A case-report of two patients with hereditary protein S deficiency treated by rivaroxaban.

: Hereditary protein S deficiency is an autosomal dominant disorder associated with a high risk of venous thromboembolism (VTE) and usually results from mutations of PROS1. Historically heparin and warfarin have been applied as recommended treatment of VTE. Recent researches showed that rivaroxaban provided more consistent and predictable anticoagulation than warfarin. However, it is unknown whether rivaroxaban is effective for the treatment of VTE in patients with thrombophilia, including protein S deficiency, due to lack of evidence. Here, we report two cases of recurrent VTE in two patients with hereditary protein S deficiency, owing to the same nonsense mutation in PROS1, which were successfully treated by rivaroxaban monotherapy.

Retinal vein thrombosis associated with a herbal phytoestrogen preparation in a susceptible patient.

A 55 year old woman, known to have systemic lupus erythematosus and protein S deficiency, presented with sudden onset of visual loss in the left eye. Three days previously, she took a herbal phytoestrogen preparation for relief of her menopausal symptoms. Ophthalmological assessment showed a left inferior hemiretinal vein thrombosis. The temporal relation between the onset of visual symptoms and ingestion of this herbal preparation suggested that in this patient with a prior non-manifest prothrombotic tendency, there may be an association between the development of retinal vein thrombosis and herbal phytoestrogen use.

Graves' disease associated with anticardiolipin antibody positivity and acquired protein S deficiency.

A 33-year-old woman had experienced recurrent pregnancy loss. She had positive anticardiolipin antibody and protein S deficiency. Her pregnancy was managed with anticoagulant therapy and she delivered a healthy infant. Three years after delivery, she reported progressive sweating, tremor, tachycardia, and a 4-kg weight loss. She was diagnosed with Graves' disease. This is a rare case of combined anticardiolipin antibody positivity, acquired protein S deficiency, and Graves' disease.

Serendipitous diagnosis of protein S deficiency.

A 46-year-old male sought periodontal care for a swelling on his right mandibular gingiva. An excisional biopsy revealed a well-differentiated squamous cell carcinoma. Surgical treatment consisted of a right segmental mandibulectomy with ipsilateral right neck dissection and fibular free flap reconstruction. Two days after the surgical procedure, a weakened Doppler signal suggested vascular compromise of the graft. The patient was returned to the operating room where complete thrombosis of the internal jugular vein (recipient vessel) was observed. This event prompted a complete hematological evaluation that disclosed low serum levels of protein S. The patient was started on systemic heparin and local medicinal leeches. A week later, systemic warfarin sodium was added and successfully resolved the vascular compromise of the graft. Two years later, the patient is active and lives a full life with occasional adjustments of warfarin sodium. This case represents the first report on the treatment of gingival carcinoma that led to the serendipitous discovery of an unrelated and unusual systemic condition, protein S deficiency.

Severe autoimmune protein S deficiency in a boy with idiopathic purpura fulminans.

Idiopathic purpura fulminans usually occurs in young children and is frequently preceded by a preparatory viral or bacterial infection. Following a severe streptococcal pharyngitis, an 8-year-old boy developed purpura fulminans with disseminated intravascular coagulation and severe protein S deficiency (total antigen < 0.05 u/ml). Despite generous plasma infusions, skin necrosis progressed rapidly into compartment syndrome which required fasciotomy and skin grafting and resulted in the loss of three digits of the right foot. Total protein S remained low for over a month despite plasma supplementation and complete normalization of protein C levels. A polyclonal anti-protein S IgG was demonstrated in the patient's plasma, which decreased to 25% of baseline titre after 1 month and was undetectable 6 months after purpura fulminans, when plasma protein S had returned to normal. Transient, isolated and severe deficiencies of protein S have been reported in patients with idiopathic purpura fulminans and a previous preparatory infection. Autoimmune protein S deficiency may play a key role in the aetiopathogenesis of idiopathic purpura fulminans.