Safety and efficacy of recombinant granulocyte colony-stimulating factor as an adjunctive therapy for Streptococcus pneumoniae meningitis in non-neutropenic adult patients: a pilot study

Fausto de Lalla*, Roberto Nicolin and Luca Lazzarini

Department of Infectious Diseases, S. Bortolo Hospital, via Rodolfi, 36100 Vicenza, Italy


    Abstract
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 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 
Twenty-two non-neutropenic adult patients with Streptococcus pneumoniae meningitis received granulocyte-colony stimulating factor (G-CSF) (300–450 Ìg/day subcutaneously for 6 days) in addition to cefotaxime plus dexamethasone (9–12 g/day for 10 days and 16 mg/day for 3 days iv, respectively). Patients recovered without evident sequelae in all cases but one (with bilateral hearing deficit). No adverse event was recorded. Improvement of inflammation indices in the cerebrospinal fluid was rapid. The most rapid improvement was seen in glucose concentration, which returned to normal ranges within 24–48 h of treatment. In this study G-CSF administration appeared to be safe and effective; further controlled clinical trials are justified.


    Introduction
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 
The mortality and morbidity rates related to Streptococcus pneumoniae meningitis remain unacceptably high, despite treatment with potent bactericidal agents.

Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein that specifically regulates survival, proliferation and differentiation of neutrophilic granulocyte precursors and stimulates the function of mature neutrophils.1 Studies on the administration of G-CSF before experimental infection of non-neutropenic animals have repeatedly shown significant treatment benefits of G-CSF alone or in combination with antibiotics.2,3 Furthermore, G-CSF appears to attenuate the proinflammatory cytokine response in lipopolysaccharide-stimulated blood from G-CSF-treated human volunteers.4 In experimental pneumococcal meningitis in the rabbit, G-CSF pretreatment attenuates neutrophil pleocytosis and cerebrospinal fluid (CSF) IL-8 levels, and delays significantly the occurrence of alterations in TNF-{alpha}, IL-1ß, protein and glucose levels in the CSF.5 Anti-inflammatory properties have therefore been ascribed to this cytokine.6

Based on these observations, the present pilot study was performed with the aim of evaluating the value of G-CSF as an adjunctive agent in the standard treatment of non-neutropenic adult patients affected by S. pneumoniae meningitis.


    Materials and methods
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 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 
We recruited a cohort of patients over 18 years of age admitted consecutively to our unit from January 1995 to March 1999, with evidence of severe meningeal inflammation and demonstrable S. pneumoniae on Gram staining of CSF. Patients with either a prosthetic central nervous system device, or a history of hypersensitivity to ß-lactam antibiotics, or displaying whatever contraindication to G-CSF administration, or having received any antibiotic treatment during the week before recruitment were excluded. Confidential informed consent to G-CSF administration was obtained.

CSF specimens from all patients were examined at admission, during therapy and after 10 days of treatment (usually at the end of the antibiotic course). Leucocyte count, WBC differential count, lactates, glucose and proteins were determined on all CSF specimens. CSF samples were routinely cultured. In some cases, CSF specimens were immediately frozen and held at –80°C pending testing for IL-8 and IL-10. A set of blood cultures was performed at enrolment, and the Simplified Acute Physiology Score (SAPS II) was determined for all patients.7 Renal and liver function tests were performed on admission and on at least every alternate day thereafter; complete blood and WBC differential counts were determined every 12 h. On admission, all patients underwent chest X-ray. Audiometric testing and, when indicated, CT scanning were also performed before discharging the patient. Neurological examination, complete blood counts, renal and liver function tests, audiometric testing and, in the event of abnormal findings, CT scanning, were repeated for each patient within 2 months of discharge.

Intravenous cefotaxime (3 g tid for patients weighing <70 kg and 4 g tid for patients >70 kg) was administered to all patients; they also received both subcutaneous recombinant G-CSF 300 µg/day (450 µg for patients weighing >70 kg) for 6 days and iv dexamethasone 16 mg/day for 3 days. The first dose of dexamethasone was administered 10–15 min before starting cefotaxime. G-CSF was administered at enrolment to the study, usually with the first dose of cefotaxime. If the neutrophil count exceeded 40 x 109 cells/L within 6 days of commencement of therapy, G-CSF treatment was temporarily discontinued and re-administered at the same dosage only when the count fell to <40 x 109 cells/L.

IL-8 and IL-10 levels in CSF samples were determined with an ELISA assay (Bender MedSystems, Vienna, Austria) run according to the manufacturer's instructions (lower detection limits: IL-8, 11 pg/mL; IL-10, 2 pg/mL).

All results are presented as means and ranges (SAS statistical package, SAS Institute, Cary, NC, USA)


    Results
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 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 
A total of 22 patients (six males and 16 females) were enrolled in this study. The mean age was 59 ± 11.7 years (range: 33–77) and 12 were over 60. Twelve patients displayed an underlying disease: CSF rhinorrhoea from previous skull fracture or chronic otitis media (four patients each), decompensated diabetes mellitus (three patients; glucose levels in these three patients are excluded from the table) and common variable hypogammaglobulinaemia (one patient). On admission, the mean SAPS II was 33 ± 12 (range: 17–65). Coma was present in 13 patients, four of whom required mechanical ventilation for 7–10 days. Culture-proven S. pneumoniae meningitis was diagnosed in all cases, and blood cultures were positive for S. pneumoniae in 12 out of 18 cases (66.7%). The mean duration of symptoms before initiation of treatment was 17 ± 13 h (range: 4–48 h).

All patients displayed an uneventful course; coma resolved in 24–72 h and fever subsided after 3.0 ± 1.5 days (range: 2–5 days). All CSF cultures performed 24–48 h after the establishment of therapy were sterile. Recovery was achieved without evident neurological sequelae in all but one case (bilateral hearing deficit)

G-CSF was administered for 4.5 ± 1.2 days (range: 3–6 days). The neutrophil counts were as follows: at recruitment, neutrophils ranged from 10 x 109 to 25 x 109 cells/L (global mean 18.7 x 109 ± 8.8 x 109 cells/L); the highest count found in a single patient during G-CSF therapy ranged from 25 x 109 to 50 x 109 cells/L (global mean: 35.6 x 109 ± 7.8 x 109 cells/L).

The Table shows the progressive improvement of the indices of inflammation in the CSF during the course of treatment. The most rapid improvement was seen in glucose concentration, which generally attained values within the normal range within the first 24–48 h of therapy. The high CSF levels of both IL-10 and IL-8 (>1100 pg/mL) found on admission declined progressively during treatment (TableGo).


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Table. Streptococcus pneumoniae meningitis: indices of inflammation in the CSF at diagnosis, during treatment and at the end of therapy in 22 patients treated with antibiotics, dexamethasone and G-CSF
 
Neither complication nor clinical adverse reactions attributable to G-CSF treatment were recorded in the course of treatment or during the follow-up period. Modifications of baseline serum chemistry values were observed at the end of therapy in only one patient (serum albumin level: –5 g/L; serum potassium level: –0.4 mmol/L). Audiological assessment at the time of discharge demonstrated a mild–moderate monolateral or bilateral hearing deficit in four patients; further follow-up audiograms performed 30–60 days later were normal in all but one of these patients.


    Discussion
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 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 
The results of this pilot study appear to be very encouraging. All 22 patients (66.7% of whom had been bacteraemic, 54.5% displayed an underlying disease, 59.1% were comatose and 18.2% had required assisted ventilation) recovered after an uneventful course. Return to normal of both neurological status and indices of CSF inflammation were quickly achieved, and only one of the patients suffered permanent sequelae (hearing impairment); no side effect related to therapy was recorded. Interestingly, in 48 adult patients (26 males and 22 females, mean age 45.6 ± 12.5 years) with culture-proven pneumococcal meningitis admitted previously to our unit in the years 1987–1994 (who had displayed bacteraemia in 49.9%, an underlying disease in 54.2% and coma in 56.3% of cases, respectively, and had required assisted ventilation in 18.7% of cases), worse outcomes had been demonstrated in spite of treatment with an antibiotic (either penicillin G or cefotaxime) plus dexamethasone using the same doses, but without G-CSF. In this historical group, the fatality rate was 10.4%, and four patients survived with significant neurological sequelae. If we analyse the figures related to our historical control patients (TableGo), the concern that administration of G-CSF could stimulate a rise in leucocyte concentration in the CSF, leading to an exacerbation of the deleterious effects related to subarachnoid space inflammation, does not seem to be realized, certainly if a G-CSF–corticosteroid combination is given. Indeed, the CSF indices of inflammation appeared either to remain unchanged (e.g. neutrophilic pleocytosis) or to improve more rapidly (e.g. lactate, proteins and glucose) when G-CSF was administered. In particular, glycorrhachia returned to normal range after 24–48 h of treatment, exhibiting values significantly (P = 0.002) higher than those found in the historical controls (TableGo). The results obtained by Østergaard et al.5 using the rabbit model of experimental pneumococcal meningitis, seem therefore to be in line with our experience; in fact, those authors also found that pretreatment with G-CSF delayed significantly the emergence of alterations in CSF glucose levels, and attenuated neutrophil pleocytosis, IL-8 level and proteins. It seems also noteworthy that in our patients the G-CSF treatment was started only in cases with overt meningitis: this could probably explain some differences from the animal model (e.g. lack of effect on pleocytosis), when G-CSF was administered 48 h before intracisternal inoculation of S. pneumoniae. No increase in CSF leucocytosis was found by Schmidt et al.8 in experimental meningitis in rabbits treated intracisternally or intravenously with G-CSF.

It is difficult to hypothesize the mechanism by which G-CSF acts in pneumococcal meningitis. According to some authors, however, a complex range of causes (including a decreased production of IL-8, an impaired mobility of neutrophils toward a chemotactic gradient, a significant reduction of bacterial concentration and an increase in bacterial killing) may explain the attenuation of the inflammatory response achieved by G-CSF administration in experimental pneumococcal meningitis.5

In conclusion, we think that the safety and efficacy displayed in this pilot study by G-CSF justifies further randomized controlled clinical trials aimed at defining precisely its therapeutic role in S. pneumoniae meningitis.


    Acknowledgments
 
We thank Vito Toso MD, Michela Alecci MSc and Elisabetta Galloni MSc (Department of Neurology, S. Bortolo Hospital, Vicenza) who performed determination of CSF cytokine levels, and Paolo Benedetti MD for assistance in preparing the manuscript.


    Notes
 
* Corresponding author. Tel: +39-0444-993998; Fax: +39-0444-993616; E-mail: fdl.vi{at}gpnet.it Back


    References
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 
1 . Souza, L. M., Boone, T. C., Gabrilove, J., Lai, P. H., Zsebo, K. M., Murdock, D. C. et al. (1986). Recombinant human granulocyte colony-stimulating factor: effects on normal and leukemic myeloid cells. Science 232, 61–5.[ISI][Medline]

2 . Daifuku, R., Andresen, J. & Morstyn, G. (1993). Recombinant methionyl human granulocyte colony-stimulating factor for the prevention and treatment of non-neutropenic infectious diseases. Journal of Antimicrobial Chemotherapy 32, Suppl. A, 91–7.[ISI][Medline]

3 . Nelson, S. (1994). Role of granulocyte colony-stimulating factor in the immune response to acute bacterial infection in the non-neutropenic host: an overview. Clinical Infectious Diseases 18, Suppl. 2, S197–204.[ISI][Medline]

4 . Hartung, T., Docke, W. D., Gantner, F., Krieger, G., Sauer, A., Stevens, P. et al. (1995). Effect of granulocyte colony-stimulating factor treatment on ex vivo blood cytokine response in human volunteers. Blood 85, 2482–9.[Abstract/Free Full Text]

5 . Østergaard, C., Benfield, T., Gesser, B., Kharazmi, A., Frimodt-Møller, N., Espersen, F. et al. (1999). Pretreatment with granulocyte colony-stimulating factor attenuates the inflammatory response but not the bacterial load in cerebrospinal fluid during experimental pneumococcal meningitis in rabbits. Infection and Immunity 67, 3430–6.[Abstract/Free Full Text]

6 . Hartung, T. (1998). Anti-inflammatory effects of granulocyte colony-stimulating factor. Current Opinion in Hematology 5, 221–5.[Medline]

7 . Le Gall, J. R., Lemeshow, S. & Saulnier, F. (1993). A new simplified acute physiology score (SAPS II) based on a European/North American multicenter study. Journal of the American Medical Association 270, 2957–63.[Abstract]

8 . Schmidt, H., Stuertz, K., Bruck, W., Chen, V., Stringaris, A. K., Fischer, F. R. et al. (1999). Intravenous granulocyte colony-stimulating factor increases the release of tumour necrosis factor and interleukin-1beta into the cerebrospinal fluid, but does not inhibit the growth of Streptococcus pneumoniae in experimental meningitis. Scandinavian Journal of Immunology 49, 481–6.[ISI][Medline]

Received 26 January 2000; returned 27 April 2000; revised 6 June 2000; accepted 24 July 2000