Novel diagnosis of fungal endophthalmitis by broad-range real-time PCR detection of fungal 28S ribosomal DNA

Universal PCR for bacteria, mycobacteria, and fungi: a 10-year retrospective review of clinical indications and patient outcomes

IMPORTANCE

Our work provides a retrospective analysis of universal PCR orders for bacteria, mycobacteria, and fungi across our institution across a 10-year period. We assessed the positivity rates for this diagnostic tool by test type and specimen type and, critically, studied whether and how the results influenced the outcomes from treatment change, to readmission, to death.

Consensus and controversies in the science of endophthalmitis management: Basic research and clinical perspectives

Infectious endophthalmitis is a severe intraocular infection caused by bacteria, or less commonly by fungi. It can occur after penetrating eye procedures, trauma, or the spread of infection from contiguous structures or via emboli from distant organs. Because of the time-critical nature of the treatment, endophthalmitis is treated with the clinical diagnosis and modified by the microbiological report of the intraocular contents. The current strategy for managing endophthalmitis relies on pre-clinical literature, case series, and one large multi-center randomized clinical trial on post-cataract surgery endophthalmitis. Culture-susceptibility of the microorganisms from undiluted vitreous guides the definitive treatment in non-responsive cases. Strategies to reduce the incidence of endophthalmitis after penetrating eye procedures have been developed concurrently with refined means of treatment. Despite these advances, outcomes remain poor for many patients. Although consensus articles have been published on managing endophthalmitis, treatment patterns vary, and controversies remain. These include (1) the use of newer methods for early and precise microbiological diagnosis; (2) the choice of intravitreal antibiotics; (3) the need for systemic therapy; (4) early and complete vitrectomy. Here, we review the current consensus and address controversies in diagnosing and managing endophthalmitis. This review is intended to familiarize physicians and ophthalmologists with different aspects of endophthalmitis management to make informed decisions.

Acute postoperative endophthalmitis: Microbiology from the laboratory to the bedside

Postoperative endophthalmitis is a dreaded complication of intraocular surgery. Acute presentations need prompt management and good knowledge of differential diagnoses. In the last 10 years, progress in direct microbial detection and identification from intraocular samples included the use of blood culture systems and, more recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, improving the rate of bacterial identification. Whatever the method used, diagnostic sensitivity is better for vitreous samples than for aqueous humor samples. Besides, molecular biology techniques have further improved the identification rate of infectious agents in intraocular samples. They also provide faster results compared to culture-based techniques. Quantitative real-time PCR (qPCR) can also determine the bacterial load in intraocular samples. Several studies have shown that intraocular bacterial loads in endophthalmitis patients are usually high, which helps differentiating infection from contamination. The prognostic value of qPCR remains to be validated. Whole genome DNA sequencing technologies facilitate direct and sequencing of single DNA molecules. They have the potential to increase the rate of microbiological identification. Some antibiotic resistance markers (e.g., methicillin resistance in staphylococci and vancomycin resistance in enterococci) may be detected earlier using molecular techniques (usually real-time PCR tests). Early determination of the involved microorganism and their antibiotic resistances can help establishing an earlier therapeutic strategy.

Epstein-Barr viral corneal stromal keratitis occurring during rheumatoid arthritis treatment: a case report

Background

A case of Epstein-Barr viral (EBV) corneal stromal keratitis during rheumatoid arthritis (RA) treatment is presented.

Case presentation

A 74-year-old female undergoing RA treatment was previously treated for bacterial corneal ulcer and herpetic keratitis and healed with antibiotic eye drops and topical anti-herpes ointment. At the first visit to our hospital, she presented with findings of monocular posterior interstitial keratitis with neovascularization mostly located in the inferior cornea with a corneal epithelial defect. The right eye showed no thinning of the corneal periphery and anterior uveitis. Her RA had subsided with oral steroid treatment, and infectious mononucleosis (IM) had not developed. EBV DNA could be detected in her corneal sample. After an extended but ineffective period to antibiotic treatment the corneal infiltrate responded rapidly to topical corticosteroids.

Conclusion

EBV can cause stromal keratitis without IM during treatment for RA.

Clinical features of uveitis in elderly patients in central Tokyo (2013-2018)

PURPOSE

To clarify the clinical features of uveitis in elderly patients in central Tokyo.

METHODS

We retrospectively identified 1424 patients with uveitis who visited the Uveitis Clinic of the University of Tokyo Hospital between January 2013 and December 2018. The patients were categorized into two groups based on their ages at the time of disease onset: patients aged 65 years or older were included in Group A, whereas those younger than 65 years were included in Group B. The etiological classification of uveitis and its causes were investigated for each group.

RESULTS

Group A presented significantly higher rates of infectious uveitis (35.5% vs. 17.8%, p < 0.0001) and masquerade syndromes (17.9% vs. 5.0%, p < 0.0001) than Group B. Furthermore, Group A had significantly higher rates of sarcoidosis (23.1% vs. 9.3%, p < 0.0001), intraocular lymphoma (16.6% vs. 4.6%, p < 0.0001), cytomegalovirus iritis (11.0% vs. 5.6%, p = 0.0043), and cytomegalovirus retinitis (5.2% vs. 1.5%, p = 0.0020) than Group B.

CONCLUSION

Our results demonstrate a clear difference in the causative diseases of uveitis between elderly and non-elderly patients. These findings may support ophthalmologists in their diagnostic process for elderly patients with uveitis.

Practical use of multiplex and broad-range PCR in ophthalmology

BACKGROUND

Polymerase chain reaction (PCR) can be used to confirm or deny infectious ocular inflammation such as uveitis. The purpose of this article is to review the current practical use of PCR examination in ophthalmology, especially multiplex and broad-range PCR, and a novel PCR, termed Strip PCR. At first, in the Introduction, we show the development of the PCR examination in ophthalmology. We next show the clinical applications of multiplex PCR and broad-range PCR. These advances in PCR continue to contribute greatly to the ophthalmology field. We also show how the sample for PCR is collected. Recently, we established a novel examination, a multiplex real-time PCR (Strip PCR) prototype for detecting 24 pathogens responsible for ocular infectious diseases. Moreover, we developed the Direct Strip PCR method, which skips the DNA extraction step in the procedure. This PCR is anticipated to ease etiologic evaluation, increasing pathogen detection in the intraocular fluids of uveitis patients even by general ophthalmologists. We also describe the following: (1) representative cases in which PCR is useful, (2) representative cases in which PCR can exclude a diagnosis, (3) the current status of PCR in the diagnosis of infectious uveitis and advanced medical service, and (4) the prospects for clinical PCR in ophthalmology.

CONCLUSION

We have established and developed the multiplex PCR, broad-range PCR, Strip PCR, and Direct Strip PCR methods and have reported the efficacy of such tests in multicenter studies. Our goal is "rapid and simple comprehensive PCR diagnosis anywhere and by anyone" for ocular infections.

Exogenous Fungal Endophthalmitis: Clues to Aspergillus Aetiology with a Pharmacological Perspective

Exogenous fungal endophthalmitis (EXFE) represents a rare complication after penetrating ocular trauma of previously unresolved keratitis or iatrogenic infections, following intraocular surgery such as cataract surgery. The usual latency period between intraocular inoculation and presentation of symptoms from fungal endophthalmitis is several weeks to months as delayed-onset endophthalmitis. Aspergillus spp., is the most common causative mould pathogen implicated in this ocular infection and early diagnosis and prompt antimicrobial treatment, concomitantly in most cases with expert surgical attention, reduce unfavorable complications and increase the possibility of eye function preservation. Topical, intravitreal and systemic antifungal molecules are the mainstay of a medical approach to the disease and azoles, polyenes and in particular cases echinocandins are the pharmacological classes most commonly used in clinical practice. This review discusses pharmacokinetics and pharmacodynamic of antifungal agents in their principal modes of administration with a focus on their ability to achieve high drug concentration in the vitreous and ocular tissues.

The cereus matter of Bacillus endophthalmitis

Bacillus cereus (B. cereus) endophthalmitis is a devastating intraocular infection primarily associated with post-traumatic injuries. The majority of these infections result in substantial vision loss, if not loss of the eye itself, within 12-48 h. Multifactorial mechanisms that lead to the innate intraocular inflammatory response during this disease include the combination of robust bacterial replication, migration of the organism throughout the eye, and toxin production by the organism. Therefore, the window of therapeutic intervention in B. cereus endophthalmitis is quite narrow compared to that of other pathogens which cause this disease. Understanding the interaction of bacterial and host factors is critical in understanding the disease and formulating more rational therapeutics for salvaging vision. In this review, we will discuss clinical and research findings related to B. cereus endophthalmitis in terms of the organism's virulence and inflammogenic potential, and strategies for improving of current therapeutic regimens for this blinding disease.

Diagnostic Performance of MALDI-TOF MS Compared to Conventional Microbiological Cultures in Patients with Suspected Endophthalmitis

Purpose: To evaluate the performance and speed of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) when identifying the pathogenic microorganism of endophthalmitis compared to conventional microbiological culturing.Methods: Forty-four patients with suspected endophthalmitis who had undergone vitrectomy were enrolled. Vitreous specimen was analyzed using either conventional culturing or MALDI-TOF MS.Results: The identification rates of the conventional microbiological culture and MALDI-TOF MS were 45.5% (20/44) and 65.9% (29/44), respectively (Kappa value 0.787, P < 0.000). The mean detection times by the standard culturing method and MALDI-TOF MS were 5.39 ± 0.56d and 3.17 ± 0.40d (P < 0.001). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MALDI-TOF MS were 70.59%, 54.17%, 80.00%, and 86.67%, respectively. Polymicrobial endophthalmitis was identified in 6.82% of the patients (3/44) using conventional microbiological culturing. However, MALDI-TOF MS failed to identify any polymicrobial infection.Conclusions: With a higher sensitivity, acceptable specificity and a shorter detection time, MALDI-TOF MS was an efficient technique for the rapid identification of a pathogenic microorganism in endophthalmitis.

Bilateral granulomatous panuveitis in two patients with T-cell type of chronic active Epstein-Barr virus infection

Background

To report 2 cases of bilateral granulomatous panuveitis accompanied by chronic active Epstein-Barr virus infection (CAEBV).

Case presentation

Case 1 was a 38-year-old man who had a history of bilateral mild panuveitis who was diagnosed with CAEBV. Fifteen months later, a severe bilateral granulomatous panuveitis developed. White infiltrates covered the optic disc and all the retinal vessels of the right eye, and white nodules were seen along the retinal veins and arteries of the left eye. Case 2 was a 34-year-old man with bilateral panuveitis showing mutton-fat keratic precipitates and diffuse vitreous opacity in both eyes. A snow ball-like vitreous opacity was present in the right eye. Systemic investigations revealed the presence of CAEBV. In both cases, a comprehensive polymerase chain reaction (PCR) analyses of the aqueous humor detected significant copy numbers of EBV-DNA. The intraocular inflammation did not respond to steroid, methotrexate, and other immunosuppressive therapies, but was ameliorated after hematopoietic stem cell transplantation with preceding chemotherapy and low-dose total body irradiation in both cases.

Conclusion

Granulomatous panuveitis can develop in eyes with CAEBV as a primary symptom. Ophthalmologists should rule out CAEBV when EBV-DNA is positive in the intraocular fluids of steroid-resistant panuveitis.

Chronic postcataract endophthalmitis caused by Penicillium species in an immunocompetent patient

Objective

Penicillium species are abundant, generally saprophytic, and widely distributed in the environment. On rare occasions, they cause endophthalmitis in immunocompromised patients or in immunocompetent patients with uncontrolled diabetic mellitus or immunosuppressive agents. We report a case of endophthalmitis caused by Penicillium species in an immunocompetent patient without any disorders.

Case presentation

A 67-year-old woman presented with ocular pain, hyperemia, and blurred vision in her right eye. She was in an immunocompetent condition and had received cataract surgery without complications 3 months ago. Severe cell infiltration and a clump of 3 mm diameter were found in the anterior chamber of the right eye, and there was no abnormality in the posterior segment. Serum β-d-glucan was not elevated; bacterial culture, histological analysis, and PCR using aqueous humor did not detect any pathogen (28S rDNA 2.4×10² copies/mL). However, because the clinical findings suggested fungal endophthalmitis, anti-fungal medication was initiated. The inflammation was gradually resolved with contraction of the clump; however, it recurred 47 days after the initiation by discontinuation of antifungal medication. Examination of culture identified Penicillium species in samples from both the anterior chamber and the vitreous.

Conclusion

Chronic postoperative endophthalmitis by Penicillium species can occur in an immunocompetent patient without any systemic diseases.

Epidemiology of uveitis (2013-2015) and changes in the patterns of uveitis (2004-2015) in the central Tokyo area: a retrospective study

Background

The distribution of uveitis varies with genetic, ethnic, geographic, environmental, and lifestyle factors. Epidemiological information about the patterns of uveitis is useful when an ophthalmologist considers the diagnosis of uveitis. Therefore, it is important to identify the causes of uveitis over the years in different regions. The purposes of this study were to characterize the uveitis patients who first arrived at the University of Tokyo Hospital in 2013–2015, and to analyze the changes in the patterns of uveitis from 2004 to 2012 to 2013–2015.

Methods

We retrospectively identified 750 newly arrived patients with uveitis who visited the Uveitis Clinic in the University of Tokyo Hospital between January 2013 and December 2015, using clinical records. We extracted data on patient age, sex, diagnosis, anatomic location of inflammation, laboratory test results of blood and urine, and chest X-ray and fluorescein fundus angiography findings for each patient. In addition, we compared these data with those from 2004 to 2012 to analyze the changes in the patterns of uveitis.

Results

A definite diagnosis was established in 445 patients (59.3%). The most common diagnoses were herpetic iridocyclitis (7.5%), sarcoidosis (6.1%), Behçet’s disease (4.4%), Vogt–Koyanagi–Harada disease (4.1%), and intraocular lymphoma (4.1%). The most frequent unclassified type of uveitis was suspected sarcoidosis (22.3%). Analysis of the changes in the patterns of uveitis in the central Tokyo area from 2004 to 2012 to 2013–2015 revealed notable increasing trends of herpetic iridocyclitis and intraocular lymphoma, and increasing trends of bacterial endophthalmitis, fungal endophthalmitis, and juvenile chronic iridocyclitis. In contrast, the frequency of sarcoidosis, Behçet’s disease, and Vogt–Koyanagi–Harada disease decreased.

Conclusions

The patterns of uveitis changed considerably from 2004 to 2012 to 2013–2015. Continuous investigations about the epidemiology of uveitis are needed to diagnose uveitis more accurately.

Assessment of diagnostic and therapeutic vitrectomy for vitreous opacity associated with uveitis with various etiologies

Vitreous opacity (VO) is a common feature of intermediate uveitis, posterior uveitis, and panuveitis. Fundus observation is critical for determining the etiology of uveitis, however, is often interfered with VO. In these clinical settings, vitrectomy contributes to a correct diagnosis and guides alternative management strategies. The purpose of this study was to evaluate the diagnostic yield and surgical outcome of vitrectomy in uveitic patients with VO and compare the visual outcome between infectious and noninfectious uveitis. Forty-five eyes with uveitis-associated VO underwent diagnostic and therapeutic vitrectomy, and etiological diagnosis of uveitis was confirmed in 34 of 45 eyes (75.6%). The diagnoses were infectious uveitis in 13 eyes (28.9%), noninfectious uveitis in 21 eyes (46.7%), and unidentified uveitis in 11 eyes (24.4%). Visual acuity (VA) improvement rates at 6 months after surgery were 69.2%, 76.2%, and 90.9% in the infectious, noninfectious, and unidentified uveitis groups, with no significant difference among 3 groups. Significant decrease in inflammation score after vitrectomy was observed only in the infectious uveitis group. This study demonstrated that diagnostic vitrectomy for inflammatory eyes with VO of unknown etiology was effective in infectious and noninfectious uveitis, and the therapeutic effect of VA improvement was observed in both types of uveitis.

Multiplex polymerase chain reaction for pathogen detection in donor/recipient corneal transplant tissue and donor storage solution

Corneal transplantation is a safe, reliable method of restoring visual acuity in patients with corneal disorders. Although it has a very high success rate, rejection can still occur, especially if the site is infected. Therefore, seeking to find better ways to manage infection risk, this study investigated a new technique, based on multiplex polymerase chain reaction (mPCR), to identify pathogens, including viruses, bacteria, and fungi, in corneal transplantation recipient sites, donor corneas and the donor cornea storage solution. The subjects comprised 50 patients who underwent corneal transplantation at Tohoku University Hospital between July 2014 and April 2015. We obtained extracted (recipient) cornea samples in 37 cases, donor cornea samples in 50 cases, and corneal storage solution samples in 50 cases (18 of these 50 samples contained DNA). Herpes simplex virus type 1 DNA was detected in four recipient corneas, Parvovirus B19 DNA was detected in two recipient corneas, Human herpes virus type 6 was detected in two donor corneas, and Aspergillus DNA was detected in one corneal storage solution sample. Thus, mPCR successfully identified pathogenic DNA in corneal tissues and storage solution, suggesting that evaluation with mPCR may improve the ability to predict the risk of infection after corneal transplantation.

Uveitis incidence in Jichi Medical University Hospital, Japan, during 2011-2015

PURPOSE

To investigate uveitis incidence of new patients who visited Jichi Medical University Hospital, Tochigi, north of Tokyo, during 2011-2015, and to compare the results with previously reported data from other facilities.

METHODS

We retrospectively analyzed clinical records of new patients with uveitis from April 2011 to March 2015 and compared the uveitis incidence with those from other hospitals.

RESULTS

A total of 502 patients were enrolled in the study; definite diagnoses were made in 262 patients (52.2%). The top 4 diseases were sarcoidosis, 47 patients (9.4%); Vogt-Koyanagi-Harada (VKH) disease, 35 patients (7.0%); herpetic iritis, 29 patients (5.8%); and Behçet's disease, 21 patients (4.2%).

CONCLUSION

The most commonly diagnosed diseases in our study were sarcoidosis, VKH disease, herpetic iritis, and Behçet's disease. Compared with the latest nationwide survey in Japan, our results showed similar trends.

Comprehensive polymerase chain reaction assay for detection of pathogenic DNA in lymphoproliferative disorders of the ocular adnexa

Infectious agents have been identified as a major cause of specific types of human cancers worldwide. Several microorganisms have been identified as potential aggravators of ocular adnexal neoplasms; however, given the rarity of these neoplasms, large epidemiological studies are difficult to coordinate. This study aimed to conduct an exhaustive search for pathogenic DNA in lymphoproliferative disorders (LPD) of the ocular adnexa in a total of 70 patients who were diagnosed with LPD of the ocular adnexa between 2008 and 2013. Specimens were screened for bacterial, viral, fungal, and parasitic DNA by multiplex polymerase chain reaction (PCR) and quantitative real-time PCR. Among cases of conjunctival mucosa-associated lymphoid tissue lymphoma, human herpes virus (HHV)-6, HHV-7, chlamydia, Epstein-Barr virus (EBV) and bacterial 16S ribosomal DNA were detected. In cases of IgG4-related ocular disease, similar pathogens were detected but in a larger number of patients. Our PCR assays detected DNAs of various infectious agents in tumor specimens, especially HHV6, HHV7, and EBV, with different positive rates in various types of LPD. Chronic inflammatory stimulation or activation of oncogenes from these infectious agents might be involved in the pathogenesis of LPD of the ocular adnexa.

The Role of Vitrectomy in the Management of Fungal Endophthalmitis

Fungal endophthalmitis is an important cause of vision loss worldwide with a large body of literature describing the treatment of the disease. The evidence supporting the use of pars plana vitrectomy in the management of fungal endophthalmitis is largely comprised of case reports and case series and demonstrates the important role of vitrectomy surgery. Vitrectomy can improve the likelihood of establishing the diagnosis, enhance the treatment of infection by removing fungal elements in the vitreous, aid in the removal of other inoculated intraocular structures, and is an important tool in the management of vision-threatening post-infectious sequelae like retinal detachment and epiretinal membrane.

A new era of uveitis: impact of polymerase chain reaction in intraocular inflammatory diseases

Uveitis is a sight-threatening intraocular inflammatory disorder which may occur from both infectious and non-infectious or autoimmune causes. The frequency of infectious uveitis and autoimmune uveitis varies depending on countries and regions. According to a nationwide survey conducted by the Japanese Ocular Inflammation Society, infectious and non-infectious uveitis accounted for 16.4 and 50.1% of new patients, respectively while the remaining 33.5% of new uveitis cases were not classified or were idiopathic uveitis. Infectious uveitis is particularly important because it causes tissue damage to the eye and may result in blindness unless treated. However, it can be treated if the pathogenic microorganisms are identified promptly and accurately. Remarkable advancements in molecular and immunological technologies have been made in the last decade, and the diagnosis of infectious uveitis has been greatly improved by the application of molecular and immunological investigations, particularly polymerase chain reaction (PCR). PCR performed on a small amount of ocular samples provides a prompt, sensitive, and specific molecular diagnosis of pathogenic microorganisms in the eye. This technology has opened a new era in the diagnosis and treatment of uveitis, enabling physicians to establish new clinical entities of uveitis caused by infectious microorganisms, identify pathogens in the eyes of many patients with uveitis, and determine prompt diagnosis and appropriate therapy. Here we review the PCR process, new PCR tests specialized for ocular diseases, microorganisms detected by the PCR tests, diseases in the eye caused by these microorganisms, and the clinical characteristics, diagnosis, and therapy of uveitis.

Outcomes of Primary Transconjunctival 23-Gauge Vitrectomy in the Diagnosis and Treatment of Presumed Endogenous Fungal Endophthalmitis

PURPOSE

To report the outcomes of primary transconjunctival 23-gauge (23-G) vitrectomy in the diagnosis and treatment of presumed endogenous fungal endophthalmitis (EFE).

METHODS

Retrospective analysis of patients with EFE who underwent diagnostic transconjunctival 23-G vitrectomy at a tertiary referral center.

RESULTS

Nineteen eyes of 15 patients with EFE were included in the study. Four patients had bilateral and 11 patients unilateral disease. Sixteen eyes of 15 patients underwent 23-G vitrectomy to confirm the diagnosis using vitreous culture, polymerase chain reaction, and histopathologic examinations. All affected eyes were treated with intravitreal amphotericin B 5 µg/0.1 mL. Fourteen patients received additional systemic antifungal therapy. Diagnostic 23-G vitrectomy confirmed the diagnosis of EFE in 75% of the eyes (12/16). Candida was found to be a causative agent in 62.5% and Aspergillus in 12.5% of the eyes. Retinal detachment was the most common complication (42% of eyes).

CONCLUSIONS

EFE can be easily confirmed using primary 23-G vitrectomy.

Emerging techniques for pathogen discovery in endophthalmitis

PURPOSE OF REVIEW

Despite the inability to detect certain organisms and relatively low yield, microbial culture is the current gold standard for the diagnosis of most intraocular infections. Research on alternative molecular diagnostic methods has produced an array of strategies that augment and improve pathogen detection. This review summarizes the most recent literature on this topic.

RECENT FINDINGS

The yield of traditional microbial culture has not improved since the Endophthalmitis Vitrectomy Study results were published 20 years ago. Advances in PCR methods have enabled quantification of pathogen load and screening for multiple organisms at once. More recently, deep sequencing techniques allow highly sensitive detection of any DNA-based life form in a specimen. This offers the promise of not only improved detection of traditional organisms but can also identify organisms not previously associated with endophthalmitis.

SUMMARY

Molecular diagnostic methods enhance the results of microbial culture and may become the new standard in the diagnosis of intraocular infections.

Endophthalmitis: state of the art

Endophthalmitis is an uncommon diagnosis but can have devastating visual outcomes. Endophthalmitis may be endogenous or exogenous. Exogenous endophthalmitis is caused by introduction of pathogens through mechanisms such as ocular surgery, open-globe trauma, and intravitreal injections. Endogenous endophthalmitis occurs as a result of hematogenous spread of bacteria or fungi into the eye. These categories of endophthalmitis have different risk factors and causative pathogens, and thus require different diagnostic, prevention, and treatment strategies. Novel diagnostic techniques such as real-time polymerase chain reaction (RT-PCR) have been reported to provide improved diagnostic results over traditional culture techniques and may have a more expanded role in the future. While the role of povidone-iodine in prophylaxis of postoperative endophthalmitis is established, there remains controversy with regard to the effectiveness of other measures, including prophylactic antibiotics. The Endophthalmitis Vitrectomy Study (EVS) has provided us with valuable treatment guidelines. However, these guidelines cannot be directly applied to all categories of endophthalmitis, highlighting the need for continued research into attaining improved treatment outcomes.

Bilateral endogenous Candida albicans subretinal abscess with suspected mixed bacterial infection

Purpose

Candida albicans subretinal abscess is extremely rare. To our knowledge, only one unilateral case has been reported. Herein, we report one bilateral case. Mixed bacterial infection was also suspected based on broad-range real-time polymerase chain reaction.

Methods

A 64-year-old man being treated with oral corticosteroids for interstitial pneumonia visited us for visual loss in the left eye. Best corrected visual acuity (BCVA) was 20/20 in the right eye and 8/200 in the left eye. Funduscopy revealed round yellowish-white subretinal lesions with retinal hemorrhage in both eyes.

Results

Broad-range polymerase chain reaction of the vitreous fluid from the left eye showed a high copy count of bacterial 16s ribosome RNA. Despite large doses of antibiotics, the abscess expanded and vision decreased to light perception in the left eye. Exenteration of the left eye was performed followed by microscopic examination showing Gram-negative bacilli, and C. albicans was also cultured. Antibiotics and the maximum doses of antifungal drugs were administered. However, the abscess in the right eye expanded, and BCVA decreased to 2/200. Vitrectomy and silicone oil tamponade were performed. Vitreous fluid culture revealed C. albicans. At 16 months follow-up, BCVA was stable at 4/200 with healing of the subretinal abscess under silicone oil.

Conclusion

Since C. albicans subretinal abscess is extremely rare and there was a concurrent mixed bacterial infection, diagnostic procedures in our bilateral case were more complicated than usual. C. albicans infection should be included in the differential diagnosis of subretinal abscesses.

Acute anterior uveitis after discontinuation of tocilizumab in a patient with rheumatoid arthritis

Background

Tocilizumab is a humanized monoclonal anti-interleukin-6 (IL-6) receptor antibody and has been approved in Japan for the treatment of Castleman’s disease, rheumatoid arthritis (RA), and systemic juvenile idiopathic arthritis. Conjunctivitis and dry eye are known ocular adverse effects, but uveitis has not been reported.

Case report

A 72-year-old woman had undergone bilateral cataract surgery without complications. Six months after the surgery, she was diagnosed with RA and treated with tocilizumab infusion every 4 weeks. However, severe malaise and dizziness occurred after the third tocilizumab infusion, and the treatment was suspended. Since the symptoms associated with RA had resolved, she was followed without any medication thereafter. At 5 weeks after the third tocilizumab infusion, she developed severe anterior inflammation with hypopyon in her left eye, and her visual acuity dropped to less than 2/200. Considering her age and history of cataract surgery, endophthalmitis was suspected and a vitrectomy was performed, but no pathogens were detected from the intraocular fluid samples collected during surgery. The ocular inflammation was gradually resolved with systemic antibiotics and corticosteroids. However, severe anterior uveitis recurred in the same eye during the tapering of the systemic corticosteroids, when the aqueous humor IL-6 level was 46,100 pg/mL. The recurrent ocular inflammation was resolved with increased doses of topical and systemic corticosteroids, and the patient has since remained relapse-free. No symptom of inflammation was observed in the right eye during the follow-up period.

Conclusion

This case indicates a possibility that acute anterior uveitis may have been an adverse effect after the discontinuation of anti-IL-6 receptor antibody therapy in a patient with RA.

Establishment and application of real-time quantitative PCR for diagnosing invasive aspergillosis via the blood in hematological patients: targeting a specific sequence of Aspergillus 28S-ITS2

BACKGROUND

Invasive aspergillosis (IA) is an important cause of morbidity and mortality in immunocompromised individuals. This study was conducted to identify a desirable target DNA sequence for the diagnosis of aspergillosis using real-time quantitative polymerase chain reaction (qPCR).

METHODS

Genomic DNA was extracted from Aspergillus, Candida, and bacteria species, and qPCR was applied to validate a partial ribosomal DNA 28S-ITS2 sequence. Ethylenediaminetetraacetic acid-anticoagulated blood samples were collected from 72 febrile hematological patients, while total DNA was isolated from plasma and whole blood for the Aspergillus qPCR. The results were analyzed using a receiver operating characteristic curve. All cases were evaluated using the revised European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) diagnostic criteria.

RESULTS

Use of qPCR yielded positive results for 15 Aspergillus species but negative results for Candida species, bacterial strains, and human DNA. The limit of detection was one copy per microliter of DNA. Analytical sensitivity and specificity were six copies of DNA and 100%, respectively. The standard curve showed that qPCR was reliable for Aspergillus detection and that significantly more DNA copies were obtained from whole blood than from plasma (P < 0.001). At a cut-off value ≥ 25 copies/μL, the diagnostic sensitivity and specificity for IA using 28S-ITS2 qPCR were 90.9% and 73.4%, respectively.

CONCLUSIONS

The use of qPCR with whole blood to detect and verify the 28S-ITS2 sequence is a specific and useful way to diagnose IA.

Use of a comprehensive polymerase chain reaction system for diagnosis of ocular infectious diseases

PURPOSE

To measure the genomic DNA of ocular infectious pathogens in ocular fluids and to analyze the clinical relevance of these pathogens in uveitis and endophthalmitis.

DESIGN

Prospective clinical case series.

PARTICIPANTS

A total of 500 patients with infectious uveitis and endophthalmitis were examined at Tokyo Medical and Dental University, Tokyo Medical University, Kyushu University, Osaka University, and Kyoto Prefectural University, all in Japan.

METHODS

Genomic DNA of bacteria, fungi, parasites, and viruses in collected intraocular samples were examined by comprehensive polymerase chain reaction (PCR). Samples were analyzed first by multiplex PCR and quantitative real-time PCR for human herpes viruses (HHVs) 1 through 8 and toxoplasma. Subsequently, samples were examined by broad-range real-time PCR for bacterial 16S and fungal 18S/28S ribosomal DNA (rDNA).

MAIN OUTCOME MEASURES

Infectious uveitis and endophthalmitis diagnoses were obtained when using the PCR system. Calculations of the positivity and the diagnostic parameters such as sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) also were evaluated.

RESULTS

In all of the tested infectious uveitis and endophthalmitis patients, either herpes simplex virus type 1 (n = 18), herpes simplex virus type 2 (n = 4), varicella-zoster virus (n = 55), Epstein-Barr virus (n = 17), cytomegalovirus (n = 68), HHV type 6 (n = 2), toxoplasma (n = 6), bacterial 16S (n = 33), or fungal 18S/28S (n = 11) genome was detected. Neither HHV type 7 nor HHV type 8 DNA was detected in any of the samples. Of the 21 false-negative results found during the PCR analyses, 12 cases were negative for patients clinically suspected of having bacterial endophthalmitis. Conversely, false-positive results for the comprehensive PCR examinations occurred in only 3 cases that subsequently were found to have bacterial 16S rDNA. Diagnostic parameters for the sensitivity, specificity, PPV, and NPV of our PCR examinations were 91.3%, 98.8%, 98.6%, and 92.4%, respectively.

CONCLUSIONS

Use of our comprehensive PCR assay to examine ocular samples in patients with endophthalmitis and uveitis seems to be clinically useful for detecting infectious antigen DNA. Thus, this PCR method is a reliable tool for both diagnosing ocular disorders and further screening of patients for intraocular infections.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Fungal polymerase chain reaction testing in equine ulcerative keratitis

OBJECTIVE

To assess the diagnostic utility of fungal polymerase chain reaction (PCR) in forty-three horses with naturally acquired corneal ulcers presenting to a private practice.

METHODS

Routine evaluation of cytologic, histologic, and microbiologic samples was performed. Two PCR approaches were compared - generic and specific fungal nested PCR followed by sequencing and quantitative PCR (qPCR). PCRs were applied to pure control fungal cultures, corneal tissue from ulcerated eyes and in a subset of 9 horses, to swabs from contralateral normal eyes.

RESULTS

The expected fungus was identified by nested PCR and qPCR in all control fungal cultures. In all fungal culture-positive affected eyes (10/43), one or more fungi were identified by nested PCR and 4/10 were positive by qPCR. In 6/10 animals, the same fungus was identified by nested PCR and culture. Of these 6, only three were positive by qPCR. Fungal agents were identified by morphology in 8/10 horses. Diagnosis of fungal keratitis was reserved for only those cases in which the same fungus could be identified by PCR, culture, and morphology (5 horses). In 33/43 culture-negative affected eyes and in 6/9 unaffected eyes, one or more fungi were identified by nested PCR in 26 samples and by qPCR in 2 samples. Apart from Aspergillus spp, similar fungi were identified in affected and control eyes. Most eyes harbored mixed bacterial and fungal agents.

CONCLUSIONS

Nested PCR results confirmed all cytologically positive cases of fungal keratitis. Nested PCR identified a greater spectrum of agents than either culture or qPCR.