悪液質診断の検査値の違い

血液腫瘍とその他の腫瘍・心不全で悪液質診断に使用する検査値が異なるという論文を紹介します。

Letilovic T, Perkov S, Mestric ZF, Vrhovac R. Differences in routine laboratory parameters related to cachexia between patients with hematological diseases and patients with solid tumors or heart failure -- is there only one cachexia? Nutr J. 2013 Jan 7;12(1):6. [Epub ahead of print]

対象は血液腫瘍（悪性リンパ腫）55人とその他の腫瘍・心不全の患者64人です。悪液質の診断基準にはEvansらの基準を用いています。Evansらの基準には検査値異常としてCRP0.5mg/dl以上、Hb12g/dl未満、Alb3.2g/dl未満が含まれています。

119人のCRP、Hb、Albを評価して、血液腫瘍とその他の腫瘍・心不全で検査値に違いがないかを評価しました。結果ですが、疾患の違いにかかわらず、悪液質群ではCRPが有意に高く、HbとAlbが有意に低かったです。

疾患の違いで、血液腫瘍群ではCRPが有意に低く（1.598 vs. 2.871）mg/dl、Albが有意に高いという結果でした（4.095 vs. 3.601）g/dl。Evansの定義で検査値以上を判断すると、感度と陰性的中率が低かったです。以上より疾患群で検査値が異なり、カットオフ値のさらなる研究が必要という結論です。

CRPだけカットオフ値が0.5mg/dl以上に対して、今回の症例では血液疾患で非悪液質というもっともCRPの低い群でも平均が0.975±1.29mg/dlと高かったです。標準偏差が大きいので、CRPを平均値で表すことは不適切かもしれません。中央値も知りたいですね。

Abstract

ABSTRACT:

BACKGROUND: Cachexia is a state of involuntary weight loss common to many chronic diseases. Experimental data, showing that cachexia is related to the enhancement of acute phase response reaction, led to the new definition of cachexia that included, aside from the principal criterion of weight loss, other "minor criteria", Amongst them are levels of C-reactive protein (CRP), albumin and hemoglobin. However, there is paucity of data regarding possible differences of these laboratory parameters in patients with various diseases known to be related to cachexia.

METHODS:

CRP, albumin and hemoglobin were evaluated in 119 patients, divided into two disease groups, hematological (ones with diagnosis of non-Hodgkin lymphoma or Hodgkin disease) and non-hematological (solid tumor patients and patients with chronic heart failure). Patients were further subdivided into two nutritional groups, cachectic and non-cachectic ones according to the principal criterion for cacxehia i.e. loss of body weight.

RESULTS:

We found that cachectic patients had higher levels of CRP, and lower levels of both hemoglobin and albumin compared to non-cachectic patients, regardless of the disease group they fitted. On the other hand, the group of hematological patients had lower levels of CRP primarily due to the differences found in the non-cachectic group. Higher levels of albumin were also found in the hematological group regardless of the nutritional group they fitted. Limitations of cut-off values, proposed by definition, were found, mostly regarding their relatively low sensitivity and low negative predictive value.

CONCLUSIONS:

As expected, differences in values of routine laboratory parameters used in definition of cachexia were found between cachectic and non-cachectic patients. Their values differed between hematological and non-hematological patients both in cachectic and non-cachectic group. Cut-off levels currently used in definition of cachexia have limitations and should be further evaluated.