Centrality of G6PD in COVID-19: The Biochemical Rationale and Clinical Implications

Introduction: COVID-19 is a novel and devastating disease. Its manifestations vary from asymptomatic to lethal. Moreover, mortality rates differ based on underlying health conditions and ethnicity. We investigated the biochemical rationale behind these observations using machine reasoning by the sci.AI system (https://sci.ai/). Facts were extracted and linked from publications available in nlm.nih.gov and Europe PMC to form the dataset which was validated by medical experts. Results: Based on the analysis of experimental and clinical data, we synthesized detailed biochemical pathways of COVID-19 pathogenesis which were used to explain epidemiological and clinical observations. Clinical manifestations and biomarkers are highlighted to monitor the course of COVID-19 and navigate treatment. As depicted in the Graphical Abstract, SARS-CoV-2 triggers a pro-oxidant (PO) response leading to the production of reactive oxygen species (ROS) as a normal innate defense. However, SARS-CoV-2's unique interference with the antioxidant (AO) system, through suppression of nitric oxide (NO) production in the renin- angiotensin-aldosterone system (RAAS), leads to an excessive inflammatory PO response. The excessive PO response becomes critical in cohorts with a compromised AO system such as patients with glucose-6-phosphate dehydrogenase deficiency (G6PDd) where NO and glutathione (GSH) mechanisms are impaired. G6PDd develops in patients with metabolic syndrome. It is mediated by aldosterone (Ald) which also increases specifically in COVID-19. Conclusion: G6PD is essential for an adequate immune response. Both G6PDd and SARS-CoV-2 compromise the AO system through the same pathways rendering G6PDd the Achilles' heel for COVID-19. Thus, the evolutionary antimalarial advantage of the G6PDd cohort can be a disadvantage against SARS-CoV-2.

Antibiotic Stewardship for Non-Infectious Disease Physicians: Focusing on When to Withhold, Modify and Discontinue Antibiotics

The multiple drug resistant organism (MDRO) and Clostridium difficile infection (CDI) epidemics are progressing relentlessly. Antibiotic stewardship (ABS) has evolved to confront these scourges. The Joint Commission has formulated a standard for its implementation and this should promote its use where others have failed. However, precisely how to intervene needs definition. Healthcare workers need practicable guidelines. The article discusses clinical scenarios where antibiotics should be withheld (Table 1), how they should be modified (Table 2) and when they should be discontinued (Table 3), three focal points of ABS.

Fever notions of the misinformed: a quality improvement project

Tracking temperatures graphically, recognizing their normal quotidian variations, and acknowledging that fever may be a beneficial physiological response to infection, have been lost in modern hospital care. Further, injudicious use of antibiotics for "low-grade fever" contributes to the multiple drug resistant organism and Clostridium difficile epidemics. This essay discusses these issues and proposes changing common misperceptions of fever as a quality improvement project.

The major genetic determinants of HIV-1 control affect HLA class I peptide presentation

Infectious and inflammatory diseases have repeatedly shown strong genetic associations within the major histocompatibility complex (MHC); however, the basis for these associations remains elusive. To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and we analyzed the effects of individual amino acids within the classical human leukocyte antigen (HLA) proteins. We identified >300 genome-wide significant single-nucleotide polymorphisms (SNPs) within the MHC and none elsewhere. Specific amino acids in the HLA-B peptide binding groove, as well as an independent HLA-C effect, explain the SNP associations and reconcile both protective and risk HLA alleles. These results implicate the nature of the HLA-viral peptide interaction as the major factor modulating durable control of HIV infection.

Infectious-appearing diseases, and infections that present in disquises

Several disorders can appear to be infections when actually they are not. Conversely, certain infectious diseases can manifest themselves as something other than infection. These unwittingly mistaken diagnoses segue into misguided therapy-misuse of antibiotics in particular-and consequently fail to improve. These disorders have been described separately. Grouping them together draws attention to their importance in an infectious disease differential diagnosis. This article systematically assembles and briefly discusses some of these infectious-appearing diseases.

Laboratory-acquired vaccinia infection

BACKGROUND

Complications following vaccination with vaccinia virus have been well described but are not commonly observed. The use of vaccinia as a tool in molecular biology, in the development of therapeutics, and the anticipated increase of vaccinations in the general population due to the threat of bioterrorism have created a renewed awareness of the post-vaccination complications and the consequent need for clinical and laboratory diagnosis.

OBJECTIVES

To report the clinical presentation and subsequent diagnosis of generalized vaccinia that resulted from a laboratory accident in an unvaccinated subject.

STUDY DESIGN

The patient was seen by a local infectious disease's specialist and evaluated clinically and with laboratory support relative to a differential diagnosis.

RESULTS

Careful assessment of the patient's history, an evaluation of the workplace, and the elimination of likely microbial etiologies led to the diagnosis of generalized vaccinia. Laboratory confirmation was obtained by use of electron microscopy (EM) to observe poxvirus particles in infected cell cultures.

CONCLUSIONS

Exposure to vaccinia virus should raise the index of suspicion for patients with skin lesions. Rapid diagnosis may be accomplished by direct examination of lesion material by EM. The virus also readily replicates in commonly available cell cultures and in the absence of immune reagents, typical poxvirus particles may be observed in the infected cells by EM.

Ganciclovir treatment of systemic cytomegalovirus in an immunocompetent host

Cytomegalovirus (CMV) infects a significant number of otherwise healthy individuals. Although most cases are subclinical and therefore not diagnosed, some patients present with a mononucleosis-type illness. Ganciclovir, an agent effective against CMV, has primarily been studied for use in immunocompromised patients. No formal studies have been done in immunocompetent individuals. We report a case of an otherwise healthy adult female with severe heterophile negative infectious mononucleosis. Her symptoms included high fever, malaise, myalgias, cough, and abdominal pain. Work-up revealed an acute CMV infection. Intravenous ganciclovir was given with dramatic clinical and laboratory improvement.

The merits of varicella vaccination for varicella non-immune health care workers

Immunity against varicella can be reliably established by history and, if negative, confirmed or refuted by serology. If non-immune, the merits of varicella vaccine for a health care worker (HCW) can be stated clearly: Protection from a disease which may be particularly severe in an adult, and evading the inconvenience (investigation time and possible work restriction) and cost of managing an exposure. This paper discusses implementation of a varicella immunity program for HCWs at Columbia Presbyterian Hospital in Oklahoma City.

Twice daily intramuscular imipenem/cilastatin in the treatment of skin and soft tissue infections

One hundred and two patients were enrolled in an open-label evaluation of intramuscular imipenem/cilastatin using doses of either 500 or 750 mg every 12 h in the treatment of mild to moderately severe skin and soft tissue infections. Seventy-four of 102 patients were clinically evaluable. Thirty-one patients had abscesses, 20 had cellulitis and 23 had wound infections. One hundred seventy-eight isolates were recovered from these 74 patients (average 2.4 isolates/patient). Sixty of 74 evaluable patients (82%) were cured; 12 of 74 (16%) were improved. Two patients failed to improve. Therapy was well tolerated. Adverse effects occurred in 8 patients. All of these effects were minor, and none required discontinuation of therapy. Eighty-two percent of patients reported no pain with injections. Therapy did not need to be interrupted or discontinued in the remaining 18% of patients reporting moderate local pain with injections. Peak and trough serum imipenem levels were measured in 15 patients receiving a 500-mg intramuscular dose of imipenem/cilastatin. The mean peak imipenem concentration in 15 patients was 10.7 micrograms/ml (range 3.3-17.8); the mean trough concentration was 2.1 micrograms/ml (range 0.8-4.9). The trough levels were higher than those found in healthy volunteers and may reflect the age and mild renal dysfunction in this group of treated patients. Imipenem/cilastatin used for mild or moderate skin and soft tissue infections was both efficacious and well tolerated. Intramuscular therapy with this agent offers advantages over intravenous therapy because of its long apparent half-life and pharmacokinetics.

Unusual skin sites of herpes simplex eruptions: delay in diagnosis

Whereas Herpes simplex labialis and genitalis are common and simple to diagnose, herpetic eruptions in other areas are relatively rare and often misdiagnosed. We report five cases of Herpes simplex eruption at unusual sites. Diagnosis was delayed up to 20 years and resulted in unnecessary antibiotic treatment. The recurrent nature of this eruption is the key to diagnosis.

Ethanol inhibition of granulocyte adherence

Ethanol inhibits granulocyte adherence (GA) in whole blood. To determine the mechanism, GA was measured by the nylon fiber assay. In vitro addition of 300 mg/dl ethanol to whole blood caused a 28.1% decrease of GA compared with the control value (p less than 0.009) but did not affect GA of pure PMNs suspended in plasma or in HBSS. Similarly, GA measured in whole blood from intoxicated rabbits fell 48.8% from preintoxication values, but adherence of isolated postintoxication PMNs suspended in postintoxication plasma was not inhibited. Therefore, inhibition of GA by ethanol requires the presence of other cellular components of whole blood. To determine which cell(s) mediate the inhibition, PMNs were suspended with isolated blood components: platelet-rich and platelet-poor plasma, with and without the addition of mononuclear leukocytes and RBCs. Although the reconstitution of whole blood from its components allowed alcohol-induced inhibition of GA (decrease of 32.9%), none of the incomplete blood component mixtures demonstrated this effect. It was concluded that inhibition of GA by ethanol is mediated by an interaction between the components of whole blood.