined to have older age (74,6 vs 61,85, p=0,018) and more severe lymphopenia (0,47 vs 1,18, p=0,001).
There is no specific therapeutic agent for Covid-19 disease. Treatment of the disease and prevention of its spread are provided by travel restrictions, patient isolation and supportive medical care. Some of the treatment options used in the current treatment of Covid-19 are hydroxychloroquine, lopinavir / ritonavir, azithromycin, favipiravir and Interleukin-6 (IL-6) inhibitors.
Remdesivir, a nucleoside analogue and a broad spectrum antiviral and CP therapy has been approved by the FDA for experimental use. CP means of antibody transfer to provide passive immunity. The history of CP therapy is based on the 1890s used to protect against bacterial toxins. Intravenous immunoglobulins collected from thousands of healthy donors are still used today to prevent viral infections in some patient populations. CP transfusion has been reported in the treatment of various infections over the past decades.
In the past two decades, CP therapy has been used with satisfactory efficacy and safety in the treatment of SARS-CoV-1, MERS-CoV and 2009 H1N1 outbreak. Therefore, the use of passive antibody transfer is considered for treating Covid-19 patients. The FDA has approved the use of experimental CP therapy in clinical trials and critical Covid-19 patients without other treatment options, and has published a guideline for this purpose.
In order for CP treatment to be effective, it is a prerequisite to find suitable donors with a high level of neutralizing antibodies. Ahn et al. applied 200 mL CP therapy to two serious Covid-19 patients aged 67 and 71, whose anti-SARS-CoV-2 IgG antibody titer was measured by the Elisa test. CP treatment was started on the 7th day of admission to one patient and on the 22th day to the other patient. A decrease in viral load has been shown after CP treatment.
Duan et al. added 200 mL of CP containing high neutralizing antibody titers (> 1: 640) to the treatment of 10 critical patients with Covid-19 (age range 34-78) after an average of 16.5 days of admission to the hospital. CP treatment increased the neutralizing antibody titer, oxygen saturation and lymphocyte count in patients; however, it has been observed that it reduces CRP, SARS-CoV-2 viral load and lung lesions in radiological imaging.
Compared to the CP treatment group and the control group (10 patients), there was no significant difference between the basic features of the patients, while the clinical results of the patient group given CP treatment were superior (p <0.001. Shen et al. has applied 400 mL CP therapy including SARS-CoV-2 antibodies (titer> 1:40) to 5 critical patients (age range 30-70, two women) determined by Elisa test.
After CP transfusion between the 10th and 22nd days of admission to the hospital, symptoms such as an increase in viral antibody titers, a decrease in SARS-Cov-2 viral loads and normalization of ARDS and fever decreased were observed. Brown BL and McCullough J performed a meta-analysis to investigate the effect of CP therapy on Covid-19 diseas.
They identified the reliability of CP treatment. CP therapy has been shown to reduce viral load. Its reliability was demonstrated in China, where it was used for the first time in this outbreak. In the current outbreak, CP has been used in our clinic for the second time in the world after China.
Author: Mehmet Ali Erkurt