Thromboembolic involvement and its possible pathogenesis in COVID-19 mortality: lesson from post-mortem reports.

The emergence of Coronavirus Disease 19 (COVID-19) as a pandemic has claimed hundreds of thousands of lives worldwide since its initial breakout. With increasing reports from clinical observations and autopsy findings, it became clear that the disease causes acute respiratory distress syndrome (ARDS), as well as a broad spectrum of systemic and multiorgan pathologies, including angiopathy, endothelialitis, and thrombosis. Coagulopathy is associated with the activity of megakaryocytes, which play crucial roles in modulating the platelet homeostasis. Only a few autopsy reports include findings on thrombosis formation and the presence of megakaryocytes. Here we review and summarize the possible involvement and the pathophysiology of the thromboembolic events in COVID-19 patients based on post-mortem reports. We reviewed post-mortem reports from March 2020 to September 2020. Eleven autopsy reports that demonstrated thromboembolic involvement findings, either macroscopically or microscopically, were included in this review. All studies reported similar pulmonary gross findings. Not all studies described thrombi formation and megakaryocyte findings. Pulmonary embolism, coagulopathy, severe endothelial injury, and widespread thrombosis are frequent in COVID-19 patients, following many patients with high-level D-Dimer, increased fibrinogen, abnormal prothrombic coagulation, and thrombocytopenia. Reports showed that thrombus was also found in the lower extremities' deep veins and the prostatic venous plexus. In conclusion, a complex interaction of SARS-CoV-2 virus invasion with platelets, leukocytes, endothelial cells, inflammation, immune response, and the possible involvement of megakaryocytes may increase the cumulative risk of thrombosis by a yet unclear cellular and humoral interaction.

The hematopoietic stem cell transplantation in Indonesia: an unsolved dilemma.

Allogeneic BMT was performed in Indonesia, but had to be stopped prematurely because of the small number of patients. In the beginning, only patients with sufficient financial resources to travel to western countries could undergo transplant procedures. When neighbouring countries (Singapore and Malaysia) began performing transplant, patients were referred to those centres. In both countries, the procedure is more economical and therefore patients come from a broader range of economic classes. The Indonesian hematologist must deal with the post-transplantation side effects, such as GVHD, which are mostly of the chronic type of GVHD. The types of the post-transplant complications do not differ too much from other centres and need the same treatment used in the transplant centres. Hematologists in Indonesia also treat complications of HSCT performed in other countries. When there is no recovery of HSCT development in Indonesia so far, many commercially oriented companies or centres from other countries see Indonesia as a good commercial market and offer services, some of which are not scientifically sound. One of the main problems is umbilical cord blood stem cell banking from foreign countries, which is eagerly offered to parents expecting a baby. Moreover, parents are not fully protected by law. In conclusion, Indonesia needs to revive its own HSCT program to serve and protect its own patients of being used as commercial targets by other countries.

Levels of plasma fibrinopeptide-A during surgery and the severity of the operation.

There is evidence to suggest that the rise of fibrinopeptide A (FPA) during surgery is influenced by tissue thromboplastin released during tissue damage. To investigate whether FPA correlates with the severity of the damage of the operation, 39 patients were recruited and venous blood samples were taken pre-operatively, during skin incision, during bowel manipulation and post-operatively for the assay of FPA. The operations are grouped as minor (A), moderate (B), major (C) and very major (D). The peak FPA levels occurred during bowel manipulation in every degree of operations, and ranged between 6.0 to 22.2 pmol/ml. There was a tendency that peak FPA values rose according to the severity of the surgery, however only very major operations (D) are significantly higher when compared with minor operations (A) (p < 0.01). There was no good correlation between peak FPA levels and length of skin incision (p = 0.83, r = 0.04) as well as peak FPA levels and duration of operation (p = 0.90, r = 0.03). Significantly higher levels of FPA in very major operation (D) was due to more excessive tissue damage during surgery, while due to relatively minimal tissue injury, size of skin incision correlated poorly with FPA.

Effect of physiological concentrations of vasopressin on components of the fibrinolytic system.

High physiological concentrations of plasma vasopressin (aVP) when achieved by infusion cause an increase in plasma factor VIII coagulant activity and shortening of the euglobulin clot lysis time (ECLT). To investigate the effects of aVP on components of the fibrinolytic pathway and on thrombin generation, 9 healthy volunteers were infused with saline for 30 min followed by aVP for 1 hour and blood samples taken every 30 min for measurement of aVP, ECLT, tissue-type plasminogen activator (t-PA), t-PA inhibition (tPA-I), plasminogen activator inhibitor 1 (PAI-1 Ag), activated partial thromboplastin time (APTT), fibrinopeptide A (FPA), fibrinopeptide B 15-42 (FPB beta 15-42) and cross-linked fibrin breakdown products (XL-FDP). Plasma aVP rose to a median of 75 pg/ml after 90 min and fell to 13.8 pg/ml 30 min later. The APTT fell from 43.5 to 35 sec (p less than 0.01) but there was no change in plasma FPA or in XL-FDP. Plasminogen activator activity (10(6)/ECLT2) increased from 25 to 736 units (p less than 0.01) and t-PA from 200 to 1012 mIU/ml (p less than 0.01). tPA-I fell from 8.0 to 2.7 IU/ml at 90 min (p less than 0.05) but PAI-1 Ag remained unchanged. Plasma FPB beta 15-42 was 2.4 and 1.2 pmol/ml before infusion with aVP and showed a small rise to 3.5 pmol/ml after 60 min (p less than 0.05). The results show the effects of aVP on fibrinolysis are mediated by an increase in t-PA. In the absence of thrombin generation the rise in t-PA was not accompanied by changes in XL-FDP.