Serum activin A as a prognostic biomarker for community acquired pneumonia

Table 1 Characteristics of study patients

Characteristics	Group-I	Group-II	Group-III	P value
	n = 110	n = 42	n = 16	I vs II	II vs III
Age (years; mean ± SD)	51.36 ± 19.72	58.15 ± 16.91	61.81 ± 22.65	0.1741	0.2013
Sex (M/F)	56/54	27/15	11/5	0.5975	> 0.9999
Smoking, n (%)	72 (65.45)	27 (64.28)	11 (68.75)	0.6012	0.5812
WBC (× 109/L)	10.87 ± 4.02	11.13 ± 4.38	13.01 ± 4.18	0.0673	0.2015
CRP (mg/L)	36.76 ± 28.11	81.23 ± 51.18	132.77 ± 64.83	0.0057	0.0013
PCT (μg/L)	0.77 ± 1.42	1.01 ± 2.12	2.98 ± 3.43	< 0.0001	< 0.0001
PSI score	76.12 ± 28.94	101.3 ± 40.51	121.8 ± 48.21	< 0.0001	0.0002
CURB-65 score				0.0082	0.0013
0-1	73	20	2
2	32	13	5
3-5	5	9	9
Pathogen checked
Bacteria	28	19	6
Virus	11	7	5
Atypical pathogen	31	1	0
Mixed pathogen	15	4	1
Unknown	25	11	4
Activin A (ng/mL)	11.92 ± 8.21	17.61 ± 5.35	25.33 ± 7.37	0.0006	< 0.0001

WBC: White blood cell; CRP: C-reactive protein; PCT: Procalcitonin; CURB-65: Confusion, urea, respiratory rete, blood pressure, and age ≥ 65 years old; PSI: Pneumonia Severity Index.

Table 2 Areas under the curve and thresholds for predicting hospital mortality in patients with community-acquired pneumonia

	Threshold	Sensitivity (%)	Specificity (%)	AUC	P value	95%CI
CRP	> 84	80.65	59.12	0.722	0.0008	0.587-0.811
PCT	> 2.31	57.36	87.91	0.682	0.0005	0.601-0.824
CURB-65	> 1	73.66	81.02	0.846	< 0.0001	0.725-0.914
PSI	> 108	76.08	80.36	0.85	< 0.0001	0.748-0.937
Activin A (ng/mL)	> 19	83.27	81.44	0.854	< 0.0001	0.787-0.941

AUC: Areas under the curve; CRP: C-reactive protein; PCT: Procalcitonin; CURB-65: Confusion, urea, respiratory rete, blood pressure, and age ≥ 65 years old; PSI: Pneumonia Severity Index.

Table 3 Prognostic effect of activin A for hospital mortality in Cox proportional hazards regression analysis

Variables	Univaritate analysis		Multivaritate analysis
	HR (95%CI)	P value	HR (95%CI)	P value
Age	1.112 (1.000-1.064)	0.0624
Sex	0.881 (0.343-2.106)	0.5751
Smoking	1.113 (0.551-2.471)	0.9931
WBC	1.127 (0.931-1.202)	0.3428
CRP	1.103 (1.012-1.206)	0.0661
PCT	1.045 (1.023-1.057)	0.0232
CURB-65	2.157 (1.512-3.104)	< 0.0001
PSI	1.018 (1.005-1.037)	< 0.0001	1.024 (1.012-1.047)	< 0.0001
Activin A	1.024 (1.011-1.028)	< 0.0001	1.028 (1.014-1.031)	< 0.0001

WBC: White blood cell; CRP: C-reactive protein; PCT: Procalcitonin; CURB-65: Confusion, urea, respiratory rete, blood pressure, and age ≥ 65 years old; PSI: Pneumonia Severity Index.