Variability in bleeding phenotype in Amish carriers of haemophilia B with the 31008 C-->T mutation

The aim of this study was to characterize the variability of bleeding phenotype and its association with plasma factor IX coagulant activity (FIX:C) in haemophilia B carriers in a large Amish pedigree with a unifying genetic mutation, C-to-T transition at base 31008 of the factor IX gene (Xq27.1-27.2). A cross-sectional survey of haemophilia B carriers included a multiple choice questionnaire evaluating symptoms of mucocutaneous bleeding, joint bleeding and bleeding after haemostatic stress [menstruation, postpartum haemorrhage (PPH), dental extractions and invasive surgeries]. Severity of bleeding was graded as 0 to 4, 0 being no bleeding whereas 4 being severe bleeding. Association between total bleeding scores and the FIX:C was evaluated. Sixty-four haemophilia B carriers participated in this study. Median age: 18 years (range 1-70 years); median bleeding score: 1 (range 0-8). Besides PPH, isolated symptoms of bruising, epistaxis, menorrhagia and postsurgical bleeding including dental extraction were not associated with lower FIX:C. Bleeding score >/=3 was associated with involvement of at least two bleeding sites and a lower mean FIX:C of 42 +/- 10.3% (95% CI 36.4-47.7) while a score >3 had involvement of </=2 sites and higher mean FIX:C of 54.9 +/- 21.5% (95% CI 49-61), P = 0.005. Subcutaneous haematoma formation and bleeding after haemostatic stress requiring treatment were associated with bleeding scores >/=3. Phenotypic variability existed among the carriers of haemophilia B who belonged to a single pedigree carrying a single unifying mutation. The utility of bleeding scores to define bleeding phenotype precisely in haemophilia B carriers needs further evaluation.

Biologic response to subcutaneous and intranasal therapy with desmopressin in a large Amish kindred with Type 2M von Willebrand disease

The aim of this study was to characterize the adequacy and longevity of biological response to desmopressin (DDAVP) in a large Amish kindred of Type 2M von Willebrand disease (VWD) possessing C-to-T transition at nucleotide 4120 in exon 28 of A1 domain of von Willebrand factor (VWF) gene. Response to both intranasal (Stimate) and subcutaneous DDAVP administration was assessed. Rise in ristocetin cofactor activity (VWF:RCo) > or = 40% at 90-min post-Stimate and 1-2 h after subcutaneous DDAVP was defined as initial response; response longevity was assessed only after subcutaneous dosing by measuring VWF:RCo levels at time-points 1, 2, 4 and 6 h. Eleven patients (five males, six females; age range: 20-56 years) participated in intranasal and 9/11 (four males, five females) in subcutaneous testing. Baseline haemostatic profiles included: VWF:RCo < 15%, VWF:Ag < 40% and normal VWF multimers. Initial response was comparable by both intranasal (6/11; 54.5%) and subcutaneous (4/9; 44%) routes; sustained response (VWF:RCo > 40% for 2 h) was observed in only one in nine (11%) patients tested. Median VWF:RCo peak levels after intranasal (40%) and subcutaneous (39%) routes were equivalent. Peak VWF:Ag levels were significantly higher after subcutaneous than intranasal DDAVP (94% vs. 54%; P = 0.03). Area under the curve for VWF:RCo was significantly decreased (170 microg h mL(-1)) compared with VWF:Ag (471 microg h mL(-1)) and FVIII:C (624.60 microg h mL(-1)). This study suggests that in this population: (i) intra-individual DDAVP response is consistent with subcutaneous and intranasal administration; and (ii) extending DDAVP challenge test up to at least 6 h is required to characterize adequacy and longevity of biologic response prior to using DDAVP as a sole haemostatic intervention.

Type 2B vWD: the varied clinical manifestations in two kindreds

Type 2B von Willebrand's disease (vWD) is associated with spontaneous binding of large von Willebrand factor (vWF) multimers to platelets in vivo, followed by clearance of both the large multimers and platelets resulting in thrombocytopenia, which may be intermittent, mild to severe, and may be exacerbated by stress such as infection or pregnancy. We report our experience in two kindreds (49 caucasian individuals) with type 2B vWD and discuss their varied clinical manifestations. The largest kindred (45 patients) was traced back five generations to a presumed index case. The genetic defect in this kindred was identified as a missense mutation, with a C to T transition at a CpG dinucleotide (nucleotide 3916) resulting in an amino acid substitution (Arg 543 to Trp) within the glycoprotein Ib binding domain of vWF. Ristocetin cofactor activity varied from < 10 to 28%, and factor VIII activity from 7 to 69%. Analysis of von Willebrand multimers consistently revealed loss of large molecular weight forms. Platelet counts in those with thrombocytopenia varied from 10 x 10(9) L(-1) to 120 x 10(9) L(-1). The severity of thrombocytopenia has also varied within the same individual during the period of follow-up. The clinical manifestations were varied and ranged from mild to moderate spontaneous bleeding episodes, including epistaxis, menorrhagia and gastro-intestinal haemorrhage. Severe bleeding episodes were observed in those undergoing surgery (both elective and non-elective), and in a few patients despite aggressive replacement with exogenous source of intact vWF, antifibrinolytics when indicated, and a near normal platelet count. Thrombotic disease may be a rare and unusual sequela of this disorder as was noted in one of our patients. Obtaining a platelet count at birth in infants of mothers with type 2B vWD who exhibit thrombocytopenia, may help in the earlier detection of infants at risk for thrombocytopenia.

Fine mapping of inhibitory anti-factor V antibodies using factor V C2 domain mutants. Identification of two antigenic epitopes involved in phospholipid binding

Hemorrhagic factor V inhibitors frequently bind to the second C-type (C2) domain of factor V and interfere with phospholipid binding. To define specific residues recognized by inhibitors from four patients (one bovine thrombin-induced and three spontaneous antibodies), epitope mapping was performed using recombinant human factor V lacking most of the B-type domain (FV des B) and alanine-substituted mutants within the C2 domain (FV des B C2 mutants). FV des B C2 mutants located in the region between Lys2060 and Glu2069 were resistant to inhibition by three IgG preparations including the bovine thrombin-induced antibody in both prothrombinase and phospholipid-binding assays. In contrast, mutations at Lys2087 and Lys2092/Glu2096 were significantly resistant to inhibition by the fourth IgG preparation in both prothrombinase and phospholipid-binding assays. These results confirm interference of phospholipid binding by hemorrhagic factor V inhibitors and support the role(s) of these residues in phospholipid binding.

Central nervous system infections due to Stomatococcus mucilaginosus in immunocompromised hosts

We present a case of central nervous system (CNS) infection due to Stomatococcus mucilaginosus involving a patient with leukemia and summarize 12 additional published reports of CNS infection due to this organism in immunocompromised hosts. The infection was diagnosed most commonly in the setting of hematologic malignancy accompanied by chemotherapy-induced neutropenia. S. mucilaginosus was recovered from blood prior to discovery of the CNS infection in 62% of cases. Signs or symptoms of CNS infection were observed in all patients. Although a number of patients responded to regimens containing intravenous vancomycin, the addition of intrathecal vancomycin appeared to be of benefit in some cases.

Is hormone replacement a risk factor for ischemic stroke in women with factor V Leiden mutation?

OBJECTIVE

To describe a patient with multifocal cerebral ischemia whose only identified potential risk factors were use of postmenopausal hormone replacement and heterozygosity to factor V Leiden mutation.

DESIGN

A case report.

SETTING

A tertiary care center.

PATIENT

A 51-year-old woman taking hormone replacement (0.625 mg/d of estrogen alternating with 10 mg/d of medroxyprogesterone) presented with a generalized tonic-clonic seizure. She had persistent multifocal non-enhancing lesions on magnetic resonance imaging of the brain. A stereotactic biopsy of the brain performed to exclude gliomatosis cerebri was consistent with cerebral ischemia. An extensive evaluation to uncover the cause of stroke revealed only heterozygosity to factor V Leiden mutation.

MAIN OUTCOME AND RESULTS

Hormonal replacement was discontinued and the patient had no recurrent ischemic strokes.

CONCLUSIONS

Postmenopausal hormonal replacement may be a risk factor for ischemic stroke in women with the factor V Leiden mutation. Ongoing trials of hormonal replacement provide an opportunity to test this hypothesis.

Excessive zinc ingestion. A reversible cause of sideroblastic anemia and bone marrow depression

Two patients with sideroblastic anemia secondary to zinc-induced copper deficiency absorbed excess zinc secondary to oral ingestion. The source of excess zinc was a zinc supplement in one case; in the other, ingested coins. In each case, the sideroblastic anemia was corrected promptly after removal of the source of excess zinc. These two cases emphasize the importance of recognizing this clinical entity, since the myelodysplastic features are completely reversible.

Cisplatin-based combination chemotherapy for disseminated germ cell tumors: long-term follow-up

A retrospective analysis of the initial 229 cases of disseminated germ cell tumors treated at Indiana University with cisplatin, vinblastine, and bleomycin (PVB), with or without doxorubicin revealed 146 patients who are alive and disease-free with a minimum follow-up of 6 years and a median follow-up of 8.5 years. At 12 years, the estimated probability of survival is 65.0%, and the estimated probability of relapse-free survival for complete responders is 83.5%. Long-term complications, such as clinically significant organ toxicity or therapy-related second malignancies, have not been observed. The functional status of survivors is maintained, with 95% returning to their pretherapy status, of which 88% are fully employed. Of patients receiving chemotherapy without abdominal surgery, 35% have fathered healthy children posttherapy. Achievement of complete remission (CR) in disseminated germ cell tumors with cisplatin-based combination chemotherapy translates to long-term disease-free survival and cure for the majority of patients, with preservation of functional status.

Salvage chemotherapy for lymphoma with VP-16, ifosfamide, and cisplatin

Between 1983 and 1985, we conducted a phase II clinical trial using VP-16, ifosfamide, and cisplatin (VIP) in patients with refractory lymphoma. Twenty-eight patients with bidimensional measurable disease were treated with VP-16 (75 mg/m2), ifosfamide (1.2 g/m2), and cisplatin (20 mg/m2) as daily intravenous infusions for 5 consecutive days. N-Acetylcysteine, 2 g orally every 6 h, was given as a uroepithelial protective agent. All patients had received extensive combination chemotherapy prior to beginning VIP (median number of regimens = 2). Of the 25 patients evaluable for response, 2 patients achieved complete remission and 7 achieved partial remission for an overall objective response rate of 36%. The length of responses ranged from 2 months to 13 months. The predominant toxicity of VIP was myelosuppression. Of 23 patients receiving more than one course of VIP, 17 (73%) had dose reductions or delays related to poor hematologic tolerance of therapy. Uroepithelial and renal toxicity were mild. VIP demonstrates therapeutic activity in refractory lymphoma and appears comparable to other ifosfamide/VP-16 based salvage regimens.

Cytogenetic findings in siblings with a myelodysplastic syndrome

A brother and sister, both in their third decade, presented 6 months apart with severe pancytopenia. Bone marrow examination demonstrated morphologic changes, characteristic of the myelodysplastic syndromes, subtype refractory anemia with excess of blasts; cytogenetic studies revealed complex but different karyotypic abnormalities in both siblings. No history of exposure to mutagenic agents was obtained; there was no evidence of congenital anomalies in the family. Both siblings died within 18 months of diagnosis from complications related to their disease. This report describes the clinical course and discusses the cytogenetic findings for both siblings.

Clinical pharmacology of vinzolidine

Vinzolidine (VZL), a new semisynthetic vinca alkaloid, was studied by using 3H-labeled VZL administered PO in four patients. At single doses from 1.5 to 36.5 mg/m2 (0.034-0.919 mg/kg) radioactivity was rapidly absorbed with a half-life of absorption of 1 h and a peak at 4 h. Plasma decay of radiolabel followed a biphasic pattern with an alpha half-life of 10.48 h and a beta half-life of 172 h. The apparent plasma clearance was dose-dependent. The total radiolabel recovered was 52.9% +/- 11.4% of the administered label, with 90% in the feces. HPLC analysis revealed that in all extracted plasma, urine, and feces the predominant material was unchanged VZL. Several metabolites were observed but not identified.

Pathologic findings at orchiectomy following chemotherapy for disseminated testicular cancer

Patients with testicular cancer who have disseminated disease at presentation do not always undergo orchiectomy for diagnosis of staging before initiation of chemotherapy. Between October 1978 and November 1982 orchiectomy was performed following cisplatin combination chemotherapy in 20 patients with disseminated germ cell tumors. There were three patients with residual carcinoma in the removed testis and six patients with teratoma. Therefore, in patients with evidence of a primary testicular neoplasm that was not resected initially, orchiectomy should be performed after chemotherapy. Furthermore, the testis may be a sanctuary site for germ cell malignancies during systemic treatment.