Chinese medical pattern discrimination and genomics.

I have long been concerned that we Western practitioners of Chinese medicine have our collective heads in the sand when it comes to evidence-based advances in our medicine in China. As is typical of first-generation converts of all stripes, many of us are doctrinaire and "holier-than-thou" in our adherence to "pure" Chinese medicine, while in China, great efforts are underway to combine the most recent biomedical research with Chinese medicine in order to create an even more effective clinical medicine. While some of these efforts in China may also be overly simplistic due to Chinese "converts'" reverse infatuation with modern science, many of these advances are noteworthy and portentous. In fact, I believe that, in China, Chinese medical practitioners are poised on the threshold of a radical revolution integrating Chinese and Western medicine in new and unprecedented ways that will leave many of Chinese medicine's Western adherents sadly unprepared to enter this bold new world. Areas of particular interest to me are attempts to combine genomic, proteomic, and metabonomic research with Chinese medicine pattern discrimination. As an example of these attempts, I would like to present some of the findings from a literature review article published in the Hu Nan Zhong Yi Za Zhi (Hunan journal of Chinese Medicine) (2006;6:1-2) by Jun Yao-hui et al. Titled "Reflections on the Profound Significance of Genomic Research on Patterns," it was the lead article in that issue.

Definitions

First, I think I must define genomics and some of its key terms. My guess is that large portion of this current article's potential readers have never heard of genomics before. Genomics is the study of all of the nucleotide sequences, including structural genes, regulatory sequences, and noncoding DNA segments, in the chromosomes of an organism. In genetics, an allele is any one of a number of viable DNA codings occupying a given locus or position on a chromosome. Usually, alleles are DNA sequences that code for a gene, but sometimes the term is used to refer to a non-gene sequence. An individual's genotype for that gene is the set of alleles it happens to possess. In a diploid organism, one that has two copies of each chromosome, two alleles make up the individual's genotype. Gene frequency measures the frequency of a particular population of a particular gene relative to other genes at its locus. This frequency is a proportion (between 0 and 1) or a percentage (between 0 and 100%). In other words, gene frequency is the frequency of occurrence of an allele in relation to that of other alleles of the same gene in a population. Polymorphism is a variation in the DNA that is too common to be due merely to new mutation. A polymorphism must have a frequency of at least one percent in the population. Polymerase chain reaction/single-strand conformation polymorphism (PCR/SSCP) analysis is a simple and fast method, with high reliability necessary for the identification of mutations, polymorphisms, and sequence variants (MPSV) within many genes and many samples, such as for clarifying the genetic background of individuals with multifactorial diseases. The method is based on a property of the DNA--that the electrophoretic mobility of single stranded nucleic acids depends not only on their size but also on their sequence.

The Research

In 2000, Kan et al. published a study using PCR/SSCP analysis of the polymorphism of gene D11S4046 at chromosome 11p516,20 in a group of essential hypertension patients presenting a pattern of ascendant liver yang hyperactivity as compared to a normotensive control group. According to this study, the rate of frequency of the A1 allele was significantly higher in the hypertensive group. This allele predisposes one to increased tyrosine hydroxylase (TH) activity, and TH activity serves as a biochemical index of activity of noradrenergic neurons and the adrenal medulla. Because it is the rate-limiting enzyme in catecholamine biosynthesis, TH has been posited as an etiology for hypertension.

In 2004, Hu et al. published another PCR study on 5-HTTLPR, a common polymorphism within the promoter region of the serotonin transporter gene LSC6A4 and its relationship to liver fire flaming upward. This polymorphism has been shown to influence response time as well as overall response to selective serotonin reuptake inhibitors (SSRIs) in subjects with major depressive disorder. This research showed that the rate of this polymorphism was significantly higher in the liver fire flaming upward group than in a normal healthy control group.

In 2003, Ou et al. published a study comparing the rates of the APO E3/3 and E/3/4 phenotypes in coronary heart disease (CHD) patients presenting a phlegm pattern compared with those presenting a blood stasis pattern. Population studies have shown that compared with individuals with apolipoprotein (APO) E3/3, those with the APO E3/4 phenotype have higher plasma and low-density lipoprotein (LDL)-cholesterol concentration and increased susceptibility to coronary heart disease. The APOE gene provides instructions for making a protein called apolipoprotein E. This protein combines with fats in the body and is known as a lipoprotein. Lipoproteins are responsible for packaging cholesterol and other fats, carrying them through the bloodstream, and delivering them to the appropriate locations in the body for processing and use.

In particular, APOE is a major component of specific lipoproteins called very low-density lipoproteins (VLDLs). A key function of very low-density lipoproteins is to remove excess cholesterol from the blood and carry it to the liver for processing. Maintaining normal levels of cholesterol is essential for the prevention of disorders that affect the heart and blood vessels (cardiovascular diseases), including heart attack and stroke. There are at least three slightly different versions (alleles) of the APOE gene. The major alleles are called E2, E3, and E4. The most common allele is E3, which is found in more than half of the population. The E4 version of the APOE gene seems to increase an individual's risk for developing type 2 Alzheimer's disease, the late-onset form of this disorder. People who inherit one copy of the APOE E4 allele have an increased chance of developing the disease; those who inherit two copies of the allele are at even greater risk. According to this research, the phlegm pattern CHD patients presented a significantly higher rate of the E3/4 phenotype than did the blood stasis pattern patients.

In 2002, Cheng et al. published a PCR study comparing the rates of the deletion genotype of angiotensin-converting enzyme (ACE) l/D polymorphism in kidney vacuity pattern patients with diabetic neuropathy. The ACE gene has a 287 bp Alu insertion in intron 16.1. The presence (I) or absence (D) of this insertion produces three population genotypes, 11, ID, and DD. The D allele has been proposed as an indicator of cardiovascular risk in several studies. The deletion genotype of ACE (ID) polymorphism is also a risk factor for progressive renal function loss in non-diabetic and diabetic renal disease. Although the mechanism of this increased renal risk is poorly understood, ACE activity is elevated in the DD genotype, suggesting that alterations in the renin-angiotensin-aldosterone system (RAAS) may play a role. According to this study, the rate of DD occurrence was markedly higher in this group. In 2003, Li et at, published another PCR study showing that the rate of ID occurrence was markedly higher in a group of CHD patients presenting blood stasis, while the rate of DD occurrence was markedly higher in those who presented kidney yang vacuity.

In 2000, Sun et al. published a PCR study showing that the rate of occurrence of HLA-C1 in patients with chronic a plastic anemia (CAA) presenting a pattern of kidney yin vacuity was significantly higher than that in a healthy control. However, in those with CAA presenting a kidney yang vacuity pattern, the occurrence of HLA-A30 was significantly higher than that in a healthy control group. HLA-C belongs to the HLA class I heavy chain paralogues. This class I molecule is a heterodimer consisting of a heavy chain and a light chain (beta-2 microglobulin). The heavy chain is anchored in the membrane. Class I molecules play a central role in the immune system by presenting peptides derived from endoplasmic reticulum lumen. They are expressed in nearly all cells. Typing for these polymorphisms is routinely done for bone marrow and kidney transplantation. Over one hundred HLA-C alleles have been described.

In 2003, Wu et al. published a study on oncogene P53 and BCL2 and Bax protein in colon cancer patients presenting a spleen vacuity pattern. The P53 oncogene encodes an integral outer mitochondrial membrane protein that blocks the apoptotic death of some cells such as lymphocytes. According to this study, the rate of occurrence of P53, BCL2, and Bax proteins were ail significantly higher in those presenting spleen vacuity than in those who presented some other Chinese medical pattern. Further, the presence of spleen vacuity signs and symptoms correlated positively with the presence of serum P53 and BCL2 proteins. In 2004, Hu et al. showed that the occurrence of P21-ras, c-erbB-2, and P53 oncogenic proteins progressively increased in patients who had precancerous changes in their stomachs as the occurrence of their pattern presentations went from stomach qi and yin vacuity to simultaneous qi stagnation to simultaneous stomach heat to simultaneous blood stasis. In yet another study done by Yang et al., the degree of occurrence of the K-RAS, P53, and BCL2 oncogenes correlated exactly with the signs and symptoms of spleen vacuity in those with colon cancer.

In 2002, Yang et al. published a PCR study on the relationship between the Arg778Leu/Gln gene mutation spot in ATP7B and the Chinese medical patterns of patients with Wilson disease (WD). In the 90 WD patients, 34 with Arg778Leu/Gin of exon 8 were detected. Among these, 20 cases presented the pattern of internal stirring of liver wind.

Discussion

The above are only a selection of the studies presented by Jun et al. in their article. Altogether, 21 studies were cited, all of them conducted between 2000 and 2006. Although I will be the first to admit that I do not understand all the biomedical science involved in these studies, one thing is clear to me: genomic research is likely to find statistically significant correlations between certain phenotypes or polymorphisms and particular Chinese medical patterns in patients suffering from specific diseases. As more and more genomic research is conducted, the price and ease of these kinds of tests are going to come down, and the tests will eventually become part of routine Western medicine. This will help provide objective evidence for the existence of Chinese medical patterns as well as their prescriptive wisdom. In Chinese medicine, the main benefit of pattern discrimination is that it allows us to more accurately match Chinese herbal medicinals to patients. For instance, we know that certain Chinese medicinals are clinically effective for treating patients with spleen qi vacuity, while others are effective for treating those with internal stirring of liver wind. If the relationships similar to the above can be worked out between other genes and their polymorphisms, Western diseases, and their Chinese medical patterns, I believe that this will speed up the integration of Chinese and Western medicines and lead to better treatment for all patients.

Keywords: Chinese medicine, pattern discrimination, genomics

by BobFlaws,L.Ac., FNAAOM (USA), FRCHM (UK) www.bluepoppy.com