Human SPD(Pulmonary Surfactant Associated Protein D) ELISA Kit

Humans living at high altitude (>= 2,500 meters above sea level) have acquired unique abilities to survive the associated extreme environmental conditions, including hypoxia, cold temperature, limited food availability and high levels of free radicals and oxidants. Longterm inhabitants of the most elevated regions of the world have undergone extensive physiological and/or genetic changes, particularly in the regulation of respiration and circulation, when compared to lowland populations. Genome scans have identified candidate genes involved in altitude adaption in the Tibetan Plateau and the Ethiopian highlands, in contrast to populations from the Andes, which have not been as intensively investigated. In the present study, we focused on three indigenous populations from Bolivia: two groups of Andean natives, Aymara and Quechua, and the low-altitude control group of Guarani from the Gran Chaco lowlands. Using pooled samples, we identified a number of SNPs exhibiting large allele frequency differences over 900,000 genotyped SNPs. A region in chromosome 10 (within the cytogenetic bands q22.3 and q23.1) was significantly differentiated between highland and lowland groups. We resequenced similar to 1.5 Mb surrounding the candidate region and identified strong signals of positive selection in the highland populations. A composite of multiple signals like test localized the signal to FAM213A and a related enhancer; the product of this gene acts as an antioxidant to lower oxidative stress and may help to maintain bone mass. The results suggest that positive selection on the enhancer might increase the expression of this antioxidant, and thereby prevent oxidative damage. In addition, the most significant signal in a relative extended haplotype homozygosity analysis was localized to the SFTPD gene, which encodes a surfactant pulmonary-associated protein involved in normal respiration and innate host defense. Our study thus identifies two novel candidate genes and associated pathways that may be involved in high-altitude adaptation in Andean populations.

Surfactant protein D (SP-D) is an important component of the pulmonary host defense system. We hypothesized that bronchoalveolar lavage (BAL) SP-D levels are lower in children presenting with recurrent bronchitis, providing evidence for a role of SP-D in human respiratory diseases. SP-D levels in BAL were measured in 45 children, who suffered from recurrent bronchitis for an average of 2-3 yr. Clinical outcome was assessed 2 yr after BAL. For comparison, BAL fluids from 15 control children without respiratory symptoms were evaluated. Among the 45 children with recurrent bronchitis, 12 had no SP-D in their BAL at the time of investigation. These SP-D-deficient patients had more frequently pneumonias and their long-term outcome was worse than that of the children with detectable SP-D. No genetic cause could be identified for the SP-D deficiency. Among the children with recurrent bronchitis and SP-D clearly detectable in BAL, those with the diagnosis of allergic asthma had threefold elevated levels compared with controls. In accordance with animal and in vitro data, elevated SP-D concentrations in BAL may represent an up-regulation due to allergic airway inflammation. In contrast, SP-D deficiency due to consumption or failure to up-regulate SP-D may be linked to pulmonary morbidity in children.