Abstract

Background: Clinical presentation and immunological patterns are different in all three waves & still evolving.

Methods: Prospective,observational studydone in all three waves of COVID-19 pandemic & enrolled 8000 symptomatic, RT PCR confirmed cases in post COVID Unit.Clinical & immunological phenotypes were categorised in four types, Duration of illness (DOI) classified into transient or evolved, persistent, progressive, Topographical classification into vague or nonspecific and systemic or organic as per involvement of organ systems, Treatment responsive classified as per response into easy to treat and difficult to treat or refractory to treatment & Fourth is according genetic makeup patterns or strain patterns observed in first, second and third wave as pulmonary, extrapulmonary and pulmonary-extrapulmonary combo. Investigated with LDH, Uric acid, CRP, D-dimer, antinuclear antibody & retrospective analysis of antigenic cross reactivity/mimicry, markers as IL-6, Ferritin and interventions required during hospitalization including follow up HRCT thorax.

Results:Clinical phenotypes as per DOI & Topographical phenotypes has documented significant association with immunological markers (p<0.00001) Treatment response phenotypes has documented significant association with DOI before hospitalisation, interventions requiredand inflammatory marker (p<0.00001) Clinical phenotypes in three waves has documented significant association with four pathophysiological pathways (p<0.00001)

Conclusion:Clinical-Immunological Phenotypes of?Long COVID? can be predictedat entry point, and sequential titersof inflammatory markerhas 'vitalrole' during management in post covid care setting.