Transcription
Hey guys, it's Medicosis Perfection Alice with a new video. And today, let's talk about alkaline phosphatase.
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Alkaline phosphatase. Let's break that down: alkaline, enzyme, phosphatase. An enzyme that removes a phosphate group from molecules. Alkaline because this enzyme is stable and works best in an alkaline medium. This is different from a kinase, which adds a phosphate group. Phosphatase removes a phosphate group, but kinase adds a phosphate group. Please make sure not to confuse alkaline phosphatase and acid phosphatase, because acid phosphatase is a phosphatase that works in an acidic environment. Acid phosphatase can be used to monitor the response to treatment in cases of prostate cancer. Acid phosphatase is used to differentiate between B-ALL, which is acute lymphoblastic leukemia, and T-ALL. In B-ALL, acid phosphatase is negative, while T-ALL is acid phosphatase positive. The way I remember it: T looks like a plus sign, so T positive acid phosphatase.
Now I want you to forget about acid phosphatase and focus on alkaline phosphatase, which is today's topic. Phosphatase: it dephosphorylates compounds, which means it removes a phosphate group. Because phosphate fixes stuff, while phosphatase removes the phosphate, so the molecule is now free to diffuse into the cell. But with the phosphate group attached to the molecule, the molecule cannot freely diffuse into the cell. Alkaline phosphatase is present in virtually every single tissue, especially bones, liver (especially the hepatobiliary system), kidneys, and placenta. Alkaline phosphatase: think hepatobiliary and musculoskeletal. Alkaline phosphatase can be high in some conditions and low in certain conditions. If you remember these organs—bone, hepatobiliary, placenta, and kidney—you can pretty much memorize all of these.
So, high levels of alkaline phosphatase in the blood are seen in cases of biliary disease, hepatitis, or cirrhosis. So we have the liver and the bile system; leukemoid reaction, which we will talk about later; osteomalacia, bone Paget disease, bone; hyperthyroidism; and hyperparathyroidism. Hyperparathyroidism is related to bone and pregnancy because there is a placenta. Low levels of alkaline phosphatase in the blood are seen in cases of Wilson disease—this is liver—CML. Now pay close attention: so alkaline phosphatase is high in leukemoid reaction but low in chronic myeloid leukemia. Alkaline phosphatase is high in hyperthyroidism, low in hypothyroidism. If alkaline phosphatase is high in pregnancy, it will be low in a post-menopausal woman. See how easy it is?
Now this slide is a big deal. Okay, what's the difference between ALT, AST, alkaline phosphatase, amylase, and lipase? So, for liver disease, expect to see high levels of ALT and AST—alanine aminotransferase and aspartate aminotransferase. In biliary disease, expect to see high levels of alkaline phosphatase. In pancreatic disease, expect to see high levels of amylase and lipase. Amylase is more sensitive; lipase is more specific. Why? Amylase is not specific because there is also a salivary amylase; it's not specific to the pancreas.
Enough for today. In the next video, we will talk about leukocyte alkaline phosphatase, which is an alkaline phosphatase in the white blood cells, of course. Don't forget to check my playlists in the Medicosis channel of YouTube: play this on biochemistry stuff, another playlist for laboratory stuff. Hey, if you like this video, make sure to subscribe to my YouTube channel. Like to see on Facebook, where I post a lot of stuff and you can communicate with me. Also SoundCloud, and please consider supporting this channel on Patreon. This is Medicosis Perfection Alice. Be safe, stay happy, and study hard. I'll see you next time.