Immediate diagnosis of ventriculits: evaluation of parameters independent of microbiological culture

Generally accepted reference values in CSF diagnostics are not valid in cerebrospinal fluid (CSF) containing large amounts of blood. Residual blood may obscure ventriculitis as diagnostics largely depend on parameters such as cell count, lactic acid and total protein measurement. We sought to improve the diagnostics by evaluating a cytokine panel and soluble CD62L as markers of ventriculitis. In addition, we tested an algorithm of established parameters to predict ventriculitis in a specific patient collective.

Analysis was performed on ventricular CSF samples from 50 consecutive patients. Gram staining, microbiological culture, total cell count, total protein and CD62L expression on neutrophil granulocytes were analysed immediately. Cytokines and soluble CD62L were measured by flow cytometry.

Positive culture was detected in ten patients. Of all parameters tested only IL1-beta, IL8 and CD62L on neutrophils were significantly different between culture-positive and -negative patients. The highest predictive value was obtained when analysing IL1-beta. The predictive value of a parameter combination (IL6 in CSF, C-reactive protein and leukocytes in periphereal blood) was comparable to IL1-beta. Half of the patients in this analysis were identified as culture positive because of the lack of inflammatory response.

IL1-beta and perhaps also IL8 provide very good analytical performance when looking for ventriculitis in patients with residual blood in CSF. Turn-around time is short, and results could be reported within 1 h for 24 h a day. In some patients application of glucocorticoids may result in restricted inflammatory response. Even in these patients IL1-beta provides a reliable parameter for the immediate diagnosis of ventriculitis.