Table 1.

Synovial fluid examination for α-defensins (HNP1–3) by HPLC, microbial culture cultivation, and PCR, in patients with orthopedic diseases of infectious and noninfectious origin.

Patient	Cultivation	PCR	AD by HPLC	Diagnosis
1	neg.	pos.	pos.	IA
2	neg.	pos.	pos.	IA
3	neg.	pos.	pos.	IA
4	neg.	neg.	pos.	IA
5	neg.	pos.	pos.	IA
6	neg.	pos.	pos.	IA
7	pos.	pos.	pos.	PJI
8	neg.	pos.	pos.	PJI
9	pos.	pos.	pos.	PJI
10	neg.	pos.	pos.	PJI
11	neg.	pos.	pos.	PJI
12	neg.	pos.	pos.	PJI
13	neg.	neg.	pos.	PJI
14	neg.	neg.	neg.	TEP *
15	neg.	pos.	neg.	TEP *
16	neg.	neg.	neg.	TEP *
17	neg.	neg.	neg.	TEP *
18	neg.	neg.	neg.	TEP *
19	neg.	neg.	pos.	REA *
20	neg.	neg.	neg.	REA *
21	neg.	neg.	neg.	RHA *
22	neg.	neg.	neg.	AR *
23	neg.	neg.	neg.	AR *
24	neg.	neg.	neg.	AR *

AR = arthrosis, IA = infectious arthritis, neg. = negative test result, PJI = periprosthetic joint infection, pos. = positive test result, REA = reactive arthritis, RHA = rheumatoid arthritis, TEP = total endoprosthesis. A positive test in the case of AD means a finding greater than the determined cutoff concentration. In the cases of cultivation and PCR, positive means a presence of bacteria was determined. A negative test in the case of AD means a finding less than the determined cutoff concentration. In the cases of cultivation and PCR, negative means an absence of bacteria was determined. Weighted kappa (κ) values showing the diagnostic validity of the methods used with respect to the determination of infections were as follow: HPLC: κ = 0.905, PCR: κ = 0.755, microbial cultivation: κ = 0.402. The diagnostic validity of AD measured by HPLC is most significant. The noninfectious diseases are marked with an asterisk (*).