Purtscher-like retinopathy in a patient with COVID-19-associated coagulopathy / Retinopatia tipo Purtscher em paciente com coagulopatia associada ao COVID-19

ABSTRACT The most frequently reported ophthalmic manifestation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is conjunctivitis. We have described a case of Purtscher-like retinopathy in a patient with severe coronavirus disease 2019 (COVID-19)-associated coagulopathy. A young woman with multiple comorbidities was admitted for COVID-19-related acute respiratory distress syndrome. Her course was complicated by fungemia. Ophthalmic examination revealed bilateral posterior pole, intraretinal lesions and fluconazole was added for presumed fungal retinitis. At 1-week follow-up, widespread peripapillary cotton-wool spots and hemorrhages suggestive of Purtscher-like retinopathy were observed. The levels of D-dimers, fibrinogen, and C-reactive protein were markedly elevated prior to our consultation, indicating preceding prothrombotic and pro-inflammatory states. Subsequent venous duplex revealed deep venous thrombosis in the right subclavian and internal jugular veins. Von Willebrand factor indices were markedly elevated, suggesting severe COVID-19-associated coagulopathy. Purtscher-like retinopathy, a rare occlusive microangiopathy has been described in various pro-inflammatory and prothrombotic conditions. To the best of our knowledge, this is the first report of Purtscher-like retinopathy in COVID-19-associated coagulopathy.

RESUMO A manifestação oftálmica mais frequentemente re­latada da infecção por SARS-CoV-2 é a conjuntivite. Trata-se de estudo de caso de retinopatia tipo Purtscher em uma paciente com coagulopatia grave associada ao COVID-19. Uma jovem com múltiplas comorbidades foi admitida por síndrome do desconforto respiratório agudo relacionado ao COVID-19. Seu quadro foi complicado pela fungemia. O exame oftálmico revelou pólo posterior bilateral, lesões intraretinianas e o fluconazol foi adicionado para tratar a retinite fúngica presumida. No decorrer de uma semana, manchas largas peripapilares de algodão e hemorragias sugestivas de retinopatia tipo Purtscher foram observadas. Os dímeros D, o fibrinogênio e a proteína c-reativa estavam acentuadamente elevados antes da nossa consulta, indicando um estado pró-trombótico e pró-inflamatório precedente. O duplex venoso subsequente revelou trombose venosa profunda nas veias subclávia direita e jugular interna. Os índices de fatores von Willebrand estavam marcadamente elevados, sugerindo coagulopatia grave associada ao COVID-19. A retinopatia tipo Purtscher, uma microangiopatia oclusiva rara foi descrita em várias condições pró-inflamatórias e pró-trombóticas. Para nosso conhecimento, este é o primeiro relatório de retinopatia tipo Purtscher com coagulopatia associada ao COVID-19.

Purtscher-like retinopathy in a patient with COVID-19-associated coagulopathy.

The most frequently reported ophthalmic manifestation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is conjunctivitis. We have described a case of Purtscher-like retinopathy in a patient with severe coronavirus disease 2019 (COVID-19)-associated coagulopathy. A young woman with multiple comorbidities was admitted for COVID-19-related acute respiratory distress syndrome. Her course was complicated by fungemia. Ophthalmic examination revealed bilateral posterior pole, intraretinal lesions and fluconazole was added for presumed fungal retinitis. At 1-week follow-up, widespread peripapillary cotton-wool spots and hemorrhages suggestive of Purtscher-like retinopathy were observed. The levels of D-dimers, fibrinogen, and C-reactive protein were markedly elevated prior to our consultation, indicating preceding prothrombotic and pro-inflammatory states. Subsequent venous duplex revealed deep venous thrombosis in the right subclavian and internal jugular veins. Von Willebrand factor indices were markedly elevated, suggesting severe COVID-19-associated coagulopathy. Purtscher-like retinopathy, a rare occlusive microangiopathy has been described in various pro-inflammatory and prothrombotic conditions. To the best of our knowledge, this is the first report of Purtscher-like retinopathy in COVID-19-associated coagulopathy.

Eliminating Extravasation Events: A Multidisciplinary Approach.

Administration of chemotherapy agents can give rise to many safety issues. Extravasation of a vesicant agent causes tissue blistering and necrosis. This complication of chemotherapy administration causes additional pain and suffering in patients who are already suffering with a diagnosis of cancer. Nurses hold key responsibilities for educating patients about administration issues and following practice standards to minimize the risk of extravasation. Defining a path of shared responsibilities among team members is a critical step in assuring the safe administration of drugs classified as vesicants. This article describes a clinical practice change that is used at a large midwestern academic medical cancer center. This practice and policy change has resulted in a 90% reduction in the administration of vesicant agents peripherally, with no occurrence of extravasations in the first 6 months of implementation.

Eliminating extravasation events: a multidisciplinary approach.

Administration of chemotherapy agents can give rise to many safety issues. Extravasation of a vesicant agent causes tissue blistering and necrosis. This complication of chemotherapy administration causes additional pain and suffering in patients who are already suffering with a diagnosis of cancer. Nurses hold key responsibilities for educating patients about administration issues and following practice standards to minimize the risk of extravasation. Defining a path of shared responsibilities among team members is a critical step in assuring the safe administration of drugs classified as vesicants. This article describes a clinical practice change that is used at a large midwestern academic medical cancer center. This practice and policy change has resulted in a 90% reduction in the administration of vesicant agents peripherally, with no occurrence of extravasations in the first 6 months of implementation.

Accumulation of ergot alkaloids during conidiophore development in Aspergillus fumigatus.

Production of ergot alkaloids in the opportunistic fungal pathogen Aspergillus fumigatus is restricted to conidiating cultures. These cultures typically accumulate several pathway intermediates at concentrations comparable to that of the pathway end product. We investigated the contribution of different cell types that constitute the multicellular conidiophore of A. fumigatus to the production of ergot alkaloid pathway intermediates versus the pathway end product, fumigaclavine C. A relatively minor share (11 %) of the ergot alkaloid yield on a molar basis was secreted into the medium, whereas the remainder was associated with the conidiating colonies. Entire conidiating cultures (containing hyphae, vesicle of conidiophore, phialides of conidiophore, and conidia) accumulated higher levels of the pathway intermediate festuclavine and lower levels of the pathway end product fumigaclavine C than did isolated, abscised conidia, indicating that conidiophores and/or hyphae have a quantitatively different ergot alkaloid profile compared to that of conidia. Differences in alkaloid accumulation among cell types also were indicated by studies with conidiophore development mutants. A ∆medA mutant, in which conidiophores are numerous but develop poorly, accumulated higher levels of pathway intermediates than did the wildtype or a complemented ∆medA mutant. A ∆stuA mutant, which grows mainly as hyphae and produces very few, abnormal conidiophores, produced no detectable ergot alkaloids. The data indicated heterogeneous spatial distribution of ergot alkaloid pathway intermediates versus pathway end product in conidiating cultures of A. fumigatus. This skewed distribution may reflect differences in abundance or activity of pathway enzymes among cell types of those conidiating cultures.

Ergot cluster-encoded catalase is required for synthesis of chanoclavine-I in Aspergillus fumigatus.

Genes required for ergot alkaloid biosynthesis are clustered in the genomes of several fungi. Several conserved ergot cluster genes have been hypothesized, and in some cases demonstrated, to encode early steps of the pathway shared among fungi that ultimately make different ergot alkaloid end products. The deduced amino acid sequence of one of these conserved genes (easC) indicates a catalase as the product, but a role for a catalase in the ergot alkaloid pathway has not been established. We disrupted easC of Aspergillus fumigatus by homologous recombination with a truncated copy of that gene. The resulting mutant (ΔeasC) failed to produce the ergot alkaloids typically observed in A. fumigatus, including chanoclavine-I, festuclavine, and fumigaclavines B, A, and C. The ΔeasC mutant instead accumulated N-methyl-4-dimethylallyltryptophan (N-Me-DMAT), an intermediate recently shown to accumulate in Claviceps purpurea strains mutated at ccsA (called easE in A. fumigatus) (Lorenz et al. Appl Environ Microbiol 76:1822-1830, 2010). A ΔeasE disruption mutant of A. fumigatus also failed to accumulate chanoclavine-I and downstream ergot alkaloids and, instead, accumulated N-Me-DMAT. Feeding chanoclavine-I to the ΔeasC mutant restored ergot alkaloid production. Complementation of either ΔeasC or ΔeasE mutants with the respective wild-type allele also restored ergot alkaloid production. The easC gene was expressed in Escherichia coli, and the protein product displayed in vitro catalase activity with H(2)O(2) but did not act, in isolation, on N-Me-DMAT as substrate. The data indicate that the products of both easC (catalase) and easE (FAD-dependent oxidoreductase) are required for conversion of N-Me-DMAT to chanoclavine-I.

Controlling a structural branch point in ergot alkaloid biosynthesis.

The ergot alkaloids are a diverse class of fungal-derived indole alkaloid natural products with potent pharmacological activities. The biosynthetic intermediate chanoclavine-I aldehyde 1 represents a branch point in ergot biosynthesis. Ergot alkaloids festuclavine 2 and agroclavine 3 derive from alternate enzymatic pathways originating from the common biosynthetic precursor chanoclavine-I aldehyde 1. Here we show that while the Old Yellow Enzyme homologue EasA from the ergot biosynthetic gene cluster of Aspergillus fumigatus acts on chanoclavine-I aldehyde 1 to yield festuclavine 2, EasA from Neotyphodium lolii, in contrast, produces agroclavine 3. Mutational analysis suggests a mechanistic rationale for the switch in activity that controls this critical branch point of ergot alkaloid biosynthesis.

An old yellow enzyme gene controls the branch point between Aspergillus fumigatus and Claviceps purpurea ergot alkaloid pathways.

Ergot fungi in the genus Claviceps and several related fungal groups in the family Clavicipitaceae produce toxic ergot alkaloids. These fungi produce a variety of ergot alkaloids, including clavines as well as lysergic acid derivatives. Ergot alkaloids are also produced by the distantly related, opportunistic human pathogen Aspergillus fumigatus. However, this fungus produces festuclavine and fumigaclavines A, B, and C, which collectively differ from clavines of clavicipitaceous fungi in saturation of the last assembled of four rings in the ergoline ring structure. The two lineages are hypothesized to share early steps of the ergot alkaloid pathway before diverging at some point after the synthesis of the tricyclic intermediate chanoclavine-I. Disruption of easA, a gene predicted to encode a flavin-dependent oxidoreductase of the old yellow enzyme class, in A. fumigatus led to accumulation of chanoclavine-I and chanoclavine-I-aldehyde. Complementation of the A. fumigatus easA mutant with a wild-type allele from the same fungus restored the wild-type profile of ergot alkaloids. These data demonstrate that the product of A. fumigatus easA is required for incorporation of chanoclavine-I-aldehyde into more-complex ergot alkaloids, presumably by reducing the double bond conjugated to the aldehyde group, thus facilitating ring closure. Augmentation of the A. fumigatus easA mutant with a homologue of easA from Claviceps purpurea resulted in accumulation of ergot alkaloids typical of clavicipitaceous fungi (agroclavine, setoclavine, and its diastereoisomer isosetoclavine). These data indicate that functional differences in the easA-encoded old yellow enzymes of A. fumigatus and C. purpurea result in divergence of their respective ergot alkaloid pathways.

A role for Old Yellow Enzyme in ergot alkaloid biosynthesis.

Ergot alkaloids, secondary metabolites produced by filamentous fungi, elicit a diverse array of pharmacological effects. The biosynthesis of this class of natural products has not been fully elucidated. Here we demonstrate that a homologue of Old Yellow Enzyme encoded in the Aspergillus fumigatus ergot gene cluster catalyzes reduction of the alpha,beta unsaturated alkene of chanoclavine-I aldehyde 3. This reduction, which yields dihydrochanoclavine aldehyde, facilitates an intramolecular reaction between a secondary amine and aldehyde to form the D ring of the ergot alkaloid structural framework.

Association of ergot alkaloids with conidiation in Aspergillus fumigatus.

Ergot alkaloids are mycotoxins that affect the nervous and reproductive systems of exposed individuals through interactions with monoamine receptors. They have been studied more widely in ergot fungi and grass endophytes but also are found in Aspergillus fumigatus, an opportunistic human pathogen that reproduces and disseminates exclusively through conidia. The ergot alkaloids festucla-vine and fumigaclavines A, B and C are present in or on conidia of A. fumigatus. Cultures of the fungus that are free of conidia are difficult to obtain, obscuring comparisons of conidia versus vegetative hyphae as sources of the ergot alkaloids. To create conidiation-deficient strains of A. fumigatus we manipulated the bristle A gene (brlA), which controls vesicle formation or budding growth necessary for conidiation in Aspergillus spp. Disruption of brlA in A. fumigatus, via homologous recombination, resulted in a nonconidiating mutant that produced bristle-like structures instead of conidiophores and conidia. Moreover the disrupted strain failed to produce ergot alkaloids as verified by HPLC analyses. Complementation with a wild-type allele restored conidiation and ergot alkaloid production. These results suggest that ergot alkaloids are not produced within the vegetative mycelium of the fungus and are associated directly with conidiation.

Abundant respirable ergot alkaloids from the common airborne fungus Aspergillus fumigatus.

Ergot alkaloids are mycotoxins that interact with several monoamine receptors, negatively affecting cardiovascular, nervous, reproductive, and immune systems of exposed humans and animals. Aspergillus fumigatus, a common airborne fungus and opportunistic human pathogen, can produce ergot alkaloids in broth culture. The objectives of this study were to determine if A. fumigatus accumulates ergot alkaloids in a respirable form in or on its conidia, to quantify ergot alkaloids associated with conidia produced on several different substrates, and to measure relevant physical properties of the conidia. We found at least four ergot alkaloids, fumigaclavine C, festuclavine, fumigaclavine A, and fumigaclavine B (in order of abundance), associated with conidia of A. fumigatus. Under environmentally relevant conditions, the total mass of ergot alkaloids often constituted >1% of the mass of the conidium. Ergot alkaloids were extracted from conidia produced on all media tested, and the greatest quantities were observed when the fungus was cultured on latex paint or cultured maize seedlings. The values for physical properties of conidia likely to affect their respirability (i.e., diameter, mass, and specific gravity) were significantly lower for A. fumigatus than for Aspergillus nidulans, Aspergillus niger, and Stachybotrys chartarum. The demonstration of relatively high concentrations of ergot alkaloids associated with conidia of A. fumigatus presents opportunities for investigations of potential contributions of the toxins to adverse health effects associated with the fungus and to aspects of the biology of the fungus that contribute to its success.

An ergot alkaloid biosynthesis gene and clustered hypothetical genes from Aspergillus fumigatus.

The ergot alkaloids are a family of indole-derived mycotoxins with a variety of significant biological activities. Aspergillus fumigatus, a common airborne fungus and opportunistic human pathogen, and several fungi in the relatively distant taxon Clavicipitaceae (clavicipitaceous fungi) produce different sets of ergot alkaloids. The ergot alkaloids of these divergent fungi share a four-member ergoline ring but differ in the number, type, and position of the side chains. Several genes required for ergot alkaloid production are known in the clavicipitaceous fungi, and these genes are clustered in the genome of the ergot fungus Claviceps purpurea. We investigated whether the ergot alkaloids of A. fumigatus have a common biosynthetic and genetic origin with those of the clavicipitaceous fungi. A homolog of dmaW, the gene controlling the determinant step in the ergot alkaloid pathway of clavicipitaceous fungi, was identified in the A. fumigatus genome. Knockout of dmaW eliminated all known ergot alkaloids from A. fumigatus, and complementation of the mutation restored ergot alkaloid production. Clustered with dmaW in the A. fumigatus genome are sequences corresponding to five genes previously proposed to encode steps in the ergot alkaloid pathway of C. purpurea, as well as additional sequences whose deduced protein products are consistent with their involvement in the ergot alkaloid pathway. The corresponding genes have similarities in their nucleotide sequences, but the orientations and positions within the cluster of several of these genes differ. The data indicate that the ergot alkaloid biosynthetic capabilities in A. fumigatus and the clavicipitaceous fungi had a common origin.