The clinical heterogeneity of entirely nonenhancing CNS lymphoma: a case series

CNS lymphoma often presents with atypical imaging characteristics leading to delay in diagnosis and initiation of treatment. Among the most rarely reported of these is entirely nonenhancing CNS lymphoma, which is estimated at an incidence of about 1%. Here, we present three cases of nonenhancing CNS lymphoma in immune competent patients at both initial presentation and recurrence and in primary as well as secondary CNS lymphoma. Diffusion- and perfusion-weighted imaging was found helpful in diagnosis in some cases.

Coexistent pulmonary cryptococcal infection and pulmonary sarcoidosis: a case report and literature review

Cryptococcus is an encapsulated, yeast-like fungus commonly responsible for infections in individuals with impaired T cell-mediated immune responses, including those with acquired immune deficiency syndrome or taking immunosuppressive agents such as steroids or cyclosporine. However, pulmonary fungal infection is rare in patients with untreated sarcoidosis. We report a case of coexistent pulmonary cryptococcal infection in a 43-year-old man with pulmonary sarcoidosis in North-western China. The patient was diagnosed with sarcoidosis via right anterior mediastinal lymph node biopsy and lung biopsy by bronchoscopy. He was treated with oral prednisone 25 mg/day and achieved complete remission of all symptoms. However, repeat chest computed tomography examination revealed enlarged nodules in the left lower lobe, but decreased bilateral diffuse small nodules in the lungs. Computed tomography-guided percutaneous lung puncture biopsy revealed cryptococcal infection. This case highlights the need to consider fungal infection in patients with sarcoidosis at initial presentation, irrespective of their use of immunosuppressive medication.

Fatal renal mucormycosis with Apophysomyces elegans in an apparently healthy male

Mucor is an angioinvasive fungus that was reported mainly in immunocompromised patients. It usually presents as rhino-orbital, pulmonary, gastrointestinal, and disseminated disease. Isolated renal mucormycosis is an extremely rare infection in immunocompetent patients and is associated with high fatality rate. Early diagnosis, prompt antifungal treatment, and surgery give the patient the best chance for cure and survival. We describe herein a case of renal zygomycosis caused by Apophysomyces elegans (A. elegans) in an immunocompetent host. To the best of our knowledge, this is the first case of renal A. elegans to be reported from Qatar and the Middle East.

Coccidiomycosis immitis Resulting in a Prosthetic Joint Infection in an Immunocompetent Patient after a Total Hip Arthroplasty: A Case Report and Review of the Literature

Coccidiomycosis immitis is a fungal infection that is a rare cause of prosthetic joint infection (PJI) in patients. This case report describes an immunocompetent patient who had a right total hip arthroplasty (THA) complicated with Coccidiomycosis immitis. This patient is the 9th reported case of Coccidiomycosis immitis causing a PJI and only the second case to be reported in a THA. Once progressed, it can be difficult to treat, often reoccurring and requiring repeat sur-gical and prolonged therapy. We discuss the clinical presentation in this patient and review the literature on the current pub-lished cases.

Assessing the virulence of Cryptococcus neoformans causing meningitis in HIV infected and uninfected patients in Vietnam

We previously observed a substantial burden of cryptococcal meningitis in Vietnam atypically arising in individuals who are uninfected with human immunodeficiency virus (HIV). This disease was associated with a single genotype of Cryptococcus neoformans (sequence type [ST]5), which was significantly less common in HIV-infected individuals. Aiming to compare the phenotypic characteristics of ST5 and non-ST5 C. neoformans, we selected 30 representative Vietnamese isolates and compared their in vitro pathogenic potential and in vivo virulence. ST5 and non-ST5 organisms exhibited comparable characteristics with respect to in vitro virulence markers including melanin production, replication at 37°C, and growth in cerebrospinal fluid. However, the ST5 isolates had significantly increased variability in cellular and capsular sizing compared with non-ST5 organisms (P < .001). Counterintuitively, mice infected with ST5 isolates had significantly longer survival with lower fungal burdens at day 7 than non-ST5 isolates. Notably, ST5 isolates induced significantly greater initial inflammatory responses than non-ST5 strains, measured by TNF-α concentrations (P < .001). Despite being generally less virulent in the mouse model, we hypothesize that the significant within strain variation seen in ST5 isolates in the tested phenotypes may represent an evolutionary advantage enabling adaptation to novel niches including apparently immunocompetent human hosts.

Leclercia Adecarboxylata Causing Necrotizing Fasciitis in an Immunocompetent Athlete Injecting Illicit Testosterone Supplements

Leclercia adecarboxylata (L. adecarboxylata) is an uncommon and often misdiagnosed cause of multiple infection types including skin and soft tissue, cholecystitis, and septicemia. It commonly afflicts immunocompromised hosts or individuals who experience trauma in aquatic environments. We present a case where this bacteria causes necrotizing fasciitis as a consequence of injecting street bought testosterone supplements. This patient was treated successfully with excisional debridement of the wound as well as a one week course of Linezolid and Bactrim. 

The great masquerader: Hemophagocytic lymphohistiocytosis secondary to cytomegalovirus infection in an immunocompetent young man

Hemophagocytic lymphohistiocytosis (HLH) is a rare, poorly recognized and underdiagnosed syndrome of excessive immune activation, which is rapidly fatal. HLH can occur as a familial or secondary disorder. Secondary HLH is most commonly associated with infections, malignancies, or autoimmune diseases. It primarily affects patients with a compromised immune system and rarely presents in immunocompetent individuals. Acute cytomegalovirus (CMV) associated HLH in the immunocompetent individual is extremely rare and only documented in five case reports till date. We, hereby, report a case of 18 years old young immunocompetent man who was diagnosed to have HLH secondary to CMV infection.

Unilateral Maxillary Sinus Plasmablastic Lymphoma in an Immunocompetent Patient. An Unusual Occurrence Report and Literature Review

Plasmablastic lymphoma (PBL) is a rare and aggressive form of mature B cell neoplasms almost exclusively identified in patients infected with the human immunodeficiency virus (HIV). The small number of HIV-negative PBL cases reported in the literature to date is composed of single case reports and small case series which characteristically are present involving the oral cavity mucosa or gingiva. We present a 72-year-old HIV-negative Australian patient without any cause of immunodeficiency, with an isolated left maxillary sinus PBL.

An Immunocompetent Mouse Model of HPV16(+) Head and Neck Squamous Cell Carcinoma

The incidence of human papilloma virus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) is increasing and implicated in more than 60% of all oropharyngeal carcinomas (OPSCCs). Although whole-genome, transcriptome, and proteome analyses have identified altered signaling pathways in HPV-induced HNSCCs, additional tools are needed to investigate the unique pathobiology of OPSCC. Herein, bioinformatics analyses of human HPV(+) HNSCCs revealed that all tumors express full-length E6 and identified molecular subtypes based on relative E6 and E7 expression levels. To recapitulate the levels, stoichiometric ratios, and anatomic location of E6/E7 expression, we generated a genetically engineered mouse model whereby balanced expression of E6/E7 is directed to the oropharyngeal epithelium. The addition of a mutant PIK3CA^E545K allele leads to the rapid development of pre-malignant lesions marked by immune cell accumulation, and a subset of these lesions progress to OPSCC. This mouse provides a faithful immunocompetent model for testing treatments and investigating mechanisms of immuno- suppression.

Carper et al. present the ‘‘iKHP’’ mouse, in which HPV16 oncogenes are inducibly activated in vivo in a tissue-specific and temporal manner. Oropharyngeal- specific expression of E6/E7 with PIK3CA^E545K in these mice promotes the development of premalignant lesions marked by immune cell infiltration, but only a subset spontaneously convert to OPSCC.

Relapse of Plasmablastic Lymphoma With Cutaneous Involvement in an Immunocompetent Male

Plasmablastic lymphoma (PBL) is a rare type of non-Hodgkin lymphoma frequently found in the context of immunosuppression and infection with human immunodeficiency virus (HIV) and/or Epstein-Barr virus (EBV). A 33-year-old immunocompetent male presented with recurrent episodes of epistaxis and a growing intranasal mass. Excisional biopsy of the mass revealed an immunohistochemical profile diagnostic of PBL. Upon completion of chemoradiation, he underwent a transnasal endoscopic mucosal flap tissue rearrangement to restore patency for both functional and surveillance purposes. There was no endoscopic evidence of residual or recurrent disease. However, 8 months later, he was found to have a relapse involving the skin. The nasal cavity is one of the most common sites affected by PBL. Involvement of the nasal cavity may present with symptoms of persistent epistaxis accompanied by an enlarging mass. A plasmablastic immunophenotype in combination with HIV or EBV positivity can aid diagnosis.

Concomitant Varicella Zoster Virus and Cytomegalovirus Corneal Endotheliitis in an Immunocompetent Patient

PURPOSE

To describe an immunocompetent patient with corneal endotheliitis caused by concomitant infection of cytomegalovirus and varicella zoster virus (VZV).

CASE PRESENTATION

A 37-year-old immunocompetent woman was referred to our hospital because of persistent corneal endotheliitis in the left eye. Slit-lamp examination revealed mild conjunctival injection, localized stromal corneal edema with underlying pigmented keratic precipitates, and inferior superficial corneal neovascularization. Anterior chamber examination revealed grade 2+ inflammatory cells. Real-time polymerase chain reaction analysis of aqueous humor supported a diagnosis of concomitant cytomegalovirus and VZV corneal endotheliitis. Treatment comprised oral valganciclovir and oral acyclovir for 6 weeks. During 12 months of follow-up, the cornea was clear, keratic precipitates were absent, and anterior chamber inflammation was resolved. No recurrences were noted.

CONCLUSIONS

Untreated corneal endotheliitis can cause corneal decompensation and permanent endothelial cell loss. Dual infection must be considered in patients with corneal endotheliitis, particularly those with inadequate treatment responses. Timely detection of causative agents and administration of an appropriate treatment regimen can prevent corneal damage.

3D Immunocompetent Organ-on-a-Chip Models

In recent years, engineering of various human tissues in microphysiologically relevant platforms, known as organs-on-chips (OOCs), has been explored to establish in vitro tissue models that recapitulate the microenvironments found in native organs and tissues. However, most of these models have overlooked the important roles of immune cells in maintaining tissue homeostasis under physiological conditions and in modulating the tissue microenvironments during pathophysiology. Significantly, gradual progress is being made in the development of more sophisticated microphysiologically relevant human-based OOC models that allow the studies of the key biophysiological aspects of specific tissues or organs, interactions between cells (parenchymal, vascular, and immune cells) and their extracellular matrix molecules, effects of native tissue architectures (geometry, dynamic flow or mechanical forces) on tissue functions, as well as unravelling the mechanism underlying tissue-specific diseases and drug testing. In this Progress Report, we discuss the different components of the immune system, as well as immune OOC platforms and immunocompetent OOC approaches that have simulated one or more components of the immune system. We also outline the challenges to recreate a fully functional tissue system in vitro with a focus on the incorporation of the immune system.

Disseminated Nocardia beijingensis Infection in an Immunocompetent Patient

Nocardia is a genus of aerobic, non-motile and non-spore-forming filamentous branching bacteria with fragmentation into bacillary or coccoid forms. Infections caused by Nocardia often occur in immunocompromised hosts and are potentially life-threatening. Nocardia beijingensis has rarely been reported to cause infection in immunocompetent hosts. We present a case of disseminated infection due to Nocardia beijingensis in a patient with no known medical comorbidities, who presented with new-onset seizure. Another interesting finding in our case is that our patient did not have any pulmonary symptoms despite chest CT showing the pulmonary system as the likely primary site of infection. As per our literature review, this is the seventh reported case of infection due to Nocardia beijingensis in an immunocompetent host.

LEARNING POINTS

To recognize Nocardia beijingensis, a slow-growing weakly acid-fast filamentous bacteria commonly causing opportunistic infections in immunocompromised hosts, as an emerging pathogen in immunocompetent patients.Tissue biopsy with Gram staining showing variable filamentous bacteria and confirmation of species using restriction enzyme analysis and 16S rRNA analysis is needed to establish a diagnosis of infection.Trimethoprim/sulfamethoxazole has been successfully used to treat infection due to Nocardia beijingensis.

Tuberculosis in an Immunocompetent Immigrant Patient

Peritoneal tuberculosis (TB) is a rare medical condition in developed nations like the United States, and it is uncommon to observe this condition in patients without underlying immunosuppression. This report describes a patient who developed abdominal pain, constipation, and ascites. And later on, he was diagnosed with peritoneal TB following laparoscopy with peritoneal biopsy. The patient was an immigrant from a high TB burden country but had no other common risk factors for the development of peritoneal TB. Treatment with anti-TB therapy resulted in significant clinical improvement.

An Unusual Case of Moraxella osleonsis Bacteremia in an Immunocompetent Patient With SARS-CoV-2 Infection

Moraxella osleonsis (M.osleonsis ) is an organism that rarely presents with bacteremia in immunocompetent patients. We report a case of an immunocompetent 59-year-old male with a recent SARS-CoV-2 infection that developed M.osleonsis bacteremia. We believe that SARS-CoV-2 infection may have played a role in developing M.osleonsis bacteremia in this patient and may be one of the first reported cases of such bacteremia in a COVID-19 patient. 

Angio-invasive Cerebral Aspergillosis Resulting in Hemispheric Infarct in an Immunocompetent Man

BACKGROUND

Cerebral aspergillosis usually affects immunocompromised hosts and may rarely occur in immunocompetent individuals. Due to its angio-invasive nature, Aspergillus may cause various vascular complications, particularly mycotic aneurysms and infarcts.

CASE PRESENTATION

A 22-year-old immunocompetent male with diagnosed case of sino-cerebral aspergillosis was taking voriconazole for two months. His headache worsened and repeat imaging showed an increase in the size of the lesion. The patient was managed with right frontal craniotomy and surgical debridement, and voriconazole was continued. After ten days of uneventful post-operative course, the patient developed left-sided hemispheric infarct. The patient is doing well at nine months' follow-up, and he is off voriconazole for three months after the follow-up imaging showed complete resolution of disease.

CONCLUSION

Treatment of choice for cerebral aspergillosis is voriconazole. Surgical debridement may be a useful adjunct in patients not responding to voriconazole alone.

Human Papillomavirus (HPV)-Associated Squamous Cell Carcinoma In situ With Positive p16 and Ki-67 Immunohistochemical Stains in a Young Immunocompetent Patient

There is an oncogenic role of human papillomavirus (HPV) in the development of premalignant and malignant skin cancers, especially squamous cell carcinomas (SCCs). Some of the major risk factors for SCC include older age, fair skin types, immunosuppression, ultraviolet radiation (UVR), history of epidermodysplasia verruciformis (EV), and co-carcinogenesis by the HPV. Our case report exemplifies a unique case of a low-risk, 34-year-old female who developed an HPV-associated squamous cell carcinoma in situ (SCCIS) on her left palmar hand, despite having none of the contributing risk factors. The biopsy also showed full-thickness keratinocyte atypia and increased mitotic activity throughout all the layers of the epidermis. Immunohistochemical stains showed strong and diffuse nuclear staining of p16 and Ki-67 throughout the SCCIS, confirming HPV etiology. We speculate that tumor development in our patient relied on the combined effects of UVR exposure, localized immunosuppression, and the co-carcinogenic effects of HPV infection.

Miliary abscess of the liver: unusual complication of intestinal perforation

Miliary abscess of the liver represents a rare presentation of multiple liver abscesses. They often occur in immunosuppressed patients, or those with underlying liver disease. We report the case of a 22-year-old patient, without known immunodeficiency factors, surgical history or notion of tuberculous contacts, who was admitted for generalized peritonitis and ileal perforation. An ileostomy was performed. The infectious syndrome persisted in post-operative period, associated with painful hepatomegaly. An contrast-enhanced abdominal CT scan led to the diagnosis of miliary abscess of the liver. A blood culture isolated Escherichia coli. The treatment included antibiotics and the clinical evolution was favorable. The follow-up abdominal CT scan was normal. Intestinal continuity was restored without complications. Miliary abscess of the liver is rare and requires rapid diagnosis. The treatment is based on antibiotic therapy.

Herpes zoster in an 11-month-old immunocompetent infant: A rare case report

Herpes zoster generally occurs after the exposure of VZV following varicella. This case report emphasizes a rare case of HZ in an infant without prior history of varicella or its exposure in the baby, other siblings, and mother during or after the pregnancy.

Aggregatibacter actinomycetemcomitans Causing Empyema Necessitans and Pyomyositis in an Immunocompetent Patient

Empyema necessitans is a relatively rare clinical entity in which the empyema extends through the parietal pleura into the adjacent soft tissue and musculature of the chest wall. It usually occurs due to inadequate treatment of a primary lung infection. Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans is a facultative anaerobic gram-negative coccobacillus that is part of the normal oral flora. Infections due to this organism usually result from aspiration in conjunction with dental disease or trauma to the oral mucosa resulting in pneumonia or empyema. It often coinfects with Actinomyces and is known to cause empyema necessitans. Cases of monomicrobial empyema necessitans due to Aggregatibacter actinomycetemcomitans in adults have rarely been reported with four such publications found on review of the literature. We present a patient with severe periodontitis who developed empyema necessitans due to Aggregatibacter actinomycetemcomitans likely from aspiration complicated by pyomyositis of the right triceps brachii and a left posterior thigh abscess.

Aspergillus flavus Infection of Lower Limb in an Immune-Competent Patient

Isolated aspergillus infection of the lower limb is uncommon and needs more focus in terms of understanding the pathogenicity, ecological and geographical distribution, identification of species, management and follow-up. Aspergillus flavus involving the lower limb in an immunocompetent individual is a rare entity. Surgical management and antifungal therapy are the mainstays of treatment. We report a 44-year-old farmer who presented with right lower limb swelling of short duration, operated, diagnosed with isolated species of Aspergillus flavus, treated successfully with oral voriconazole to produce excellent wound healing and functional outcome at four years follow-up.

Intravital Imaging of Adoptive T-Cell Morphology, Mobility and Trafficking Following Immune Checkpoint Inhibition in a Mouse Melanoma Model

Efficient T-cell targeting, infiltration and activation within tumors is crucial for successful adoptive T-cell therapy. Intravital microscopy is a powerful tool for the visualization of T-cell behavior within tumors, as well as spatial and temporal heterogeneity in response to immunotherapy. Here we describe an experimental approach for intravital imaging of adoptive T-cell morphology, mobility and trafficking in a skin-flap tumor model, following immune modulation with immune checkpoint inhibitors (ICIs) targeting PD-L1 and CTLA-4. A syngeneic model of ovalbumin and mCherry-expressing amelanotic mouse melanoma was used in conjunction with adoptively transferred OT-1+ cytotoxic T-cells expressing GFP to image antigen-specific live T-cell behavior within the tumor microenvironment. Dynamic image analysis of T-cell motility showed distinct CD8+ T-cell migration patterns and morpho-dynamics within different tumor compartments in response to ICIs: this approach was used to cluster T-cell behavior into four groups based on velocity and meandering index. The results showed that most T-cells within the tumor periphery demonstrated Lévy-like trajectories, consistent with tumor cell searching strategies. T-cells adjacent to tumor cells had reduced velocity and appeared to probe the local environment, consistent with cell-cell interactions. An increased number of T-cells were detected following treatment, traveling at lower mean velocities than controls, and demonstrating reduced displacement consistent with target engagement. Histogram-based analysis of immunofluorescent images from harvested tumors showed that in the ICI-treated mice there was a higher density of CD31+ vessels compared to untreated controls and a greater infiltration of T-cells towards the tumor core, consistent with increased cellular trafficking post-treatment.

Radiosensitisation of Hepatocellular Carcinoma Cells by Vandetanib

Hepatocellular Carcinoma (HCC) is increasing in incidence worldwide and requires new approaches to therapy. The combination of anti-angiogenic drug therapy and radiotherapy is one promising new approach. The anti-angiogenic drug vandetanib is a tyrosine kinase inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2) and RET proto-oncogene with radio-enhancement potential. To explore the benefit of combined vandetanib and radiotherapy treatment for HCC, we studied outcomes following combined treatment in pre-clinical models. Methods: Vandetanib and radiation treatment were combined in HCC cell lines grown in vitro and in vivo. In addition to 2D migration and clonogenic assays, the combination was studied in 3D spheroids and a syngeneic mouse model of HCC. Results: Vandetanib IC50s were measured in 20 cell lines and the drug was found to significantly enhance radiation cell kill and to inhibit both cell migration and invasion in vitro. In vivo, combination therapy significantly reduced cancer growth and improved overall survival, an effect that persisted for the duration of vandetanib treatment. Conclusion: In 2D and 3D studies in vitro and in a syngeneic model in vivo, the combination of vandetanib plus radiotherapy was more efficacious than either treatment alone. This new combination therapy for HCC merits evaluation in clinical trials.

A misleading CMV myocarditis during the COVID-19 pandemic: case report

Coronavirus disease 2019 (COVID-19) has been reported as the possible cause of acute myocarditis. Myocarditis is an inflammatory heart disease mostly caused by viral infections. Cytomegalovirus (CMV) primary infection is often not suspected as a cause of myocarditis in immune-competent adults. We report the case of a 37-year-old male admitted with fever, cough and dyspnea. Chest CT showed typical ground-glass changes indicative of viral pneumonia. He was tested negative for COVID-19 but had biological markers that made us still suspect it. He had elevated troponin I level (up to 111.5 ng/mL) and diffuse myocardial dyskinesia along with a decreased left ventricular ejection fraction (LVEF). He was diagnosed with CMV myocarditis with cardiac insufficiency and totally recovered without antiviral therapy. During the COVID-19 pandemic patients may develop myocarditis, still every myocarditis is not a COVID infection. Myocarditis linked to CMV infection may be rare, but life-threatening.

The Influence of Selank on the Level of Cytokines Under the Conditions of "Social" Stress

BACKGROUND

It was previously thought that inflammation and an immune response were the only factors capable of causing IL-1β, IL-6 and other cytokine`s production. In recent years data have appeared that stressful effects can also occupy an important place, enhancing production of IL- 1β, IL-6 and other cytokines; the result will be a change in the functional activity of a particular cell element, for example immunocompetent cells with subsequent development of inflammation, or a change in the functional activity of neurons. This experiment is aimed at studying the effect of the Selank glyprolin neuropeptide drug on the level of cytokines in animals under conditions of "social" stress, the results of which indicate the presence of stress-protective activity.

METHODS

White nonlinear rats were used as experimental animals. A model of confrontations between males was chosen to create a "social" stress. The animals were in pairs in a cage which were separated by a septum preventing physical contact but having openings that provide sensory contact. Each day, the septum was removed for 10 minutes leading in an overwhelming majority to agonistic collisions (confrontations). Laboratory animals were divided into 3 groups: a group of intact males, a group of animals that were subjected to stress (sensory contact) for 20 days and a group that received intraperitoneally Selank at a dose of 100 mcg/kg/day under conditions of 20-day stress. The level of cytokines under study was determined by enzyme-linked immunosorbent assay.

RESULTS

As a result of the work performed to determine the concentration of pro-inflammatory and anti- inflammatory cytokines, it was found that in the serum of animals exposed to stress, there was a statistically significant increase in the level of IL-1β, IL-6 and TGF-β1 in individuals with both types of behavior. It should be noted that, under the conditions of this stressful impact, there was a tendency to decrease the concentration of IL-4 and increase the level of TNF-α but these indicators were not statistically significant. Evaluation of the effect of Semax on the level of the cytokines in a stress-induced state showed that this neuropeptide causes a decrease in the concentration of IL-1β and IL-6, restoration of the level of IL-4, as well as suppression of the production of TGF-β1 and TNF-α in these conditions.

CONCLUSION

This peptide is able to reduce the concentration of IL-1β, IL-6 and TNF-α, as well as TGF-β1, practically reaching control values, when studying the effect of Selank on the level of cytokines under conditions of " social" stress. There is the need for a detailed study of the role of cytokines in the development of stress-induced changes in order to find optimal correction tools.