Cytokine Storm Syndrome is also termed as HYPER-CYTOKINEMIA , meaning a huge excess of CYTOKINES in our body system, which is quite damaging as well as potentially FATAL.
CYTOKINE STORM is not exclusive to the COVID PANDEMIC……it can also occur in :
Macrophage Activation Syndrome in Rheumatological disorders, like Rheumatoid & Lupus Arthritis.
HLH Hemophagocytic Lympho-Histiocytosis.
CAR T- cell therapy, the last treatment option in Refractory Lymphomas, which is very costly ( to the tune of 3 lakh dollars )
Infections , mainly VIRAL like Covid 19, SARS, MERS + Viral Influenza ( Seasonal Flu ) . Spanish Flu ( H1N1 ) of 1918 saw millions of deaths due to this phenomenon.
CYTOKINES play an important role in normal immune responses. They are Messengers for the Immune Cells. However, having a very large amount of them released in the body, all of a sudden , can be extremely harmful .
FOUR Structural Groups of CYTOKINES
Interferons , esp Type 1. ( range 1 – 20 )
Interleukines , like IL 6 . ( range 1 – 35 )
Tumor Necrosis Factor ( TNF ) esp. TNF alpha.
Colony Stimulating Factors ( CSF ) like G – CSF, GM – CSF etc.
Chemokines are just another category, clearly different from Cytokines. They are chemo-attractants that lure all white blood cells towards the infection site.
CLINICAL HALLMARKS of CYTOKINE STORM
ARDS , caused due to Acute Lung Injury. Viral replication inside the Pneumocytes invites the Immune cells and the Pro-inflamatory Cytokines – leading to Oedema and Alveolar Membrane dysfunction. The obvious result is ARDS , leading to Pulmonary insufficiency and falling SpO2 levels on Pulse Oximetry. Another hypothesis for ARDS is the severe depletion of Surfactant, normally produced by the Pneumocytes.
COAGULATION DYSREGULATION : Cytokines promote the Blood Clotting cascade. There is a distinct HYPER-COAGULATION phenomenon happening.
SEVERE VASCULITIS, caused by Vascular Endothelium damage and resultant Thrombus formation, can cause hypo-perfusion led ORGAN DYSFUNCTION everywhere, finally leading to Multi-Organ failure and eventual Death.
SYSTEMIC HYPER – INFLAMMATION The huge impact of PRO-INFLAMATORY CYTOKINES can cause Swelling and Malfunction of all the Vital Organs – Heart, Liver, Brain, Kidneys and the GI System, as these organs too have ACE – 2 receptors, allowing virus entry.
These are detected by the Lab. Values of LFT, RFT, TROPONIN and are RED FLAG signs for poor prognosis in end-stage COVID illness.
MARKERS of CYTOKINE STORM
SERUM FERRITIN levels. Normally under 300. In COVID, it jumps above 1000. Serum Ferritin is an ACUTE PHASE REACTANT.
CRP is a protein, produced by the Liver and is a good lab. indicator of IL – 6 activity . CRP levels are used to monitor PROGRESS of the Cytokine Storm , as a surrogate correlate of IL – 6 levels. Assays of IL – 6 can also be done from a blood sample or from the Broncho – Alveolar Lavage fluid.
D-DIMER is a Fibrin Degradation product, generated after the Plasmin-mediated Dissolution of Blood Clots. In severe COVID, there is a Hyper-Coagulation state and the production of D-DIMER is elevated ( far in excess of its elimination )
Normally, D-DIMER LEVELS are under 500 ng / ml . Exponentially elevated in severe COVID disease.
Lab . Markers of Vital Organ Dysfunction like LFT, RFT, CARDIAC TROPONIN, Serum LDH etc. are additional Lab. Tests in complicated COVID End Stage disease.
TREATMENT MODALITIES of CYTOKINE STORM : This part will be dealt with in a separate Blog in the near future
Dr. Dhananjay Shah
Ped. Practice of 40 years
FELLOW IAP 2006
Crusader @ IAP
Worthy Candidate for IAP PRESIDENT ELECT 2022