Medical Literature - 1998 |
A randomized, controlled trial to study the efficacy and safety of C1 inhibitor concentrate in treating hereditary angioedema
Kunschak M, Engl W, Maritsch F, Rosen FS, Eder G, Zerlauth G, et al 6/1998 Transfusion
BACKGROUND: No effective treatment exists in the United States for acute attacks of hereditary angioedema (HAE).
STUDY DESIGN AND METHODS: To evaluate the efficacy and safety of C1 inhibitor concentrate in treating HAE, a large primary care and referral center hospital conducted a randomized, placebo-controlled, double-blind trial with intent-to-treat analysis. Of the 36 patients enrolled in the study, 23 received treatment, and 22 completed the trial. C1 inhibitor concentrate or albumin (placebo) infusions were administered in a blind fashion to HAE patients who came to the hospital for treatment no later than 5 hours after an attack began. RESULTS: Relief was almost twice as fast in persons receiving C1 inhibitor concentrate than in the controls: 7.62 hours (mean; SD 7.08) versus 15.35 hours (mean; SD 8.31), respectively. The difference for time-to-relief was highly significant (p = 0.007, Mann-Whitney U test). The median time-to-relief was 6.17 hours (interquartile range 0.33-15.35) in the treatment group and 15.35 hours (interquartile range 14.00-22.83) in the control group. Resolution of symptoms was one-third faster in the C1 inhibitor concentrate group than in the placebo group: 23.98 hours (mean; SD 14.81) and 34.58 hours (mean; SD 13.56), respectively (p = 0.09, Mann-Whitney U test). Recovery of functional C1 inhibitor was 119.65 percent (mean; SD 50.80), and half-life was 37.87 hours (mean; SD 19.75). Recovery of antigenic C1 inhibitor was 147.75 percent (mean; SD 97.68), and half-life was 24.01 hours (mean; SD 9.70). There were no viral infections or serious adverse effects from the drug after 70 attacks in the treatment group and 96 attacks in the control group. CONCLUSIONS: C1 inhibitor concentrate is a safe, effective treatment for acute attacks of HAE.
RESULTS: Relief was almost twice as fast in persons receiving C1 inhibitor concentrate than in the controls: 7.62 hours (mean; SD 7.08) versus 15.35 hours (mean; SD 8.31), respectively. The difference for time-to-relief was highly significant (p = 0.007, Mann-Whitney U test). The median time-to-relief was 6.17 hours (interquartile range 0.33-15.35) in the treatment group and 15.35 hours (interquartile range 14.00-22.83) in the control group. Resolution of symptoms was one-third faster in the C1 inhibitor concentrate group than in the placebo group: 23.98 hours (mean; SD 14.81) and 34.58 hours (mean; SD 13.56), respectively (p = 0.09, Mann-Whitney U test). Recovery of functional C1 inhibitor was 119.65 percent (mean; SD 50.80), and half-life was 37.87 hours (mean; SD 19.75). Recovery of antigenic C1 inhibitor was 147.75 percent (mean; SD 97.68), and half-life was 24.01 hours (mean; SD 9.70). There were no viral infections or serious adverse effects from the drug after 70 attacks in the treatment group and 96 attacks in the control group.
CONCLUSIONS: C1 inhibitor concentrate is a safe, effective treatment for acute attacks of HAE.
Jun;38(6):540-549
Available online at: onlinelibrary.wiley.com/doi/10.1046/j.1537-2995.1998.38698326333.x/abstract (small fee)
Beta-amyloid augments platelet aggregation: reduced activity of familial angiopathy-associated mutants
Wolozin B, Maheshwari S, Jones C, Dukoff R, Wallace W, Racchi M, et al 11/1998 Molecular Psychiatry (Mol.Psychiatry)
The beta-amyloid (A beta) peptide is present both in serum and in platelets, however it is unclear whether A beta plays a role in platelet function. We have now investigated the effects of soluble A beta on platelet function and have found that low levels (0.1-1 nM) of soluble A beta augment ADP-dependent platelet aggregation and translocation of focal adhesion kinase to the platelet cytoskeleton. Addition of A beta to gel-filtered platelets along with concentrations of adenosine diphosphate (ADP) producing submaximal aggregation responses increased the aggregation response by over 2-fold depending on the ADP:A beta ratios. The structure activity requirements for A beta activity showed intriguing constraints. Only full length A beta has significant activity. Truncated A beta peptides, such as A beta(1-16) or A beta(25-35), or reverse A beta(40-1) all show little or no activity. We also examined the activity of mutant A beta peptides, corresponding with the APP(692A-G) and APP(693E-Q) (at A beta21 and A beta22, respectively) which are found in familial Alzheimer’s disease and hereditary cerebral hemorrhagic amyloidosis, Dutch type (HCHWA-D), and found that these peptides showed little or no activity. These results suggest that A beta interacts with platelets in a highly specific manner and may play a role in regulating platelet function.
Nov;3(6):500-507
Available online at: nature.com/mp/journal/v3/n6/abs/4000451a.html
C1-esterase inhibitor transfusions in patients with hereditary angioedema
Visentin DE, Yang WH, Karsh J 6/1998 Annals of Allergy, Asthma, & Immunology
BACKGROUND: Hereditary angioedema results from the deficiency of C1-esterase inhibitor (C1-INH), and C1-INH replacement would represent definitive treatment for angioedema attacks. In Canada, C1-INH is available only on a compassionate basis at select medical facilities. Our objective is to assess the efficacy of C1-INH transfusions during angioedema attacks at a single Canadian institution.
METHODS: A retrospective chart review of transfusion data between January 1, 1995 and June 30, 1996 was performed. Phone interviews with patients elicited their opinions of the treatment. Data collected included the number and duration of angioedema attacks, dose of transfused C1-INH, and side effects of treatment.
RESULTS: Of a cohort of 13 patients with hereditary angioedema, seven received transfusions with C1-INH. Attacks totaled 87, and more than 100,000 units of the product were transfused. The mean time for abatement of an attack after initiation of transfusion was 50 +/- 8 minutes (1 SD). There were no reports of adverse effects. Although patients were satisfied with the treatment, they raised concerns regarding long-term safety and availability.
CONCLUSIONS: C1-INH transfusion is a satisfactory means of treating angioedema attacks.
Jun;80(6):457-461
Available online at: annallergy.org/article/S1081-1206%2810%2963067-0/abstract (small fee)
Molecular genetics of C1 inhibitor
Tosi M 8/1998 Immunobiology
More than 100 different C1 inhibitor gene mutations have been described in hereditary angioedema (HAE) patients. Sixty-nine mutations have been reported in patients with the quantitative C1 inhibitor defect (type 1 HAE) in two recent large-scale studies. These changes were found distributed over all exons and exon/intron boundaries. The molecular defects can be divided as follows: Alu-repeat-mediated deletions or duplications (accounting for 21% of all cases), missense mutations (> 36%), frameshifts (14%), Stop codon mutations (10%), promoter variants (4%), splice site mutations (7-10%), deletions of a few amino acids (less than 3%). Several recent studies indicate that up to 25% of these changes are found in patients without a family history of angioedema and represent de novo mutations. Pathogenic amino acid substitutions were found distributed over the entire length of the coding sequence, except for the 100 amino-acid-long glycosylated amino-terminal extension, whose sequence tolerates extensive variation, as indicated by comparisons across species. Functional studies have been carried out only on a fraction of these amino acid substitutions and indicate that defects affecting intracellular transport are often at the basis of type 1 hereditary angioedema. An interesting promoter variant (a C to T transition at position -103) was found in an exceptional family with recessive transmission of the disease. Regulatory elements in the promoter region and in intron 1 were revealed by their sequence conservation in mouse and man and by functional studies. C1 inhibitor “minigene” constructs directing correct mRNA and protein synthesis in transgenic mice have provided valuable information on hormonal control and cell-type specificity of gene expression. [References: 23].
Aug;199(2):358-365
Available online at: sciencedirect.com/science/article/pii/S0171298598800405 (small fee)
Funding for Canadian Hereditary Angioedema Network has been generously provided by unrestricted grants from: |
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