G protein‐coupled receptor for asthma susceptibility associates with respiratory distress syndrome

Figures & data

Table I. Study subjects for genetic analyses. The number of excluded samples after quality assurance is indicated in brackets. RDS = respiratory distress syndrome; GA = gestation age.

Gestation age	Term control subjects	Premature control subjects	Subjects with RDS
GA<32 weeks		57 (15)	117 (35)
32⩽GA⩽35 weeks		99 (12)	59 (16)
GA>37 weeks	189 (8)
Total number for final analysis	181	129	125

Table II. Haplotypes H1–H8 defined by the six tagging single nucleotide polymorphisms in a 70.7 kb interval of the GPRA gene intron 2 and haplotype frequencies among near‐term (32 weeks⩽gestation age<35 weeks) infants with respiratory distress syndrome (RDS) compared to the gestation‐age‐matched controls (Ctrl).

NT_007819	34037316	34044455	34051648	34077700	34085796	34107975	RDS (n = 43)	Ctrl (n = 87)	P	OR (95% CI)
NT_000380	515224	522363	529556	555608	563704	585883
SNP	rs323917	rs323922	rs324377	rs324384	rs324396	rs740347
	C/G	G/C	A/C	T/C	C/T	G/C
H1	C	G	C	C	T	G	0.244	0.408	0.01	0.5 (0.3–0.8)
H2	C	C	A	T	C	G	0.302	0.218	NS
H3	C	G	C	C	C	G	0.081	0.092	NS
H4/H5	C	C	A	T	C	C	0.198	0.086	0.01	2.6 (1.2–5.5)
H6	C	G	C	T	C	G	0.058	0.103	NS
H7	G	C	A	T	C	G	0.047	0.080	NS
H8	C	G	A	T	C	G	0.035	0.011	NS
Others							0.035	0.000	NS

Table III. Immunohistochemical analysis of paraffin‐embedded autopsy specimens with the GPRA‐A and ‐B isotype specific antibodies. The results are presented as the intensity of the expression (mean±SEM, score from 0 to 3) in the large bronchioles. GA = gestation age; SMC = smooth muscle cells; RDS = respiratory distress syndrome; BPD = bronchopulmonary dysplasia.

Group	GPRA‐A					GPRA‐B
		GA (weeks)	Age at death (days)	Epith. staining	SMC staining		GA (weeks)	Age at death (days)	Epith. staining	SMC staining
	n	mean±SD		mean±SEM		n	mean±SD		mean±SEM
Fetus	6	20.4±4	aborted	0	0	8	20.5±4	aborted	0	0
Term	4	36.8±3	0.8±0.3	0.8±0.1	1±0.4	5	39.2±2	1±0.7	0.3±0.2	0
RDS	9	26.1±1	6.6±5.2	0.5±0.1	1.2±0.3	10	26.9±2	6.8±6.1	0.8±0.3	1.1±0.3
BPD	4	28.9±2	176±94	0.1±0.1	1.8±0.1	7	28.5±2	180±84	1.3±0.4	0.9±0.2

Table IV. Pairwise linkage disequilibrium values (D´) and allele frequencies of the markers defining the haplotypes H1–H8 in the GPRA gene intron 2.

Figure 1. Immunohistochemical analysis of paraffin‐embedded specimens of fetuses (A, B), term infants without lung injury (C, D) and preterm infants with respiratory distress syndrome (RDS) (E, F) or bronchopulmonary dysplasia (BPD) (G, H) with the GPRA‐A (left panel) and ‐B isoform (right panel) specific antibodies. GPRA‐A and ‐B expression in the bronchial epithelium is absent in fetal samples and is induced in term samples. GPRA‐A is additionally expressed in the smooth muscle cells of the bronchioles. GPRA‐B expression is upregulated in the smooth muscle cells of the bronchioles in RDS and BPD.

Figure 2. Immunohistochemical staining of paraffin‐embedded adult human distal lung with GPRA‐A (A) and ‐B isoform (B) specific antibodies. Both isoforms are present in alveolar macrophages and B isoform additionally in alveolar epithelium.

Figure 3. Quantitative real‐time polymerase chain reaction analysis of GPRA mRNA expression in samples taken from nasal respiratory epithelium of 10 adults, 6 term and 7 preterm infants. Cytokeratin 18 (CK18) mRNA expression was used as an epithelial marker for GPRA mRNA normalization.