Clinical features of pulmonary cryptococcosis in non-HIV patients in Japan

A ketogenic diet enhances fluconazole efficacy in murine models of systemic fungal infection

Invasive fungal infections are a significant public health concern, with mortality rates ranging from 20% to 85% despite current treatments. Therefore, we examined whether a ketogenic diet could serve as a successful treatment intervention in murine models of Cryptococcus neoformans and Candida albicans infection in combination with fluconazole-a low-cost, readily available antifungal therapy. The ketogenic diet is a high-fat, low-carbohydrate diet that promotes fatty acid oxidation as an alternative to glycolysis through the production of ketone bodies. In this series of experiments, mice fed a ketogenic diet prior to infection with C. neoformans and treated with fluconazole had a significant decrease in fungal burden in both the brain (mean 2.66 ± 0.289 log10 reduction) and lung (mean 1.72 ± 0.399 log10 reduction) compared to fluconazole treatment on a conventional diet. During C. albicans infection, kidney fungal burden of mice in the keto-fluconazole combination group was significantly decreased compared to fluconazole alone (2.37 ± 0.770 log10-reduction). Along with higher concentrations of fluconazole in the plasma and brain tissue, fluconazole efficacy was maximized at a significantly lower concentration on a keto diet compared to a conventional diet, indicating a dramatic effect on fluconazole pharmacodynamics. Our findings indicate that a ketogenic diet potentiates the effect of fluconazole at multiple body sites during both C. neoformans and C. albicans infection and could have practical and promising treatment implications.IMPORTANCEInvasive fungal infections cause over 2.5 million deaths per year around the world. Treatments for fungal infections are limited, and there is a significant need to develop strategies to enhance antifungal efficacy, combat antifungal resistance, and mitigate treatment side effects. We determined that a high-fat, low-carbohydrate ketogenic diet significantly potentiated the therapeutic effect of fluconazole, which resulted in a substantial decrease in tissue fungal burden of both C. neoformans and C. albicans in experimental animal models. We believe this work is the first of its kind to demonstrate that diet can dramatically influence the treatment of fungal infections. These results highlight a novel strategy of antifungal drug enhancement and emphasize the need for future investigation into dietary effects on antifungal drug activity.

Pulmonary cryptococcosis suspected due to inhalation of swallow excreta presenting with multiple infiltrative shadows

A 70-year-old woman had been treated with methotrexate for rheumatoid arthritis by a rheumatologist who opened a clinic near our hospital. In January of a certain year, she had respiratory symptoms of cough, sputum, and fever. Laboratory test results showed a white blood cell count of 8600/μL (neutrophil count of 5330/μL, lymphocyte count of 2490 μ/L), C-reactive protein (CRP) of 3.30 mg/dL. Chest radiography showed multiple infiltrative shadows in the right middle and lower lobes. Bronchoalveolar lavage fluid (BAL) lymphocyte count was increased (65.1%), and histopathological findings were consistent with numerous bowl-shaped cryptococcus cells stained black by Grocott staining. Added measurement of serum cryptococcal antigen titers was 4096-fold. Treatment with fluconazole 400 mg/day was initiated, and her symptoms resolved; the shadows of the lung fields improved. When asked in detail, the cryptococcus infection route was suspected from swallow excreta. There have been no reported cases of pulmonary cryptococcosis suspected due to inhalation of swallow excreta presenting with multiple infiltrative shadows.

Cryptococcosis with pulmonary cavitation in an immunocompetent child: a case report and literature review

BACKGROUND

Pulmonary cryptococcosis (PC) rarely occurs in immunocompetent children.

CASE PRESENTATION

A 13-year-old boy was admitted to the First Affiliated Hospital of Ningbo University in February 2023 with complaints of cough and chest pain. Physical examination showed slightly moist rales in the right lung. Chest computed tomography (CT) suggested a lung lesion and cavitation. Blood routine test, lymphocyte subsets, immunoglobulin, and complement tests indicated that the immune system was normal. However, the serum cryptococcal antigen test was positive. Next-generation sequencing revealed Cryptococcus infection. The child was diagnosed with PC and was discharged after treating with fluconazole 400 mg. Four months later, chest CT showed that the lung lesion diminished, and reexamination of serum cryptococcal antigen test turned positive.

CONCLUSION

PC should be considered in an immunocompetent child with pulmonary cavities with nonspecific symptoms.

Pulmonary cryptococcosis coexisting with lung adenocarcinoma: A case report and review of the literature

Pulmonary cryptococcosis (PC) is an invasive pulmonary fungal disease caused by Cryptococcus neoformans or Cryptococcus gattii. It often presents as a single nodule or mass on radiology, which is easily misdiagnosed as lung cancer or metastases. However, cases of PC coexisting with lung cancer are rare and when this scenario is encountered in clinical practice, it is easy to be misdiagnosed as metastatic lung cancer. The present study reported the case of a 65-year-old immunocompetent patient with PC coexisting with lung adenocarcinoma. Percutaneous lung biopsy was performed on the nodule in the anterior segment of the left upper lobe and the nodule in the posterior basal segment of the left lower lobe, which were diagnosed as primary adenocarcinoma and cryptococcus, respectively. Lung cancer was treated by surgery and PC was treated successfully by antifungal treatment. During the 5-year follow-up, contrast-enhanced CT showed no recurrence of either disease. This case reminds us of the possibility of dualism in the diagnosis of multiple pulmonary nodules based on CT examination, such as the coexistence of lung carcinoma and PC. In addition, early diagnosis and treatment contribute to good prognosis.

Cryptococcosis in Southern China: Insights from a Six-Year Retrospective Study in Eastern Guangdong

Objective

Cryptococcosis is a fatal infection that can affect both immunocompetent and immunocompromised patients, and it is little understood in China's various regions. This research aimed to look at the epidemiology, risk factors, and antifungal susceptibility pattern of Cryptococcus neoformans in eastern Guangdong, China.

Methods

A six-year (2016-2022) retrospective study was conducted at Meizhou People's Hospital, China. Demographical, clinical, and laboratory data of cryptococcal patients were collected from hospital records and statistically analyzed using the chi-square and ANOVA tests.

Results

Overall, 170 cryptococcal infections were recorded, of which meningitis accounted for 78 (45.88%), cryptococcemia for 50 (29.41%), and pneumonia for 42 (24.7%). The number of cases increased 8-fold during the study duration. The median age of patients was 58 years (Inter quartile range: 47-66), and the high proportion of cases was from the male population (n = 121, 71.17%). The underlying diseases were identified only in 60 (35.29%) patients, of which 26 (15.29%) were severely immunocompromised, and 26 (15.29%) others were mildly immunocompromised. A statistically significant difference was reported for chronic renal failure, and anemia (p < 0.05) persisted in cases of three infection types. A high number of non-wild type (NWT) isolates were found against amphotericin B (n=13/145, 8.96%), followed by itraconazole (n=7/136, 5.15%) and voriconazole (n=4/158, 2.53%). Only six isolates (3.79%) were multidrug-resistant, four of which were from cryptococcemia patients. Compared to meningitis and pneumonia, cryptococcemia revealed a higher percentage of NWT isolates (p < 0.05).

Conclusion

In high-risk populations, cryptococcal infections require ongoing monitoring and management.

Comparative analysis of diagnostic methods for the detection of Cryptococcus neoformans meningitis

BACKGROUND

Cryptococcosis is a devastating opportunistic infection in immunocompromised individuals, primarily in people living with HIV/AIDS. This study evaluated a protocol for the early diagnosis of meningitis due to C. neoformans, utilizing established molecular techniques from serum and CSF samples.

METHODS

The 18S and 5.8S (rDNA-ITS) sequence-specific nested PCR assays were compared with direct India ink staining and the latex agglutination test for detection of C. neoformans in serum and cerebrospinal fluid (CSF) from 49 Brazilian suspected meningitis patients. Results were validated with samples obtained from 10 patients negative for cryptococcosis and HIV, and by analysis of standard C. neoformans strains.

PRINCIPAL FINDINGS

The 5.8S DNA-ITS PCR was more sensitive (89-100%) and specific (100%) than the 18S rDNA PCR and conventional tests (India ink staining and latex agglutination) for identification of C. neoformans. While the 18S PCR exhibited a sensitivity (72%) similar to that of the latex agglutination assay in serum samples, it was superior to the latex agglutination assay when testing CSF, with a sensitivity of 84%. However, the latex agglutination was superior to the 18SrDNA PCR in specificity in CSF (92%). The 5.8S DNA-ITS PCR yielded the highest levels of accuracy (96-100%) of any test for detection (serological and mycological) of C. neoformans in both serum and CSF.

CONCLUSION

Use of the nested 5.8S PCR was superior to other techniques for the diagnosis of cryptococcosis. The possibility of using serum, a non-invasively collected material, in a targeted 5.8S PCR analysis to identify Cryptococcus spp. is recommended, especially in immunosuppressed patients. Our results indicate that nested 5.8S PCR can increase the diagnostic capability of cryptococcosis, and we suggest its use to monitor patients in the future.

Disseminated cryptococcal infection with pulmonary involvement presenting as diffuse cavitary nodules in an immunocompromised patient: a case report

BACKGROUND

Disseminated cryptococcal infection is especially prone to occur in immunosuppressed hosts. We herein report the case of an immunosuppressed girl with disseminated cryptococcal infection in whom pulmonary cryptococcosis (PC) presented as diffuse cavitary pulmonary nodules, a finding which has rarely been reported.

CASE PRESENTATION

A 16-year-old immunocompromised girl presented with fever and a non-productive cough. A chest computed tomography (CT) scan revealed diffuse pulmonary nodules with cavities. Subsequent results were consistent with disseminated cryptococcosis with Cryptococcus identified in her blood, bone marrow and cerebrospinal fluid cultures. Thus, the patient was diagnosed with disseminated cryptococcal infection with PC, cryptococcus meningitis, cryptococcus osteomyelitis and cryptococcus sepsis. After antifungal treatment, the patient demonstrated both clinical and chest radiological improvement.

CONCLUSION

The atypical clinical manifestations of a disseminated cryptococcal infection and the rare manner of chest CT findings of PC reported in our case are easy to misdiagnose. It is necessary to carry out a thorough search for a definitive diagnosis using various methods.

Mouse Model of Latent Cryptococcal Infection and Reactivation

AbstractCryptococcus neoformans is an opportunistic fungal pathogen that frequently causes fatal meningoencephalitis in patients with impaired immune responses. This fungus, an intracellularly growing microbe, evades host immunity, leading to a latent infection (latent C. neoformans infection: LCNI), and cryptococcal disease is developed by its reactivation when host immunity is suppressed. Elucidation of the pathophysiology of LCNI is difficult due to the lack of mouse models. Here we show the established methods for LCNI and reactivation.

Comparison of the clinical manifestations and chest CT findings of pulmonary cryptococcosis in immunocompetent and immunocompromised patients: a systematic review and meta-analysis

Objective

The purpose of our study was to perform a meta-analysis and systematic review to compare differences in clinical manifestations and chest computed tomography (CT) findings between immunocompetent and immunocompromised pulmonary cryptococcosis (PC) patients.

Methods

An extensive search for relevant studies was performed using the PubMed, EMBASE, Cochrane Library, and Web of Sciences databases from inception to September 30, 2021. We included studies that compared the clinical manifestations and chest CT findings between immunocompetent and immunocompromised PC patients. Study bias and quality assessment were performed using the Newcastle–Ottawa Scale (NOS).

Results

Nine studies involving 248 immunocompromised and 276 immunocompetent PC patients were included in our analysis. The NOS score of each eligible study was above 5, indicating moderate bias. The proportion of elderly patients (> = 60 years old) in the immunosuppressed group was significantly higher than that in the immunocompetent group (OR = 2.90, 95% CI (1.31–6.43), Z = 2.63, p = 0.01). Fever (OR = 7.10, 95% CI (3.84–13.12), Z = 6.25, p < 0.000) and headache (OR = 6.92, 95% CI (2.95–16.26), Z = 4.44, p < 0.000) were more common in immunosuppressed patients. According to thin-section CT findings, lesions were more frequently distributed in the upper lobe (OR = 1.90, 95% CI (1.07–3.37), Z = 2.2, p = 0.028) in immunocompromised individuals. The proportions of patients with cavity sign (OR = 5.11, 95% CI (2.96–8.83), Z = 5.86, p = 0.00), ground-glass attenuation (OR = 5.27, 95% CI (1.60–17.35), Z = 2.73, p = 0.01), and mediastinal lymph node enlargement (OR = 2.41, 95% CI (1.12–5.20), Z = 2.24, p = 0.03) were significantly higher in immunocompromised patients.

Conclusion

No significant differences in nonspecific respiratory symptoms were found between immunocompromised and immunocompetent PC patients. Nevertheless, fever and headache were more common in immunocompromised patients. Among the CT findings, cavity, ground-glass attenuation, and mediastinal lymph node enlargement were more common in immunocompromised individuals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02175-9.

Pulmonary Cryptococcosis

Pulmonary cryptococcosis describes an invasive lung mycosis caused by Cryptococcus neoformans or Cryptococcus gattii complex. It is often a high-consequence disease in both immunocompromised and immunocompetent populations, and may be misdiagnosed as pulmonary malignancy, leading to a delay in therapy. Epidemiology follows that of cryptococcal meningoencephalitis, with C. gattii infection more common in certain geographic regions. Diagnostic tools include histopathology, microscopy and culture, and the detection of cryptococcal polysaccharide antigen or Cryptococcus-derived nucleic acids. All patients with lung cryptococcosis should have a lumbar puncture and cerebral imaging to exclude central nervous system disease. Radiology is key, both as an adjunct to laboratory testing and as the initial means of detection in asymptomatic patients or those with non-specific symptoms. Pulmonary cryptococcomas (single or multiple) may also be associated with disseminated disease and/or cryptococcal meningitis, requiring prolonged treatment regimens. Optimal management for severe disease requires extended induction (amphotericin B and flucytosine) and consolidation therapy (fluconazole) with close clinical monitoring. Susceptibility testing is of value for epidemiology and in regions where relatively high minimum inhibitory concentrations to azoles (particularly fluconazole) have been noted. Novel diagnostic tools and therapeutic agents promise to improve the detection and treatment of cryptococcosis, particularly in low-income settings where the disease burden is high.

A comparison of liposomal amphotericin B alone and in combination with flucytosine in the treatment of non-HIV Cryptococcal meningitis: A nationwide observational study

BACKGROUND

Cryptococcal meningitis (CM) is an opportunistic infectious disease that occurs in immunocompromised hosts, not only in patients living with HIV, but also in patients without HIV. The evidence regarding the treatment for CM in patients without HIV is mainly found in small retrospective studies and is extremely limited.

OBJECTIVES

In the present study, we compared the efficacy of liposomal amphotericin B (L-AMB) alone and in combination with flucytosine (5-FC) for the induction treatment of CM in patients without HIV.

PATIENTS/METHODS

Data was gathered from the Japanese Diagnosis Procedure Combination database obtained from hospitals throughout Japan. The study included 517 patients without HIV but having CM who fulfilled the inclusion and exclusion criteria. We analyzed the average effect of adding 5-FC to L-AMB treatment using the survival time within 14 days of the diagnosis after adjustment of the baseline clinical characteristics with associations with both selections of the treatment and the prognosis.

RESULTS

A total of 146 and 217 CM patients received L-AMB and L-AMB with 5-FC, respectively, within 7 days of diagnosis. L-AMB with 5-FC showed better prognosis than L-AMB on day 14 (mortality 6% vs. 11%, hazard ratio, 0.5775; 95% confidence interval, 0.2748-1.213; p = 0.1, Wald test).

CONCLUSIONS

From the results of this real-world database study, we revealed that the combination therapy of 5-FC on L-AMB for induction therapy might have an advantage on the survival time of NHNT patients with CM as well as PLHIV patients with CM.

The performance of rapid on-site evaluation of touch imprints of lung tissue biopsies for the diagnosis of pulmonary cryptococcosis in patients without HIV infection

BACKGROUND AND OBJECTIVE

The diagnosis of pulmonary cryptococcosis depends on serum testing, histopathology and mycological culture; there are few studies on touch imprints of lung tissue biopsies for the diagnosis of pulmonary cryptococcosis in patients without HIV infection. The purpose of the current study was to investigate the accuracy and timeliness of on-site touch imprint cytology in the diagnosis of pulmonary cryptococcosis during CT-guided percutaneous lung biopsy.

METHODS

We retrospectively analyzed the diagnosis and treatment of 56 patients with final proof of pulmonary cryptococcosis through histopathology and culture or surgical resection from September 2015 to February 2021. Diagnostic methods and treatment and the turnaround time for diagnosis were analyzed.

RESULTS

The sensitivity of rapid on-site evaluation was 89.3%, and the sensitivity of serology, histopathology and mycological culture was 53.6%, 91.1%, 61.5%, respectively, compared with the final diagnosis. The average turnaround time to diagnose pulmonary cryptococcosis by on-site touch imprint cytology was 8.3 ± 0.9 min, which was significantly faster than serum testing, histopathology and mycological culture.

CONCLUSION

On-site touch imprint cytology showed good sensitivity and timeliness in the diagnosis of pulmonary cryptococcosis. In addition, it contributed to the triage of biopsies based on the preliminary diagnosis. On-site touch imprint cytology should be applied and promoted in the diagnosis of pulmonary cryptococcosis during biopsy.

Rapidly enlarging pulmonary mass due to immune reconstitution inflammatory syndrome (IRIS) in an immunocompetent host with pulmonary Cryptococcus neoformans

An immunocompetent man presented with Cryptococcus neoformans disease manifesting as a large pulmonary mass (cryptococcoma). Despite an initial induction course of 4 weeks of liposomal amphotericin B (LAmB), followed by 8 weeks of fluconazole, the cryptococcoma enlarged in size. Ten days into a second course of induction therapy with LAmB and flucytosine, the cryptococcoma markedly increased in size with encroachment on critical vascular structures. Due to concern for immune reconstitution inflammatory syndrome (IRIS), prednisone was added with significant decrease in the size of the mass. To our knowledge, this is the first reported case of pulmonary cryptococcal-IRIS in an immunocompetent host.

Comparison of laboratory diagnosis, clinical manifestation, and management of pulmonary cryptococcosis: Report of the clinical scenario and literature review

BACKGROUND

Pulmonary cryptococcosis is an opportunistic aggressive mycosis in immunocompromised patients, but it can be increasingly seen in immunocompetent patients. It is still challenging to make a rapid and accurate diagnosis due to the various clinical manifestations and limitations in the diagnostic tools.

METHOD

A 54-year-old man presented with intermittent productive cough and fever for 1 week. A chest X-ray demonstrated multiple consolidations in both lungs. Blood biochemistry indicated elevated immunoglobulin G levels. Including sputum cultures, polymerase chain reaction (PCR) tests for severe acute respiratory syndrome coronavirus 2, influenza A and B virus were all negative. Computed tomography of the chest showed ground-glass opacities with a nodular pattern. The serum cryptococcal antigen test was positive; however, the cerebral spinal fluid was negative. The diagnosis of pulmonary cryptococcal infection was made. An initial bronchoscopy was performed unsuccessfully and the patient received intravenous fluconazole therapy for 2 weeks. Due to poor improvement of clinical condition, he then underwent a surgical lung biopsy. The pathology revealed several encapsulated yeast cells, diffuse pulmonary interstitial fibrosis, noncaseating granulomas surrounded by T lymphocytes and multinucleated giant cells with intracellular inclusions, confirming pulmonary yeast infection associated with hypersensitivity pneumonitis. Ultimately, fungal cultures of the pathology samples revealed Cryptococcus neoformans. Subsequently antifungal therapy combined with oral steroid treatment, his general condition improved. After a total of 6 months of antifungal therapy, the patient recovered completely.

CONCLUSIONS

Applicable laboratory diagnosis can help facilitate the accurate and rapid diagnosis of pulmonary cryptococcosis. This report elected to provide an update on the topic of laboratory diagnosis, clinical manifestation, and management of pulmonary cryptococcosis.

Deficiency of lung-specific claudin-18 leads to aggravated infection with Cryptococcus deneoformans through dysregulation of the microenvironment in lungs

Cryptococcus deneoformans is an opportunistic fungal pathogen that infects the lungs via airborne transmission and frequently causes fatal meningoencephalitis. Claudins (Cldns), a family of proteins with 27 members found in mammals, form the tight junctions within epithelial cell sheets. Cldn-4 and 18 are highly expressed in airway tissues, yet the roles of these claudins in respiratory infections have not been clarified. In the present study, we analyzed the roles of Cldn-4 and lung-specific Cldn-18 (luCldn-18) in host defense against C. deneoformans infection. luCldn-18-deficient mice exhibited increased susceptibility to pulmonary infection, while Cldn-4-deficient mice had normal fungal clearance. In luCldn-18-deficient mice, production of cytokines including IFN-γ was significantly decreased compared to wild-type mice, although infiltration of inflammatory cells including CD4⁺ T cells into the alveolar space was significantly increased. In addition, luCldn-18 deficiency led to high K⁺ ion concentrations in bronchoalveolar lavage fluids and also to alveolus acidification. The fungal replication was significantly enhanced both in acidic culture conditions and in the alveolar spaces of luCldn-18-deficient mice, compared with physiological pH conditions and those of wild-type mice, respectively. These results suggest that luCldn-18 may affect the clinical course of cryptococcal infection indirectly through dysregulation of the alveolar space microenvironment.

The clinical and radiological characteristics of pulmonary cryptococcosis in immunocompetent and immunocompromised patients

Background

We characterized the clinical features, radiographic characteristics, and response to treatment of immunocompetent and immunocompromised patients with pulmonary cryptococcosis (PC).

Methods

We retrospectively reviewed the medical records and radiological profiles of patients diagnosed with PC who received surgical resection between May 2015 and November 2020 in a tertiary referral center.

Results

A total of 21 males and 18 females were included in the study. 23 patients were immunocompetent and 20 out of the 39 were asymptomatic. Immunocompetent patients were diagnosed with PC at a younger age than immunocompromised patients (48.9 vs 57.1 years, P = 0.02). Single nodule pattern was the most frequent lesion pattern (33 out of 39, 84.6%) and right upper lobe was the most common site of location (15 out of 47, 31.9%). The majority of lesions were located peripherally (38 out of 47, 80.9%) and most lesions were 1–2 cm in diameter (30 out of 47, 63.8%). Cavitation was more likely to occur in immunocompromised patients (5 out of 11, 45.5%) than in immunocompetent patients (6 out of 36, 16.7%) (P = 0.04) and there was complete resolution of PC in all patients treated with anti-fungal therapy.

Conclusions

Immunocompetent patients were diagnosed with PC at a younger age than immunocompromised patients. Single nodule pattern was the most frequent lesion pattern in PC patients. Cavitation was more likely to occur in immunocompromised patients than in immunocompetent patients.

Characteristics of pulmonary cryptococcosis in patients with rheumatoid arthritis

Background and objective

A high frequency of infections complicating rheumatoid arthritis (RA) has been reported due to the immunomodulatory effect of RA or to agents with immunosuppressive effects used in its treatment. We aimed to assess clinical and radiological characteristics of pulmonary cryptococcosis in patients with and without RA.

Methods

We retrospectively reviewed the medical records of 52 patients with pulmonary cryptococcosis and divided them into two groups, those with RA and without RA, and compared clinical characteristics and radiological findings between them.

Results

Eleven (21.2%) of the 52 patients had RA. Median follow-up periods were 51.2 (range: 1.1–258.7) months for patients with RA and 19.1 (range: 0.63–246.9) months for patients without RA. Among the patients with RA, 81.8% were women, with a mean age of 68.1 years. Female sex and respiratory comorbidities were significantly more frequent in patients with RA than in patients without RA. Frequencies of concomitant cryptococcal meningitis and respiratory failure were not different between the groups. There were no significant differences in frequency of any radiological findings, locations and number between the two groups. Among patients with RA, all but one responded well to antifungal treatment. During the antifungal treatment course, one (9.1%) patient with RA died of cryptococcosis. Despite continuing antirheumatic drugs, no patients had recurrence of pulmonary cryptococcosis during follow-up.

Conclusion

Other than some differences in background, there were no clinical, radiological or prognostic differences between the patients with and without RA with pulmonary cryptococcosis. The administration of antirheumatic therapy had no negative effect on the clinical course of antifungal treatment.

Update on Pulmonary Cryptococcosis

Pulmonary cryptococcosis is a common but underdiagnosed opportunistic fungal infection in both immunocompromised and immunocompetent patients. The causal agents include at least eight evolutionary distinct haploid lineages as well as their hybrids of the human pathogenic Cryptococcus complex. In this update, we review recent advances in epidemiology, mode of transmission, risk factors, diagnostic methods, and therapy of pulmonary cryptococcosis. Our review suggests significant challenges and opportunities for research, from bedside to benchside and back to bedside.

Isolated pulmonary cryptococcosis in a patient with Crohn's disease treated with infliximab: A case report and literature review

Tumor necrosis factor-alpha (TNF-α) inhibitors are widely used to treat various inflammatory conditions, where they have demonstrated excellent efficacy and tolerability. However, increased risk of infections is one of the most important concerns associated with these agents. Reactivation of tuberculosis and fungal infections have emerged as significant infective complications of anti-TNF-α therapy. Cryptococcus infection is an opportunistic fungal infection that can occur in patients receiving anti-TNF-α treatment. We report a rare case of isolated pulmonary cryptococcosis in a patient undergoing anti-TNF-α therapy for Crohn's disease. Our case should alert clinicians to the increased incidence and atypical presentation of pulmonary cryptococcosis in patients receiving anti-TNF-α treatment.

Examination of a Chinese-made cryptococcal glucuronoxylomannan antigen test in serum and bronchoalveolar lavage fluid for diagnosing pulmonary cryptococcosis in HIV-negative patients

BACKGROUND

We presented the performance of a Chinese-made cryptococcal glucuronoxylomannan (GXM) antigen test using serum and bronchoalveolar lavage fluid (BALF) samples in the HIV-negative Chinese population.

METHODS

Between February 2017 and January 2019, HIV-negative patients with pulmonary cryptococcosis were recruited and followed-up every three months, including completion of a chest CT examination and collection of serum and BALF samples.

RESULTS

Here, thirty-seven confirmed and ten clinically diagnosed patients were recruited. Furthermore, samples from 174 noncryptococcosis patients that may cause false positives were also collected. The sensitivity of a lateral flow assay (LFA) for detecting cryptococcal GXM antigen in serum and BALF samples from confirmed cases was 97% and 95%, respectively, and the specificity was 98.2% and 93%, respectively, and the differences in these values between the BALF and serum samples were not significant. The serum cryptococcal GXM antigen value showed a positive correlation (r: 0.581, p < 0.001) with pulmonary lesion size, while the BALF value showed no correlation (r: 0.253, p: 0.13). The positivity rate of BALF was higher than that of serum when the diameter of the pulmonary lesion was small (diameter less than 20 mm). Moreover, the serum cryptococcal GXM antigen levels showed an overall decreasing trend with the decrease in pulmonary lesion size after antifungal therapy in patient follow-up.

CONCLUSIONS

The Chinese-made cryptococcal GXM antigen test has better sensitivity and specificity for diagnosing pulmonary cryptococcosis in the HIV-negative Chinese population, and it could be used to diagnose and to monitor this disease.

Cryptococcosis complicating diabetes mellitus: a scoping review

Background:

A better understanding of the epidemiology of cryptococcal infection in HIV-negative individuals is an international research interest. Immune dysfunction in diabetes mellitus (DM) significantly increases the risk of acquiring and reactivation of infection due to Cryptococcus neoformans. Risk factors and outcomes of cryptococcosis in DM are not well documented.

Objective:

The objective of this study was to determine the clinical characteristics and outcomes of cryptococcal infections in persons living with DM.

Methods:

MEDLINE (via PubMed), EMBASE, and the Cochrane Library databases were searched in November 2020. The searches covered the period between 1980 and 2020.We included studies that reported confirmed cryptococcosis in patients with DM. Reference lists of included articles were also searched, and additional studies were included if appropriate. No language restriction was applied. Single case reports, case series and original articles were included whereas review articles were excluded.

Results:

A total of 28 studies (24 single case reports, 4 retrospectives) were included involving 47 unique patients from Asia (17 cases), North America (six cases), South America (three cases) and Africa (two cases). Men constituted 75% (n = 18) of the cases. Median age was 60.5 (range: 27–79) years. The majority of the patients had cryptococcal meningitis (68.1%, n = 32) followed by disseminated cryptococcosis (6.4%, n = 7), and others (isolated cutaneous disease one, peritonitis one, pleural one, thyroid one, adrenal one). Diagnosis was achieved through either culture and microscopy (38/47), cryptococcal antigen tests (9/47) or histopathology (9/47) singly or in a combination. All-cause mortality was 38.3% (n = 18). Among those with meningitis mortality was 36.2%.

Conclusion:

A wide spectrum of cryptococcal infections with varying severity occurs in DM. Mortality remains unacceptably high. There is a need for more studies to characterize better cryptococcal disease in DM.

Increased mortality associated with uncontrolled diabetes mellitus in patients with pulmonary cryptococcosis: a single US cohort study

Background:

Diabetes mellitus is an established risk factor for bacterial infections, but its role in cryptococcosis is unclear. The study aimed to determine whether uncontrolled diabetes (HbA1c >7%) was an independent risk factor for mortality in cryptococcosis.

Methods:

A retrospective case–control study partially matched by age and gender was performed in patients tested for Cryptococcus infection at the University of Colorado Hospital from 2000 to 2019. A multivariable logistic regression model was used to identify mortality predictors. Cox proportional hazard model was used for survival analysis.

Results:

We identified 96 cases of cryptococcosis and 125 controls. Among cases, cryptococcal meningitis (49.0%) and pneumonia (36.5%) constituted most infections. Cases with pulmonary cryptococcosis with uncontrolled diabetes had a higher mortality at 10 weeks (50% versus 7%, p = 0.006) and 1 year (66.7% versus 13.8%, p = 0.005) compared to pulmonary cases with controlled or no diabetes. Unadjusted Cox proportional hazard model found an increased rate of death for uncontrolled diabetes at 10 weeks [hazard ratio 8.4, confidence interval (CI): 1.4–50.8, p = 0.02] and 1 year (hazard ratio 7.0, CI: 1.7–28.4, p = 0.007) among pulmonary cryptococcosis cases. Multivariable analysis showed a significantly increased odds of 10 weeks [odds ratio (OR) = 4.3, CI: 1.1–16.5, p = 0.035] and 1 year (OR = 5.0, CI: 1.4–18.3, p = 0.014) mortality for uncontrolled diabetes among pulmonary cryptococcosis cases. After adjustment for gender, age, and case/control, for every 1% increase in HbA1c levels, the odds of pulmonary cryptococcosis mortality at 1 year increased by 11% (OR = 1.6, CI 95%: 1.1–2.3, p = 0.006).

Conclusion:

Uncontrolled diabetes is associated with worse outcomes in pulmonary cryptococcosis, including a 4-fold and 6-fold increased odds of death at 10 weeks and 1 year, respectively. Glucose control interventions should be explored to improve clinical outcomes in patients with pulmonary cryptococcosis.

A case-control study of human immunodeficiency virus-negative patients with cryptococcemia and cryptococcal meningitis in a Chinese tertiary care hospital during 10 years

OBJECTIVE

This study aimed to characterize patients with cryptococcemia and compare the clinical features of cryptococcemia and cryptococcal meningitis.

METHODS

This was a retrospective, case-control study. We retrospectively identified blood cultures with Cryptococcus spp. growth. Controls were hospitalized patients who suffered from cryptococcal meningitis, but did not experience cryptococcemia. Controls and cases were matched by admission date, age, sex, and body weight. Clinical information was analyzed by two independent reviewers.

RESULTS

Eight patients with cryptococcemia and eight patients with cryptococcal meningitis were included. They were all negative for human immunodeficiency virus. The most common underlying disease was primary nephrotic syndrome. All patients presented with fever. The incidence of headache, nausea/vomiting, seizures, and cough/expectoration was significantly lower in patients with cryptococcemia than in those with cryptococcal meningitis. All clinical strains of Cryptococcus, except for one, were sensitive to fluconazole, voriconazole, itraconazole, amphotericin B, and flucytosine in vitro. The rate of receiving an amphotericin B-containing regimen was significantly higher in patients with cryptococcal meningitis than in those with cryptococcemia. In-hospital mortality was significantly higher in cryptococcemia cases compared with cryptococcal meningitis cases.

CONCLUSION

Cryptococcemia is an unusual infection characterized by a high mortality. Cryptococcemia requires early identification and prompt antifungal therapy.

Vaccines and Protective Immune Memory against Cryptococcosis

Cryptococcosis is a potentially lethal disease caused by fungal pathogens including Cryptococcus neoformans and Cryptococcus gattii species complex. These fungal pathogens live in the environment and are associated with certain tree species and bird droppings. This infectious disease is not contagious, and healthy individuals may contract cryptococcal infections by inhaling the airborne pathogens from the environment. Although cleaning a contaminated environment is a feasible approach to control environmental fungal pathogens, prophylactic immunization is also considered a promising method to regulate cryptococcal infections. We review the history of the development of cryptococcal vaccines, vaccine components, and the various forms of immune memory induced by cryptococcal vaccines.

An Elderly Patient with Pulmonary Cryptococcosis with Mediastinal Lymphadenopathy Who Was Successfully Treated with Amphotericin B and Flucytosine

Pulmonary cryptococcosis develops not only in immunocompromised patients but also in immunocompetent patients. However, lymph node involvement is relatively rare in immunocompetent patients. We herein report the case of an 80-year-old man who was not in an apparent immunocompromised state but was diagnosed with pulmonary cryptococcosis with mediastinal lymphadenopathy. The patient was resistant to fluconazole and voriconazole monotherapy; thus, his lung lesions significantly worsened. He eventually responded well to a combination therapy of amphotericin B and flucytosine, which was administered according to the treatment strategy for disseminated diseases.

A case of an AIDS patient with Cryptococcus neoformans infection

Cryptococcosis is the most common fungal disease in HIV-infected persons. It is known as the AIDS-defining illness for 60-70% of HIV-infected patients. Before antiretroviral therapy (ARV) was discovered, fungal and other opportunistic infections were a major problem for people with advanced HIV/AIDS. Presented here is a case of a 43-year-old man who was newly diagnosed HIV, in which he was admitted due to shortness of breath and decreased consciousness. His clinical symptoms, physical examination, laboratory and radiologic findings indicated a Cryptococcus neoformans infection. The patient had received treatment using anti-fungal and ARV that showed a clinical improvement during observation.

Pulmonary Cryptococcosis in a Human Immunodeficiency Virus Negative Patient: A Case Report

Cryptococcosis is a major life-threatening fungal infection in patients with severe HIV infection and other immunocompromised states. Lung and central nervous system (CNS) are the most commonly involved organs in disseminated cryptococcosis. Others include skin, prostate, medullary cavity of bones, eyes, heart, liver, etc. Pulmonary cryptococcosis may be misdiagnosed because of comparatively nonspecific clinical and radiological features. We report the case of a 61-year-old male patient who is a known case of gastroesophageal reflux disease (GERD), myasthenia gravis, and steroid-induced diabetes mellitus. He was diagnosed with gangrenous cholecystitis at another institution but refused surgery. At our hospital, he experienced loss of consciousness in the out-patient department (OPD) and was therefore admitted for further evaluation where he was found to have pulmonary cryptococcosis and pancytopenia. Pulmonary cryptococcosis is usually found in HIV-positive immunosuppressed patients. However, sometimes it is also seen in HIV-negative patients, and they tend to have a good prognosis with adequate treatment.

Pleural effusion in an immunocompetent host with cryptococcal pneumonia: A case report

BACKGROUND

Pulmonary cryptococcosis is an opportunistic infection that mainly occurs among immunocompromised patients although it can sometimes occur in immunocompetent individuals. However, the imaging findings of pulmonary cryptococcosis in immunocompetent hosts differ from those in immunosuppressed patients. In addition, the most common imaging findings of isolated pulmonary cryptococcosis are single or multiple nodules. Cavities and the halo sign are, however, prevalent in immunosuppressed patients. In immunocompetent patients, lung consolidation, pleural effusion or cavities are scarce.

CASE SUMMARY

A 29-year-old Asian male was admitted to our hospital with complaints of cough and fever that had persisted for a month. As a chest computed tomography scan showed consolidation in his left lower lobe, he was initially diagnosed with pneumonia and received antibiotic treatment. A second review of the chest computed tomography image revealed multiple cavities and pleural effusion. Flexible fiberoptic bronchoscopy was subsequently performed, bronchoalveolar lavage fluid and serum cryptococcal antigen tests were positive. Cryptococcus capsules were observed in bronchoalveolar lavage fluid ink stain. Histopathological examination of a percutaneous lung biopsy from the left lower lobe further revealed granulomatous inflammation, and periodic acid-Schiff staining showed red-colored yeast walls, signifying pulmonary cryptococcosis. The patient was then treated with a daily dose of fluconazole (0.4 g), but the cough and fever still persisted. We therefore changed treatment to voriconazole (0.2 g, twice a day), and the patient’s clinical outcome was satisfactory.

CONCLUSION

Although rare, clinicians should not disregard the possibility of cavities and pleural effusion occurring in immunocompetent hosts without underlying diseases.

Intra-cavitary pulmonary cryptococcoma in poorly controlled diabetes mellitus

A 59-year-old HIV-negative Ugandan man presented with a long-standing history of respiratory symptoms and was found to have an intra-cavitary pulmonary cryptococoma by chest imaging and sputum culture. The serum cryptococcal antigen was negative. The sputum Xpert® MTB RIF Ultra assay was negative. He was previously treated for cavitary pulmonary tuberculosis. The patient had poorly controlled diabetes (HbA1c, 9.3%). The patient was successfully treated with oral fluconazole.

Pulmonary Cryptococcosis: comparison of Cryptococcal antigen detection and radiography in Immunocompetent and Immunocompromised patients

Background

We compared the cryptococcal antigen detection and imaging findings between immunocompetent and immunocompromised patients in whom pulmonary cryptococcosis had been diagnosed. The aim of our study was to determine whether the patient’s immune status and radiography affect the detection of cryptococcal antigen.

Methods

According to whether they took immunosuppressive drugs or not, seventy and eight adult patients with pulmonary cryptococcosis were divided into two groups: the immunocompetent group and the immunocompromised group. According to the detection of CrAg, each group was divided into the CrAg+ group and the CrAg- group. Then, clinical records, laboratory examinations and computed tomography findings were collected and analyzed.

Results

No difference was found in baseline characteristics, clinical symptoms, and laboratory investigations. By comparing CrAg detection in these two groups, it was found that the number of CrAg+ cases in the immunocompetent group was more than that in the immunocompromised group. And in the immunocompetent group, diffuse lesions were more common in CrAg+ group and limited lesions were more frequently observed in CrAg- group.

Conclusions

The patient’s immune status and radiography would affect the detection of cryptococcal antigen. And serum CrAg could be a useful tool for the diagnosis of pulmonary cryptococcosis in immunocompetent patients with extensive lung involvement.

Neutrophil-mediated antifungal activity against highly virulent Cryptococcus gattii strain R265

Vaccine-induced immune responses, including neutrophil, macrophage, and T-cell responses, ameliorate cryptococcosis caused by Cryptococcus gattii. However, whether neutrophils can exert fungicidal activity against C. gattii remains to be elucidated. Therefore, in this study, we investigated the neutrophil-mediated fungicidal effect against C. gattii R265 in vitro and compared it to the related fungal pathogen, Cryptococcus neoformans standard strain H99. We found that neutrophils recognized, phagocytosed, and killed C. gattii R265 in the presence of fresh mouse serum. This antifungal effect required phagocytosis and serine protease activity but not nicotinamide adenine dinucleotide phosphate oxidase activity. We also demonstrated that C. gattii R265 was more resistant to oxidative and nitrosative stress than C. neoformans H99. Together, these findings indicate that neutrophils can exert fungicidal activity against highly virulent C. gattii, at least under in vitro conditions.

Concomitant lung adenocarcinoma and pulmonary cryptococcosis confirmed by pathologic examinations

To describe the characteristics of concomitant lung cancer and pulmonary cryptococcosis (PC) cases.A total of 8 patients with lung cancer and coexisting PC, who were admitted to Fuzhou Pulmonary Hospital of Fujian from 1st January 2009 to 31st December 2015 and whose diagnoses were confirmed by pathological examinations, were studied.One patient had a history of diabetes mellitus and 1 had a history of treated with surgery. The lesions in 7 cases manifested as nodular shadows; only 1 case showed the lesion of the 2 diseases mergedmixed together, and it manifested as a large flake-like infiltrated shadow in the same lobe. The histological type in all of the patients was lung adenocarcinoma. Lung cancer stage was advanced (III-IV) in 25.0% of the cases. The 5 patients who received surgery and drug treatment are presently healthy following resection. Recurrence and metastasis of lung cancer following surgery occurred in 2 patients in whom the tumor was controlled again after anti-tumor treatment. One patient with advanced lung cancer and PC was treated with antifungal therapy in combination with antineoplastic chemotherapy, but she failed to improve and died 10 months after symptom onset during the follow-up period.PC coexisting with pulmonary carcinoma is rare. PC can manifest as pulmonary nodules and mimic malignant lesions, so it must be considered during a differential diagnosis of pulmonary nodules, especially in immunosuppressed patients.

Pulmonary cryptococcosis: A review of pathobiology and clinical aspects

Pulmonary cryptococcosis is an important opportunistic invasive mycosis in immunocompromised patients, but it is also increasingly seen in immunocompetent patients. The main human pathogens are Cryptococcus neoformans and C. gattii, which have a worldwide distribution. In contrast to cryptococcal meningitis, pulmonary cryptococcosis is still underdiagnosed because of limitations in diagnostic tools. It can mimic lung cancer, pulmonary tuberculosis, bacterial pneumonia, and other pulmonary mycoses both clinically and radiologically. Pulmonary nodules are the most common radiological feature, but these are not specific to pulmonary cryptococcosis. The sensitivity of culture of respiratory samples for Cryptococcus is poor and a positive result may also reflect colonisation. Cryptococcal antigen (CrAg) with lateral flow device is a fast and sensitive test and widely used on serum and cerebrospinal fluid, but sera from patients with pulmonary cryptococcosis are rarely positive in the absence of disseminated disease. Detection of CrAg from respiratory specimens might assist the diagnosis of pulmonary cryptococcosis but there are very few data. Molecular detection techniques such as multiplex reverse transcription polymerase chain reaction (RT-PCR) could also provide better sensitivity but these still require validation for respiratory specimens. The first line of treatment for pulmonary cryptococcosis is fluconazole, or amphotericin B and flucytosine for those with central nervous system involvement. Pulmonary cryptococcosis worsens the prognosis of cryptococcal meningitis. In this review, we summarize the biological aspects of Cryptococcus and provide an update on the diagnosis and management of pulmonary cryptococcosis.

Pulmonary cryptococcosis characteristics in immunocompetent patients-A 20-year clinical retrospective analysis in China

Background

Pulmonary cryptococcosis (PC) is not considered an rare, opportunistic infection anymore. The immunocompetent population accounts for an increasing proportion of the morbidity.

Objective

This study investigated the clinical characteristics of PC patients spanning 20 years, in a referral centre of China.

Patients/Methods

We retrospectively investigated the clinical data of 99 patients with PC who were diagnosed at Peking Union Medical College Hospital (PUMCH) from January 1998 to December 2017.

Results

Pulmonary cryptococcosis incidence in PUMCH has seen sharp increase in two decades. There were 40.4% (40/99), 17.2% (17/99) and 42.4% (42/99) immunocompetent, mildly immunocompromised and severe immunocompromised patients, respectively. Significantly higher (P = .035) male predominance in immunocompetent and mildly immunocompromised groups (68.4%, 39/57) compared with severe immunocompromised group (45.2%, 19/42) was found. Overall, 27.5% (11/40) immunocompetent patients reported a significant difference (P = .02) in history of more than weekly drinking, higher than mildly or severe immunocompromised. No significant difference occurred in symptoms and radiographic characteristics among the groups. In pulmonary computerised tomography findings, the non‐air pathway feature was the dominant distribution characteristics in all patients with PC (P = .002). The gap in body dissemination frequency between immunocompetent combined with mildly immunocompromised (5.26%, 3/57) and severe immunocompromised (19.0%, 8/42) was marginally significant (P = .05).

Conclusions

Gender and alcohol drinking could be PC risk factors of concern in patients without severe immunodeficiency. No significant difference occurred in symptoms or radiographic characteristics between patients with different levels of immune status. The unique radiographic non‐air pathway distribution in the lung may be the feature of Cryptococcus invasion that may enhance accurate diagnosis.

Concomitant severe influenza and cryptococcal infections: A case report and literature review

Concomitant influenza and cryptococcal infections are rare. Herein, we describe an unusual case of an avian influenza A (H7N9) infection with several severe mixed bacterial infections and systemic super-infection with Cryptococcus neoformans presenting as ventilator-associated pneumonia (VAP) and bloodstream infection in a previously immunocompetent man during hospitalization.A 58-year-old man was admitted to our hospital complaining of hyperpyrexia, dyspnoea, cough, and phlegm with blood. A chest computed tomography scan revealed multiple ground-glass opacities and consolidation in both lungs with right pleural effusion. An initial sputum test was positive for influenza A (H7N9) virus. After antiviral treatment and other supportive measures, the patient's condition improved. However, the patient's condition deteriorated again approximately 2 weeks after admission, and bronchoalveolar lavage fluid (BALF) and blood cultures were positive for C. neoformans. Therapy with intravenous liposomal amphotericin B and fluconazole was started. After a 2-week antifungal treatment, BALF and blood cultures were negative for C. neoformans. However, the patient had persistent lung infiltrates with severe pulmonary fibrosis with a prolonged course of disease. On hospital day 40, BALF and blood cultures were both positive for multidrug-resistant Stenotrophomonas maltophilia. Finally, the patient developed septic shock, disseminated intravascular coagulation and multi-organ failure and succumbed to treatment failure.Cryptococcal infection can occur in patients with severe influenza during hospitalization with a more severe condition, and the clinician should be aware of this infection.

Solubilized melanin suppresses macrophage function

Melanin‐producing Cryptococcus and Aspergillus are highly invasive and can suppress or escape the immune system of the host. Since non‐melanin‐producing strains do not affect the immune system, melanin may play a role in immune system suppression. Artificial melanin synthesized using conventional methods is insoluble, making structural and functional analysis of this chemical difficult. In this study, we describe a melanin solubilization method based on polymerization of homogentisic acid (solubilizing component) and an equivalent amount of L‐DOPA in the presence of laccase. In addition, we investigated the effect of melanin on the immune system. Homogentisic acid and L‐DOPA mixed melanin (HALD), the synthetic solubilized melanin, did not exert a cytotoxic effect on mouse macrophages. HALD suppressed cytokine and reactive oxygen species production by macrophages when they were stimulated by fungal components. HALD also suppressed the phagocytosis of fungal components by macrophages. These results suggest that HALD can suppress the function of macrophages without causing cytotoxicity.

Extent of Lung Involvement and Serum Cryptococcal Antigen Test in Non-Human Immunodeficiency Virus Adult Patients with Pulmonary Cryptococcosis

Background:

Serum cryptococcal antigen (CrAg) test is the most used noninvasive method to detect cryptococcal infection. However, false-negative CrAg test is not uncommon in clinical practice. Then, the aim of this study was to investigate the factors associated with false-negative CrAg test among non-human immunodeficiency virus (HIV) adult patients with pulmonary cryptococcosis and its clinical features.

Methods:

One hundred and fourteen non-HIV adult patients with pulmonary cryptococcosis, proven by biopsy, were retrospectively reviewed. Finally, 85 patients were enrolled; 56 were CrAg positive (CrAg+ group) and 29 were negative (CrAg− group). It was a cross-sectional study. Then, baseline characteristics, underlying diseases, clinical symptoms, laboratory findings, and chest radiological findings were reviewed and analyzed. Chi-square test was used to analyze categorical variable. Odds ratio (OR) was used to measure correlation. Student's t-test was obtained to analyze continuous variable.

Results:

No difference in baseline characteristics, underlying diseases, clinical symptoms, and laboratory findings were found between two groups (P > 0.05 in all). Nevertheless, diffuse extent lesion was 82.1% in CrAg+ group and 10.3% in CrAg− group (χ²= 40.34, P < 0.001; OR = 39.87).

Conclusions:

Among patients with limited pulmonary involvement, a negative serum CrAg does not preclude the diagnosis of pulmonary cryptococcosis. However, among patients with extensive pulmonary involvement, serum CrAg is a useful diagnostic tool for pulmonary cryptococcosis. Furthermore, we also noticed that the untypical and mild presentations with extensive pulmonary lesion might be the features of pulmonary cryptococcosis, which needs further investigation.

A unique case report of endobronchial cryptococcosis and review of the literature

Cryptococcosis is an infection caused by the yeast-like fungus Cryptococcus neoformans. Pulmonary cryptococcosis is typically identified as a single mass or as multiple nodules, while endobronchial lesions are quite rare. Here we report an uncommon case of pulmonary cryptococcosis presenting as endobronchial lesion in an immunocompetent patient. A 49-year-old male patient complained of intermittent cough with hemoptysis for two years. Computerized tomography of the chest showed a filling defect in the basal segment of the right lower lobe bronchus. A flexible bronchoscopic examination revealed a white smooth-surfaced polypoid lesion completely occluding the medial basal segment of the right lower lobe bronchus. The diagnosis was confirmed by bronchial biopsy under bronchoscopy, and the histopathologic findings showed the organisms were Cryptococcal neoformans. The patient was treated with fluconazole at a dose of 400 mg daily. The endobronchial lesion was found rapidly diminished after 18 days of therapy, and disappeared after 6.5 months of therapy by repeated fiberoptic bronchoscopy. Then the patient continued fluconazole for another 2.5 months. During the total 16 months' follow-up visits, the patient repeated CT scanning for five times, the results of which were all normal. The patient's symptoms disappeared as well, and now he is still under follow-up. This case highlights the fact that pulmonary cryptococcosis can present as endobronchial lesions even in immunocompetent subjects, mimicking lung tumor. Pathological confirmation is important to establish the definite diagnosis.

Radiological characteristics of pulmonary cryptococcosis in HIV-infected patients

Background

Current understanding of human immunodeficiency virus (HIV)-associated pulmonary cryptococcosis (PC) is largely based on studies performed about 2 decades ago which reported that the most common findings on chest radiograph were diffuse interstitial infiltrates. Few studies are available regarding the computed tomography (CT) findings. The aim of this study was to characterize chest CT features of HIV-associated PC.

Methods

HIV patients with cryptococccal infection and pulmonary abnormalities on Chest CT between September 2010 and May 2016 in the Second Affiliated Hospital of the Southeast University were retrospectively analyzed. Confirmed cases of tumors, mycobacterial infections and other fungal infections were excluded from the analysis.

Results

60 cases were identified. The median CD4 T-cell counts were 20 cells/μL (range, 0–205 cells/μL). Chest CT scans demonstrated nodular lesions in 93.3% of the studied patients. Those nodular lesions were usually cavitated and solitary nodule was the most common form. Pleural effusions and pneumonic infiltrates occurred in 11.6% and 31.7% of the cases respectively. Those lesions were usually had co-existing nodular lesions. Etiological analysis suggested that 76.8% of the nodular lesions could have a relationship with PC that 12.5% of the nodular lesions were “laboratory-confirmed” cases, 48.2% were “clinically confirmed” cases and 16.1% were “clinically probable” cases. 85.7% of the pleural effusions could be “clinically confirmed” cases of PC. At least, 38.5% of the diffuse pneumonic infiltrates may be clinically attributed to pneumocystis pneumonia.

Conclusions

This study suggested that pulmonary nodules but not diffuse pneumonia are the most common radiological characteristics of HIV-associated PC. HIV-infected patients with pulmonary nodules on Chest CT should particularly be screened for cryptococcal infection.

Cryptococcosis in Patients with Nephrotic Syndrome: A Pooled Analysis of Cases

Cryptococcosis is an infection that may be lethal in patients with nephrotic syndrome (NS). However, there is relatively limited epidemiological and clinical data about cryptococcosis in NS patients. We performed a pooled analysis to systemically summarize the epidemiology, risk factors, clinical and laboratory characteristics, treatments and outcomes of cryptococcosis in NS patients. Using data pooled from our hospital and studies identified via searches of three literature databases, 17 cases were identified for inclusion in this analysis. The prevalence of cryptococcosis in NS was 0.3%, with a higher rate in more recent years. Most patients were Asian (94%) and from upper-middle to high-income countries (76%). The median time interval from NS diagnosis to cryptococcosis diagnosis among the cryptococcosis patients was 16 months, and 46% of the identified cryptococcal infections were diagnosed within the first year of NS diagnosis. Cutaneous cryptococcosis was frequently diagnosed among the included patients (35%), 58% received an erroneous diagnosis and inappropriate treatment, 90% of whom had a cryptococcal infection mistaken for a bacterial infection. The mortality rate was 35%. Standard therapeutic strategies should be emphasized for both antifungal treatment and renal disease control. Further studies conducted in various medical centers are warranted to confirm our conclusions.

Disseminated Cryptococcosis with Rapidly Growing Lung Nodules in an End-stage Renal Disease Patient

A 73-year-old man with type 2 diabetes mellitus and end-stage renal disease was diagnosed with acute myocardial infarction. He required continuous dialysis after percutaneous coronary intervention. Subsequently, multiple nodules were discovered in both lungs for the first time, and Cryptococcus neoformans was isolated from the patient's sputum, blood, bilateral pleural fluid, and cerebrospinal fluid cultures, resulting in a diagnosis of disseminated cryptococcosis. This case represents an invaluable example of disseminated cryptococcosis with rapidly growing lung nodules in a dialysis patient, and illustrates that dialysis causes innate immune disorder and the reactivation of cryptococcosis.

[Mechanism of Cryptococcus Meningoencephalitis]

Cryptococcus neoformans and Cryptococcus gattii are fungal pathogens that cause diseases in humans. Cryptococcal species mainly enter the body by inhalation and in most cases are eliminated by host defense mechanisms. Some cases, however, progress to pneumonia and subsequent dissemination of the infection to the central nervous system (CNS), leading to meningoencephalitis. Cryptococcus can cross the blood-brain barrier transcellularly, paracellularly and through infected phagocytes (the Trojan horse mechanism). The reason for the tropism of Cryptococcus to the CNS could be partially explained by the abundance of inositol in the brain, which causes the hyaluronic acid in fungal cells to bind to host CD44 receptors. There are differences in the clinical characteristics of C. neoformans and C. gattii. HIV infection is the most common risk factor for cryptococcosis due to C. neoformans, whereas C. gattii infection with CNS involvement is frequently found in otherwise healthy individuals exposed to plant propagules found in tropical and subtropical regions. As the virulence traits of C. neoformans contributing to CNS disease, high macrophage uptake and laccase activity are associated with the fungal burden and the rate of clearance of the infection from the brain. Recent reports suggested that the C. gattii VGII strain suppresses host immune responses in the lung and causes more lung infections than CNS diseases. Furthermore, the anti-GM-CSF autoantibodies are a risk factor for CNS infection by the C. gattii VGI strain. To understand the mechanism by which Cryptococcus causes CNS disease, it is important to consider the specific characteristics of the species and the molecular types.

Relapsed Pulmonary Cryptococcosis during Tumor Necrosis Factor α Inhibitor Treatment

A 35-year-old non-HIV patient developed pulmonary cryptococcosis after the initiation of infliximab. He recovered by fluconazole treatment and completed the therapy for a total of 6 months. However, he experienced a relapse 16 months later during retreatment with infliximab, revealing an interesting clinical course contradicting retreatment. This case also represents the first case of relapsed pulmonary cryptococcosis suspected during treatment with a biologic agent. Both of these aspects generated important clinical questions about the length of pulmonary cryptococcosis treatment and the necessity of introducing a second prophylaxis for such patients.

A case of multiple pleural cryptococcosis without pleural effusion

Pulmonary cryptococcosis is most likely to occur in immunocompromised patients. The radiological manifestations generally include pulmonary parenchymal lesions, namely, pulmonary nodules, cavitary lesions, and consolidation; thus, multiple pleural nodules are unusual presentation. Here, we report a woman who presented with multiple pleural cryptococcosis without pleural effusion. The patient had previously undergone surgery for stage II rectal cancer. In addition, she received 6 cycles of chemotherapy for follicular lymphoma. Computed tomography (CT) revealed multiple small nodules involving the pleura without pleural effusion, which suggested possible recurrence of rectal cancer or malignant lymphoma as pleural dissemination. Thoracoscopic examination was performed, and pleural cryptococcosis was diagnosed. Although pleural cryptococcosis without pleural effusion is extremely rare presentation, clinicians should consider it when an immunocompromised patient presents with multiple pleural nodules. Thoracoscopic exploration should be the best procedure for the definitive diagnosis of multiple pleural nodules.