Swerd, can you help an Audioholics brother understand this?
In the process of trying to understand the T cell issues raised in the first article, I found another article entitled "Presence of SARS-CoV-2 reactive T cells in COVID-19 patients and healthy donors."
If I'm reading it correctly, this one is perhaps good news because T cells from those who have not been infected with the SARS-CoV-2 virus may nevertheless have some activity against the SARS-CoV-2 virus, possibly due to prior infections with corona viruses that cause the common cold?
The comment by the person from Mount Sinai is interesting (to the extent I understand it).
I've read the following several times, but I'm not sure I understand the significance of it.
>>>We demonstrate the presence of S-reactive CD4+ T cells in 83% of COVID-19 patients, as well as in 34% of SARS-CoV-2 seronegative healthy donors, albeit at lower frequencies. Strikingly, in COVID-19 patients S-reactive CD4+ T cells equally targeted both N-terminal and C-terminal parts of S whereas in healthy donors S-reactive CD4+ T cells reacted almost exclusively to the Cterminal part that is a) characterized by higher homology to spike glycoprotein of human endemic "common cold" coronaviruses, and b) contains the S2 subunit of S with the cytoplasmic peptide (CP), the fusion peptide (FP), and the transmembrane domain (TM) but not the receptor-binding domain (RBD). S-reactive CD4+ T cells from COVID-19 patients were further distinct to those from healthy donors as they co-expressed higher levels of CD38 and HLA-DR, indicating their recent in vivo activation. . . .The presence of pre-existing SARS-CoV-2-reactive T cells in healthy donors is of high interest but larger scale prospective cohort studies are needed to assess whether their presence is a correlate of protection or pathology. <<<
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a rapidly unfolding pandemic, overwhelming health care systems worldwide1. Clinical manifestations of Corona-virus-disease 2019 (COVID-19) vary broadly, ranging from asymptomatic infection to acute respiratory failure...
www.medrxiv.org
I have now had a chance to look at that Chinese report and some others. It seem that the virus can kill vital
T-lymphocytes. The most important word to translate for you in that report is the term cell apoptosis. That means programmed cell death. All cells have a means of becoming "suicidal" if you like. This is he mechanism by which sick, injured and otherwise damaged cells.
So an increased rate of apoptosis in these immune cells was noted. However the virus could not reproduce in these cells. So this is serious but not totally disastrous.
Meanwhile the vascular complications continue to arise. A small by significant number of cases remarkable like
Kawasaki's disease are showing up in children. This is ominous. A UK wide alert has been issued to physicians. Most cases show evidence of active or past infection, but some neither. I think this latter may be false negatives especially from the ELISA tests, that they have had a lot of trouble getting reliable in the UK.
I agree with Dr Fauci, that another peak in the fall is likely. That would be typical of the behavior of past epidemics. Until we have a vaccine, I would expect repeated peaks. The intervals will depend on the length of immunity which is unknown.
This is some hot off the press of some experience from California in JAMA.
Of 16 201 tests in adults, results from 1299 patients (8.0%) were positive for SARS-CoV-2. Of these patients, 377 (29.0%) were treated as inpatients and 113 (8.7%) were treated in the ICU.
The median age was 61.0 years (interquartile range, 50.0-73.0); 56.2% were men (
Table). The most common comorbidity was hypertension (n = 164, 43.5%). Of 166 patients who underwent testing for influenza A/B or respiratory syncytial virus (44.0% of the cohort), none tested positive. Bilateral infiltrates on chest film were seen in 63.4% (n = 239). Overall, 34 patients (9.0%) received a prednisone-equivalent dosage of 20 mg/d or more.
Most patients were treated on the general ward or intermediate care unit (n = 264, 70.0%); of whom 54.9% received supplemental oxygen through nasal cannula/face mask. A total of 113 inpatients (30.0%) required ICU admission and 110 (29.2%) received invasive mechanical ventilation.
Patients aged 60 to 69 years represented the most common age group both hospitalized (n = 93, 24.6%) and admitted to the ICU (n = 31, 27.4%) (
Figure). However, adults of all ages were admitted, and the proportion of younger and middle-aged adults (≤59 years) who were hospitalized (n = 172, 45.6%) was similar to the proportion of older adults (≥60 years) who were hospitalized (n = 205, 54.4%).
Of 321 patients with discharge dispositions, 50 (15.6%) died in the hospital. Of 253 patients treated on the ward with discharge dispositions, 16 (6.3%) died. Of 68 patients treated in the ICU with discharge dispositions, 34 (50.0%) died.
We are still at the beginning of all this unfortunately.
