Diagnostic Tools in COVID-19-Associated Mucormycosis: Do We Need 3-dimensional Computed Tomography

Introduction: Early detection of COVID-19-associated mucormycosis (CAM) is critical for accurate staging and optimal treatment. Three-dimensional computed tomography (3D CT) reconstruction of the face has recently come up as a newer diagnostic tool in CAM. Method(s): This clinical study was done to evaluate the efficacy of 3D CT in diagnosing and managing CAM. We compared 3D CT reconstruction with conventional 2D CT. One hundred twenty-three confirmed cases of mucor were subjected to 3D CT reconstruction in addition to contrastenhanced magnetic resonance imaging after comprehensive clinical workup. The involvement of maxillary walls, alveolus, palate, orbital floor, zygomatic process, and other facial skeleton were noted. The plan of management was decided after assessing the extent in 3D CT. Result(s): Anterior maxillary wall was found to be the commonly involved (9.7%). Involvement of the lateral maxillary wall was noted in 8.1% of subjects. Sixty-seven subjects underwent endoscopic endonasal debridement, 19 underwent total maxillectomy, 3 had infrastructure maxillectomy, 8 had orbital exenteration, and 12 had combined endoscopic and open surgeries. In 21 patients (17%), open surgery was done based on additional 3D CT findings at the first instance and revision surgeries were avoided. Conclusion(s): 3D CT face was found to be superior to conventional CT in diagnosing the extent of disease and plays an important role in preoperative surgical planning of CAM. Minor cortex erosions are not picked up by conventional CT;it also does not show finer details and leaves the surgeon imagining the disease extent. 3D CT decreases delay in diagnosis, facilitates the surgical plan, and reduces the need for multiple surgeries. It is a valuable tool in the assessment of revision cases and follow-up.

Coronavirus-associated mucormycosis: different from sinonasal mucormycosis.

OBJECTIVE: To study unusual presentations of coronavirus-associated mucormycosis that are rarely seen in sinonasal mucormycosis cases. METHOD: The data of 400 rhino-orbito-cerebral mucormycosis patients admitted to Sawai Man Singh Hospital, Jaipur, from May 2021 to June 2021, were retrospectively collected. The diagnosis of mucormycosis was made by histological examination of biopsy samples. RESULTS: Out of 400 patients, 62 had symptoms other than common symptoms of rhino-orbito-cerebral mucormycosis. Thirty-four patients had facial palsy, 19 complained of gum ulcers, 6 developed a cheek abscess, 2 complained of maggots in the nose along with common rhino-orbito-cerebral mucormycosis symptoms, and 1 had a cerebellar infarct. CONCLUSION: Mucormycosis is a disease with various presentations, and coronavirus-associated mucormycosis has added unusual presentations to the existing list of manifestations of rhino-orbito-cerebral mucormycosis. In this coronavirus disease era, mucormycosis should always be considered as a diagnosis in patients with these unusual presentations.

Clinical Profile of COVID-19 Positive Obstetric Patients Admitted to a Tertiary Care Hospital during the Two Waves of COVID-19

Background: Coronavirus disease 2019 (COVID-19), a global pandemic which undoubtedly hit the whole world so hard. There have been multiple waves across the globe of varying time, duration, and intensity, India has also witnessed two waves sweeping the entire nation. The second wave had startling intensity with massively increased oxygen requirement, intensive care unit (ICU) admissions. The effect was even more pronounced in the pregnant women as there was increased maternal morbidity and mortality. However, there are limited reports on the impact of COVID-19 during pregnancy. Objective: This study is aimed at highlighting the variance in clinical profile of pregnant patients in first and second wave of COVID-19 in India. Materials and methods: A retrospective observational comparative hospital-based study was conducted in a tertiary care hospital in Delhi during the two waves of COVID-19. The first wave in India lasted from May 2020 to October 2020, and the second wave lasted from April 2021 to June 2021.We obtained the medical records and compiled clinical and outcome data for all pregnant patients, who were admitted in the Department of Obstetrics and Gynaecology of our Hospital during the first and second wave of pandemic with a laboratory-confirmed report of SARS-CoV-2. Results and conclusion: The second wave definitely saw more number of symptomatic patients, an increase in symptom of shortness of breath, increase in oxygen requirement, ICU admissions, marginally increase lower segment cesarean section (LSCS) rates and associated comorbidity such as hypertensive disease of pregnancy.

A SINGLE-CELL SURVEY OF GASTRIC MUSCULARIS MACROPHAGES IN DIABETIC GASTROPARESIS

Background: Gastric muscularis propria immune cells play an instrumental role in homeostasis and disease. A subset of these cells, muscularis macrophages (MMs) are involved in the pathobiology of diabetic gastroparesis (DG) but are poorly understood. This study aims to survey transcriptional and functional profiling of gastric MMs in DG and diabetes. Methods: Full-thickness gastric body biopsies were obtained from patients with DG and diabetic controls. CD45+ cells were isolated from dissociated muscle tissue using magnetic beads. 10xGenomics was used for scRNA-seq library prep and cells sequenced by Illumina HiSeq4000. Bioinformatic analyses was performed using Suite and Seurat. Myeloid cells were annotated through a pseudogating strategy that identifies cells by differential expression levels of HLA-DR, CD14, CD11b, and CD11c based on flow cytometry-based gating utilized in a recent analysis of human small intestinal MMs. Canonical signaling pathways were determined using Ingenuity Pathway Analysis (IPA). Results: A total of 21,740 high-quality single-cell transcriptomes were generated from 16 subjects (DG=6, age 32±8 yr, BMI 23.7±3.9, 48.2±40.1% 4 hr gastric retention, average GCSI score 3.7±0.5;Diabetic controls= 10, age 53±13 yr, BMI 42.2±5.7). Through annotating 8,693 myeloid cells (DG 1509, Controls 7184), we characterized 1,788 as MMs (CD45+HLA-DR+) and 448 as dendritic cells (CD14-CD11c+). Utilizing a priori markers for pseudogating, the MMs were divided into four populations (Figure 1): subset 1 (CD14+CD11c+HLA-DRint, 5.6%), subset 2 (CD14+CD11c+HLA-DRhi, 36.0%), subset 3 (CD14+CD11c-CD11b-, 41.8%), and subset 4 (CD14+CD11c-CD11b+, 16.6%). The overall proportions of cells in the 4 subsets were similar to a prior approach in small bowel using gating. The expected ratio of cells from DG/diabetic control was 21% based on imputed cells. Subsets 1 and 4 were significantly decreased in DG compared to controls with ratios 15% and 14% respectively while subsets 2 and 3 were unchanged (21% and 20%). On IPA, phagosome formation and immune cell trafficking represented canonical signaling pathways of subset 1 and coronavirus phagocytosis pathway and phagosome formation of subset 4. Canonical genes of subset 1 included S100A12, A8, A9, and CSTA and subset 4 as LYVE1, MAF, MRC1 (CD206), MS4A4, and A2M. Subset 4 also had the highest expression of neuron-related genes (NPTX2, BMP2) similar to that observed in the small intestine. Conclusions: Pseudogating based on the transcriptomic expression of gastric immune cells reveal MM clusters similar in gene expression and proportions to previously characterized MMs in human small bowel using gating. The reduction of MM clusters associated with anti-inflammatory, phagocytosis, and neuronal signaling in specialized MMs subsets may suggest candidate targets in the pathophysiology of DG. Supported by NIHDK074008. (Figure Presented) Figure 1. Single-Cell RNA-Seq Profiling of Human Gastric Muscularis Macrophages in DG and Diabetes. T-distributed Stochastic Neighbor Embedding (tSNE) plot of muscularis macrophages in DG and diabetic control subjects by their differential genes from MAST (FDR < 0.05), color-coded by Status. *Mf1 and Mf2 not visualized as distinct clusters due to inadequate separation of overall gene expression in cells distinguished by HLA-DRint (Mf1) and HLA-DRhi (Mf2)

To study the correlation between smoking (pack years) and CT severity score in COVID 19 RTPCR positive patients - Short retrospective study and also study It's effect on COVID 19 biomarkers

Background: Coronavirus Disease 2019 (COVID-19) is a contagious disease caused by SARS (SARS-COV2). It is a large family of virus that are known to cause illnesses ranging from common cold to pneumonia to Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS). The effect of smoking on COVI D 19 is under consideration. This study is aimed to evaluate the relationship between smoking (Pack years) and CT severity score and its effect on COVID 19 linked biomarkers in COVID-19 RTPCR positive patients. Materials and Methods: This is a retrospective study conducted between March 2021 to July 2021 on 50 adult COVID-19 RTPCR positive patients admitted in COVID ward and ICU in GMC, Kota. Their CTSS and biomarkers (CRP, D-Dimer, LDH, IL-6 and S. Ferrtin) were obtained at the time of admission and smoking history was obtained for the study. Results: The CT severity score was found to be high in patients with more pack years. The Pearson Correlation 'r' value was calculated as 0.575475 with a p-value of 0.000012 at 5% level of significance which is highly significant. COVID-19 linked biomarkers and its association with pack years was also evaluated. P-values at 5% level of significance for the biomarkers are CRP=0.03359, D-Dimer=0.219884, LDH=0.000028, IL-6=0.186538 and Serum Ferritin=0.00001. Conclusion: CT severity score is high in smokers and shows significant p-Value at 0.05 and is associated with poor prognosis. CRP, LDH and S. Ferritin are found to be significantly raised in smokers suffering from COVID 19 disease, out of which S. Ferritin is more significantly raised as compared to other significant markers.

Post coronavirus disease mucormycosis: a deadly addition to the pandemic spectrum.

OBJECTIVE: To study the possible association between invasive fungal sinusitis (mucormycosis) and coronavirus disease. METHODS: A prospective observational study was conducted at a tertiary care centre over four months, involving all patients with mucormycosis of the paranasal sinuses suffering from or having a history of coronavirus disease infection. RESULTS: Twenty-three patients presented with mucormycosis, all had an association with coronavirus disease 2019. The ethmoids (100 per cent) were the most common sinuses affected. Intra-orbital extension was seen in 43.47 per cent of cases, while intracranial extension was only seen in 8.69 per cent. Diabetes mellitus was present in 21 of 23 cases, and was uncontrolled in 12 cases. All patients had a history of steroid use during their coronavirus treatment. CONCLUSION: New manifestations of coronavirus disease 2019 are appearing over time. The association between coronavirus and mucormycosis of the paranasal sinuses must be given serious consideration. Uncontrolled diabetes and over-zealous use of steroids are two main factors aggravating the illness, and both of these must be properly checked.

MICROBIAL COLONIZATION SUPRESSES COLONIC ACE2 EXPRESSION

Background: Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has been responsible for the global pandemic and disease known as COVID-19. Clinical studies have found >50% of COVID-19 patients report gastrointestinal (GI) symptoms, with some studies suggesting longer viral clearance in patients with GI symptoms. SARS-CoV-2 utilizes angiotensin-converting enzyme 2 (ACE2) as a receptor for viral attachment and intracellular entry, which is expressed in the intestine, making the GI tract a potential route of infection. Aim: To determine the effect of microbial colonization on colonic ACE2 expression using a humanized mouse model. Methods: Human stool was collected from healthy volunteers and individuals with irritable bowel syndrome, a common gastrointestinal disorder, and fecal slurries were prepared. 4-6 week old female Swiss-Webster mice (N=6/group) were gavaged with fecal slurries and maintained in sterile ex-isolator cages for 6 weeks. Posthumanization stool was collected along with proximal colonic tissue. Shotgun metagenomics was done on mouse pellets. RNAseq on tissue performed at a depth of 20 million reads/ sample using NovaSeq 6000. MAP-Rseq workflow using the mm10 genome was done to identify differentially expressed genes. Associations of ACE2 expression with α –diversity between microbiome from healthy and irritable bowel syndrome humanized mice was done using linear modeling with compositional associations assessed using PERMANOVA (BrayCurtis distance). To identify taxa associated with ACE2 expression, a permutation-based approach using the F-statistic of a linear model was used with false discovery rate (FDR) to correct for multiple testing. Results: Humanized mice demonstrated significantly lower colonic ACE2 expression compared to the germ-free mice (333.4 ± 191.1 vs. 1914 4 ± 309.9, FDR<0.001). However, ACE2 expression was similar post-humanization across all mouse groups regardless of stool used for humanization, despite decreased diversity in stool from irritable bowel syndrome patients and compositional differences from healthy volunteer stool. No associations between microbiome α-diversity (Shannon p=0.825, observed p= 0.400, InvSimpson p=0.512), β-diversity (p=0.568) or individual taxa were seen with ACE2 expression. Conclusions: Commensal microbial colonization significantly suppresses colonic ACE2 expression. However, in this pilot study, mice colonized with dysbiotic and healthy microbial communities had similar ACE2 expression. Future studies will have to explore the role of commensal microbes on gastrointestinal expression of ACE2 which may in turn reflect predisposition for infection or intestinal involvement with SARS-CoV-2. Supported by DK103911, DK120745.

Rhino-Orbital Cerebral Mucormycosis in Non-Diabetic Patients with COVID-19

Rhino-orbital Cerebral Mucormycosis (ROCM), a rare invasive fungal infection, affects diabetic and immunocompromised individuals. Recent reports have raised the alarm for invasive ROCM associated with SARS-CoV-2 infection. SARS-CoV-2 infection causes immune cell dysregulation, cytokine dysregulation, and is associated with invasive fungal infections. Immunosuppressive treatment of COVID-19 with corticosteroids increases the risk of opportunistic infection. We present a series of 3 cases of invasive ROCM with different outcomes in immunocompetent nondiabetic patients who all received corticosteroids at doses higher than those recommended by the World Health Organization, and who received oxygen during their SARS-CoV-2 treatment course. Immune dysregulatory effects of COVID-19 and high-dose corticosteroids may both have caused predisposition to ROCM in these cases. Additionally, health system stress caused by responding to COVID-19 surges may have predisposed patients to exposure to mucormycosis-causing fungi through use of non-sterilized water for oxygen humidification. In light of these cases, we encourage guideline-based corticosteroid dosing in the management of COVID-19 as well as vigilance for invasive mucormycosis and prompt treatment in corticosteroid-treated patients.