Neutrophil counts distinguish between malignancy and arthritis in children with musculoskeletal pain: a case-control study.
BACKGROUND
To identify the predictive factors for malignancies using basic clinical and laboratory information in children presenting with musculoskeletal pain and eventually diagnosed with juvenile idiopathic arthritis (JIA) or malignancy.


METHODS
A retrospective case-control chart review research examining laboratory data from patients referred for musculoskeletal pain in 2001-2010 and diagnosed with malignancy or JIA was performed. The validity of each test for the diagnosis of neoplasia was assessed by calculating the sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV) and likelihood ratios.


RESULTS
A total of 134 patients were enrolled. Statistically significant differences were found in neutrophil count, Hb, LDH, IgA and C4 values, ANA, anti-EA EBV IgG and anti-CMV IgG titres. High LDH value and anti-CMV IgG were the most predictive factors for neoplasia. High specificity factors for neoplasia were abnormal values of neutrophil count, Hb, IgA and C4, and the presence of anti-EA EBV and anti-CMV IgG. High PPV were recorded for abnormal neutrophil count, Hb value and anti-CMV titre. A low NPV was found only for anti-EA EBV and anti-CMV titres.


CONCLUSIONS
In this setting of patients, minimum changes in neutrophil count, particularly if associated with low Hb and high LDH levels, are to be thoroughly considered, because they appear as the most predictive factors for the diagnosis of tumour.
Department GF Ingrassia, University of Catania, Via Santa Sofia 87, Catania 95123, Italy.
Antonella
A
Agodi
Martina
M
Barchitta
Cristina
C
Trigilia
Patrizia
P
Barone
Silvia
S
Marino
Rosaria
R
Garozzo
Manuela
M
La Rosa
Giovanna
G
Russo
Andrea
A
Di Cataldo
D000293:Adolescent; D001171:Arthritis, Juvenile / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007223:Infant; D015470:Leukemia, Myeloid, Acute / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D007958:Leukocyte Count; D016013:Likelihood Functions; D008223:Lymphoma / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D008297:Male; D059352:Musculoskeletal Pain / Q000097:blood / Q000209:etiology*; D009504:Neutrophils / Q000378:metabolism*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D014408:Biomarkers, Tumor