Role of vitamin D3 in selected pulmonary diseases with particular emphasis on lung fibrosis.

INTRODUCTION AND OBJECTIVE: For many years vitamin D3 was known only as a regulator of the calcium-phosphate and water-electrolyte balances. Recent studies have paid special attention to other biological effects of calcitriol (the bioactive form of vitamin D3) with particular emphasis on its influence on immune function. Thus, any alterations, especially deficiencies, in the physiological level of calcitriol have serious health consequences. The aim of the study was to summarise the current state of knowledge concerning the role of vitamin D3 in selected pulmonary diseases. REVIEW METHODS: The review was based on data obtained from articles published in PubMed between 2000-2022. Papers were reviewed for scientific merit and relevance. BRIEF DESCRIPTION OF THE STATE OF KNOWLEDGE: In the reviewed literature, much attention was paid to clinical studies focused on the role of vitamin D3 in the pathogenesis of selected respiratory diseases. As revealed in research over the last two decades, vitamin D3 deficiency increases the risk and worsens the course of asthma, cystic fibrosis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, as well as COVID-19. Surprisingly, vitamin D supplementation has not always proved to be an effective therapeutic strategy. The review also presents the unique concept of the possibility of using vitamin D3 in the prevention and treatment of pulmonary fibrosis in the course of hypersensitivity pneumonitis. SUMMARY: Due to the multiplicity and variety of factors that affect the metabolism of vitamin D3, effective counteracting, and even more eliminating the negative consequences of disorders in the level and activity of calcitriol in the respiratory tract, seems to be a breakneck action. On the other hand, only a deep understanding of the role of calcitriol in the pathogenesis of lung diseases provides the chance to develop an effective therapy.

COVID 19 - Possible interrelations with respiratory comorbidities caused by occupational exposure to various hazardous bioaerosols. Part II. Clinical course, diagnostics, treatment and prevention.

INTRODUCTION AND OBJECTIVE: The course of COVID-19 caused by the SARS-CoV-2 may be aggravated by bioaerosols containing other viruses, bacteria, and fungi, occurring mainly in the occupational environment. Hence, the diagnostics and treatment of COVID-19 should address such a possibility in the anamnesis, treatment and final recommendations for avoiding of adverse exposure. ABBREVIATED DESCRIPTION OF THE STATE OF KNOWLEDGE: As SARS-CoV-2 attacks primarily the respiratory system and the severe manifestation of COVID-19 is interstitial pneumonia, diagnostics should include the following clinical and laboratory examinations: chest X-ray; high resolution computed tomography (HRCT); pulmonary function tests; arterial-blood gas test; genetic tests for the presence of SARS-CoV-2, in the future with the use of highly specific and sensitive nano-based biosensors; tests for the presence of specific immunity against the antigens of microorganisms causing other infectious or allergic pulmonary diseases (in the case of anamnestic indications). Because an universally accepted treatment for COVID-19 does not exist, the hitherto prescribed antiviral and immune-modulating drugs should be used be with caution. In many cases, a better alternative could be a safe supportive therapy, such as supplementation of the diet with probiotics, prebiotics, vitamins and microelements. SUMMARY: The most important preventive measures against COVID-19 should include: vaccination; the use of filter or surgical masks; disinfection and sterilization; maintaining of well-functioning ventilation and air conditioning systems; reduction of the community air pollution which has been identified as an important factor increasing the COVID-19 severity. In the choice of preventive measures, the above should be considered for their potential efficacy against other bioaerosols as potential disease-aggravating agents.

COVID 19 - Possible interrelations with respiratory comorbidities caused by occupational exposure to various hazardous bioaerosols. Part I. Occurrence, epidemiology and presumed origin of the pandemic.

The occupational bioaerosols containing viruses, bacteria, fungi, microbial toxins and plant or animal particles, may evoke infectious, allergic or immunotoxic diseases which may co-exist as comorbidities with COVID-19 and exacerbate the course of disease. They include hypersensitivity pneumonitis (HP) caused mostly by bacteria, fungi, and particles containing animal proteins, and immunotoxic diseases such as organic dust toxic syndrome (ODTS) and byssinosis, caused mostly by bacterial and fungal toxins. The two most probable scenarios of possible interrelations between these three comorbidities (CM) and COVID-19 are: 1) 'Triggering' - when infection with SARS-CoV-2 triggers severe CM after bioaerosol exposure; 2) 'Reverse triggering' when exposure to bioaerosol exacerbates a symptomless or mild course of COVID-19, and evokes a severe disease. The occupations mostly endangered by COVID-19 as the result of exposure to SARS-CoV-2 bioaerosol, or to other bioaerosols which may exacerbate this disease, include: health care workers, social workers, breeders of fur animals, slaughterhouse workers, workers engaged in the processing and selling of seafood, and probably also agricultural workers, mainly in the developing countries. The authors present a hypothesis for the origin of the present pandemic. It assumes that a mild form of the present SARS-CoV-2 that is supposedly circulating among the Chinese population in the eastern part of the country, mutated under the influence of as yet unknown factor(s) present in the Chinese seafood markets, probably component(s) of bioaerosols, into the virulent and highly contagious form, known as the present SARS-CoV-2, under a scenario similar to that the authors have named 'Reverse triggering'.