Infectious complications following T-cell depleted hematopoietic stem-cell transplantation

BACKGROUND

Although sepsis is a common complication during stem-cell transplantation, the prevalence of infections after hematopoietic recovery is less well known.

METHODS

We undertook a retrospective analysis of infectious episodes in patients who underwent allogeneic BM (n = 77) or PBSC (n = 29) grafting from HLA identical siblings. T-cell depletion of the stem-cell grafts with anti CD 52 (CAMPATH-1) Abs was employed for the prevention of GvHD.

RESULTS

Patients' median age was 30 (4-54) years. Antibiotic prophylaxis was with oral amphotericin, ofloxacin and i.v. or oral acyclovir. Fever was treated empirically with a third generation cephalosporin and aminoglucosides until results of microbiological cultures became available. Six patients died of graft failure. GvHD was observed in 18% but in no case was it > Grade II. Only seven patients did not develop pyrexia during the initial admission or within 60 days following graft infusion. Median duration of pyrexia was 10 (range 2-49) days. A microbial source was detected in 42% and it was Gram (+) in 86%, Gram (-) in 11% and fungal in 3%. In 16 patients, indwelling venous catheters were removed due to severe infection. Subsequent to the recovery of the blood parameters, the most prevalent infection was by herpes varicella/zoster in 20; another 17 developed herpes simplex. In total 40/102 were re-hospitalized for pyrexia, which in four cases was of unknown origin. Bacterial infections with Staphylococcus Aureus and S. Epidermitis were seen in 10 and seven patients respectively. CMV was detected in seven patients. Thirteen patients died of sepsis and in 10, it was related to GvHD or graft failure. Another 20 died following recurrence of the malignancy. Overall, 39 patients died and 63% survived at a median DFS of 1992 (range 623-5092) days.

DISCUSSION

We conclude that during the initial neutropenic period the dominant infections are by Gram (+) organisms, often associated with indwelling catheters. Once the BM has recovered, the main morbidity is by viral infections, but Gram+ organisms still remain common bacterial pathogens.

Immunohistochemical study of subcutaneous phaeohyphomycoses

Immunohistochemical study of inflammatory infiltrate was carried out in five cases of subcutaneous phaeohyphomycosis before and after therapy. The infections were due to the genus Alternaria in four cases and genus Cladosporium in one. In four cases, infiltrating T cells with helper memory phenotype were slightly more abundant after therapy (70-80% versus 75-90% of T lymphocytes) and those with suppressor cytotoxic phenotype were slightly less abundant (20-25% versus 10-15%). In one case, CD8+, Tia-1+ lymphocytes constituted 50% of the T-cell infiltrate before and after therapy. In all cases, the infiltrate contained many CD79 a+ plasma cells, which increased slightly after therapy, and a high CD1a positivity of dendritic cells (presumably Langerhans cells) before and after therapy. The CD1a+ cells were detected in the epidermis and in granulomatous infiltrate; in the dermis and subcutis, many were close to fungal structures. In four cases, intra-epidermal CD1a+ cell number was slightly lower than in control skin. CD68+ cells were not found in the epidermis.

Natural history of allergic fungal rhinosinusitis: a 4- to 10-year follow-up

BACKGROUND

Numerous studies have noted the high rate of recidivism after the initial treatment of allergic fungal rhinosinusitis (AFS). Short-term studies have revealed varying recurrence rates based on therapy; however, little is currently known about the long-term natural history of the disease.

OBJECTIVE

Our goal was to address the question of long-term outcomes in AFS patients and make observations about the natural history of the disease.

PATIENTS AND METHODS

Seventeen patients with follow-up ranging from 46 to 138 months were examined and interviewed, and their charts were reviewed. A quality-of-life survey was completed, and blood was drawn to measure immunoglobulin levels.

RESULTS

All patients initially underwent treatment with a combination of surgery, systemic and/or topical corticosteroids, and immunotherapy to pertinent fungal and nonfungal antigens. Normalization of sinonasal mucosa (Kupferberg stage 0) was seen in 5 (29%) of 17 patients, whereas 76% demonstrated either normal or slight mucosal edema (Kupferberg stage 0 or 1). Serologic testing revealed fungus-specific IgE significantly elevated in all 17 patients.

CONCLUSION

The initial choice of therapy did not appear to affect the long-term outcome, and patients tended to be doing well overall. These results suggest that after successful initial treatment and control of AFS, many patients can achieve a quiescent disease state.

Clinicopathological and mycological spectrum of allergic fungal sinusitis in South India

In the present study, we describe characteristic clinicopathological and radiological features as well as fungal culture results in a series of 24 patients with allergic fungal sinusitis (AFS). Nasal obstruction and discharge with nasal polyposis was the commonest (95.8%) clinical presentation. Allergic mucin was uniformly present in all patients. Aspergillus species were the commonest fungal isolates (95.8%). One case of mixed Aspergillus and Curvularia sinusitis as well as one case of Drechslera sinusitis were also identified. Typical computerized tomography scan features of hyperdense areas interspersed with soft tissue densities in the affected sinuses were seen in all patients. Application of appropriate diagnostic criteria is essential to establish the diagnosis of AFS and distinguish it from invasive fungal sinus infections.

Cutaneous infection by Fusarium species in healthy and immunocompromised hosts: implications for diagnosis and management

Infections by Fusarium species frequently involve the skin, either as the primary or the metastatic site. To better understand the pathophysiology of these infections, 43 new patients with fusariosis were evaluated, and the literature was reviewed. A total of 259 patients (232 immunocompromised and 27 immunocompetent) were identified. Skin involvement was present in 70% of patients, particularly in immunocompromised patients (72% vs. 52%; P=.03). In immunocompetent patients, cutaneous infections were characterized by preceding skin breakdown, localized involvement, slow pace of progression, and good response to therapy. In contrast, skin involvement in immunocompromised patients was only occasionally preceded by skin breakdown and typically was presented as rapidly progressive disseminated lesions at various stages of evolution. Metastatic skin lesions were associated with fungemia, neutropenia, and death. Skin was the single source of diagnosis for the majority of immunocompromised and immunocompetent patients. Recommendations for the prevention of fatal fusariosis originating from skin are presented.

Fungus-specific IgG and IgE in allergic fungal rhinosinusitis

OBJECTIVE

Our study goal was to study fungus-specific immunoglobulins G (sIgG) and E (sIgE) in polypoid rhinosinusitis with and without evidence of allergic fungal rhinosinusitis (AFS).

STUDY DESIGN AND SETTING

A prospective analysis was conducted of fungal sIgG and sIgE using a 9-mold RAST panel in 13 AFS, 11 AFS-like, and 27 non-AFS polypoid rhinosinusitis patients. Nonpolyp controls included 17 volunteers with allergic rhinitis and 11 with no atopic history.

RESULTS

All groups had elevated fungal sIgG levels. Polyps, increasing polyp severity, and AFS were associated with elevated fungal sIgG to a greater number of molds. The AFS group had sIgE elevations (>or=class II) to an average of 5 molds versus only 0.1 in the non-AFS polyp group. Total IgE was 971 U/mL versus 64 U/mL, respectively.

CONCLUSIONS

Multiple elevations of fungal sIgE are adequate diagnostic evidence of these fungi when fungal cultures and histologic examinations are negative in diagnosing AFS. The significance of increased fungal sIgG remains unclear.

SIGNIFICANCE

Early recognition of AFS may be facilitated by screening polypoid rhinosinusitis patients with total serum IgE and RAST testing.

Cytokines in immunodeficient patients with invasive fungal infections: an emerging therapy

Immune response is the major contributor to host defense against opportunistic fungal infections such as candidiasis, aspergillosis and other rare infections. A number of cytokines have been developed and studied in vitro for activity against fungal pathogens. The most studied among them in relation to fungal infections are granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF) and interferon-gamma (IFN-gamma). The fields where these cytokines have been predominantly studied or where they may need more study are primary immunodeficiencies of the phagocytic cells, neonatal age, human immunodeficiency virus infection and cancer-related conditions such as neutropenia and hemopoietic cell transplantation. In this review, the in vitro, experimental animal and clinical data of cytokines are summarized in relation to invasive candidiasis, aspergillosis and emerging fungal infections. Cytokine administration to patients together with antifungal agents, as well as transfusion of cytokine-upgraded phagocytes, are promising immunotherapeutic modalities for further research.

Antifungal drug resistance to azoles and polyenes

There is an increased awareness of the morbidity and mortality associated with fungal infections caused by resistant fungi in various groups of patients. Epidemiological studies have identified risk factors associated with antifungal drug resistance. Selection pressure due to the continuous exposure to azoles seems to have an essential role in developing resistance to fluconazole in Candida species. Haematological malignancies, especially acute leukaemia with severe and prolonged neutropenia, seem to be the main risk factors for acquiring deep-seated mycosis caused by resistant filamentous fungi, such us Fusarium species, Scedosporium prolificans, and Aspergillus terreus. The still unacceptably high mortality rate associated with some resistant mycosis indicates that alternatives to existing therapeutic options are needed. Potential measures to overcome antifungal resistance ranges from the development of new drugs with better antifungal activity to improving current therapeutic strategies with the present antifungal agents. Among the new antifungal drugs, inhibitors of beta glucan synthesis and second-generation azole and triazole derivatives have characteristics that render them potentially suitable agents against some resistant fungi. Other strategies including the use of high doses of lipid formulations of amphotericin B, combination therapy, and adjunctive immune therapy with cytokines are under investigation. In addition, antifungal control programmes to prevent extensive and inappropriate use of antifungals may be needed.

Interactions of fungi with phagocytes

Recent advances have broadened our knowledge of the unique role that dendritic cells, macrophages and neutrophils play in protecting the host against fungal infections and the mechanisms by which fungal pathogens attempt to subvert phagocytic defenses. In this article, the interplay between phagocytes and fungi is reviewed.

DNA immunization using a secreted cell wall antigen Mp1p is protective against Penicillium marneffei infection

None of the vaccines used in dimorphic fungal infections utilized the mucosal route for immunization, whereas only one utilized a secreted protein as antigen, despite knowing that infections caused by dimorphic fungi are usually acquired through inhalation. In this study, we investigated the usefulness of Mp1p (a secreted cell wall antigen encoded by MP1)-based vaccines for generation of protective immune responses against Penicillium marneffei infection using a mouse model, and compared the relative effectiveness of intramuscular MP1 DNA vaccine, oral mucosal MP1 DNA vaccine delivered by live-attenuated Salmonella typhimurium, and intraperitoneal recombinant Mp1p protein vaccine. The serum IgM level of the Mp1p protein vaccine group at day 7 and the serum IgG levels of the Mp1p protein vaccine group at days 7 and 21 were significantly higher than those of the other groups (P<0.0001). The serum IgG level of the MP1 DNA vaccine group was significantly higher than that of the corresponding control group and oral mucosal MP1 DNA vaccine group (one dose) at day 21 (P<0.0001 and <0.05, respectively). The groups of mice immunized with intramuscular MP1 DNA vaccine, oral mucosal MP1 DNA vaccine, and intraperitoneal Mp1p protein vaccine showed significantly higher Mp1p-specific lymphocyte proliferation index (LPI) than the control groups. The interferon-gamma (IF-gamma) levels of supernatant of splenic cell cultures obtained from mice after intramuscular MP1 DNA vaccine, mucosal MP1 DNA vaccine (three doses), or intraperitoneal Mp1p protein vaccine administration were higher than that which occurred after mucosal MP1 DNA vaccine (one dose) administration or those of controls. Interleukin-4 (IL-4) was not detectable in the supernatant of splenic cell cultures obtained from all groups of mice. The percentage survival of the mice immunized with intramuscular MP1 DNA vaccine, oral mucosal MP1 DNA vaccine (three doses), oral mucosal MP1 DNA vaccine (one dose), intraperitoneal recombinant Mp1p protein, oral live-attenuated S. typhimurium control, and intramuscular pJW4303 DNA control at day 60 after wild type P. marneffei challenge were 100, 60, 40, 40, 40, and 0%, respectively. The survival of mice in the MP1 DNA vaccine group was significantly better than those of the oral mucosal MP1 DNA vaccine (three doses) group (P<0.05), oral mucosal MP1 DNA vaccine (one dose) group (P<0.005), recombinant Mp1p protein group (P<0.005), S. typhimurium aroA strain group (P<0.05), and pJW4303 group (P<0.00001). Although, the mechanism by which intramuscular MP1 DNA vaccine offered the best protection against P. marneffei infection remains to be elucidated, the present observation prompted further clinical trials on the use of MP1 DNA immunization on asymptomatic human immunodeficiency virus carriers in P. marneffei endemic areas.

Lethality of yeasts with low pathogenicity in mice immunocompromised by cyclophosphamide treatment

One strain each of Arxiozyma telluris, Saccharomyces cerevisiae, and S. kluyveri showed lethal activity in cyclophosphamide (CY)-treated mice. Accumulation of these yeast cells in the kidneys and elevation of the levels of cytokines, tumor necrosis factor-alpha, and interleukin-1alpha in the sera were recognized in the CY-treated infected-debilitated mice.

[Allergic fungal sinusitis: report of three cases]

OBJECTIVE

To discuss and analyze the diagnosis and management of allergic fungal sinusitis.

METHOD

Three middle-aged patients with allergic fungal sinusitis (AFS) were observed. The histological diagnosis was made on the mucous material and allergy evaluation based on the strong history of inhalant mold allergies, a positive result of skin test, total immunoglobulin E level and radioallergosorbent test to fungal antigens. The management included wide local endoscopic sinus debridement, adequate sinus aeration, postoperative use of systemic and intranasal corticosteroid. Systemic antifungal therapy was not used.

RESULTS

All 3 patients were immunocompetent and none demonstrated histologic evidence of tissue invasion. Two patients remained disease-free during follow-up ranging for a mean of 16 months, 1 patient recurred 17 months after operation and symptom-free for 2 months after re-cleaning of the sinus cavity.

CONCLUSION

Diagnosis of AFS required a high index of suspicion. A confirmatory diagnosis was made from the inspissated mucus, clinical and CT findings along with careful communication with mycologists and immunologists about the possibilities of fungal growth and allergy. Costly and lengthy courses of antibiotics, aggressive surgery should be avoided. Surgical debridement and systemic corticosteroids followed by intranasal corticosteroids might provide long-term control of AFS.

Fungal myocarditis

The incidence of invasive fungal disease has dramatically increased over the past few decades corresponding to the rising number of immunocompromised patients. The major risk factors for severe fungal disease include administration of broad-spectrum antibiotics, corticosteroids and cytotoxic agents, invasive medical procedures, and Human Immunodeficiency Virus (HIV) infection. Invasive fungal infections often affect multiple organs, and involvement of the myocardium frequently occurs in disseminated disease. Premortem diagnosis of fungal myocarditis is difficult since clinical findings of myocardial involvement are often absent or ambiguous and blood cultures are often negative. The major fungal pathogens responsible for myocardial infection and the clinical settings in which they occur are reviewed.

Sinobronchial allergic mycosis: the SAM syndrome

We contend that the presence of concomitant allergic fungal sinusitis (AFS) and allergic bronchopulmonary mycosis in the same patient represents an expression of the same process of fungal hypersensitivity in the upper and lower airways. We have termed this process the SAM syndrome, an acronym for sinobronchial allergic mycosis. Diagnostic criteria have been established for the SAM syndrome, and the clinical characteristics of one previously unreported and four previously reported patients have been tabulated. Patients with the SAM syndrome have chronic sinusitis involving multiple sinuses, asthma, immediate cutaneous reactivity to fungal allergens, peripheral eosinophilia, and radiographic evidence of bronchiectasis. Total serum IgE levels are usually elevated as well. A variety of chest radiographic abnormalities may occur, ranging from mass lesions to diffuse pulmonary infiltrates and even normal findings on chest radiographs. Patients present for an evaluation of either sinus or lung disease and, at that time, demonstrate no clinical features that distinguish them from patients with isolated sinus or lung disease. All patients reported to date have had clinical responses to therapy with corticosteroids. We postulate that SAM is underdiagnosed in patients with AFS, a disease recently reported from medical centers in the southeastern and western United States. Moreover, since our patient had a mutation in the cystic fibrosis transmembrane conductor regulator (CFTR) gene, we further hypothesize that CFTR gene mutations may play an important role in the pathogenesis of the SAM syndrome.

[Risk of fungal infection from foods, particularly in immunocompromised patients]

The aim of our study was the evaluation of fungal contamination of food distributed in hospitals to the immunocompromised patients. 97 samples of 10 sorts of fruit, 100 samples of 17 sorts of cheeses and 56 samples of 11 sorts of smoked meat products were investigated by cultivation on Sabourand's agar at 25 degrees C for 10 days. The yeasts (Candida, Trichosporon, Saccharomyces, Rhodotorula, Aureobasidium) were found in 82% of fruit, in 13% of cheeses and in 46% of smoked meat products. The filamentous fungi (Cladosporium, Alternaria, Penicillium, Aspergillus, Mucor and Helminthosporium) were found on all samples of fruit, in 44% of cheeses and in 3% of smoked foods. Our results show that the fungal contamination of the investigated food is not negligible. The isolated strains are agents of candidoses, phaeohyphomycoses, mucormycoses and aspergilloses and can kill immunocompromised patients.

[Prevention and therapy of infections in tumor patients]

The neutropenic patient with fever remains a great challenge. Because of the high risk of life-threatening bacterial infections, all febrile neutropenic patients should be treated with broad-spectrum bactericidal antibiotics promptly by the intravenous route and in maximal therapeutic dosages. Although the currently available diagnostic tests are not sufficiently rapid, sensitive, or specific for identifying or excluding the microbial cause of a febrile episode, a careful diagnostic work-up should be done. The concern about the problem of emerging drug resistance bacteria due to extensive antibiotic use, plus the fact that such prophylaxis has not been shown to reduce mortality rates, led to the recommendation that routine prophylaxis with these antibiotics in neutropenic patients be avoided. Vaccination should be emphasized in these patients.

Development and evaluation of an in-house enzyme-linked immunosorbent assay for early diagnosis and monitoring of human pythiosis

Human pythiosis is an emerging, fatal, infectious disease caused by Pythium insidiosum and occurs in both tropical and subtropical countries. Thalassemic patients, farmers, and aquatic-habitat residents are predisposed to this disease. Delayed treatment due to the long time required for isolation and identification of the causative organism, as well as the difficulty in obtaining internal organ specimens, results in high morbidity and mortality. To facilitate rapid diagnosis, an in-house enzyme-linked immunosorbent assay (ELISA) for the detection of immunoglobulin G antibodies against P. insidiosum was developed and evaluated for the diagnosis and monitoring of human pythiosis. Sixteen sera were collected from seven culture-proven human pythiosis cases. A total of 142 sera from thalassemic patients, from patients with other infectious diseases, and from healthy blood donors served as controls. All sera were tested in duplicate. By choosing a suitable cutoff point to maximize sensitivity and specificity, sera from pythiosis cases were all determined to be positive, whereas sera from control groups were all determined to be negative. ELISA signals from serial samples of sera taken from treated patients showed gradually declining levels of antibodies to P. insidiosum. The ELISA test was highly sensitive (100%) and specific (100%) and was useful for early diagnosis and for monitoring the treatment for pythiosis.

[Disseminated Penicillium marneffei infection associated with AIDS, report of a case]

OBJECTIVE

To explore the clinical and laboratory features of disseminated Penicillium marneffei infection in patients with AIDS.

METHODS

The HIV antibody in serum was assayed by both enzyme immunoassay (EIA) and Western immunoblot (WIB) methods. Morphology of the pathogenic fungus in smear and biopsy specimens of bone marrow was observed. The fungus was isolated from the patient's skin lesion and inoculated into the abdominal cavities of 2 rats and 2 mice. Twenty days later the rats and mice were killed and their viscera were taken out. Blood from the organs were cultured in Sabourand glucose agar at 25 degrees C and 37 degrees C. The colonies were observed. The morphology of the fungus was observed by microscopy and scanning electron microscopy.

RESULTS

The most common clinical manifestations of Penicilium marneffei infection were fever, weight loss, anemia, papular skin lesion, hepatosplenomegaly, and lymphadenectasis. Yeast-like cells were found in the culture at 37 degrees C or in tissues. The fungi outside the host cells were elongated, often curved, sausage-like and with clear central septi. When cultured at 25 degrees C, the fungus was mycelia-like and produced a characteristic red pigment, diffusing into the medium.

CONCLUSION

Disseminated Penicilliosis marneffei is one of the most important opportunistic infections in patients with AIDS in Southeast Asia and the southern part of China. Since there is no specific clinical manifestation for Penicillium marneffei infection, it is often misdiagnosed. Definite diagnosis requires culture of the pathogenic fungus from clinical specimens. The fungus is thermally dimorphic, produces red pigment, and is sausage-form with clear central septum outside the host cell. Amphotericin B and itraconazole are effective in treating Penicilliosis marneffei.