title: Absence of inferior vena cava in 14-year old boy associated with deep venous thrombosis and positive Mycoplasma pneumoniae serum antibodies--a case report.
abstract: BACKGROUND
  Absence of the inferior vena cava is a rare vascular anomaly, which usually remains asymptomatic in childhood. It is recognized as the risk factor for deep venous thrombosis, since the collateral circulation does not provide adequate drainage of the lower limbs. Mycoplasma pneumoniae is a common cause of community-acquired pneumonia in school-aged children and adolescents. Mycoplasma pneumoniae infection might be associated with deep venous thrombosis but its pathophysiology remains unknown. According to previous reports, deep venous thrombosis due to Mycoplasma pneumoniae infection is associated with positive serum anticardiolipin antibodies. To our knowledge, we describe the first case of deep venous thrombosis associated with Mycoplasma pneumoniae serum antibodies indicating early stage of infection with negative anticardiolipin serum antibodies in adolescent with absence of inferior vena cava.
  
  
  METHODS
  14-year old boy was admitted to the pediatric unit few days after the appendectomy complaining with pain of the left hip that caused him unable to walk. The pain was accompanied with subfebrile temperature. After clinical examination and additional tests, the boy was diagnosed with a deep venous thrombosis. Computed tomography revealed absence of the vena cava inferior distally to the hepatic veins and varices of the collateral circulation in the pelvis. Anticardiolipin IgM and IgG antibodies and antinuclear antibodies were not detected. Additionally, the Mycoplasma pneumoniae antibodies in classes IgM, IgA and IgG were detected in serum as another risk factor of thrombosis. After the initial treatment with low-molecular-weight heparin in combination with clarithromycin the clinical condition of the patient improved. The patient became a candidate for life-long anticoagulation therapy.
  
  
  CONCLUSIONS
  In this case Mycoplasma pneumoniae antibodies were associated with deep venous thrombosis in child with congenital absence of inferior vena cava. Uncommonly for deep venous thrombosis due to Mycoplasma pneumoniae infection, anticardiolipin antibodies were not detected in serum. It is important to remember in clinical practice that Mycoplasma pneumoniae affects coagulability and may trigger thrombosis, especially in the presence of other risk factors. The pathophysiology of this process remains unknown.
authors.affiliation: Department of Pediatrics, Pediatric Nephrology and Allergy, Military Institute of Medicine, ul. Szaserow 128, 04-141, Warsaw, Poland. kalicki@wim.mil.pl.
authors.forename: Boleslaw
authors.initials: B
authors.lastname: Kalicki
authors.affiliation: Department of Pediatrics, Pediatric Nephrology and Allergy, Military Institute of Medicine, ul. Szaserow 128, 04-141, Warsaw, Poland. monika.sdc@gmail.com.
authors.forename: Monika
authors.initials: M
authors.lastname: Sadecka
authors.affiliation: Department of Pediatrics, Pediatric Nephrology and Allergy, Military Institute of Medicine, ul. Szaserow 128, 04-141, Warsaw, Poland. awawrzyniak@wim.mil.pl.
authors.forename: Agata
authors.initials: A
authors.lastname: Wawrzyniak
authors.affiliation: Department of Radiology, Military Institute of Medicine, ul. Szaserow 128, 04-141, Warsaw, Poland. pkozinski@wim.mil.pl.
authors.forename: Piotr
authors.initials: P
authors.lastname: Kozinski
authors.affiliation: Department of Vascular and Endovascular Surgery, Military Institute of Medicine, ul. Szaserow 128, 04-141, Warsaw, Poland. dziekiewicz@wim.mil.pl.
authors.forename: Miroslaw
authors.initials: M
authors.lastname: Dziekiewicz
authors.affiliation: Department of Pediatrics, Pediatric Nephrology and Allergy, Military Institute of Medicine, ul. Szaserow 128, 04-141, Warsaw, Poland. ajung@wim.mil.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Jung
mesh_terms: D000293:Adolescent; D000906:Antibodies / Q000097:blood*; D006801:Humans; D008297:Male; D009177:Mycoplasma pneumoniae / Q000276:immunology*; D011019:Pneumonia, Mycoplasma / Q000150:complications*; D012307:Risk Factors; D014682:Vena Cava, Inferior / Q000002:abnormalities*; D020246:Venous Thrombosis / Q000150:complications*
chemical_list: D000906:Antibodies