* haemophagocytosis in bone marrow, lymph nodes or spleen
* low or absent natural killer cell activity
* ferritin >500 ng/mL
* raised soluble CD25 (IL-2 receptor)
* fasting hypertriglyceridaemia (>3 mmol/L) or hypofibrinogenaemia
_____________
The COVID-19 vaccines seem to be able to cause hyperactivations of different systems:
- hyperactivation of macrophages (and T-cells) that engulf normal haematopoietic cells in the bone marrow, liver and spleen -> HLH
- hyperactivation of mast cells -> mast cell activation syndrome
- hyperactivation of plateles (as for example an effect of endotheliitis) -> amyloid fibrin microclots -> thrombosis
- hyperactivation of T follicular helper (Tfh) cells -> increased levels of non-specific antibodies and autoimmune antibodies (see https://pubmed.ncbi.nlm.nih.gov/29739835/)
Diagnosis of HLH (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6297301/): Meeting 5 out of the following 8 criteria:
* fever
* splenomegaly (enlargement of the spleen)
* cytopenias in peripheral blood:
-*- haemoglobin <90 g/L
-*- platelets <100×109/L
-*- neutrophils <1×109/L
* haemophagocytosis in bone marrow, lymph nodes or spleen
* low or absent natural killer cell activity
* ferritin >500 ng/mL
* raised soluble CD25 (IL-2 receptor)
* fasting hypertriglyceridaemia (>3 mmol/L) or hypofibrinogenaemia
_____________
The COVID-19 vaccines seem to be able to cause hyperactivations of different systems:
- hyperactivation of macrophages (and T-cells) that engulf normal haematopoietic cells in the bone marrow, liver and spleen -> HLH
- hyperactivation of mast cells -> mast cell activation syndrome
- hyperactivation of plateles (as for example an effect of endotheliitis) -> amyloid fibrin microclots -> thrombosis
- hyperactivation of T follicular helper (Tfh) cells -> increased levels of non-specific antibodies and autoimmune antibodies (see https://pubmed.ncbi.nlm.nih.gov/29739835/)