Massive image-based single-cell profiling reveals high levels of circulating platelet aggregates in patients with COVID-19

A characteristic clinical feature of COVID-19 is the frequent incidence of microvascular thrombosis. In fact, COVID-19 autopsy reports have shown widespread thrombotic microangiopathy characterized by extensive diffuse microthrombi within peripheral capillaries and arterioles in lungs, hearts, and other organs, resulting in multiorgan failure. However, the underlying process of COVID-19-associated microvascular thrombosis remains elusive due to the lack of tools to statistically examine platelet aggregation (i.e., the initiation of microthrombus formation) in detail. Here we report the landscape of circulating platelet aggregates in COVID-19 obtained by massive single-cell image-based profiling and temporal monitoring of the blood of COVID-19 patients (n = 110). Surprisingly, our analysis of the big image data shows the anomalous presence of excessive platelet aggregates in nearly 90% of all COVID-19 patients. Furthermore, results indicate strong links between the concentration of platelet aggregates and the severity, mortality, respiratory condition, and vascular endothelial dysfunction level of COVID-19 patients.

The landscape of circulating platelet aggregates in COVID-19

A characteristic clinical feature of COVID-19 is the frequent occurrence of thrombotic events. Furthermore, many cases of multiorgan failure are thrombotic in nature. Since the outbreak of COVID-19, D-dimer testing has been used extensively to evaluate COVID-19-associated thrombosis, but does not provide a complete view of the disease because it probes blood coagulation, but not platelet activity. Due to this limitation, D-dimer testing fails to account for thrombotic events which occur despite low D-dimer levels, such as sudden stroke in young patients and autopsy-identified widespread microthrombi in multiple organs. Here we report the landscape of circulating platelet aggregates in COVID-19 obtained by large-scale single-cell image-based profiling and temporal monitoring of the blood of COVID-19 patients (n = 110). Surprisingly, our analysis shows the anomalous presence of excessive platelet aggregates in nearly 90% of all COVID-19 patients, including those who were not clinically diagnosed with thrombosis and those with low D-dimer levels (less than 1 ug/mL). Additionally, results indicate a strong link between the concentration of platelet aggregates and the severity and mortality of COVID-19. Finally, high-dimensional analysis and comparison with other diseases reveal that COVID-19 behaves as a product of thrombosis (localized) and infectious diseases (systemic), as a cause of systemic thrombosis.

The landscape of circulating platelet aggregates in COVID-19

A characteristic clinical feature of COVID-19 is the frequent occurrence of thrombotic events. Furthermore, many cases of multiorgan failure are thrombotic in nature. Since the outbreak of COVID-19, D-dimer testing has been used extensively to evaluate COVID-19-associated thrombosis, but does not provide a complete view of the disease because it probes blood coagulation, but not platelet activity. Due to this limitation, D-dimer testing fails to account for thrombotic events which occur despite low D-dimer levels, such as sudden stroke in young patients and autopsy-identified widespread microthrombi in multiple organs. Here we report the landscape of circulating platelet aggregates in COVID-19 obtained by large-scale single-cell image-based profiling and temporal monitoring of the blood of COVID-19 patients (n = 110). Surprisingly, our analysis shows the anomalous presence of excessive platelet aggregates in nearly 90% of all COVID-19 patients, including those who were not clinically diagnosed with thrombosis and those with low D-dimer levels (≤1 µg/mL). Additionally, results indicate a strong link between the concentration of platelet aggregates and the severity and mortality of COVID-19. Finally, high-dimensional analysis and comparison with other diseases reveal that COVID-19 behaves as a product of thrombosis (localized) and infectious diseases (systemic), as a cause of systemic thrombosis.

The PfAP2-HS transcription factor protects malaria parasites from febrile temperatures

Periodic fever is the most characteristic clinical feature of human malaria1-3, but how parasites survive febrile episodes is not known. While Plasmodium spp. genomes encode a full complement of chaperones4, they lack an ortholog of the conserved transcription factor HSF1, which in most eukaryotes activates the expression of key chaperones upon heat shock (HS)5-8. Here we identified PfAP2-HS, a transcription factor of the ApiAP2 family9-11, as the key regulator of the P. falciparum protective HS response. The PfAP2-HS-dependent HS response is largely restricted to rapid activation of hsp70-1, the predominant direct target of PfAP2-HS, and hsp90. Deletion of PfAP2-HS dramatically reduced HS survival and also resulted in severe growth defects at 37°C, but not at 35°C, and increased sensitivity to imbalances in protein homeostasis (proteostasis) produced by artemisinin, the current frontline antimalarial drug12,13. These results demonstrate that PfAP2-HS contributes to general maintenance of proteostasis and drives a rapid chaperone-based protective response against febrile temperatures. While several ApiAP2 transcription factors regulate life cycle transitions in malaria parasites11,14,15, PfAP2-HS is the first identified Plasmodium transcription factor that controls a protective response to a within-host environmental challenge.

Role of therapeutic phlebotomy in management of case of porphyria cutanea tarda (PCT) admitted in tertiary care hospital Vadodara

Porphyria cutanea tarda is the most frequent type of Porphyria worldwide & presents with skin symptoms mainly. Porphyrias can affect peripheral, autonomic and central nervous system. In Porphyria conditions there is accumulation of heme precursors 5 Aminolevulinic acid, Porphobilinogen and porphyrins which are associated with characteristic clinical feature with acute neurovisceral attacks and skin lesions. This case report summarizes Case of PCT that was successfully managed with Therapeutic Phlebotomy.

Mid-Frequency Hearing Loss Is Characteristic Clinical Feature of OTOA-Associated Hearing Loss

The OTOA gene (Locus: DFNB22) is reported to be one of the causative genes for non-syndromic autosomal recessive hearing loss. The copy number variations (CNVs) identified in this gene are also known to cause hearing loss, but have not been identified in Japanese patients with hearing loss. Furthermore, the clinical features of OTOA-associated hearing loss have not yet been clarified. In this study, we performed CNV analyses of a large Japanese hearing loss cohort, and identified CNVs in 234 of 2262 (10.3%, 234/2262) patients with autosomal recessive hearing loss. Among the identified CNVs, OTOA gene-related CNVs were the second most frequent (0.6%, 14/2262). Among the 14 cases, 2 individuals carried OTOA homozygous deletions, 4 carried heterozygous deletions with single nucleotide variants (SNVs) in another allele. Additionally, 1 individual with homozygous SNVs in the OTOA gene was also identified. Finally, we identified 7 probands with OTOA-associated hearing loss, so that its prevalence in Japanese patients with autosomal recessive hearing loss was calculated to be 0.3% (7/2262). As novel clinical features identified in this study, the audiometric configurations of patients with OTOA-associated hearing loss were found to be mid-frequency. This is the first study focused on the detailed clinical features of hearing loss caused by this gene mutation and/or gene deletion.

Preauricular pilomatrixoma in a 3 year-old girl: A case study

Objectives: To report a case of preauricular pilomatrixoma in a 3-year-old girl.Methods: Retrospective review on a case reportResults: A three-year-old girl presented with six month history of painless right pre-auricular swelling that was gradually increasing in size. The mass was small, soft, non tender with normal overlying skin. She underwent excisional biopsy of lesion and histopathological examination showed pilomatrixoma. She was well post operatively and no recurrence after 2 years of follow up.Conclusion: Pilomatrixoma is often misdiagnosed clinically as epidermoid cyst, sebaceous cyst, dermoid cyst, foreign body reaction, calcification in lymph node, fat necrosis, pyogenic granuloma, chalazion and keratoacanthoma, but a high index of suspicion and careful histological examination of its characteristic clinical feature can help clinicians to differentiate it from other tumors. DOI: http://dx.doi.org/10.3329/bjo.v18i1.10426 Bangladesh J Otorhinolaryngol 2012; 18(1): 84-86

Temporal evolution of remission following multiple sclerosis relapse and predictors of outcome

Background: Relapse is a characteristic clinical feature of multiple sclerosis (MS) and is commonly employed as a measure of efficacy following therapeutic intervention. However, less is known about the temporal evolution of subsequent disability or factors predicting recovery. Objectives: The objective of this study was to assess the pattern of recovery following relapse and identify factors which predict recovery and residual disability following relapse. Methods: A total of 226 relapses were studied prospectively in a cohort of 144 patients with standardised clinical assessments of physical disability including Expanded Disability Status Scale (EDSS), 10-m timed walk, 9-hole peg test and Multiple Sclerosis Impact Scale (MSIS-29) at 0, 2, 6 and 12 months. A total of 82 patients completed 12 months of follow up without further relapse. Results: Thirty per cent of relapses were severe (change in EDSS >2.0) of which 11% failed to recover. All measures showed significant improvement at 2 months but additional improvement was also observed in 9-hole peg test and MSIS-29 up to 12 months following initial assessment. Mean time to second relapse was 382 days. The only predictor of relapse severity in the model tested was younger age; however, increasing age and initial relapse severity were also predictors of poor outcome. Conclusions: This study shows that the majority of improvement in physical disability following relapse occurs by 2 months but that more subtle recovery can take place over 12 months in a small sub-group of patients. These data will aid in patient counselling and will also inform the timing of therapeutic intervention and physical support.

Fourth branchial pouch anomaly

We present an extremely rare case of fourth branchial fistula in a 23-year-old male. The characteristic clinical feature was a recurrent left lower neck abscess which did not respond to appropriate medical and surgical therapy. Radiography and a computed tomographic scan with contrast material revealed a fistula running from the apex of the left pyriform sinus (internal opening) to the left lower neck abscess. The fistula tract was excised surgically. Histological examination of the excised fistula revealed a squamous epithelial lining and subepithelial lymphoid tissue. This pyriform sinus fistula is thought to be of fourth pharyngeal pouch origin, because of its surgical aspects and the histologicalfindings of the excised fistula.