Peripheral retinal neovascularization (Eales disease) associated with the factor V Leiden mutation.

PURPOSE: To illustrate a case of peripheral retinal neovascularization (Eales disease) in a patient who tested positive for the factor V Leiden mutation. METHODS: A 42-year-old woman had a 1-week history of blurred vision in her right eye. Her medical history was remarkable for a cerebrovascular accident. Ophthalmoscopy of the right eye disclosed a mild vitreous hemorrhage and a ridge of retinal neovascularization in the temporal periphery. The left fundus showed evidence of temporal retinal ischemia. A laboratory evaluation for hypercoagulability was positive for factor V Leiden mutation. RESULTS: Peripheral scatter laser photocoagulation was applied to the ischemic retina, and the neovascularization regressed. The patient began taking warfarin sodium to prevent further thrombotic events. CONCLUSION: A laboratory evaluation for coagulopathy, including the factor V Leiden mutation, should be added to the examination of patients with Eales disease, especially individuals with a history of a previous thrombotic event.

HIV resistance testing: methods, utility, and limitations.

Widespread use of combination antiretroviral therapy for HIV has led to increased incidence of HIV resistance and a need for antiretroviral resistance testing to optimize therapeutic choices. Antiretroviral resistance analysis is performed using either genotypic or phenotypic assays. Genotypic assays identify resistance-associated mutations in the HIV genome. They are faster and less technically demanding than phenotypic assays; however, the associations between mutations and resistance patterns are often complicated, making interpretation difficult. Phenotypic assays directly measure the ability of antiviral compounds to inhibit replication of patient-derived virus. Phenotypic assays provide results that are easier to interpret; however, there is little data that relates the degree of resistance detected in phenotypic assays to patient clinical response. Despite limitations, the improved therapeutic outcome of therapies guided by resistance testing is leading to incorporation of resistance testing into the standard of care for HIV treatment.

Arterial thromboembolic events in patients with the factor V Leiden mutation.

BACKGROUND: The factor V Leiden mutation affects 6% of the United States population and is known to be associated with venous thrombosis. We identify, herein, 30 individuals with the Leiden mutation and known arterial thromboembolic events. METHODS: The factor V mutation was assessed using polymerase chain reaction. RESULTS: In the 16 patients sustaining a cerebrovascular accident, the mean age was 44.1 and 11 (69%) were younger than 50. Similarly, the 13 patients presenting with an acute myocardial infarction were relatively young with a mean age of 45.5, and 9 (65%) patients presented at less than 50 years of age. Radiographic information was available for 19 patients in this study. No significant arterial atherosclerotic disease was demonstrated in 18 (95%) of these patients. CONCLUSIONS: This study demonstrates an association between the factor V Leiden mutation and the development of unexplained arterial thromboembolic events, especially in younger patients without existing atherosclerotic disease.

Lamivudine treatment of advanced and decompensated liver disease due to hepatitis B.

The purpose of this study was to evaluate the effectiveness and safety of lamivudine treatment in patients with advanced and end-stage liver disease caused by hepatitis B. Nine cases of advanced or end-stage liver disease due to hepatitis B infection were treated with lamivudine. Four received liver transplants while receiving lamivudine. Moreover, each of these four has been maintained on lamivudine therapy post-transplantation while receiving immunosuppression. No cases of HBV reactivation have been seen. More importantly, the allograft liver tissue has been HBc and HBs antigen negative as well as HBV-DNA negative by PCR. This report suggests that: 1) lamivudine can be given safely to liver transplant candidates; 2) lamivudine suppresses HBV replication, so much so that HBV-DNA becomes undetectable in the serum; 3) despite powerful immunosuppression associated with transplantation, HBV reactivation does not occur under lamivudine therapy; and 4) the observations should cause transplant physicians, surgeons and third-party payers to reconsider their positions relative to transplantation of individuals with HBV-associated cirrhosis.

Combination treatment of advanced HCV associated liver disease with interferon and G-CSF.

BACKGROUND/AIMS: Interferon (IFN) is the only therapy currently approved for chronic hepatitis C treatment. Unfortunately, not all patients respond to IFN therapy with a disease remission. Some people consider advanced histologic disease to be either a contraindication for treatment or a predictor of a poor response to treatment. To assess the validity of the two preceding widely held views, a total of 30 consecutive patients with advanced histologic disease associated with hepatitis C were studied. MATERIALS AND METHODS: Patients were treated with 5 million units of IFN administered SQ daily either alone or in combination with G-CSF (300 micrograms SQ on Mondays and Thursdays). RESULTS: Both groups responded to the IFN therapy with 53 and 60% respectively being HCV-RNA negative after 6 months of therapy and 40 and 53% respectively continuing as HCV-RNA negative after 6 months of follow-up after IFN. The mean white blood cell (WBC) count and peak WBC counts of those receiving G-CSF were greater than those not receiving G-CSF therapy. The nadir values for both groups, however, were similar. CONCLUSIONS: Based upon this study, utilizing daily high dose IFN (5 MU) therapy, it can be concluded that individuals with advanced histologic disease can be treated successfully with IFN and obtain a prolonged remission. The addition of G-CSF during IFN therapy of patients with histologically advanced disease increases the mean WBC and peak WBC count levels achieved during the course of IFN therapy but without significantly increasing the response rate defined as clearance of HCV-RNA at the end of treatment and follow-up.

Genomic testing: the clinical laboratory perspective.

The expansion of genetic testing in the clinical laboratory is well under way, with many clinically validated genetic tests already in use. As sequencing technology becomes more efficient and less costly, clinical laboratories will make the transition from single-gene testing to multigene panels. Early, more targeted applications will gradually be replaced by more comprehensive genomic offerings, including exome and whole-genome analysis. Despite significant technological advancements, many obstacles remain for full incorporation of whole-genome testing.

Medium dependence for rapid detection of thermonuclease activity in blood culture broths.

The thermonuclease test for rapid identification of Staphylococcus aureus in blood cultures was evaluated by using 16 different blood culture media and 4 DNase agar media. The reliability of this test was profoundly medium dependent, and the source of the DNase agar was particularly important.

Genetics of resistance in a non-beta-lactamase-producing gonococcus with relatively high-level penicillin resistance.

A penicillin-resistant (Penr) non-penicillinase-producing Neisseria gonorrhoeae strain responsible for an outbreak affecting 199 persons in Durham, N.C., in 1983 was studied to determine the genetic basis of its unusually high-level (MIC, 2.0 micrograms/ml) Penr. Plasmid screening of the strain revealed no plasmids other than the 2.6-megadalton cryptic plasmid. Penr was found to be partially due to mutations genotypically and phenotypically similar to the previously characterized chromosomal loci penA, mtr, and penB. Resistance loci from the epidemic donor strain were transformed into susceptible recipients FA19 and F62 in a stepwise fashion; the combination of the three loci resulted in moderate levels of penicillin resistance (MIC, 0.5 micrograms/ml), but donor levels of resistance were not obtainable in either recipient, for uncertain reasons. Occurrence of an antibiotic-susceptible (env) mutation in a clinical isolate of the Penr epidemic strain also was documented.

Recombination near the antibiotic resistance locus penB results in antigenic variation of gonococcal outer membrane protein I.

In gonococci, the nonspecific antimicrobial resistance locus penB is known to be closely linked to loci designated nmp that alter the Mr and antigenicity of the outer membrane porin protein I (P.I). We report that after selection for the linked donor penB locus, occasional recombinants expressed P.I with some epitopes from each parent. These hybrid P.I antigens were stable on subculture and were transformed at a locus closely linked to penB. The hybrid P.I antigens were detected with monoclonal antibodies in both coagglutination and Western blot assays. The alterations of P.I antigenicity may have resulted from recombination between structural genes for P.I that are closely linked to penB.

Heterosexual HIV-1 transmission and viral load in hemophilic patients.

Only one fifth or fewer of the female sexual partners of HIV-1-infected men with hemophilia become infected. The risk factors associated with heterosexual transmission of HIV-1 are not well understood. To investigate the hypothesis that HIV-1 viral load may be related to heterosexual HIV-1 transmission, we measured HIV-1 RNA by polymerase chain reaction (PCR) in frozen samples from 39 men with hemophilia and HIV-1 infection obtained between 20 and 62 months after HIV-1 seroconversion, during at least a 6-month relationship with a female sexual partner. The median time from the hemophilic viral load determination to the estimated date of transmission to the female partner was 9 months (range, 4-41 months). The proportion of HIV-positive hemophilic men with >100,000 HIV RNA copies/ml was significantly higher in transmitters (TR) (3 of 5 [60%]), than in nontransmitters (NTR) (3 of 34 [9%]; p = 0.027). There were no differences between TR and NTR in age at seroconversion (32.4 years each), in time from seroconversion to AIDS (67 versus 79 months), in mean CD4 number (245/microl] versus 260/microl); nor in the proportion who developed AIDS (4 of 5 [80%] versus 24 of 34 [71%]). These findings appear to suggest that high HIV viral load in HIV-infected hemophilic men increases the risk of HIV transmission to heterosexual partners. Viral load determinations may be helpful in counseling hemophilic couples regarding transmission to female partners.

A community-based outbreak of infection with penicillin-resistant Neisseria gonorrhoeae not producing penicillinase (chromosomally mediated resistance).

From February through November of 1983, 199 cases of penicillin-resistant Neisseria gonorrhoeae infection were identified in a localized epidemic in Durham, North Carolina. The isolates did not produce beta-lactamase but were unusually resistant to penicillin (minimum inhibitory concentration, 2.0 to 4.0 micrograms per milliliter), and 15 of 16 patients treated with 4.8 million units of penicillin G procaine plus 1.0 g of probenecid did not respond to therapy. Recognition of the outbreak was impeded by a lack of routine surveillance for resistance other than that mediated by beta-lactamase. All epidemic isolates had a single serotype, auxotype, and antibiotic-susceptibility profile. The outbreak was halted by changing the treatment for all patients and their contacts to spectinomycin, and by intensive epidemiologic case-finding efforts. The emergence of such resistant strains poses potential major public health problems and indicates a need for reassessment of current surveillance procedures.

Effect of calcium on in vitro activity of LY146032 against Clostridium difficile.

The in vitro MICs of LY146032 against 63 isolates of Clostridium difficile tested in Wilkins-Chalgren broth ranged from 0.5 to greater than 32 micrograms/ml, with MICs of 4 and 8 micrograms/ml for 50 and 90% of the isolates, respectively. However, when the test medium was supplemented with physiologic concentrations of calcium, the MIC for 90% of the isolates was reduced to less than or equal to 0.12 microgram/ml.

The factor V Leiden mutation: spectrum of thrombotic events and laboratory evaluation.

PURPOSE: This study aims to describe the spectrum of clinical thrombotic events and to compare the methods of laboratory evaluation for the newly described prothrombotic factor V Leiden mutation. METHODS: Specimens from 1376 patients with thrombotic events or their relatives were tested for the factor V Leiden mutation by polymerase chain reaction plus restriction digest from Jan. 1, 1995, to Mar. 31, 1996. Activated protein C (APC) resistance test data was available for 554 of these patients. Clinical information was available for 166 patients with the mutation. RESULTS: Of 1376 patients tested for factor V Leiden mutation, 270 (19.6%) were positive, with 12 homozygotes and 258 heterozygotes. Of 554 patients for whom APC resistance data was available, 221 (39.9%) had low APC resistance ratios (< or = 2.4); of these only 97 (43.9%) were factor V Leiden-positive. Among 333 samples with normal or elevated APC resistance ratios, 19 (5.7%) were later identified with the factor V Leiden mutation, despite the normal screening test. One hundred fourteen of 166 patients (68.7%) with the mutation had at least one thrombotic event, most commonly deep venous thrombosis and pulmonary embolus. Arterial cerebrovascular thrombotic events occurred in 11 patients (10%), and myocardial infarctions in eight (7%). The mean age of all patients with arterial thrombotic events was 45.4 years. CONCLUSIONS: The factor V mutation is a common cause of venous thromboses but may also be associated with the early presentation of arterial thrombotic events. The APC resistance test is a sensitive screening assay but has limitations of its specificity in clinical practice.

New approach to HCV treatment. Recognition of disease process as systemic viral infection rather than as liver disease.

Chronic viral hepatitis C is a problem of immense proportions. The only therapy that currently exists and is FDA approved is interferon (IFN). Much controversy exists regarding the dose and duration as well as the effectiveness of IFN therapy. This study was performed to determine whether a new endpoint of successful treatment, HCV-RNA negativity in plasma and liver, would produce a greater number of long-term responders than is achievable with the currently recommended six months of therapy. The 45 patients enrolled in this study were randomized 2 to 1 in a treatment paradigm consisting of 5 MU IFN three times a week for six months or the same dose of IFN daily until HCV-RNA was undetectable in plasma X 3 over 3 consecutive monthly determinations followed by demonstrated HCV-RNA negativity in liver biopsy tissue. No differences in age, initial WBC count, platelet count, or hepatic injury measures were evident between the two treatment groups. At the end of therapy, 43% of those in group 1 vs 100% in group 2 responded to the IFN therapy as defined by the serum ALT level. More importantly, all of those in group 1, but only half of those in group 2, relapsed and became HCV-RNA positive with discontinuation of the IFN therapy. These data suggest that: (1) IFN therapy is more effective when given for a longer rather than a shorter period; (2) virologic response definitions are now possible and are preferred; (3) using longer therapy and a virologic endpoint, the responses achieved are more durable.

A preliminary experience with GM-CSF plus interferon in patients with HBV and HCV resistant to interferon therapy.

An open label trial of GM-CSF plus high-dose interferon (IFN) alpha 2b was performed in eight patients with chronic hepatitis B infection and 16 patients with chronic hepatitis C, who either failed to clear virus with 6 months of daily high-dose IFN (5 MU daily) therapy (n = 22) or were considered untreatable because of advanced disease and leukopenia (n = 2). The dose of GM-CSF used was 500 micrograms subcutaneously twice weekly. The dose of IFN used was 5 MU daily. Both agents were administered for 4 months. Five of the eight hepatitis B patients and five of the 16 hepatitis C virus patients responded to combined therapy having previously failed IFN therapy alone. The hepatitis B virus responders had low entry ALT, AST, and gamma GPT levels as compared to the non-responders. No such differences for responders and non-responders were seen with the hepatitis C virus patients. These data suggest that the combination of GM-CSF and IFN may be more effective at achieving viral clearance than IFN alone.

Utility of hepatitis C virus RNA determinations in hepatic tissue as an end point for interferon treatment of chronic hepatitis C.

A total of 41 patients with chronic hepatitis C virus (HCV) defined as abnormal liver injury test results for 6 months or more and HCV RNA positivity in plasma were studied to determine if the liver might not be the only focus of HCV infection in individuals treated with interferon alfa (IFN-alpha). All patients were examined for the presence of confounding liver disease and tested negatively for such findings. All tested positively for HCV RNA and had an abnormal hepatic histology. All were treated with IFN for 6 months at a dosage of 5 million units daily. After 6 months of therapy, 29 (71%) had normal alanine transaminase (ALT) values, and 25 (61%) tested negatively for HCV RNA. After 6 months of follow-up, without IFN therapy, 17 (41%) still had normal ALT values, and 16 (39%) still tested negatively for HCV RNA in serum. Patients who continued to test negatively for HCV RNA in serum after 6 months of follow-up also tested negatively for HCV RNA in the liver at the end of IFN therapy. Only 2 subjects who tested negatively for HCV RNA in the liver at the end of treatment relapsed after discontinuing IFN therapy. In contrast, patients who tested positively for HCV RNA in the liver after 6 months of therapy relapsed and tested positively for HCV RNA in serum during the 6 months of follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of cytomegalovirus in formalin-fixed paraffin-embedded donor, native and allograft liver tissue using a multiplex polymerase chain reaction-liquid hybridization assay.

A multiplex polymerase chain reaction (PCR)-liquid hybridization assay detecting a minimum 10 fg of cytomegaloviral (CMV) DNA has been developed. This assay successfully detected viral nucleic acids in 25/26 (96.2%) routinely embedded allograft liver biopsies with CMV hepatitis. No CMV DNA was detected in 15 native and 12 donor liver tissues sampled at the time of liver transplantation. These results indicate that archived formalin-fixed, paraffin-embedded liver tissues obtained from patients with significant liver disease can be successfully analyzed for CMV by PCR, retrospectively. Failure to detect CMV in native and donor livers implies that any latent virus present within these tissues is very focally distributed, or is below the threshold of detection applicable to PCR.