Drug-induced thrombocytopenia is associated with increased binding of IgG to platelets both in vivo and in vitro

Abstract Thrombocytopenia is a common serious adverse effect of drug treatment. A variety of in vitro diagnostic techniques to confirm the diagnosis are available, but the majority lack sufficient sensitivity to detect all cases of drug-induced thrombocytopenia. We studied 19 patients with suspected drug-induced thrombocytopenia and demonstrated that platelet- associated IgG (PAIgG) was elevated in all at the time of thrombocytopenia, and PAIgG returned to normal levels as the thrombocytopenia resolved. In the majority of patients, the platelet count rapidly returned to normal after the drug was discontinued; however, in six patients, the thrombocytopenia persisted well beyond the period of time that the offending drug would be expected to be cleared from the blood. In 13 patients, serum obtained after recovery was used to identify the drug responsible for the thrombocytopenia in an in vitro assay. In all cases, the addition of the drug historically associated with the thrombocytopenic episode was associated with an increased binding of IgG to control platelets. For uncertain reasons, the concentration of drug required to increase the in vitro binding of IgG to test platelets was often more than the concentration usually achieved in vivo. Wider application of these techniques may provide better understanding of the clinical characteristics and mechanisms responsible for drug-induce thrombocytopenia.

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Drug-induced thrombocytopenia is associated with increased binding of IgG to platelets both in vivo and in vitro

Blood ◽

10.1182/blood.v58.3.524.bloodjournal583524 ◽

1981 ◽

Vol 58 (3) ◽

pp. 524-529 ◽

Cited By ~ 1

Author(s):

JG Kelton ◽

D Meltzer ◽

J Moore ◽

AR Giles ◽

WE Wilson ◽

...

Keyword(s):

Diagnostic Techniques ◽

In Vitro Assay ◽

Suspected Drug ◽

Drug Induced ◽

Vitro Assay ◽

In Vitro Binding ◽

Vitro Binding ◽

In Vitro Diagnostic

Thrombocytopenia is a common serious adverse effect of drug treatment. A variety of in vitro diagnostic techniques to confirm the diagnosis are available, but the majority lack sufficient sensitivity to detect all cases of drug-induced thrombocytopenia. We studied 19 patients with suspected drug-induced thrombocytopenia and demonstrated that platelet- associated IgG (PAIgG) was elevated in all at the time of thrombocytopenia, and PAIgG returned to normal levels as the thrombocytopenia resolved. In the majority of patients, the platelet count rapidly returned to normal after the drug was discontinued; however, in six patients, the thrombocytopenia persisted well beyond the period of time that the offending drug would be expected to be cleared from the blood. In 13 patients, serum obtained after recovery was used to identify the drug responsible for the thrombocytopenia in an in vitro assay. In all cases, the addition of the drug historically associated with the thrombocytopenic episode was associated with an increased binding of IgG to control platelets. For uncertain reasons, the concentration of drug required to increase the in vitro binding of IgG to test platelets was often more than the concentration usually achieved in vivo. Wider application of these techniques may provide better understanding of the clinical characteristics and mechanisms responsible for drug-induce thrombocytopenia.

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Quantitative Correlation of in Vivo Properties with in Vitro Assay Results: The in Vitro Binding of a Biotin–DNA Analogue Modifier with Streptavidin Predicts the in Vivo Avidin-Induced Clearability of the Analogue-Modified Antibody

Molecular Pharmaceutics ◽

10.1021/mp5008579 ◽

2015 ◽

Vol 12 (8) ◽

pp. 3097-3103 ◽

Cited By ~ 3

Author(s):

Shuping Dou ◽

John Virostko ◽

Dale L. Greiner ◽

Alvin C. Powers ◽

Guozheng Liu

Keyword(s):

In Vitro Assay ◽

Vitro Assay ◽

Quantitative Correlation ◽

In Vitro Binding ◽

Vitro Binding

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ADP-ribosylation of integrin α7 modulates the binding of integrin α7β1 to laminin

Biochemical Journal ◽

10.1042/bj20040590 ◽

2004 ◽

Vol 385 (1) ◽

pp. 309-317 ◽

Cited By ~ 23

Author(s):

Zhefeng ZHAO ◽

Joanna GRUSZCZYNSKA-BIEGALA ◽

Anna ZOLKIEWSKA

Keyword(s):

C2c12 Myotubes ◽

Post Translational Modification ◽

Integrin Β1 ◽

Adp Ribosylation ◽

In Vitro Binding ◽

Vitro Binding ◽

C2c12 Skeletal Muscle Cells ◽

Adp Ribosyltransferase

The extracellular domain of integrin α7 is ADP-ribosylated by an arginine-specific ecto-ADP-ribosyltransferase after adding exogenous NAD+ to intact C2C12 skeletal muscle cells. The effect of ADP-ribosylation on the structure or function of integrin α7β1 has not been explored. In the present study, we show that ADP-ribosylation of integrin α7 takes place exclusively in differentiated myotubes and that this post-translational modification modulates the affinity of α7β1 dimer for its ligand, laminin. ADP-ribosylation in the 37-kDa ‘stalk’ region of α7 that takes place at micromolar NAD+ concentrations increases the binding of the α7β1 dimer to laminin. Increased in vitro binding of integrin α7β1 to laminin after ADP-ribosylation of the 37-kDa fragment of α7 requires the presence of Mn2+ and it is not observed in the presence of Mg2+. In contrast, ADP-ribosylation of the 63-kDa N-terminal region comprising the ligand-binding site of α7 that occurs at approx. 100 μM NAD+ inhibits the binding of integrin α7β1 to laminin. Furthermore, incubation of C2C12 myotubes with NAD+ increases the expression of an epitope on integrin β1 subunit recognized by monoclonal antibody 9EG7. We discuss our results based on the current models of integrin activation. We also hypothesize that ADP-ribosylation may represent a mechanism of regulation of integrin α7β1 function in myofibres in vivo when the continuity of the membrane is compromised and NAD+ is available as a substrate for ecto-ADP-ribosylation.

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DIGESTIBLE ENERGY IN FORAGE BYIN VIVOANDIN VITROASSAYS

Canadian Journal of Animal Science ◽

10.4141/cjas70-076 ◽

1970 ◽

Vol 50 (3) ◽

pp. 557-562 ◽

Cited By ~ 4

Author(s):

J. E. TROELSEN

Keyword(s):

Energy Analysis ◽

Energy Content ◽

In Vitro Assay ◽

Pure Species ◽

Vitro Assay ◽

Digestible Energy ◽

The Relationship ◽

Cattle And Sheep

Forage of six pure species was harvested for hay at several maturity stages during four years. The digestible energy content of 102 different lots of hay was determined by feeding to four groups of sheep during the same period, and by in vitro digestions and energy analysis of the undigested residues. The relationship between digestible energy content assayed by the two methods was highly significant (r = 0.85) and did not differ between years and species. Exclusion from regression of the hays containing less than 2 or more than 3 digestible kcal/g revealed that the in vitro assay could reproduce the in vivo digestible energy value with a standard deviation of 0.31 in over 70% of the hays. This represented the maturity and quality range of forage commonly fed to cattle and sheep. The in vitro assay therefore appeared promising for commercial quality determinations.

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Use of whole blood directly for single-cell gel electrophoresis (comet) assay in vivo and white blood cells for in vitro assay

Mutation Research/Genetic Toxicology and Environmental Mutagenesis ◽

10.1016/j.mrgentox.2004.07.013 ◽

2004 ◽

Vol 564 (1) ◽

pp. 75-82 ◽

Cited By ~ 46

Author(s):

Cheng-Hung Chuang ◽

Miao-Lin Hu

Keyword(s):

Comet Assay ◽

Whole Blood ◽

Blood Cells ◽

Gel Electrophoresis ◽

White Blood Cells ◽

In Vitro Assay ◽

Vitro Assay ◽

Single Cell Gel Electrophoresis

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Mutagenicity evaluation of Anastatica hierochuntica L. aqueous extract in vitro and in vivo

Experimental Biology and Medicine ◽

10.1177/1535370217748574 ◽

2017 ◽

Vol 243 (4) ◽

pp. 375-385 ◽

Cited By ~ 1

Author(s):

Siti Rosmani Md Zin ◽

Zahurin Mohamed ◽

Mohammed A Alshawsh ◽

Won F Wong ◽

Normadiah M Kassim

Keyword(s):

Aqueous Extract ◽

Positive Control ◽

In Vitro Assay ◽

In Vivo Study ◽

Sufficient Evidence ◽

Aqueous Extracts ◽

Mutagenic Potential ◽

Vitro Assay

Anastatica hierochuntica L. ( A. hierochuntica), a folk medicinal plant, was evaluated for mutagenic potential via in vitro and in vivo assays. The in vitro assay was conducted according to modified Ames test, while the in vivo study was performed according to Organisation for Economic Co-operation and Development guideline for mammalian erythrocyte micronucleus assay. Four groups ( n= 5 males and 5 females per group) Sprague Dawley rats were randomly chosen as the negative control, positive control (received a single intramuscular injection of cyclophosphamide 50 mg/kg), 1000 and, 2000 mg/kg A. hierochuntica aqueous extracts. All groups except the positive control were treated orally for three days. Findings of the in vitro assay showed mutagenic potential of AHAE at 0.04 and 0.2 mg/ml. However, no mutagenic effect was demonstrated in the in vivo study up to 2000 mg/kg. No significant reduction in the polychromatic and normochromatic erythrocytes ratio was noted in any of the groups. Meanwhile, high micronucleated polychromatic erythrocytes frequency was seen in cyclophosphamide-treated group only. These findings could perhaps be due to insufficient dosage of A. hierochuntica aqueous extracts to cause genetic damage on the bone marrow target cells. Further acute and chronic in vivo toxicity studies may be required to draw pertinent conclusion on the safety aspect of A. hierochuntica aqueous extracts consumption. Impact statement In this paper, we report on the mutagenicity evaluation of Anastatica hierochuntica aqueous extract. This is a significant research in view of the popularity of this herb consumption by the people across the globe despite of limited scientific evidence on its toxicity potential. This study is intended to encourage more extensive related research in order to provide sufficient evidence and guidance for determining its safe dosage.

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