Contemporary Homozygous Familial Hypercholesterolemia in the United States: Insights From the CASCADE FH Registry

Background Homozygous familial hypercholesterolemia (HoFH) is a rare, treatment-resistant disorder characterized by early-onset atherosclerotic and aortic valvular cardiovascular disease if left untreated. Contemporary information on HoFH in the United States is lacking, and the extent of underdiagnosis and undertreatment is uncertain. Methods and Results Data were analyzed from 67 children and adults with clinically diagnosed HoFH from the CASCADE (Cascade Screening for Awareness and Detection) FH Registry. Genetic diagnosis was confirmed in 43 patients. We used the clinical characteristics of genetically confirmed patients with HoFH to query the Family Heart Database, a US anonymized payer health database, to estimate the number of patients with similar lipid profiles in a "real-world" setting. Untreated low-density lipoprotein cholesterol levels were lower in adults than children (533 versus 776 mg/dL; P=0.001). At enrollment, atherosclerotic cardiovascular disease and supravalvular and aortic valve stenosis were present in 78.4% and 43.8% and 25.5% and 18.8% of adults and children, respectively. At most recent follow-up, despite multiple lipid-lowering treatment, low-density lipoprotein cholesterol goals were achieved in only a minority of adults and children. Query of the Family Heart Database identified 277 individuals with profiles similar to patients with genetically confirmed HoFH. Advanced lipid-lowering treatments were prescribed for 18%; 40% were on no lipid-lowering treatment; atherosclerotic cardiovascular disease was reported in 20%; familial hypercholesterolemia diagnosis was uncommon. Conclusions Only patients with the most severe HoFH phenotypes are diagnosed early. HoFH remains challenging to treat. Results from the Family Heart Database indicate HoFH is systemically underdiagnosed and undertreated. Earlier screening, aggressive lipid-lowering treatments, and guideline implementation are required to reduce disease burden in HoFH.

Evaluation of the new OxyPlate™ Anaerobic System for the isolation of ocular anaerobic bacteria

AIM

Anaerobic bacteria can cause ocular infections. We tested the OxyPlate™ Anaerobic System (OXY) to isolate pertinent anaerobic bacteria that can cause ocular disease.

METHODS

OXY, which does not require direct anaerobic conditions (i.e. bags, jars), was compared to conventional isolation of incubating culture media in anaerobic bags. Standard colonies counts were performed on anaerobic ocular bacterial isolates under aerobic and anaerobic conditions (anaerobic bags) using agar media: 1) OXY (aerobic only), 2) 5% sheep blood (SB), 3) Chocolate, and 4) Schaedler. The bacteria tested were de-identified ocular isolates cultured from endophthalmitis and dacryocystitis that include 10 Propionibacterium acnes and 3 Actinomyces species. The colony counts for each bacteria isolate, on each culturing condition, were ranked from largest to smallest, and non-parametrically compared to determine the best culturing condition.

RESULTS

All anaerobic conditions were positive for all of the anaerobic isolates. SB and Schaedler's agar under aerobic conditions did not support the growth of anaerobic bacteria. Sparse growth was noted on chocolate agar with Propionibacterium acnes. As an anaerobic system, SB in an anaerobic bag isolated higher colony counts than OXY (P=0.0028) and chocolate agar (P=0.0028).

CONCLUSION

Although OXY did not test to be more efficient than other anaerobic systems, it appears to be a reasonable alternative for isolating anaerobic bacteria from ocular sites. The use of an agar medium in a specially designed plate, without the requirement of an anaerobic bag, rendered OXY as an advantage over other anaerobic systems.

Validation of PCR for the detection of Pseudomonas aeruginosa from corneal samples

AIM

To determine a species-specific real-time polymerase chain reaction (PCR) assay to detect Pseudomonas aeruginosa (PA), a secondary DNA target for PA that may provide a universal target for other bacterial pathogens, and validate both assays for diagnostic testing.

METHODS

PCR detection was established against the ecfX PA gene and the 16S rRNA gene using known PA keratitis isolates. The outcome parameters for both assays were "limit of detection" (LOD), amplification efficiency (AE), and PAGE amplified product analysis. Both assays were validated against 20 true-positive clinical samples positive for PA DNA and 20 true-negative samples containing no PA DNA. Descriptive statistics and PAGE analysis were used as outcome parameters.

RESULTS

AE of the ecfX assay was 96.6%, and LOD was 33.6 copies of target DNA per microliter. AE of the 16S rRNA assay was 103.4%, and LOD was 8.12 copies per microliter. The sensitivity, specificity, positive predictive value, negative predictive value, and efficiency for the ecfX and 16S rRNA assays were [75%, 95%, 94%, 79%, and 85%], and [70%, 100%, 100%, 77%, and 85%], respectively. Both PCR assays were validated, followed by confirmation of DNA patterns from PAGE analysis.

CONCLUSION

The PCR methodology described here may be a useful adjunct to standard methods in the diagnosis of PA keratitis.

A 13-year retrospective review of polymerase chain reaction testing for infectious agents from ocular samples

PURPOSE

Polymerase chain reaction (PCR) is a molecular technique for the diagnosis of ocular infectious disease. In this large patient sample and multiyear study, the impact of PCR for detecting infectious agents from ocular samples was reviewed in comparison with nonmolecular diagnostic techniques.

DESIGN

A retrospective laboratory review of PCR testing.

PARTICIPANTS

Three thousand fifty-six patient samples with a differential of ocular infection.

METHODS

The daily laboratory logs for diagnostic testing were reviewed for PCR, cell culture isolation, shell vial isolation, and Acanthamoeba isolation from January 1997 through May 2010 for herpes simplex virus (HSV), adenovirus, varicella zoster virus (VZV), Chlamydia trachomatis, Acanthamoeba, and infrequent pathogens of intraocular inflammation.

MAIN OUTCOME MEASURES

Incidence of the positive presence of ocular infectious agents.

RESULTS

Polymerase chain reaction results were positive more often than culture results for HSV (P = 0.0001), VZV (P = 0.00001), C. trachomatis (P = 0.00005), and Acanthamoeba (P = 0.04). For adenovirus, cell culture isolation results were positive more often than PCR results (P = 0.001). Polymerase chain reaction was the primary diagnostic test for detecting cytomegalovirus and Toxoplasma.

CONCLUSIONS

The current study demonstrated the importance of PCR as a routine diagnostic test for detecting both common and infrequent ocular pathogens. Cell culture isolation is still a definitive test for adenovirus and a confirmatory test for HSV and Acanthamoeba.

An independent in vitro comparison of povidone iodine and SteriLid

AIM

Povidone iodine (PI) and SteriLid (SL) are biocides used to decrease bacterial load on the eyelid margin. We compared the antibacterial activity of PI and SL to determine the better antiseptic.

METHODS

Time-kill studies of PI and SL against a battery of bacteria that included Staphylococcus epidermidis, methicillin-susceptible Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Streptococcus pneumoniae, Bacillus cereus, Pseudomonas aeruginosa, Escherichia coli, Serratia marcescens, and Branhamella catarrhalis were conducted at time points 1, 2, 10, and 30 min. The comparative outcome measures were based on 90% and 99.9% decreases in bacterial colony counts.

RESULTS

PI was more effective at a 90% kill than SL at time points, 1 min (8/9 vs. 7/9), 2 min (9/9 vs. 6/9), 10 min (9/9 vs. 8/9), and 30 min (9/9 vs. 8/9). PI was more effective at a 99.9% kill than SL at time points, 1 min (5/9 vs. 3/9), 2 min (7/9 vs. 4/9), 10 min (9/9 vs. 4/9), and 30 min (9/9 vs. 6/9).

CONCLUSIONS

Our study supports PI as an effective antiseptic for decreasing the bacterial load that can exist on the eyelid margin. SL appears to be a less effective alternative.

Cell culture isolation can miss the laboratory diagnosis of HSV ocular infection

AIM

We compared polymerase chain reaction (PCR) to cell culture isolation for the laboratory diagnosis of ocular herpes simplex virus (HSV) disease.

METHODS

Laboratory and medical records of consecutive patients were reviewed for results of 1) HSV PCR testing, 2) HSV cell culture isolation, and 3) clinical diagnosis. PCR results were statistically compared to cell culture isolation and patients initially diagnosed for ocular HSV infection.

RESULTS

Of 581 cases submitted for laboratory testing, 520 were PCR negative, cell culture negative (89.6%); 0 were PCR negative, cell culture positive (0%); 27 were PCR positive, cell culture negative (4.6%); and 34 were PCR positive, cell culture positive (5.8%). PCR tested more positive than cell culture isolation (McNemar's, P=0.0001). Of 47 HSV PCR positive cases with complete medical records, 19 were cell culture negative for HSV and 28 were cell culture positive for HSV. Fourteen of 19 cell culture negative cases (74%) (Without PCR, 5 cases of HSV would be missed) and 25 of the 28 cell culture positive cases (89%) (Laboratory testing was necessary for diagnosing 3 cases) were clinically diagnosed with HSV at the initial examination.

CONCLUSION

PCR was a more definitive test for diagnosing HSV ocular infection than cell culture isolation. Cell culture isolation alone can miss an atypical presentation of HSV ocular infection.

The in vitro impact of moxifloxacin and gatifloxacin concentration (0.5% vs 0.3%) and the addition of benzalkonium chloride on antibacterial efficacy

PURPOSE

Varied concentrations of moxifloxacin (MOX) and gatifloxacin (GAT) and the addition of 0.005% benzalkonium chloride (BAK) were evaluated for eliminating Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA), and coagulase-negative Staphylococcus (CNS).

DESIGN

In vitro laboratory investigation.

METHODS

The time-kill survival of SA, PA, and CNS were tested at one, two, three, six, eight, and 24 hours to: (1) Mueller-Hinton broth, (2) BAK, (3) 0.5% MOX, (4) 0.5% GAT, (5) 0.3% MOX, (6) 0.3% GAT, (7) 0.3% GAT plus BAK, (8) 0.5% MOX plus BAK, (9) 8 microg/ml GAT, and (10) 8 mug/ml MOX. Antibiotic interactions (GAT and BAK) were determined by checkerboard testing. The outcome measures were (1) time-to-kill, (2) killing-rates, and (3) fractional inhibitory concentration (FIC) indices.

RESULTS

MOX and GAT at either 0.5% or 0.3% had equivalent antibacterial effects. BAK alone or the addition of BAK to either antibiotic eliminated SA and CNS within one hour, whereas 0.3% GAT plus BAK eliminated bacteria faster than 0.5% MOX (P = .016). For PA, BAK alone had no antibacterial effect. The kill rates of MOX and GAT were equivalent. FIC indices indicated that GAT and BAK were indifferent against SA and CNS, but antagonistic to PA.

CONCLUSION

As a preservative, MOX and GAT have equivalent antibacterial activity with similar killing rates. BAK appears to independently complement GAT for eliminating SA and CNS, but has no effect on PA. The in vitro predictive clinical effect due to varied antibiotic concentration and the addition of BAK requires confirmatory clinical studies for validation.

Evaluation of the SmartCycler II System for Real-Time Detection of Viruses and Chlamydia From Ocular Specimens

OBJECTIVE

To compare the SmartCycler II system (Cepheid, Sunnyvale, Calif) results with those of standard cell culture, to compare the SmartCycler II system results with those of a dedicated polymerase chain reaction facility, and to establish the SmartCycler II system as a polymerase chain reaction method for detecting viral and chlamydial DNA from ocular specimens.

METHODS

True-positive samples (test-positive specimens based on standard testing) and true-negative samples (test-negative specimens based on standard testing) were processed for polymerase chain reaction using the SmartCycler II system for adenovirus, herpes simplex virus type 1, varicella-zoster virus, and Chlamydia trachomatis. Sensitivity, specificity, positive predictive value, negative predictive value, and efficiency were based on the testing of true-positive and true-negative specimens.

RESULTS

The descriptive statistics for adenovirus, herpes simplex virus type 1, varicella-zoster virus, and C trachomatis were, respectively, as follows: sensitivity, 85%, 98%, 100%, and 94%; specificity, 98%, 100%, 100%, and 100%; positive predictive value, 98%, 100%, 100%, and 100%; negative predictive value, 85%, 91%, 100%, and 98%; and efficiency, 92%, 95%, 100%, and 99%. Test sensitivity for the SmartCycler II system was equivalent to that from a central molecular laboratory.

CONCLUSION

The descriptive statistics of the SmartCycler II system obtained in a small laboratory were comparable to those of a central molecular laboratory for detecting viruses and Chlamydia species. Clinical Relevance Polymerase chain reaction has great potential in the routine diagnosis of ocular infections in any conventional laboratory.