Background
Kawasaki disease (KD) is an acute febrile illness characterized by
multisystemic vasculitis, which usually may be associated with coronary
artery lesions (CALs), and has been considered as the most common cause
of acquired heart disease among children in industrialized countries.
Although the treatment of intravenous immunoglobulin (IVIG) plus aspirin
has greatly decreased the incidence of CALs within the first 10 days of
fever onset, previous studies indicated that 10-20% of patients with KD
were unresponsive to initial treatment with IVIG, and even 20-30% of
patients resistant to initial treatment with IVIG did not respond to a
second dose of IVIG [1, 2]. This condition could be more prone to
risk of CALs.
Increasing evidence has confirmed that systemic inflammation and immune
responses play a crucial role in the pathogenesis and progression of KD.
Several prognostic models for IVIG resistant KD have been widely
investigated, such as the Formosa scoring system from Taiwan, China, the
San Diego scoring system from American, and the Kobayashi, Egami and
Sano scoring system from Japan. However, these models have been
relatively lacking in the Mainland of China [3]. A large number of
studies also attempted to search markers for predicting IVIG resistant
KD. Recently, it was reported that the peripheral biomarker of
immunity/inflammation, the neutrophil-to-lymphocyte ratio (NLR), and
platelet (PLT)-to-lymphocyte ratio (PLR) were identified as significant
prognostic indicators in KD with IVIG resistance [4-6]. In addition,
serum albumin, known as an indicator of host inflammatory and
nutritional status, had been confirmed to have a prognostic role in the
Chinese population with IVIG resistant KD [7]. However, these models
or indicators were not satisfactory for predicting IVIG resistance in
clinical practice. Recently, it has been hypothesized that
immunonutritional status could reflect the general condition of
patients, including immunocompetence, protein turnover and physical
condition. The prognostic nutritional index (PNI) based on a combination
of albumin levels and peripheral blood lymphocyte count, was supposed to
show a more accurate representation of the nutritional and immunological
status in various types of cancer [8]. Its prognostic value in
various types of tumor, such as urinary cancer, tongue squamous cell
carcinoma [9], osteosarcoma [10], gynecological cancer [11],
non-small cell lung cancer[12] and pulmonary embolism[13], acute
myocardial infarction[14, 15], idiopathic dilated cardiomyopathy
[16] and heart failure [17] has been widely investigated.
Recently, Tai et al reported that a low pre-treatment PNI level
(PNI<55) correlated to a high incidence of CALs, as well as
IVIG non-responder in 275 children with KD from Taiwan [18], but the
sample size was small and cases were came from only one institution.
Therefore, the present study was designed in order to further determine
whether PNI could predict IVIG resistance in large cohort of patients
with KD from six institutions.