Identification of factor VIII gene mutations in patients with severe haemophilia A in Venezuela: identification of seven novel mutations

Haemophilia A is caused by mutations in the gene encoding coagulation factor VIII (FVIII). In severe Haemophilia A (sHA), two inversions are responsible for approximately 50% of the genetic alterations (intron 22 and intron 1 inversions). The other mutations are extremely diverse and each affected family generally has its own mutation. Our aim was to detect the genetic alterations present in the FVIII gene (F8) in 54 unrelated male patients with sHA in Venezuela. We initially detected the presence of the intron 22 inversion by performing inverse PCR, and the negative patients for this inversion were analysed for the intron 1 inversion by PCR. Patients negative for both inversions were analysed using Conformation Sensitive Gel Electrophoresis for mutations in all exons, promoter region and 3'-UTR. sHA causative mutations were identified in 49 patients. Intron-22 and -1 inversions were detected in 41% and 0% of patients respectively. Besides these two mutations, 25 different mutations were identified, including nine nonsense, four small deletions, two small insertions, four missense, three splicing mutations and three large deletions. Seven novel mutations were identified, including two nonsense mutations, two small deletions, one small insertion, one missense mutation and one splicing mutation. Thirty one percent of the patients with identified mutations developed inhibitors against exogenous FVIII. This is the first report of F8 mutations in patients with sHA in Venezuela; the data from this study suggests that the spectrum of gene defects found in these patients is as heterogeneous as reported previously for other populations.

Chemical synoviorthesis with oxytetracycline clorhydrate (Emicine) in recurrent haemarthrosis

This is a non-controlled experimental prospective clinical study that evaluates the satisfactory results in the chemical synovectomy (synoviorthesis) with oxytetracycline clorhydrate (Emicine, Lab. Pfizer Ltda, Guarulhos, Sao Paulo, Brazil) in recurrence haemarthrosis in different joints, demonstrating that it is an effective method in the treatment of these recurrent haemarthrosis in haemophilia. 84 patients of whom 77 concluded the full course of treatment. 82 joints were injected. The dosage injected was 5 cm(3) of the drug (25 mg) in 5 cm(3) of anaesthesia for the knee, 2 cm(3) with 1 cm(3) of anaesthesia for the elbow and 1 cm(3) plus 1 cm(3) of anaesthesia for the ankle. These injections were administered once weekly with a reinforcement in 1 month. In case of failure the same can be administered repeatedly. Subjective parameters included pain, range of movement and use of the joint involved. Pain decreased from a mean of 6.5 to 0.9 (Likert scale). Range of movement increased from 5.9 to 9 and joint use increased from 5.9 to 9.2. Objective parameters included joint diameter and range of movement. Range of movement for flexion and extension improved from 72.2 and 149.2 to 73.7 and 167, respectively, for the knees. From 57.3 and 160 to 66.6 and 170, respectively, for the shoulder. And, from 22.7 and 10.8 to 34 and 18.6, respectively, for the ankle. This procedure has multiple advantages such as immediate therapeutic effect, short period of treatment, easy technique, much less AHF coverage (30% above coagulation level), less costly than radiocolloid treatment, which make it a perfect alternative treatment for developing countries.

Pharmacokinetics, thrombogenicity and safety of a double viral inactivated factor IX concentrate compared with a prothrombin complex concentrate

Therapeutic options for developing countries have to assure an optimum safety and efficacy and low-cost antihaemophilic concentrates. A single blind randomized crossover study was carried out in 12 previously treated HB patients, comparing the pharmacokinetics (PK), thrombogenicity (TG) and safety of two plasma-derived double-inactivated (solvent/detergent heating at 100 degrees C, 30 min) factor IX (FIX) concentrates, UMAN COMPLEX DI (product A) [plasma-derived prothrombin concentrates (PCC)] and a high purity FIX concentrate AIMAFIX DI (product B, HPFIX). In a non-bleeding state, they received one single intravenous dose 50 IU FIX kg(-1) of PCC or HPFIX, and after a wash-out period of 14 days, the other product. We evaluated acute tolerance and determined PK parameters based on FIX levels measured over a 50 h postinfusion period. We studied fibrinogen, platelets, antithrombin, F1 + 2, TAT, D-dimer, over a 360 min postinfusion period. Ten cases remained in on-demand treatment for 6 months, five with PCC and five with HPFIX. PK and anti-FIX inhibitors were repeated at 3 and 6 months. No inhibitors were detected. PK values (PCC vs. HPFIX): clearence (CL; mL h(-1) kg(-1)) 5.2 +/- 1.4 vs. 6.5 +/- 1.4; the volume of distribution at steady state (mL kg(-1)) 154.9 +/- 54.9 vs. 197.5 +/- 72.5; mean residence time (h) 29.7 +/- 8.1 vs. 30.7 +/- 9.2; T(1/2) (h) 22.3 +/- 7 vs. 23.5 +/- 12.3; incremental recovery (IR; U dL(-1) U(-1) kg(-1)) 0.96 +/- 0.17 vs. 0.76 +/- 0.13. HPFIX showed significant lower IR and higher CL. There were no differences in PK at 3 and 6 months. In TG, significant increments in TAT and F1 + 2 at 30 min and 6 h were found with PCC. Product B PK results agrees with reported results for other HPFIX preparations. Use of PCC product A has to consider its thrombogenic activity.

Intra-articular hyaluronic acid in the treatment of haemophilic chronic arthropathy

We report our preliminary experience with the use of hyaluronic acid (Synvisc) in 29 joints from 25 different haemophilic patients (17 knees, six shoulders, four ankles, one elbow and one hip). All the joints were grade III of our classification, characterized by synovial thickening, axial deformities and muscle atrophy (chronic arthropathy). In view of the very satisfactory results obtained with this procedure, we have substituted Synvisc for the previous use of intra-articular long-standing corticosteroids that we had been used for some years. This method is theoretically more physiological and does not destroy the joint cartilage further, as corticosteroids can.

Synovectomy with rifampicine in haemophilic haemarthrosis

The purpose of this paper was to assess the effectiveness of intra-articular injected rifampicine in haemophilic patients in order to achieve synovectomy by preventing repeated intra-articular bleeding. We have used this technique in haemophilic patients previously and reported our results on 13 cases [1]. Two hundred and fifty milligrams of rifampicine was injected into the elbow and ankle joints and 500 mg was injected into knee joints with 3-10 mL of lidocaine, depending on the joint size. The injections were repeated once a week for 7 weeks. Patients were only covered with antihaemophilic factor on the day of the injection at 30% above their coagulation level. We evaluated the results using two measures: subjective reports from the patient and objective assessment by the examiner. In the subjective reports the patient graded the results from their own perspective from 1 (poor) to 10 (excellent): 1-3, poor; 4-6, fair; 7-8, good; and 9-10, excellent. In the objective reports the grading was: excellent ('dry joint', full function, no haemarthrosis, no synovitis); good (clinical improvement, synovitis, reduction of haemarthroses, full function); fair synovitis (reduction of haemarthroses, no change in function); poor synovitis (persistent haemarthroses). This paper reports on the results of 38 patients with 39 joints with more that 3 years follow up, mean 1.8 years. There were 22 knees, nine elbows and eight ankles. Subjectively, there were excellent results in 21 joints (11 knees, six elbows and four ankles) good results in 15 joints (eight knees, three elbows and four ankles), fair results in two knees and a poor result in one knee. Objectively, results obtained were excellent in 20 joints (11 knees, six elbows and three ankles); good in 17 (nine knees, three elbows and five ankles); fair in one knee and poor in one knee.