Professor Jean-Francois Rossi
Medical Hematology and Oncology
CHU Lapeyronie, Montpellier
C-reactive protein (CRP) is an acute-phase protein that has long been recognized as a marker of systemic inflammation. CRP measurement can complement a range of diagnostic markers to monitor infection and direct treatment. However, as economic rationalization becomes a necessity throughout the health care sector, it is apparent that such areas of frequent laboratory testing may need careful consideration and revision. Hematology is just one of these areas that deserve attention. We assess whether near-patient testing can reduce costs and improve patient diagnosis, treatment and recovery time.
Complete Blood Count (CBC) and CRP measurement are two possible hematological tests that could be relocated from the clinical laboratory to the patients bedside. CBC forms an integral part of hematology and guides numerous therapeutic interventions. CRP, an acute phase plasma protein, is involved in the innate inflammatory response and is a well known marker of systemic inflammation. CRP is secreted rapidly, within a few hours of the immunological insult, upon activation by specific cytokines. CRP is, therefore, a particularly sensitive and interesting tool for monitoring inflammatory conditions and has numerous clinical applications. CRP measurement is used in the monitoring of adult and neonatal infection and immune disorders, and is also an approved risk marker for cardiovascular disease.
CBC and CRP measurement are useful tests which are carried out, on average, 15 times during the period of a patients hospitalization, particularly during intensive chemotherapy, with subsequent threat of infection and possible need for blood transfusion.
Bone marrow aplasia is confirmed by evidence of pancytopenia determined by CBC testing. The severity of the bone m arrow aplasia is defined by two parameters: the extent and the duration of cytopenias, particularly neutropenia. There is a clear relation between these two parameters and the incidence of infection, which is high after one week of polynuclear levels below 500 cells/mm3. The same applies to thrombopenia and the risk of bleeding, which increases with platelet counts below 30,000 platelets/mm3, and becomes more serious as counts drop further. A distinction is made between short-term aplasia (<1 week) and long term aplasia (>1 week). Anti-infection strategies take into account the expected duration of the aplasia, its conditions of onset (e.g. during leukemia induction therapy, which may be associated with a pre-existing infection), and fever monitoring, associated with pathogen identification in only 25-30% of these cases, leading to emergency requirements in some instances. Based on solid clinical analysis and a few simple laboratory tools, such as CBC and CRP measurement, concise decisions on patient management can be made.
CRP testing is used in monitoring infection profiles by noting increasing levels, which correlate with temperature fluctuations during fever. This allows a dynamic analysis of the infection progression and can lead to more accurate and prompt administration of antibiotic treatment, or withdrawal of antibiotic therapy if required. Conversely an observed drop in CRP levels and a rise in white blood cells (WBC) can allow an earlier patient discharge. The combination of CRP and CBC analyses can therefore improve the follow-up of aplasia patients who may have other hematological diseases. Thus, relocating these tests closer to the patients bedside is obvious as it provides reliability, simplicity and a rapid turnaround of results. Used as part of a cost-control plan, near-patient CRP and CBC testing can reduce the costs associated with inappropriate antibiotic treatment and prolonged hospital stays. Moreov er, results are comparable to those achieved in a laboratory. Recent data1 comparing results of near-patient and centralized laboratory-based tests for CRP and CBC analysis have demonstrated a clear correlation between the two, a well as a significant reduction in the turnaround time from sampling to result delivery in the former. Thus the relocation of such tests would not compromise the accuracy of results, but may offer distinct advantages compared with centralized laboratory-based tests.
Blood transfusions are performed regularly in patients with chronic bone marrow failure such as myelodysplasia. The management of conventional chemotherapy, with procedures such as blood transfusions, is based on a certain number of laboratory results. Transfusion strategies (red blood cells and platelet concentrates) rely on almost daily CBC monitoring in addition to screening for irregular agglutinins in transfusion cases or measuring markers of other vital functions in chemotherapy cases. In this context, the processing of such fundamental aids to decision making as the CBC and the CRP test may benefit from being closer to the patient, and there may be situations where CBCs must be double-checked or combined with a CRP assay. Recent evidence1 has implied that the rapid results obtained from near-patient testing can offer sound economic benefits in addition to improving patient care and prognosis. The percentage of unjustified red blood cell or platelet transfusions can potentially be reduced through a more precise monitoring system, which can provide options for alternative treatments. Administration of hematopoietic growth factor (G-CSF) is one such option. Results obtained from near-patient testing could allow both the length of time before G-CSF is prescribed and the duration of hospitalization to be shortened. In this way, both the associated risk of transfusion and its unnecessary cost are redu ced.
In conclusion, there are at least two clinical situations: aplasia and transfusion management, where near-patient monitoring of CRP in real time may reduce costs and is beneficial for improved patient care. Rapid CRP results in conjunction with CBC results can steer treatment plans away from use of unnecessary antibiotics and transfusions, and reduce costly hospital stays.
1Rossi JF1, Kanouni T1, Bouhya S1, Tournier E2, Daures JP3, Milian P2. Delocalozed Biology for Sequential Measurements of C-Reactive Protein (CRP) and Cell Blood Counts (CBC) has Potential Clinical and Economic Impact on the Management of Patients Having High Dose Therapy (HDT).
1Hematology-Oncology Department, University Hospital Montpellier, 375 avenue Doyen Giraud 34295 Montpellier France.
2HORIBA ABX, Montpellier.
3Department of Statistics University of Montpellier.
This study was carried out on patients undergoing intensive chemotherapy from the Conventional and Intensive Care Units of the Hematology Department in the Montpellier University Hospital, France. Both CRP and CBC tests were carried out using whole blood samples in the ABX Micros CRP200 (HORIBA ABX).
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