Pleural effusion can arise as a result of more
than 50 recognized causes and the differentiation between
benign and malignant origin of the fluid is still a diagnostic
challenge. The ability of tumor markers and other biological
markers to make better diagnosis of malignant pleural
effusion (MPE) remains questionable. Out of these, the
calcium-related proteins S100-A8 and S100-A9 (the
noncovalent heterodimer calprotectin) were demonstrated in
a small amount in malignant not in benign pleural effusion.
Objectives This research aimed to assess the diagnostic
value of calprotectin in the differentiation between infectious
or benign and MPE.
Patients and methods Sixty patients were divided into group
I: malignant and group II: infectious pleural effusions (which
were further divided into group IIA: parapneumonic effusion
and group IIB: tuberculous effusion) Quantitative
measurement of calprotectin was done using the enzymelinked
immunosorbent assay technique in pleural effusion.
Results Pleural calprotectin level in MPEs (229.2±168.6 ng/
ml) was significantly lower than its level of infectious pleural
effusions (3202.2±1304.8 ng/ml; P