Neglected vitamin K deficiency causing coagulation dysfunction in an older patient with pneumonia: a case report

Clinical, Laboratory, and Molecular Characteristics of Inherited Vitamin K-Dependent Coagulation Factors Deficiency

Vitamin K-dependent coagulation factors deficiency (VKCFD) is a rare autosomal recessive genetic disease characterized by impaired levels of multiple coagulation factors (II, VII, IX, and X) and natural anticoagulants (proteins C and S). VKCFD is part of familial multiple coagulation factor deficiencies, reporting overall 50 affected families thus far. Disease manifestations are quite heterogeneous, bleeding symptoms may vary, and even, although generally mild, some patients may succumb to fatal outcomes. VKCFD diagnosis may be delayed because the disease phenotype simulates the most frequently acquired deficiencies of vitamin K. First-line coagulation assays, prothrombin time/international normalized ratio (PT/INR) and activated partial thromboplastin time (aPTT), are both prolonged; mixing test typically normalizes the clotting times; and vitamin K-dependent coagulation factors will be variably decreased. Molecularly, VKCFD is associated with mutations in γ-glutamyl-carboxylase (GGCX) or vitamin K epoxide reductase complex subunit 1 (VKORC1) genes. Vitamin K is involved not only in the biosynthesis of coagulation proteins but also in bone metabolism and cell proliferation. Therapeutic options are based on vitamin K supplementation, coagulation factors (prothrombin complex), and fresh frozen plasma, in case of severe bleeding episodes. Two case studies here illustrate the diagnostic challenges of VKCFD: case 1 depicts a woman with a history of bleeding episodes, diagnosed, only in her third decade of life with inherited homozygous GGCX gene mutation. Case 2 shows a man with an acquired vitamin K deficiency caused by Crohn's disease. Better understanding of GGCX and VKORC1 mutations aids in prognosis and treatment planning, with emerging insights suggesting potential limitations in the effectiveness of vitamin K supplementation in certain mutations.

Cefmetazole-Induced Coagulopathy in a Patient With Vitamin K Deficiency: A Case Report With Literature Review

Cefmetazole (CMZ), a cephamycin antibiotic containing an N-methyltetrazolethiol (NMTT) group, is known to interfere with vitamin K metabolism, potentially causing coagulation disorders. We present the case of a 78-year-old man with chronic kidney disease who developed a coagulation disorder during CMZ administration, exacerbated by chronic vitamin K deficiency from prolonged enteral nutrition. In the context of chronic vitamin K deficiency precipitated by prolonged enteral nutrition for renal disease, the administration of CMZ-a medication that disrupts vitamin K metabolism and reduces coagulation factor activity through a mechanism similar to that of warfarin-led to abnormal blood coagulation test results. Clinical improvement followed the discontinuation of CMZ and vitamin K supplementation. This report highlights the importance of monitoring vitamin K status in patients receiving CMZ, particularly those with risk factors for deficiency, and reviews the relevant literature to highlight the mechanisms and management strategies for such complications.

Difference in activated partial thromboplastin time values with two different reagents according to C-reactive protein values

BACKGROUND

Activated partial thromboplastin time (APTT) is susceptible to reagent composition. This study aimed to investigate a large number of specimens and determine the cause of discrepancies.

METHOD

This study included 18,994 subjects who underwent coagulation tests at our hospital from May 2020 to December 2020. Measuring reagents included HemosIL SynthASil APTT (APTT-SS, Instrumentation Laboratory) and Coagpia APTT-N (APTT-N, Sekisui Medical).

RESULTS

A total of 451 patients demonstrated APTT-N of >39 seconds and an APTT-N/SS ratio of >1.3. A C-reactive protein (CRP) level of ≥1.4 mg/L demonstrated a significant positive correlation, with a higher APTT-N/SS indicating higher CRP levels. All 28 subjects receiving no anticoagulants and who had remaining specimens underwent a cross-mixing test (CMT). Of them, 17 were suspected for lupus anticoagulant (LA) by both the waveform shape and the index of circulating anticoagulant (ICA) value, 6 by the ICA value, and 5 were difficult to determine.

CONCLUSION

This study revealed that the APTT-N prolongation correlated with CRP degree and the transient involvement of LA in CMT results due to CRP. This study indicated various reactivities depending on the assay reagents used. Further testing is warranted if LA is suspected, considering the patient's background.