Differentiation of presumed sepsis from acute graft-versus-host disease by C-reactive protein and serum total IgE in bone marrow transplant recipients

Inflammatory markers in patients after hematopoietic stem cell transplantation

Infections are one of the most common complications after hematopoietic stem cell transplantation (HSCT). Diagnosis is established by analysis of clinical symptoms and results of diagnostic tests such as biochemical panels, microbiological cultures, and visual diagnostics. As the microbiological cultures yield positive results in only some patients and visual diagnostics might miss the infectious source, the diagnosis and proper treatment often depends on clinical assessment supported by laboratory test results. The most commonly used makers of inflammation include C-reactive protein and procalcitonin. However, these tests have serious limitations when used in patients after HSCT. The drugs used in conditioning, neutropenia, and graft-versus-host disease might influence the results of the tests and misguide the physician. In this review, we summarize the current knowledge on profiles of expression of basic markers of inflammation used in clinical practice in patients after HSCT.

Early elevation of C-reactive protein correlates with severe infection and nonrelapse mortality in children undergoing allogeneic stem cell transplantation

C-reactive protein (CRP) is an acute phase reactant that is a reliable marker of systemic inflammation and has been associated with increased morbidity and mortality following hematopoietic stem cell transplantation (HSCT) in adults. In this study, we evaluated whether early elevations of CRP were associated with various complications and nonrelapse mortality following HSCT in pediatric patients. Seventy pediatric patients had CRP levels drawn at regular time points during the first week following their transplants. Patients were followed for 100 days following transplant, and transplant-related complications were documented. Patients who subsequently developed severe infections had higher median CRP values than those without severe infections (median 8.03 mg/dL versus 1.64 mg/dL, P = .0008) as did those who suffered nonrelapse mortality compared with those who did not (12.6 mg/dL versus 2.44 mg/dL, P = .02). These findings suggest that elevated CRP values may be useful as a marker of individual pediatric patients with a higher risk for treatment-related morbidity and mortality.

C-reactive protein and fever in neutropenic patients

The predictive value of daily C-reactive protein (CRP) monitoring to distinguish causes of fever in neutropenic patients was studied retrospectively. A total of 143 fever episodes during 113 consecutive hospitalizations were studied in 71 patients who had been referred for chemotherapy or haemopoietic stem cell transplantation (HSCT). There were, on average, 1.3 fever episodes per hospital stay, attributed to: infection (55, 27 invasive bacterial, 5 fungal, 3 viral and 20 probable infections); acute graft vs host disease (GvHD) (20); drugs (22); transfusions (7); and not attributable (39). 130 (91%) fever episodes were accompanied by a rise in CRP, 6 (4%) episodes were fatal. Maximal CRP levels (CRPmax) and maximal temperature (Tmax) were higher in invasive bacterial infections than in aGvHD and higher in aGvHD than in drug- or transfusion-related fever (p < 0.0001). Temperature and CRP rose in parallel. A total of 16 patients developed grade II-IV aGvHD by day 11 (9-21) (median, range) after allogeneic HSCT. Acute GvHD was preceded by fever for 3 d (1-7), and by CRP increase for 5 d (0-15) (p < 0.0001). CRP monitoring may be useful to distinguish between causes of fever. Very high CRP levels tend to be associated with invasive bacterial infections. CRP is not an early warning sign. An increase in CRP and fever may precede other clinical manifestations of aGvHD.

The effects of pretransplant conditioning, graft-versus-host disease and sepsis on the CRP levels in bone marrow transplantation

To evaluate the diagnostic utility of C-reactive protein (CRP) for the detection of sepsis in bone marrow transplantation, CRP levels were analyzed after pretransplant conditioning and variably combined in septic, focal or viral infections with graft-versus-host disease (GvHD) in 64 bone marrow recipients. The CRP levels after pretransplant conditioning were low. The peak levels of CRP were influenced independently by the type of infection (p = 0.016; septic and viral infections were significantly different) and GvHD (p = 0.003). The area under the receiver-operator characteristic (ROC) curve for peak CRP in sepsis was 0.653 and 0.618 with and without GvHD, respectively. It was concluded that GvHD and the type of infection were independent determinants of the CRP responses. GvHD did not affect the extent of the CRP response. Therefore, although not highly specific for sepsis, CRP remains a useful detector of sepsis in bone marrow transplantation.

Clinical applications of C-reactive protein in pediatrics

The body of literature concerning studies of the applications of CRP measurement in the pediatric population continues to grow. Based on current data serial CRP measurements appear to be most useful for monitoring patient response to therapy after the primary diagnosis of invasive infectious or inflammatory diseases, for monitoring patients after major surgical procedures and those with serious burns. Monitoring CRP over time may be used to assess for recrudescent disease, a secondary process or ineffective therapy. In addition CRP appears to be suited to most applications for which the ESR is used but offers many advantages. At present there are no objective outcome-based clinical trial data to justify using CRP values alone, whether elevated or normal, as a basis for management decisions regarding instituting or withholding antimicrobial therapy, or its early discontinuance for patients suspected of having neonatal sepsis, meningitis, bacteremia or pneumonia, regardless of immune status. In addition, because of significant inconsistencies among studies for which CRP has been applied to differential diagnosis of bacterial vs. viral diseases, including meningitis, acute otitis media and lower respiratory tract infection, we cannot recommend it for this purpose. Data do not support a role for CRP in differential diagnosis of acute appendicitis or for localizing urinary tract infections.

C-reactive protein: a critical review

We have reviewed the literature to determine the value of C-reactive protein (CRP) measurements in the diagnosis and management of a wide range of conditions. CRP levels are of value in 6 clinical situations: (a) monitoring the response to antibiotic treatment in patients with known bacterial infections, (b) in obstetric patients with premature rupture of membranes, a rise in CRP can give early warning of intrauterine infections, (c) differentiation between active disease and infections in patients with systemic lupus and ulcerative colitis where the level of response to active disease has been previously established, (d) as a measure of disease activity and response to disease-modifying drugs in rheumatoid arthritis, (e) early detection of complications in postoperative patients, (f) in differentiating between infection and graft-versus-host-disease in bone marrow transplant patients. CRP levels have been used in an attempt to differentiate between bacterial and viral infections in various clinical situations, however the published literature does not support this role.

C-reactive protein in the management of children with fever after allogeneic bone marrow transplantation

The value of C-reactive protein (CRP) determinations in the analysis of fever after allogeneic bone marrow transplantation (BMT) was studied prospectively by serial measurements of serum CRP levels during 30 BMT episodes in 28 children and adolescents. The treatments and procedures accompanying BMT did not elicit a significant CRP response. Forty-three febrile episodes were registered and analyzed, without previous knowledge of the results of CRP determinations. The incidence of bacterial infection and acute graft-versus-host disease (GvHD) was low, 8/30 and 5/30, respectively. Raised CRP levels occurred only once in association with GvHD. A CRP level higher than 50 mg/l was not sensitive as an indicator of bacterial infection (4/8). A CRP level below 50 mg/l in the presence of fever, however, excluded bacterial infection with a specificity of 86% and a negative predictive value of 88%. When timed properly and interpreted together with clinical and microbiological findings, CRP measurements can be a valuable aid in the management of fever after BMT, especially as a negative predictor.

Potential clinical applications of C-reactive protein

This article reviews the clinical applications of C-reactive protein (CRP). This acute-phase protein is a distinct and sensitive marker for inflammation and tissue injury. It is a simple, fast, and relatively inexpensive latex agglutination test. The aspects of CRP reviewed include diagnostic support, serial measurements to evaluate disease course and therapeutic response, and screening studies.