Dear Sir,

I hope the following information may help you

1. Scand J Infect Dis. 2003;35(2):121-6.

Evaluation of laboratory markers for the detection of infections in open-heart surgery patients.

1. Lannergård A1, Hersio K, Larsson A, Pauksen K, Venge P, Ståhle E, Friman G.

Mymensingh Med J. 2008 Jul;17(2 Suppl):S72-6.

Comparison between CRP and IL-6 as early markers of neonatal sepsis.

Noor MK1, Shahidullah M, Mutanabbi M, Barua C, Mannan MA, Afroza S.

I will try to see if there is more available,

PR Bollam, MD, MSChe

University Neurosurgery

LSU-Health, Shreveport

Thank you, Dr. Bollam, for your post. To my best knowledge, papers on the application of IL-6 as a biomarker for acute infection in orthopaedic surgery (i.e. THA,TKA) are very scarce. 

Dear Panayot

IL-6 is reviewed as an indicator of inflammation (in general) and also infection but the authors believe that it may be raised in inflammation but may not be necessary to become a routine investigation that will be used as tool to diagnose infection

Here there are some papers on Orthopaedic subjects

Giannoudis PV, Hildebrand F, Pape HC (2004) Inflammatory serum markers in patients with multiple trauma. Can they predict outcome? J Bone Joint Surg Br 86:313–323

Minetto MA, Oprandi G, Saba L, Mussino S, Aprato A, Massè A, Angeli A,Gallinaro P(2006) Serum interleukin-6 response to elective total hip replacement surgery. Int Orthop. 30(3): 172–176

Villacis D, Merriman JA, Yalamanchili R, Omid R, Itamura J, Rick Hatch GF 3rd (2014). Serum interleukin-6 as a marker of periprosthetic shoulder infection. J Bone Joint Surg Am. 96(1):41-45

Demura S, Takahashi K, Kawahara N, Watanabe Y, Tomita K.J (2006) Serum interleukin-6 response after spinal surgery: estimation of surgical magnitude. Orthop Sci. 11(3):241-247

There is a tendency though that in case of joint aspiration and for revision surgery planning it would be advisable but not necessary to investigate the aspirate for a combination of Interleukin-6, Interleukin-8 as well as α(2) macroglobuline, vascular inodthelial growth factor and CRP (Thomas P. Sculco, ‎Moe R. Lim, ‎Andrew D. Pearle - 2012)

Thank you, George, for the references. Wirtz  et al. (2000) found that serum IL-6 concentration peaks within the first 6-12 hours postoperatively and rapidly returns to normal within 48-72 hours. This finding makes the persistent elevation of IL-6 concentration an excellent marker of acute postsurgical wound infection. In comparison, ESR and CRP normalize slowlier within 3 months and 3 weeks, respectively. Despite this promising indicator, there are only a few studies to validate the use of IL-6 for monitoring wound infection debute and decourse. IL-6 measuring  could be very useful for early intervention in case of acute infection onset. Probably, it is a very expensive test for general application in the era of cost containment in healthcare.

Wirtz DC, Heller KD, Miltner O et al (2000) Interleukin-6: a potential inflammatory marker after total hip replacement. Int Orthop 24:194-196 

Dear Panayot

You are very right that expense plays its role here but  the only reference that it is linked directly to infection investigating is this of Villacis et al who say that it will not be necessary as  he applied it in infected shoulder replacements and the Sculco et el who they say that we need a combination of different markers to make sure that something is wrong and we need to use it on the aspirate of the joint. All others say about inflammation that is seen post-operatively (spines or joints) or post fracture controlling healing or even for potential monitoring on pulmonary embolism. But yes despite the controversies I agree with you that money talk.

Obviously, a definitive diagnosis of an infection is determined by growth of bacteria on culture of aspirate and intraoperative specimens.

This is very true

Hello everyone, haven't gone through all the discussions above. I also can't add much to the IL-6 topic, but just wanted to share The Musculoskeletal Infection Society criteria for PJI. I find them somewhat useful. Please excuse me if I am slightly off topic.

One of the following is necessary for diagnosing PJI:

(1) A sinus tract communicating with the prosthesis

(2) A pathogen is isolated by culture from two separate tissue or fluid samples obtained from the affected prosthetic joint

(3) Four of the following six criteria exist:

(a) Elevated ESR and CRP (ESR > 30 mm/hour; CRP > 10 mg/L)

(b) Elevated synovial fluid WBC count (> 3000 cells/μL)

(c) Elevated synovial fluid neutrophil percentage (> 65%)

(d) Presence of purulence in the affected joint

(e) Isolation of a microorganism in one periprosthetic tissue or fluid culture

(f) > 5 neutrophils per highpowered field in 5 highpower fields observed from histologic analysis of periprosthetic tissue at ×400 magnification

Sincerely,

Hristo