Therapeutic plasma exchange decreases plasma anti-SARS-CoV-2 spike IgG without increasing the proximate incidence of COVID-19

BACKGROUND

Therapeutic plasma exchange (TPE) removes both pathologic and protective immunoglobulins (Ig). SARS-CoV-2 immunity is partially mediated by anti-SARS-CoV-2 spike antibodies (SAb), which impair viral host-cell invasion. Nonetheless, the systematic effect of TPE on SAb concentration and SARS-CoV-2 immunity is unknown.

METHODS

Paired plasma waste specimens from the first (first-TPE) and last (last-TPE) TPE treatment were collected from 9 patients between July 21, 2021 and March 1, 2022. The effects of TPE on Ig levels were assessed by quantitatively comparing the SAb, total IgG, and total IgM levels first-/last-TPE treatment. Complementary qualitative assessment for these changes was achieved via protein electrophoresis (PEP) and immunofixation (IFE). A retrospective review was performed to investigate the incidence of new SARS-CoV-2 infections following TPE v. other treatment at the same outpatient apheresis/infusion center during the same time frame.

RESULTS

Median SAb levels between the first- and last-TPE waste specimens decreased significantly from 424.6 AU/mL to 17.0 AU/mL (P = 0.004). Concordantly, PEP and IFE analysis demonstrated broad Ig decreases. Cumulative incidence of subsequent COVID-19 diagnosis at 30, 90, and 180 days post-procedure did not differ between the TPE v. other treatment groups (n = 709 total patients).

CONCLUSIONS

TPE significantly reduced SAb levels, a marker of SARS-CoV-2 immunity, but did not appear to provoke increased incidence of COVID-19 infections. Further investigation of the kinetics of TPE-mediated SAb decrease and post-TPE recovery are warranted.

Analytic Sensitivity of 3 Nucleic Acid Detection Assays in Diagnosis of SARS-CoV-2 Infection

Background

Detection of SARS-CoV-2 by reverse transcriptase polymerase chain reaction is the primary method to diagnose Coronavirus Infectious Disease 2019 (COVID-19). Yet, the analytical sensitivity required is not well defined and it is unclear how available assays compare.

Methods

For the Abbott RealTime SARS-CoV-2 assay (Abbott Molecular Inc.; abbreviated as m2000), we determined that it could detect viral concentrations as low as 26 copies/mL, we defined the relationship between cycle number and viral concentrations, and we tested naso- and oropharyngeal swab specimens from N = 8,538 consecutive individuals. Using the m2000 as a reference assay method, we described the distribution of viral concentrations in these patients. We then used selected clinical specimens to determine the positive percent agreement of two other assays with more rapid turnaround times (Cepheid Xpert Xpress (Cepheid Inc.; GeneXpert, N = 27 specimens) and a laboratory developed test on the Luminex ARIES system (Luminex Corporation; ARIES LDT, N = 50)) as a function of virus concentrations, from which we projected their false negative rates in our patient population.

Results

SARS-CoV-2 was detected in 27% (95% confidence interval of 26-28%) of all specimens. Estimated viral concentrations were widely distributed and 17% (16-19%) of positive individuals had viral concentrations below 845 copies/mL. Positive percent agreement was strongly related to viral concentration and reliable detection (i.e. ≥95%), was observed at concentrations >100 copies/mL for the GeneXpert but not the ARIES LDT, corresponding to projected false negative rates of 4% (0-21%) and 27% (11-46%), respectively.

Conclusions

Substantial proportions of clinical specimens have low to moderate viral concentrations and may be missed by methods with lesser analytical sensitivity.

Zucker and Wistar diabetic fatty rats show different response to adrenalectomy

The short-term effects of adrenalectomy on certain aspects of glucose homeostasis and adiposity were examined in Zucker and Wistar diabetic fatty (WDF) rats. Ten-week-old male obese and lean WDF and Zucker rats were adrenalectomized or underwent sham operation. Obese rats of each strain were pair fed the intake of obese adrenalectomized rats. Intragastric glucose tolerance tests showed that sham-operated obese rats of both strains were severely hyperinsulinemic compared with leans; adrenalectomy and pair feeding reduced palsma insulin to lean levels in Zucker but not WDF rats. At the time they were killed, sham-operated obese WDF rats were significantly hyperglycemic and hyperinsulinemic compared with other groups, but adrenalectomy reduced plasma glucose and insulin to lean levels in both strains. Adrenalectomy reduced inguinal and retroperitoneal fat pad weights more in Zucker than WDF obese rats. Although adrenalectomy decreased epididymal and inguinal fat cell size in both obese rat strains, the effect was greater in Zucker compared with WDF rats. These data suggest that the basis for the differential response to adrenalectomy in obese WDF and Zucker rats may reside in their different genetic backgrounds.

Cardiovascular risk factor prevention in black schoolchildren: two-year results of the "Know Your Body" program

A five-year intervention study of the effectiveness of the "Know Your Body" program in reducing coronary heart disease risk factors among black students in the District of Columbia, who were in grades 4-6 at baseline, was begun in 1983. Nine schools were stratified on socioeconomic status and randomly assigned to control and intervention groups. The "Know Your Body" curriculum focuses on nutrition, fitness, and the prevention of cigarette smoking. At baseline, 1,234 students were eligible for the screening in which the following target risk factors were measured: systolic and diastolic blood pressures, ponderosity index, triceps skinfold thickness, postexercise pulse recovery rate, serum total and high density lipoprotein (HDL) cholesterol, and serum thiocyanate. After two years of intervention, results indicated that the program may have had a favorable impact on the following risk factors: systolic and diastolic pressures, HDL cholesterol, ratio of total to HDL cholesterol, fitness (postexercise pulse recovery rate), and smoking. Significant net changes in the favorable direction also were found for health knowledge and attitude toward smoking. Blood pressure reduction was associated with decreased ponderosity and improved fitness, and increased HDL cholesterol was associated with decreased ponderosity. These results are consistent with other evaluations of the "Know Your Body" program, suggesting that the program may be effective in reducing chronic disease risk in diverse school populations.

Cardiovascular risk factors among black schoolchildren: comparisons among four Know Your Body studies

Baseline cardiovascular risk factor variables were obtained from 1,041 black District of Columbia children in Grades 4-6 as part of a Know Your Body evaluation project. Screening included height, weight, triceps skinfold measurements, systolic and diastolic blood pressures, step-test for fitness, serum cholesterol, high-density lipoprotein cholesterol and thiocyanate. Results were compared with those in three other Know Your Body studies, Bronx, New York, Westchester, New York, and Los Angeles, and indicated that District of Columbia black children are more likely to have high cholesterol levels and to fail the fitness test than black children in the other studies. In the District of Columbia, obese children had significantly higher total serum cholesterol, systolic, diastolic, and high-density lipoprotein levels, and were less fit than other District of Columbia children; almost three-fourths of all of the children had one or more risk factors. Socioeconomic status was negatively correlated with diastolic blood pressure, skinfold thickness, and cholesterol levels and was positively correlated with high-density lipoprotein cholesterol. Rates of obesity and diastolic blood pressure were consistent with Bronx and Westchester comparisons suggesting that socioeconomic status interacts with ethnicity to determine risk factor levels. The existence of children with multiple risk factors in all of the Know Your Body studies supports the need for early intervention.

Pretransplant conditioning with donor-specific transfusions using heated blood and cyclosporine. Preservation of the transfusion effect in the absence of sensitization

Previous studies from our laboratory showed that pretransplant conditioning with fresh donor-specific blood (DST) combined with cyclosporine (CsA) resulted in long-term prolongation of ACI heterotopic cardiac allografts in LEW recipients treated with subtherapeutic doses of CsA. The concomitant administration of CsA profoundly reduced but did not eliminate the DST-induced sensitization. The purpose of the present study was to investigate in the ACI-to-LEW cardiac allograft model whether heat-treatment of the blood would further reduce the sensitizing potential of DST while maintaining their benefits in our protocol. Fresh heparinized ACI blood was heated at 45 degrees C for 60 min. Then 1.5 ml was administered i.v. to LEW rats on day -8 with respect to grafting (day 0). Controls received heat-treated BUF blood. Donor heat-treated blood (HT-DST), unlike fresh blood, did not induce a humoral cytotoxic response and resulted in the prolongation of cardiac allograft survival (13.2 +/- 2.7 vs. 7.2 +/- 1.0; P less than 0.01). Treatment of HT-DST recipients with postoperative subtherapeutic doses of CsA (2.5 mg/kg/day x 30) extended graft survival (46.6 +/- 22.0 vs. 7.7 +/- 2.0 days; P less than 0.01). The combined pretransplant administration of HT-DST and CsA followed by posttransplant subtherapeutic doses of CsA led to long-term prolongation of cardiac grafts (122.0 +/- 73.0 vs. 31.7 +/- 22.0 days; P less than 0.01). These studies demonstrate that heat-treatment of allogeneic blood eliminates the humoral responses to DST and actually enhances their beneficial effects in terms of graft survival. Such effects can be dramatically increased by CsA. The possible mechanism of these phenomena are discussed.

Effect of triiodothyronine injection on levels of triiodothyronine and thyroid-stimulating hormone in sera and milk of lactating rats and in sera of their sucklings; precocious development of jejunal alpha-disaccharidases in the sucklings

Administration of high doses of triiodothyronine (T3) for 4 days to lactating rats evokes an increase in T3 levels in their sera and milk, as well as in the sera of pups suckled by them. Thyroid-stimulating hormone levels in sera of mothers and sucklings are decreased. Suckling rats of T3-treated mothers exhibit a precocious increase in the activity of jejunal sucrase and maltase as well as in activity of several liver acid beta-glycosidases.

Prenatal development of acid beta-glycosidases in the rat liver, effect of triiodothyronine or cortisone administered to pregnant rats

We have found that acid beta-galactosidase, beta-glucuronidase and N-acetyl-beta-glucosaminidase in the rat fetal liver increase during the last week of pregnancy. These enzyme activities were influenced by treatment of pregnant rats (daily from day 16) with L-tri-iodothyronine (20 or 50 microgram/100 gm b.w.) or cortisone acetate (10 or 50 mg/100 gm b.w.) as studied in their fetuses obtained on day 22 by caesarian section.

Effect of cortisone or triiodothyronine administration to pregnant rats on lysosomal hydrolases in fetal forebrain and cerebellum

Triiodothyronine injected daily to pregnant rats for the last week of gestation (50 microgram/100 g b.wt) increased the specific activities of 5 acid glycosidases in the fetal forebrain and cerebellum. Cortisone (50 mg/100 g b.wt) administered in the same period had no effect on cerebellum acid hydrolases, but decreased their activity in the forebrain.

Prenatal induction of sucrase activity in rat jejunum

Daily application of cortisone acetate (10mg/100g body wt.) or L-tri-iodothyronine (20 microng/100g body wt.) to female rats in the last (third) week of pregnancy elicits a precocious appearance of jejunal sucrase in their foetuses.

Effect of cortisone or L-triiodothyronine administration to pregnant rats on the activity of fetal intestinal disaccharidases and lysosomal acid beta-galactosidase

Activities of maltase, sucrase, lactase and acid-beta-galactosidase were studied in jejunum and ileum of term rat fetuses obtained by cesarian section. Female rats were either untreated or injected daily in the last (3rd) week of pregnancy with cortisone acetate (10 or 50 mg/100 g body weight) or L-triiodothyronine (20 or 50 microgram/100 g body weight). Two other control groups were injected with appropriate solvents. Cortisone or T3 treatment to mothers increased sucrase and maltase activity in jejunum and ileum of the offspring. Generally, higher doses of hormone were more effective. Lactase activity was increased by 25% in the jejunum by the higher dose of cortisone. Both doses of cortisone increased ileal lactase. Jejunal acid-beta-galactosidase activity was decreased in fetuses of T3-treated mothers.

Comparison of postnatal development of several acid glycosidases in the rat forebrain and cerebellum

Changes of activity of several glycosidases (beta-galactosidase, beta-glucuronidase, N-acetyl-beta-D-glucosaminidase, alpha-D-mannosidase and alpha-L-fucosidase) were compared in the forebrain and cerebellum during postnatal development of the rat. Detailed analysis of the data showed similarities, but also substantial differences in their development in both organs. This is interpreted as an indication of the presence of common regulatory mechanisms, as well as of other factors which differently influence development of the glycosidases studied in both CNS parts.

Experimental visceral aspergillosis

Studies conducted to gain insight into the pathogenesis of experimental aspergillosis indicated that mice pretreated with cortisone acetate and then injected intraperitoneally with nongerminating spores of Aspergillus flavus developed a high incidence of lethal visceral hyphal aspergillosis. A similar, high incidence of fatal infections was observed in cortisone-treated animals in which the number of peritoneal macrophages had been increased by prior injection of thioglycollate. To determine whether germination of spores within the host was important to the subsequent development of disseminated hyphal aspergillosis, germinating spores of A flavus were injected intraperitoneally into normal animals. While a similar dose of nongerminating spores, administered intraperitoneally into normal mice, induced a low incidence of lethal injection, germinating spores induced a high incidence of fatal disease associated with widely disseminated visceral hyphal aspergillosis. Our studies indicate that phagocytic cells in the peritoneal cavity of normal mice are able to ingest nonperminating spores of A flavus and kill them, preventing germination. However, the phagocytic cells are unable to cope with early germinating spores, which then continue to proliferate, leading to extensive hyphal invasion of visceral organs and death.