Medicinal agents, beside occupational and environmental agents, remain one of the most common causes for interstitial lung diseases (ILD). A major problem with ILD is the recognition of the causative agent. In some cases more or less characteristic features of presentation are described.

Often, the connection between drug-use and the development of related inflammatory damage or idiosyncratic toxicities is hard to recognize and objectify. Cocaine, a xenobiotic and the most commonly used illicit drug, causes serious medical and social problems. An increasing incidence of lung toxicity related to cocaine or crack-use is being reported worldwide. However, the mechanism of the resulting lung injury is not fully understood. This review summarizes possible molecular mechanisms explaining intra-individual variability in cocaine response and lung toxicity.

The importance of including pharmacogenomics in the work-up of patients with suspected drug-induced lung toxicity is highlighted.

Respiratory syncytial virus (RSV) is the leading cause of respiratory tract infection in infants and young children throughout the world. Although preterm birth has for years been considered the major risk factor for severe disease and hospitalization, recent findings indicate that prematurity is not a necessary condition, but one of the independent risk factors for severe RSV infection, together with chronic lung diseases, congenital heart disease and immunodeficiency.

Furthermore, over 50% of infants hospitalized for RSV infections during the first year of life are healthy, full-term newborns, suggesting that other environmental and individual factors may be involved. Unfortunately, there is still no specific therapy against RSV infection and therefore prophylactic measures seem to be the only intervention to avoid disease complications. No safe and effective RSV vaccine is available for the prevention of serious RSV infection. Therefore, in addition to hygienic measures, the only approach is passive immunoprophylaxis with humanized monoclonal anti-RSV antibodies, such as palivizumab that have been developed for clinical use. Because of the high cost of these antibodies, a better definition of the individual risk profile for severe RSV infection and timing of administration is needed for optimal effectiveness and careful use of limited health care resources.

In this article, we have reviewed the clinical and pharmacological aspects of immunoprophylaxis with monoclonal antibodies for preventing RSV infection in high-risk infants.

The classic role of vitamin D in the regulation of calcium and phosphate metabolism, and its effects on bone health, are well established. More recently a critical role in immunity and respiratory health has been proposed.

This arises from evidence for the capacity to generate the active metabolite, 1α,25-dihydroxyvitamin D3 (1,25(OH)D3), locally in many tissues beyond the kidney; expression of the vitamin D receptor (VDR) in immune and structural cells not involved in calcium-phosphate homeostasis; and control by 1,25(OH)D3 of the transcription of genes associated with numerous different biological processes through its nuclear VDR. Abnormalities in the vitamin D axis, including a high prevalence of vitamin D insufficiency worldwide, now appear important in a wide range of pulmonary diseases including viral and bacterial respiratory infection, asthma, chronic obstructive pulmonary disease, and cancer.

Actions of vitamin D on innate immune responses, for example, production of antimicrobial peptides and autophagy, and on adaptive immune responses, for example, promoting regulatory lymphocytes, are believed to underpin these associations.

Common genetic risk variants identified by Genome-Wide Association (GWA) studies over the past decade have explained a small portion of disease heritability in complex diseases. It is becoming apparent that each gene/locus is heterogeneous and that multiple rare independent risk alleles across the population contribute to disease risk.

Next generation sequencing technologies have reached the maturity and low cost necessary to perform whole genome, whole exome, and targeted region sequencing to identify all rare risk alleles across a population, a task that is not possible to achieve by genotyping. Design of whole genome, whole exome, and targeted sequencing projects to identify disease variants for complex lung diseases requires the balancing issues related to the four main steps in projects - library preparation, sequencing, sequence data analysis, and statistical analysis. Although data analysis approaches are still evolving, a number of published studies have successfully identified rare variants associated with complex disease.

Despite many challenges that lie ahead in applying these technologies to lung disease, rare variants are likely to be a critical piece of the puzzle that needs to be solved to understand genetic basis of complex lung disease and to use this information to develop better therapies.