Incubated PTT Mix: What Constitutes Correction?

From Sylvia Bunting, Children’s Healthcare of Atlanta: We do an immediate and incubated mixing study. For deciding on whether there is a time-dependent inhibitor, what criteria do you use to decide that the PTT was prolonged after incubation? Any prolongation beyond the immediate mix PTT? Thanks. Hi, Sylvia, and thank you for your question. If the PTT […]

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Lupus Anticoagulant

Aug 29 2012

george

Prolonged Mixing Study in Dialysis

From “Balasubm” at Einstein Healthcare in Philadelphia: Hi George, I have a 74 year old female renal dialysis patient who is asymptomatic with prolonged prothrombin time (PT) of 38 seconds and activated partial thromboplastin time (APTT, PTT) of 116 seconds, with a normal thrombin time. Mixing performed immediately reveals PT of 30.3 seconds (N 9.5-13.5) and […]

Lupus Anticoagulant

Mix Corrects with NP, But not with Deficient Plasmas

From “Japgi,” I have a 6 year old boy, well till a month back, when he had a post-traumatic gum bleed. The bleed was stopped after about half an hour, but a small ooze restarted and stayed for 3 days. His prothrombin time (PT) is 14 seconds (RI 11–16), activated partial thromboplastin time (APTT, PTT) […]

Lupus Anticoagulant

Mixing Studies While on Pradaxa?

From Sara Sneeden, Lee Memorial. Our hematologists are ordering mixing studies on patients who have been on Pradaxa® at home. These patients arrive at the hospital with VMax prothrombin time (PT) and activated partial thromboplastin time (PTT, APTT) and some time later the mixing study is ordered on a subsequent draw. Is there anything to be […]

Mixing Studies

Validating the Rosner Index

From “Maria:” Hello, I am looking into using the Rosner Index to assess mixing studies correction or not. Literature states that the Rosner Index must be validated with each new lot # of partial thromboplastin time (PTT) or prothrombin time (PT) reagent. Do we also need to validate each new lot of CaCl2? Also, what […]

Mixing Studies

Standard Mixing Study Calculation?

From “axnzak:” Is there a widely used (most current) calculation that is successful at interpreting inhibitor vs factor deficiency. Wanted to see what you would use to determine mixing study results, both prothrombin time (PT) and partial thromboplastin time (PTT), when comparing results to patient normal PT and PTT reference ranges. If not can you […]

Mixing Studies

How to Remove IgG

This question was posted on Wednesday, May 23 on Pat Letendre’s Medlab list and is reposted here with Linda Stang’s permission: We have a patient with lymphoma and an IgG peak (we think). The antibodies are interfering (and I mean really interfering) in the coags: INR >5.0 but has had clinical challenges with no bleeding. Is there any way to remove […]

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Anticoagulant Therapy

May 7 2012

george

More on Mixing Studies: Dr. Ortel

We’ve had three posts and several comments regarding lupus anticoagulant (LA) mixing studies since March. These are… March 18, 2012: Test for LA When Mixing Study Corrects? March 22, 2012: Mixing Study Results: Long PT and PTT April 3, 2012: More on LA Mixing Studies In these posts several experts held that it is necessary […]

Lupus Anticoagulant

Mixing Studies: Do You Incubate?

Here is a message from Ms. Khaldee Lindsey Davenport-Landry (Lindsey), a graduate student in this spring’s University of Medicine and Dentistry of New Jersey’s graduate course, CLSC 5124, Advanced Hemostasis. Lindsey is an experienced medical laboratory scientist; she asks about mixing studies: We do a rare mixing study at our hospital, and even more rare PTT mixing study. […]

Mixing Studies

More on LA Mixing Studies

I received this message from Dr. Rich Cambereri on March 8, and have been holding it pending additional data, but given our March 18, 2012 post from Vanessa Chan in Toronto, and subsequent responses from Herb Crown and Dr. Larry Brace, I’ve decided to use Dr. Cambereri to start a discussion about the use of mixing studies in the lupus anticoagulant (LA) profile: Hi […]

Comments (3)

Lupus Anticoagulant

Mixing Studies

Incubated PTT Mix: What Constitutes Correction?

Prolonged Mixing Study in Dialysis

Mix Corrects with NP, But not with Deficient Plasmas

Mixing Studies While on Pradaxa?

Validating the Rosner Index

Standard Mixing Study Calculation?

How to Remove IgG

More on Mixing Studies: Dr. Ortel

Mixing Studies: Do You Incubate?

More on LA Mixing Studies

George Fritsma MS MLS

Cheat Sheets from George

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