Methemoglobinemia in Patient with G6PD Deficiency and SARS-CoV-2 Infection

Uncovering an undisclosed diagnosis: a glucose-6-phosphate dehydrogenase deficiency diagnosis in a critically ill adult

Glucose-6-phosphate dehydrogenase (G6PD) deficiency affects over 400 million people worldwide. The most common variant of G6PD deficiency in the United States is the A-variant, which is present amongst African-Americans. Most people with this variant, however, do not experience severe hemolysis unless under extreme circumstances. Here, we present the case of a 44-year-old African-American male who under circumstances of multiple admissions for critical illness eventually presented with a masked diagnosis of G6PD deficiency.

Detection of methaemoglobinaemia in a COVID-19 patient on dapsone

Methaemoglobinaemia occurs when iron in haemoglobin is oxidised into a form that cannot transport oxygen. At low levels, it is asymptomatic, though at rising levels symptoms arise from impaired oxygenation, and it can ultimately be fatal. While uncommon, it is important to consider in hypoxaemic COVID-19 patients, especially if they are not clinically improving on standard treatments and workup for other causes does not explain the ongoing hypoxaemia. It is often diagnosed through a mismatch in peripheral and arterial oxygen, with the former typically less than the latter. We present the case of a COVID-19 patient who was found to have methaemoglobinaemia due to dapsone use for Pneumocystic jirovecii pneumonia (PJP) prophylaxis while on chemotherapy. Dapsone was stopped and supplemental high-flow nasal cannula was provided, and methaemoglobin levels improved over a 5-day period. She was discharged to follow-up with her haematologist in the clinic.

Gout Treatment and Clinical Considerations: The Role of Pegloticase, Colchicine, and Febuxostat

Gout treatment has evolved rapidly in recent decades, and various drugs have been designed for acute and chronic management. Three medications used to treat gout include pegloticase, colchicine, and febuxostat. When prescribing these drugs, important factors to consider include pharmacokinetics, pharmacodynamics, population specifics, benefits, and contraindications. Pharmacokinetic considerations of each drug include absorption, distribution, metabolism, and elimination factors. Pharmacodynamics factors are assessed by their potential for toxicity and effects on serum uric acid levels. Additionally, the drug's targeted population must be considered to avoid unwanted complications in certain pre-existing conditions such as cardiovascular disease or glucose-6-dehydrogenase (G6PD) deficiency. In this paper, we aim to provide insight into the gout medications, pegloticase, colchicine, and febuxostat. This review will include their pharmacokinetics, pharmacodynamics, population specifics, benefits, and contraindications.

Co-Occurring Hemolysis and Methemoglobinemia After COVID-19 Infection in Patient With G6PD Deficiency

Hemolytic anemia and methemoglobinemia are known complications in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. They can be elicited by various oxidative stressors. Here we report a case of an adult with the first episode of G6PD deficiency associated hemolysis and methemoglobinemia after acquiring COVID-19 infection, who had no recent exposure to oxidative drugs or fava beans. A 52-year-old gentleman known to have myocardial bridging on aspirin and beta-blocker, with no other medical illnesses, developed anemia symptoms, jaundice, and hypoxia after contracting COVID-19 infection. Further laboratory work revealed non-immune hemolytic anemia, methemoglobinemia, and a positive G6PD screen test. He was treated conservatively with a blood transfusion, and his oxygen saturation improved thereafter. With the widespread COVID-19 infection and its morbidity worldwide, it is crucial to consider methemoglobinemia in the differential diagnosis of hypoxia. Testing for G6PD is an essential next step in such cases, as starting methylene blue in G6PD deficiency can worsen hemolysis. Apart from COVID-19, there is no other identified trigger for the acute event in this patient. It is not known whether COVID-19 infection alone is enough to result in G6PD deficiency-associated hemolysis and methemoglobinemia simultaneously.

Hydroxychloroquine Therapy Led to the Diagnosis of Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency in an Elderly Patient with COVID-19 Involvement: A Case Report and Review of the Literature

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common RBC abnormality, affecting 400 million people globally. Neonatal jaundice, hemolytic anemia, icteric skin, dark urine, and fever are usually the primary signs of this condition, which is generally diagnosed between the ages of infancy and 16 years old. Therefore, its first manifestation in old age is an unexpected phenomenon. Here, we present the case of a 70-year-old man with no past medical history of G6PD deficiency that was admitted to our hospital due to COVID-19 infection and developed acute hemolytic anemia while receiving hydroxychloroquine (HCQ) medication for COVID-19-related pneumonia.

Hemolytic anemia in COVID-19

COVID-19 is a global pandemic triggered by the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 entry point involves the interaction with angiotensin-converting enzyme 2 (ACE2) receptor, CD147, and erythrocyte Band3 protein. Hemolytic anemia has been linked to COVID-19 through induction of autoimmune hemolytic anemia (AIHA) caused by the formation of autoantibodies (auto-Abs) or directly through CD147 or erythrocyte Band3 protein-mediated erythrocyte injury. Here, we aim to provide a comprehensive view of the potential mechanisms contributing to hemolytic anemia during the SARS-CoV-2 infection. Taken together, data discussed here highlight that SARS-CoV-2 infection may lead to hemolytic anemia directly through cytopathic injury or indirectly through induction of auto-Abs. Thus, as SARS-CoV-2-induced hemolytic anemia is increasingly associated with COVID-19, early detection and management of this condition may prevent the poor prognostic outcomes in COVID-19 patients. Moreover, since hemolytic exacerbations may occur upon medicines for COVID-19 treatment and anti-SARS-CoV-2 vaccination, continued monitoring for complications is also required. Given that, intelligent nanosystems offer tools for broad-spectrum testing and early diagnosis of the infection, even at point-of-care sites.

SARS-CoV-2 infection, pulse oximetry, and interpretive caveats

Hypoxaemia in COVID-19 does not necessarily imply COVID pneumonia or post-COVID lung fibrosis, and the caveats of finger pulse oximetry should be remembered. Drug-induced methaemoglobinemia should be considered in individuals with unexplained cyanosis, refractory hypoxaemia, or the presence of a saturation gap. Here, we share our recent encounter of ‘spurious hypoxia’ in a patient with COVID-19 and methaemoglobinemia.

Occurrence of Methemoglobinemia due to COVID-19: A Case Report

Methemoglobinemia (MetHb) is a rare, life-threatening condition that occurs when the body is exposed to oxidative stress. It is typically corrected through the glucose-6-phosphate dehydrogenase (G6PD)-dependent shunt. G6PD deficiency is the most common enzymatic deficiency worldwide. This genetic disorder makes patients susceptible to oxidative stress and reduces the expected life span of erythrocytes (red blood cells (RBCs)) among other cells. G6PD deficiency is asymptomatic in most cases unless exogenous stressors are introduced, whether they are dietary, iatrogenic, or infections, such as the highly transmissible serotype of coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

We report a case of an 11-year-old male with known insulin-dependent diabetes mellitus (IDDM) and glucose-6-phosphate dehydrogenase (G6PD) deficiency, who was found to develop methemoglobinemia after being infected by the SARS-CoV-2 virus.

The direct effects of COVID-19 on children were reported to be lower than on adults. However, the effects of COVID-19 on children with comorbidities, such as G6PD deficiency in our patient, are understood only to a minimal extent. Moreover, identifying cases of G6PD deficiency prior to initiating treatment with methylene blue, hydroxychloroquine (HCQ), or other contraindicated agents is essential to prevent further deterioration in symptoms.

Implication of COVID-19 on Erythrocytes Functionality: Red Blood Cell Biochemical Implications and Morpho-Functional Aspects

Several diseases (such as diabetes, cancer, and neurodegenerative disorders) affect the morpho-functional aspects of red blood cells, sometimes altering their normal metabolism. In this review, the hematological changes are evaluated, with particular focus on the morphology and metabolic aspects of erythrocytes. Changes in the functionality of such cells may, in fact, help provide important information about disease severity and progression. The viral infection causes significant damage to the blood cells that are altered in size, rigidity, and distribution width. Lower levels of hemoglobin and anemia have been reported in several studies, and an alteration in the concentration of antioxidant enzymes has been shown to promote a dangerous state of oxidative stress in red blood cells. Patients with severe COVID-19 showed an increase in hematological changes, indicating a progressive worsening as COVID-19 severity progressed. Therefore, monitored hematological alterations in patients with COVID-19 may play an important role in the management of the disease and prevent the risk of a severe course of the disease. Finally, monitored changes in erythrocytes and blood, in general, may be one of the causes of the condition known as Long COVID.

Treatment strategies for glucose-6-phosphate dehydrogenase deficiency: past and future perspectives

Glucose-6-phosphate dehydrogenase (G6PD) maintains redox balance in a variety of cell types and is essential for erythrocyte resistance to oxidative stress. G6PD deficiency, caused by mutations in the G6PD gene, is present in ~400 million people worldwide, and can cause acute hemolytic anemia. Currently, there are no therapeutics for G6PD deficiency. We discuss the role of G6PD in hemolytic and nonhemolytic disorders, treatment strategies attempted over the years, and potential reasons for their failure. We also discuss potential pharmacological pathways, including glutathione (GSH) metabolism, compensatory NADPH production routes, transcriptional upregulation of the G6PD gene, highlighting potential drug targets. The needs and opportunities described here may motivate the development of a therapeutic for hematological and other chronic diseases associated with G6PD deficiency.

Glucose-6-Phosphate Dehydrogenase Deficiency-Associated Hemolytic Anemia and Methemoglobinemia in a Patient Treated With Hydroxychloroquine in the Era of COVID-19

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymatic disorder of red blood cells worldwide. The severity of hemolytic anemia varies among individuals with G6PD deficiency, depending on the genetic variant in the G6PD gene; this makes the diagnosis of the condition more challenging in some cases. In this report, we present a case of severe hemolytic anemia and methemoglobinemia in a patient with G6PD deficiency who had been exposed to hydroxychloroquine prescribed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. To the best of our knowledge and based on a literature search, this is one of the first case reports in the literature about hemolytic crisis and methemoglobinemia in a patient with critical illness due to severe coronavirus disease 2019 (COVID-19) who was exposed to hydroxychloroquine. It is critical for physicians and caregivers to recognize the effects of oxidative stressors such as hydroxychloroquine, particularly in this era of the COVID-19 pandemic and in regions with a high prevalence of G6PD deficiency, for the appropriate management of this unique subset of patients.

The Affinity of Hemoglobin for Oxygen Is Not Altered During COVID-19

Background: A computational proteomic analysis suggested that SARS-CoV-2 might bind to hemoglobin (Hb). The authors hypothesized that this phenomenon could result in a decreased oxygen (O₂) binding and lead to hemolytic anemia as well. The aim of this work was to investigate whether the affinity of Hb for O₂ was altered during COVID-19. Methods: In this retrospective, observational, single-center study, the blood gas analyses of 100 COVID-19 patients were compared to those of 100 non-COVID-19 patients. Fifty-five patients with carboxyhemoglobin (HbCO) ≥8% and 30 with sickle cell disease (SCD) were also included ("positive controls" with abnormal Hb affinity). P₅₀ was corrected for body temperature, pH, and PCO₂. Results: Patients did not differ statistically for age or sex ratio in COVID-19 and non-COVID-19 groups. Median P₅₀ at baseline was 26 mmHg [25.2-26.8] vs. 25.9 mmHg [24-27.3], respectively (p = 0.42). As expected, P₅₀ was 22.5 mmHg [21.6-23.8] in the high HbCO group and 29.3 mmHg [27-31.5] in the SCD group (p < 0.0001). Whatever the disease severity, samples from COVID-19 to non-COVID-19 groups were distributed on the standard O₂-Hb dissociation curve. When considering the time-course of P₅₀ between days 1 and 18 in both groups, no significant difference was observed. Median Hb concentration at baseline was 14 g.dl^-1 [12.6-15.2] in the COVID-19 group vs. 13.2 g.dl^-1 [11.4-14.7] in the non-COVID-19 group (p = 0.006). Among the 24 COVID-19 patients displaying anemia, none of them exhibited obvious biological hemolysis. Conclusion: There was no biological argument to support the hypothesis that SARS-CoV-2 could alter O₂ binding to Hb.

Drugs, Metabolites, and Lung Accumulating Small Lysosomotropic Molecules: Multiple Targeting Impedes SARS-CoV-2 Infection and Progress to COVID-19

Lysosomotropism is a biological characteristic of small molecules, independently present of their intrinsic pharmacological effects. Lysosomotropic compounds, in general, affect various targets, such as lipid second messengers originating from lysosomal enzymes promoting endothelial stress response in systemic inflammation; inflammatory messengers, such as IL-6; and cathepsin L-dependent viral entry into host cells. This heterogeneous group of drugs and active metabolites comprise various promising candidates with more favorable drug profiles than initially considered (hydroxy) chloroquine in prophylaxis and treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections/Coronavirus disease 2019 (COVID-19) and cytokine release syndrome (CRS) triggered by bacterial or viral infections. In this hypothesis, we discuss the possible relationships among lysosomotropism, enrichment in lysosomes of pulmonary tissue, SARS-CoV-2 infection, and transition to COVID-19. Moreover, we deduce further suitable approved drugs and active metabolites based with a more favorable drug profile on rational eligibility criteria, including readily available over-the-counter (OTC) drugs. Benefits to patients already receiving lysosomotropic drugs for other pre-existing conditions underline their vital clinical relevance in the current SARS-CoV2/COVID-19 pandemic.

The Role of Methemoglobin and Carboxyhemoglobin in COVID-19: A Review

Following the outbreak of a novel coronavirus (SARS-CoV-2) associated with pneumonia in China (Corona Virus Disease 2019, COVID-19) at the end of 2019, the world is currently facing a global pandemic of infections with SARS-CoV-2 and cases of COVID-19. Since severely ill patients often show elevated methemoglobin (MetHb) and carboxyhemoglobin (COHb) concentrations in their blood as a marker of disease severity, we aimed to summarize the currently available published study results (case reports and cross-sectional studies) on MetHb and COHb concentrations in the blood of COVID-19 patients. To this end, a systematic literature research was performed. For the case of MetHb, seven publications were identified (five case reports and two cross-sectional studies), and for the case of COHb, three studies were found (two cross-sectional studies and one case report). The findings reported in the publications show that an increase in MetHb and COHb can happen in COVID-19 patients, especially in critically ill ones, and that MetHb and COHb can increase to dangerously high levels during the course of the disease in some patients. The medications given to the patient and the patient’s glucose-6-phospate dehydrogenase (G6PD) status seem to be important factors determining the severity of the methemoglobinemia and carboxyhemoglobinemia. Therefore, G6PD status should be determined before medications such as hydroxychloroquine are administered. In conclusion, MetHb and COHb can be elevated in COVID-19 patients and should be checked routinely in order to provide adequate medical treatment as well as to avoid misinterpretation of fingertip pulse oximetry readings, which can be inaccurate and unreliable in case of elevated MetHb and COHb levels in the blood.

Methemoglobinemia and hemolytic anemia after COVID-19 infection without identifiable eliciting drug: A case-report

We report a second case of methemoglobinemia and non-autoimmune hemolytic anemia after contracting the SARS-CoV-2 infection in the absence of an identifiable eliciting drug. A 35-year old male without previous known comorbidities was admitted after he was diagnosed with the COVID-19 infection and had large pulmonary involvement. Seven days later, he desaturated but was without any signs of respiratory distress. A check of arterial blood gas revealed normal partial pressure of oxygen and follow-up tests confirmed a methemoglobinemia diagnosis. Over the next few days, hemolysis was established after decreased levels of hemoglobin and increased levels of indirect bilirubin and lactate dehydrogenase. A hemolytic anemia investigation panel came back normal, including G6PD. A second G6PD test was ordered at the 5-month follow-up appointment and revealed decreased levels. Clinicians should thus be aware of possible false negative tests when testing for G6PD during hemolytic crisis. In addition, whether the COVID-19 infection alone would be responsible for this chain of events remains a challenging question.

COVID-19/SARS-CoV-2 Infection: Lysosomes and Lysosomotropism Implicate New Treatment Strategies and Personal Risks

In line with SARS and MERS, the SARS-CoV-2/COVID-19 pandemic is one of the largest challenges in medicine and health care worldwide. SARS-CoV-2 infection/COVID-19 provides numerous therapeutic targets, each of them promising, but not leading to the success of therapy to date. Neither an antiviral nor an immunomodulatory therapy in patients with SARS-CoV-2 infection/COVID-19 or pre-exposure prophylaxis against SARS-CoV-2 has proved to be effective. In this review, we try to close the gap and point out the likely relationships among lysosomotropism, increasing lysosomal pH, SARS-CoV-2 infection, and disease process, and we deduce an approach for the treatment and prophylaxis of COVID-19, and cytokine release syndrome (CRS)/cytokine storm triggered by bacteria or viruses. Lysosomotropic compounds affect prominent inflammatory messengers (e.g., IL-1B, CCL4, CCL20, and IL-6), cathepsin-L-dependent viral entry of host cells, and products of lysosomal enzymes that promote endothelial stress response in systemic inflammation. As supported by recent clinical data, patients who have already taken lysosomotropic drugs for other pre-existing conditions likely benefit from this treatment in the COVID-19 pandemic. The early administration of a combination of antivirals such as remdesivir and lysosomotropic drugs, such as the antibiotics teicoplanin or dalbavancin, seems to be able to prevent SARS-CoV-2 infection and transition to COVID-19.