Pneumocystis carinii pneumonia and mucosal candidiasis in previously healthy homosexual men: evidence of a new acquired cellular immunodeficiency

Four previously healthy homosexual men contracted Pneumocystis carinii pneumonia, extensive mucosal candidiasis, and multiple viral infections. In three of the patients these infections followed prolonged fevers of unknown origin. In all four cytomegalovirus was recovered from secretions. Kaposi's sarcoma developed in one patient eight months after he presented with esophageal candidiasis. All patients were anergic and lymphopenic; they had no lymphocyte proliferative responses to soluble antigens, and their responses to phytohemagglutinin were markedly reduced. Monoclonal-antibody analysis of peripheral-blood T-cell subpopulations revealed virtual elimination of the Leu-3 / helper/inducer subset, an increased percentage of the Leu-2 + suppressor/cytoxic subset, and an increased percentage of cells bearing the thymocyte-associated antigen T10. The inversion of the T/ helper to suppressor/cytotoxic ratio suggested that cytomegalovirus infection was an important factor in the pathogenesis of the immunodeficient state. A high level of exposure of male homosexuals to cytomegalovirus-infected secretions may account for the occurrence of this immune deficiency.

Secukinumab, an Interleukin-17A Inhibitor, in Ankylosing Spondylitis

BACKGROUND

Secukinumab is an anti-interleukin-17A monoclonal antibody that has been shown to control the symptoms of ankylosing spondylitis in a phase 2 trial. We conducted two phase 3 trials of secukinumab in patients with active ankylosing spondylitis.

METHODS

In two double-blind trials, we randomly assigned patients to receive secukinumab or placebo. In MEASURE 1, a total of 371 patients received intravenous secukinumab (10 mg per kilogram of body weight) or matched placebo at weeks 0, 2, and 4, followed by subcutaneous secukinumab (150 mg or 75 mg) or matched placebo every 4 weeks starting at week 8. In MEASURE 2, a total of 219 patients received subcutaneous secukinumab (150 mg or 75 mg) or matched placebo at baseline; at weeks 1, 2, and 3; and every 4 weeks starting at week 4. At week 16, patients in the placebo group were randomly reassigned to subcutaneous secukinumab at a dose of 150 mg or 75 mg. The primary end point was the proportion of patients with at least 20% improvement in Assessment of Spondyloarthritis International Society (ASAS20) response criteria at week 16.

RESULTS

In MEASURE 1, the ASAS20 response rates at week 16 were 61%, 60%, and 29% for subcutaneous secukinumab at doses of 150 mg and 75 mg and for placebo, respectively (P<0.001 for both comparisons with placebo); in MEASURE 2, the rates were 61%, 41%, and 28% for subcutaneous secukinumab at doses of 150 mg and 75 mg and for placebo, respectively (P<0.001 for the 150-mg dose and P=0.10 for the 75-mg dose). The significant improvements were sustained through 52 weeks. Infections, including candidiasis, were more common with secukinumab than with placebo during the placebo-controlled period of MEASURE 1. During the entire treatment period, pooled exposure-adjusted incidence rates of grade 3 or 4 neutropenia, candida infections, and Crohn's disease were 0.7, 0.9, and 0.7 cases per 100 patient-years, respectively, in secukinumab-treated patients.

CONCLUSIONS

Secukinumab at a subcutaneous dose of 150 mg, with either subcutaneous or intravenous loading, provided significant reductions in the signs and symptoms of ankylosing spondylitis at week 16. Secukinumab at a subcutaneous dose of 75 mg resulted in significant improvement only with a higher intravenous loading dose. (Funded by Novartis Pharma; ClinicalTrials.gov numbers, NCT01358175 and NCT01649375.).

Phase 3 Studies Comparing Brodalumab with Ustekinumab in Psoriasis

BACKGROUND

Early clinical studies suggested that the anti-interleukin-17 receptor A monoclonal antibody brodalumab has efficacy in the treatment of psoriasis.

METHODS

In two phase 3 studies (AMAGINE-2 and AMAGINE-3), patients with moderate-to-severe psoriasis were randomly assigned to receive brodalumab (210 mg or 140 mg every 2 weeks), ustekinumab (45 mg for patients with a body weight ≤100 kg and 90 mg for patients >100 kg), or placebo. At week 12, patients receiving brodalumab were randomly assigned again to receive a brodalumab maintenance dose of 210 mg every 2 weeks or 140 mg every 2 weeks, every 4 weeks, or every 8 weeks; patients receiving ustekinumab continued to receive ustekinumab every 12 weeks, and patients receiving placebo received 210 mg of brodalumab every 2 weeks. The primary aims were to evaluate the superiority of brodalumab over placebo at week 12 with respect to at least a 75% reduction in the psoriasis area-and-severity index score (PASI 75) and a static physician's global assessment (sPGA) score of 0 or 1 (clear or almost clear skin), as well as the superiority of brodalumab over ustekinumab at week 12 with respect to a 100% reduction in PASI score (PASI 100).

RESULTS

At week 12, the PASI 75 response rates were higher with brodalumab at the 210-mg and 140-mg doses than with placebo (86% and 67%, respectively, vs. 8% [AMAGINE-2] and 85% and 69%, respectively, vs. 6% [AMAGINE-3]; P<0.001); the rates of sPGA scores of 0 or 1 were also higher with brodalumab (P<0.001). The week 12 PASI 100 response rates were significantly higher with 210 mg of brodalumab than with ustekinumab (44% vs. 22% [AMAGINE-2] and 37% vs. 19% [AMAGINE-3], P<0.001). The PASI 100 response rates with 140 mg of brodalumab were 26% in AMAGINE-2 (P=0.08 for the comparison with ustekinumab) and 27% in AMAGINE-3 (P=0.007). Rates of neutropenia were higher with brodalumab and with ustekinumab than with placebo. Mild or moderate candida infections were more frequent with brodalumab than with ustekinumab or placebo. Through week 52, the rates of serious infectious episodes were 1.0 (AMAGINE-2) and 1.3 (AMAGINE-3) per 100 patient-years of exposure to brodalumab.

CONCLUSIONS

Brodalumab treatment resulted in significant clinical improvements in patients with moderate-to-severe psoriasis. (Funded by Amgen; AMAGINE-2 and AMAGINE-3 ClinicalTrials.gov numbers, NCT01708603 and NCT01708629.).

Candida glabrata: review of epidemiology, pathogenesis, and clinical disease with comparison to C. albicans

Until recently, Candida glabrata was considered a relatively nonpathogenic commensal fungal organism of human mucosal tissues. However, with the increased use of immunosuppressive agents, mucosal and systemic infections caused by C. glabrata have increased significantly, especially in the human immunodeficiency virus-infected population. A major obstacle in C. glabrata infections is their innate resistance to azole antimycotic therapy, which is very effective in treating infections caused by other Candida species. Candida glabrata, formerly known as Torulopsis glabrata, contrasts with other Candida species in its nondimorphic blastoconidial morphology and haploid genome. C. glabrata currently ranks second or third as the causative agent of superficial (oral, esophageal, vaginal, or urinary) or systemic candidal infections, which are often nosocomial. Currently, however, there are few recognized virulence factors of C. glabrata and little is known about the host defense mechanisms that protect against infection. Two established animal models (systemic and vaginal) have been established to study treatment, pathogenesis, and immunity. Treatment of C. glabrata infections can include azoles but often requires amphotericin B or flucytosine. This review summarizes all known clinical and experimental information about C. glabrata infections with comparisons to C. albicans as a means of contrasting the two species commonly observed and emphasizing the many recognized differences.

Phase 3 Trials of Ixekizumab in Moderate-to-Severe Plaque Psoriasis

BACKGROUND

Two phase 3 trials (UNCOVER-2 and UNCOVER-3) showed that at 12 weeks of treatment, ixekizumab, a monoclonal antibody against interleukin-17A, was superior to placebo and etanercept in the treatment of moderate-to-severe psoriasis. We report the 60-week data from the UNCOVER-2 and UNCOVER-3 trials, as well as 12-week and 60-week data from a third phase 3 trial, UNCOVER-1.

METHODS

We randomly assigned 1296 patients in the UNCOVER-1 trial, 1224 patients in the UNCOVER-2 trial, and 1346 patients in the UNCOVER-3 trial to receive subcutaneous injections of placebo (placebo group), 80 mg of ixekizumab every 2 weeks after a starting dose of 160 mg (2-wk dosing group), or 80 mg of ixekizumab every 4 weeks after a starting dose of 160 mg (4-wk dosing group). Additional cohorts in the UNCOVER-2 and UNCOVER-3 trials were randomly assigned to receive 50 mg of etanercept twice weekly. At week 12 in the UNCOVER-3 trial, the patients entered a long-term extension period during which they received 80 mg of ixekizumab every 4 weeks through week 60; at week 12 in the UNCOVER-1 and UNCOVER-2 trials, the patients who had a response to ixekizumab (defined as a static Physicians Global Assessment [sPGA] score of 0 [clear] or 1 [minimal psoriasis]) were randomly reassigned to receive placebo, 80 mg of ixekizumab every 4 weeks, or 80 mg of ixekizumab every 12 weeks through week 60. Coprimary end points were the percentage of patients who had a score on the sPGA of 0 or 1 and a 75% or greater reduction from baseline in Psoriasis Area and Severity Index (PASI 75) at week 12.

RESULTS

In the UNCOVER-1 trial, at week 12, the patients had better responses to ixekizumab than to placebo; in the 2-wk dosing group, 81.8% had an sPGA score of 0 or 1 and 89.1% had a PASI 75 response; in the 4-wk dosing group, the respective rates were 76.4% and 82.6%; and in the placebo group, the rates were 3.2% and 3.9% (P<0.001 for all comparisons of ixekizumab with placebo). In the UNCOVER-1 and UNCOVER-2 trials, among the patients who were randomly reassigned at week 12 to receive 80 mg of ixekizumab every 4 weeks, 80 mg of ixekizumab every 12 weeks, or placebo, an sPGA score of 0 or 1 was maintained by 73.8%, 39.0%, and 7.0% of the patients, respectively. Patients in the UNCOVER-3 trial received continuous treatment of ixekizumab from weeks 0 through 60, and at week 60, at least 73% had an sPGA score of 0 or 1 and at least 80% had a PASI 75 response. Adverse events reported during ixekizumab use included neutropenia, candidal infections, and inflammatory bowel disease.

CONCLUSIONS

In three phase 3 trials involving patients with psoriasis, ixekizumab was effective through 60 weeks of treatment. As with any treatment, the benefits need to be weighed against the risks of adverse events. The efficacy and safety of ixekizumab beyond 60 weeks of treatment are not yet known. (Funded by Eli Lilly; UNCOVER-1, UNCOVER-2, and UNCOVER-3 ClinicalTrials.gov numbers NCT01474512, NCT01597245, and NCT01646177, respectively.).

Cyclosporin A in patients receiving renal allografts from cadaver donors

Seven patients on dialysis with renal failure received transplants from mismatched cadaver donors and were treated with cyclosporin A (CyA), initially as the sole immunosuppressive agent. CyA was effective in inhibiting rejection but there was clear evidence of both nephrotoxicity and hepatotoxicity. A cyclophosphamide analogue was added to the CyA treatment in six of the patients. Five patients are out of hospital with functioning allografts, and two of these have received no steroids. One patient required an allograft nephrectomy because of pyelonephritis in the graft. Another died of systemic aspergillus and candida infection. Further careful study of this potentially valuable drug will by required before it can be recommended in clinical practice.

Leukocyte myeloperoxidase deficiency and disseminated candidiasis: the role of myeloperoxidase in resistance to Candida infection

The neutrophils and monocytes of a patient with disseminated candidiasis were found to lack detectable levels of the lysosomal enzyme myeloperoxidase (MPO), although they had normal levels of other granule-associated enzymes. Leukocytes from one of the patient's sisters also lacked detectable MPO; leukocytes from his four sons contained approximately one-third of mean normal peroxidase levels. Neither the patient nor his affected relatives had experienced frequent or unusual bacterial infections. The phagocytic activity of the patient's MPO-deficient neutrophils was intact, and the cells displayed normal morphologic and metabolic responses to phagocytosis. In contrast to normal leukocytes which killed 30.5+/-7.3% of ingested Candida albicans in 1 hr, however, the patient's neutrophils killed virtually none. His leukocytes also failed to kill the strain of C. albicans recovered from his lesions, as well as other Candida species. These MPO-deficient neutrophils killed Serratia marcescens and Staphylococens aureus 502A at an abnormally slow rate, requiring 3-4 hr to achieve the bactericidal effect attained by normal leukocytes after 45 min. No other abnormalities in his cellular or humoral immune responses were demonstrated. These findings suggest that hereditary MPO deficiency is transmitted as an autosomal recessive characteristic, that the homozygous state conveys enhanced susceptibility to disseminated candidiasis, and that MPO is necessary for candidacidal activity in human neutrophils. Although lending support to the suggested bactericidal role of MPO in leukocytes, the data indicate that alternative bactericidal mechanisms, effective in the absence of MPO, are functionally dominant in the human neutrophil.

Candidemia in cancer patients: a prospective, multicenter surveillance study by the Invasive Fungal Infection Group (IFIG) of the European Organization for Research and Treatment of Cancer (EORTC)

In a surveillance study of candidemia in cancer patients that was conducted by the European Organization for Research and Treatment of Cancer, 249 episodes were noted; Candida albicans was isolated in 70% (63) of the 90 cases involving patients with solid tumors (tumor patients) and in 36% (58) of the 159 involving those with hematologic disease (hematology patients). Neutropenia in tumor patients and acute leukemia and antifungal prophylaxis in hematology patients were significantly associated with non-albicans candidemia in a multivariate analysis. Overall 30-day mortality was 39% (97 of 249). In a univariate analysis, Candida glabrata was associated with the highest mortality rate (odds ratio, 2.66). Two multivariate analyses showed that mortality was associated with older age and severity of the underlying disease. Among hematology patients, additional factors associated with mortality were allogeneic bone marrow transplantation, septic shock, and lack of antifungal prophylaxis.

The commonality of risk factors for nosocomial colonization and infection with antimicrobial-resistant Staphylococcus aureus, enterococcus, gram-negative bacilli, Clostridium difficile, and Candida

Recent years have witnessed a rapidly growing crisis in antimicrobial resistance, especially among microorganisms that cause nosocomial infection. To better understand common risk factors among multiresistant organisms, this review explores risk factors for nosocomial infection with methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococcus, Clostridium difficile, extended-spectrum beta-lactamase-producing gram-negative bacilli, and Candida. This review comprises data from 74 published studies; 53 (71%) were retrospective studies and addressed few risk factors or did not quantify risk. The analysis shows impressive commonality of risk factors across these diverse multiresistant organisms: advanced age; underlying diseases and severity of illness; inter-institutional transfer of the patient, especially from a nursing home; prolonged hospitalization; gastrointestinal surgery or transplantation; exposure to invasive devices of all types, especially central venous catheters; and exposure to antimicrobial drugs, especially cephalosporins. More restricted use of antibiotics, especially cephalosporins, and strategies to prevent medical device-related infection and cross-infection in the hospital would yield benefit with all types of resistant organisms. Preemptive isolation of all patients with risk factors for infection by resistant organisms would very likely reduce secondary spread within the hospital. Conversely, programs that focus on only one organism or one antimicrobial drug are unlikely to succeed. Prospective studies of sufficient size that address all potential risk factors, especially individual anti-infective agents, and that use matched controls who are shown by surveillance cultures to be free of colonization by resistant organisms would enhance understanding of the epidemiology of antimicrobial resistance in institutions and guide efforts to develop more effective strategies for prevention.

Critical role of Bcr1-dependent adhesins in C. albicans biofilm formation in vitro and in vivo

The fungal pathogen Candida albicans is frequently associated with catheter-based infections because of its ability to form resilient biofilms. Prior studies have shown that the transcription factor Bcr1 governs biofilm formation in an in vitro catheter model. However, the mechanistic role of the Bcr1 pathway and its relationship to biofilm formation in vivo are unknown. Our studies of biofilm formation in vitro indicate that the surface protein Als3, a known adhesin, is a key target under Bcr1 control. We show that an als3/als3 mutant is biofilm-defective in vitro, and that ALS3 overexpression rescues the biofilm defect of the bcr1/bcr1 mutant. We extend these findings with an in vivo venous catheter model. The bcr1/bcr1 mutant is unable to populate the catheter surface, though its virulence suggests that it has no growth defect in vivo. ALS3 overexpression rescues the bcr1/bcr1 biofilm defect in vivo, thus arguing that Als3 is a pivotal Bcr1 target in this setting. Surprisingly, the als3/als3 mutant forms a biofilm in vivo, and we suggest that additional Bcr1 targets compensate for the Als3 defect in vivo. Indeed, overexpression of Bcr1 targets ALS1, ECE1, and HWP1 partially restores biofilm formation in a bcr1/bcr1 mutant background in vitro, though these genes are not required for biofilm formation in vitro. Our findings demonstrate that the Bcr1 pathway functions in vivo to promote biofilm formation, and that Als3-mediated adherence is a fundamental property under Bcr1 control. Known adhesins Als1 and Hwp1 also contribute to biofilm formation, as does the novel protein Ece1.

The formation of biofilms (surface-attached microbial communities) on implanted medical devices such as catheters is a major cause of fungal and bacterial infections. Prior studies of the fungal pathogen Candida albicans have shown that the regulator Bcr1 is required for biofilm formation in vitro, but the mechanism through which it promotes biofilm formation and its significance for biofilm formation in vivo was uncertain. The authors demonstrate that Bcr1 is required for biofilm formation in vivo in a rat model of catheter-based infection. Manipulation of Bcr1 target genes through mutation and gene overexpression shows that the known surface adhesin Als3 has a pivotal role in biofilm formation and that adhesins Als1 and Hwp1 also contribute to biofilm formation. The results thus indicate that adherence is the key property regulated by Bcr1 and highlight a group of adhesins as potential therapeutic targets.

Cerebrovascular complications in patients with cancer

In an autopsy study of patients with cancer, 14.6% had pathologic evidence of cerebrovascular disease (CVD), and in 7.4% clinical symptoms of CVD had been present in life. The usual risk factors for CVD were overshadowed by pathophysiologic abnormalities related to the neoplasm, including direct effects of the tumor, coagulation disorders, infections and diagnostic or therapeutic procedures. In patients with leukemia, hemorrhages (72.4%) were much more common than ischemic infarcts. In lymphoma patients, the incidence of cerebral bleeding was lower (36.3%). In both groups, the leading causes of ischemic infarction were septic thrombi and intravascular coagulation. In patients with carcinoma, cerebral infarctions (54.1%) were more frequent than hemorrhages. NBTE (18.5%) and intravascular coagulation (9.6%) were the most common etiologies. Hemorrhages other than intratumoral bleeding in patients with melanoma or germ cell tumors were unusual. The clinical presentation of CVD in patients with cancer is more often a diffuse encephalopathy, with or without localizing signs, than the typical acute onset of a focal deficit. This was particularly true with intravascular coagulation, septic infarction and subdural hematoma. Our study suggests that by knowing the clinical setting, neurologic features and laboratory findings, one can, in many instances, make an accurate clinical diagnosis that, in some cases, leads to effective treatment.

Fungemia in a cancer hospital: changing frequency, earlier onset, and results of therapy

Two hundred episodes of fungemia that occurred at Memorial Sloan-Kettering Cancer Center between January 1, 1978, and June 30, 1982, are reviewed and compared with those seen from 1974 through 1977. The total number of episodes of fungemia per year increased by 30.6%, episodes per 100 new lymphoma and solid tumor patients increased by 73% and 95%, respectively, and episodes per 100 new leukemia patients decreased by 50%. Fungemia also occurred earlier during hospitalization, and embolic skin lesions were a common early sign of Candida tropicalis fungemia. Mortality was not significantly different with and without amphotericin B therapy in fungemic patients with leukemia, lymphoma, or aplastic anemia (51 of 70 vs. 21 of 24) or solid tumors (29 of 36 vs. 29 of 43); however, some patients appeared to benefit from combination therapy with amphotericin B and flucytosine. The prevalence of disseminated candidiasis at autopsy was the same in treated (11 of 15) and untreated (8 of 11) patients with leukemia, lymphoma, and aplastic anemia, but it was significantly lower in treated (none of 8) than in untreated (5 of 11) patients with solid tumors.

Nosocomial candidiasis: emerging species, reservoirs, and modes of transmission

During the 1980s, the frequency of nosocomial candidiasis increased dramatically. This trend has continued into the 1990s, and Candida species remain a major cause of nosocomial infections. Although Candida albicans remains the most frequent cause of fungemia and hematogenously disseminated candidiasis, a number of reports have documented infections caused by other Candida species: C. tropicalis, C. glabrata, C. parapsilosis, C. krusei, and C. lusitaniae. Many of these infections arise from an endogenous source, and their frequency is influenced by the patient population, the various treatment regimens, and the antibiotics or other supportive care measures employed at specific institutions. Additional infections may be accounted for by exogenous acquisition via the hands of health care workers, contaminated infusates and biomaterials, and the inanimate environment. Ongoing investigation should help improve our understanding of the epidemiology of candidiasis and facilitate the development of rational preventive measures.

Lymphoproliferative disorder and imbalanced T-helper response in C/EBP beta-deficient mice

C/EBP beta is considered a key element of interleukin-6 (IL-6) signalling as well as an important transcriptional regulator of the IL-6 gene itself. We describe here how mice lacking C/EBP beta develop a pathology similar to mice overexpressing IL-6 and nearly identical to multicentric Castleman's disease in human patients, with marked splenomegaly, peripheral lymphadenopathy and enhanced haemopoiesis. Humoral, innate and cellular immunity are also profoundly distorted, as shown by the defective activation of splenic macrophages, the strong impairement of IL-12 production, the increased susceptibility to Candida albicans infection and the altered T-helper function. Our data show that C/EBP beta is crucial for the correct functional regulation and homeostatic control of haemopoietic and lymphoid compartments.

Hickman catheter infections in patients with malignancies

The infectious complications associated with implantation of 1,088 Hickman catheters (HCs) in 992 patients reported in 18 published series are presented (including data on 129 previously unreported HCs from our own institution). HCs allow reliable long-term venous access (mean, 92.4 days) with low complication and infection rates (0.30 and 0.14 cases per 100 catheter days, respectively). Exit site infections were the most common form of infection encountered (45.5%), followed by septicemia alone (30.8%), tunnel infections (20.3%), and septic thrombophlebitis (3.5%). Staphylococcus epidermidis (54.1%) and S. aureus (20.0%) were the most common pathogens responsible for catheter infections. HC infections were associated with a low mortality rate (maximum rate of 0.5%). Risk factor analysis of 129 HCs demonstrated that catheter thrombosis was the major risk factor associated with development of catheter infection. Presence of fever, distant infection, neutropenia or antibiotic administration on the day of catheter insertion was not significantly associated with HC infection in this series (although there was a trend suggesting an increased risk of infection of HCs inserted during febrile episodes). Based on observations at our institution and from a review of the literature, tentative recommendations for management of the various types of HC infections are outlined.

The acquired immunodeficiency syndrome

Recently, a new epidemic illness, the acquired immunodeficiency syndrome, has dramatically emerged in the United States, Europe, and Haiti. The syndrome represents an unprecedented epidemic form of immunodeficiency involving prominent defects of the T-lymphocyte arm of the immune system. Pneumocystis carinii pneumonia, other opportunistic infections, and the previously rare cancer, Kaposi's sarcoma, are the most conspicuous illnesses that have this profound state of immune compromise as their underlying basis. Two years after the onset of clinical illness the case-fatality rate may exceed 90%. A steadily growing body of epidemiologic evidence indicates an infectious (probably viral) cause of the immunodeficiency although the responsible agent(s) remains obscure. Critical issues surrounding the diagnosis, screening of blood products, treatment of complicating infections and cancers, and prognosis for immunologic recovery in affected persons are unresolved. The identification of the cause of acquired immunodeficiency syndrome and the institution of effective preventive measures require the urgent attention of the medical and scientific community worldwide.

Clinical manifestations of AIDS in the era of pneumocystis prophylaxis. Multicenter AIDS Cohort Study

BACKGROUND

Among patients infected with human immunodeficiency virus type 1 (HIV-1), early and widespread use of prophylactic regimens against Pneumocystis carinii is changing the pattern of illnesses related to the acquired immunodeficiency syndrome (AIDS).

METHODS

We conducted a subcohort analysis of 844 men with AIDS (87 percent of whom have since died) from a prospectively followed cohort of 2592 HIV-1-infected homosexual men.

RESULTS

A total of 138 men received prophylaxis before the diagnosis of AIDS, but 39 (28 percent) nevertheless had P. carinii pneumonia at some time. Only four illnesses occurred more frequently in men who received P. carinii prophylaxis before the onset of AIDS: Mycobacterium avium complex disease, which developed in 33.4 percent, as compared with 17.3 percent of the 706 men who did not receive early prophylaxis; wasting syndrome (18.4 percent vs. 6.4 percent); cytomegalovirus disease (44.9 percent vs. 24.8 percent); and esophageal candidiasis (21.3 percent vs. 12.8 percent). Collectively, these four diseases accounted for the initial AIDS-related illness in 42.7 percent of those who received prophylaxis before the onset of AIDS, as compared with 10.7 percent of those who did not. During the three six-month periods before the diagnosis of AIDS (0 to 6, > 6 to 12, and > 12 to 18 months), the geometric mean CD4+ cell counts were 48, 87, and 147 per cubic millimeter, respectively, in men who received prophylaxis against P. carinii, as compared with 118, 211, and 279 per cubic millimeter in those who did not.

CONCLUSIONS

M. avium complex disease, esophageal candidiasis, wasting syndrome, and cytomegalovirus disease are more common in HIV-infected patients who have received prophylaxis against P. carinii than in those who have not. Prophylaxis may delay the first AIDS illness for 6 to 12 months.

Burn wound infections: current status

The burn wound represents a susceptible site for opportunistic colonization by organisms of endogenous and exogenous origin. Patient factors such as age, extent of injury, and depth of burn in combination with microbial factors such as type and number of organisms, enzyme and toxin production, and motility determine the likelihood of invasive burn wound infection. Burn wound infections can be classified on the basis of the causative organism, the depth of invasion, and the tissue response. Diagnostic procedures and therapy must be based on an understanding of the pathophysiology of the burn wound and the pathogenesis of the various forms of burn wound infection. The time-related changes in the predominant flora of the burn wound from gram-positive to gram-negative recapitulate the history of burn wound infection. Proper clinical and culture surveillance of the burn wound permits early diagnosis of gram-positive cellulitis, and the stable susceptibility of beta-hemolytic streptococci to penicillin has eliminated the threat of this once common burn wound pathogen. Selection and dissemination of intrinsic and acquired resistance mechanisms increase the probability of burn wound colonization by resistant species such as Pseudomonas aeruginosa. Even so, effective topical antimicrobial chemotherapy and early burn wound excision have significantly reduced the overall occurrence of invasive burn wound infections. Individual patients, usually those with extensive burns in whom wound closure is difficult to achieve, may still develop a variety of bacterial and nonbacterial burn wound infections. Consequently, the entirety of the burn wound must be examined on a daily basis by the attending surgeon. Any change in wound appearance, with or without associated clinical changes, should be evaluated by biopsy. Quantitative cultures of the biopsy sample may identify predominant organisms but are not useful for making the diagnosis of invasive burn wound infection. Histologic examination of the biopsy specimen, which permits staging the invasive process, is the only reliable means of differentiating wound colonization from invasive infection. Identification of the histologic changes characteristic of bacterial, fungal, and viral infections facilitates the selection of appropriate therapy. A diagnosis of invasive burn wound infection necessitates change of both local and systemic therapy and, in the case of bacterial and fungal infections, prompt surgical removal of the infected tissue. Even after the wounds of extensively burned patients have healed or been grafted, burn wound impetigo, commonly caused by Staphylococcus aureus, may occur in the form of multifocal, small superficial abscesses that require surgical debridement. Current techniques of burn wound care have significantly reduced the incidence of invasive burn wound infection, altered the organisms causing the infections that do occur, increased the interval between injury and the onset of infection, reduced the mortality associated with infection, decreased the overall incidence of infection in burn patients, and increased burn patient survival.

Identification and characterization of TUP1-regulated genes in Candida albicans

TUP1 encodes a transcriptional repressor that negatively controls filamentous growth in Candida albicans. Using subtractive hybridization, we identified six genes, termed repressed by TUP1 (RBT), whose expression is regulated by TUP1. One of the genes (HWP1) has previously been characterized, and a seventh TUP1-repressed gene (WAP1) was recovered due to its high similarity to RBT5. These genes all encode secreted or cell surface proteins, and four out of the seven (HWP1, RBT1, RBT5, and WAP1) encode putatively GPI-modified cell wall proteins. The remaining three, RBT2, RBT4, and RBT7, encode, respectively, an apparent ferric reductase, a plant pathogenesis-related protein (PR-1), and a putative secreted RNase T2. The expression of RBT1, RBT4, RBT5, HWP1, and WAP1 was induced in wild-type cells during the switch from the yeast form to filamentous growth, indicating the importance of TUP1 in regulating this process and implicating the RBTs in hyphal-specific functions. We produced knockout strains in C. albicans for RBT1, RBT2, RBT4, RBT5, and WAP1 and detected no phenotypes on several laboratory media. However, two animal models for C. albicans infection, a rabbit cornea model and a mouse systemic infection model, revealed that rbt1Delta and rbt4Delta strains had significantly reduced virulence. TUP1 appears, therefore, to regulate many genes in C. albicans, a significant fraction of which are induced during filamentous growth, and some of which participate in pathogenesis.

The association of third-generation cephalosporin use and invasive candidiasis in extremely low birth-weight infants

OBJECTIVES

Previous studies have shown that incidence of invasive candidiasis varies substantially among centers, and previous use of broad-spectrum antibiotics is a risk factor for candidiasis in extremely low birth-weight infants. Differences in center practices, such as antibiotic strategies and the effects of these strategies on center incidence of candidiasis, are not reflected in assessments of an individual's risk of candidiasis. We evaluated the relationship between empirical antibiotic practices for extremely low birth-weight infants and center incidence of candidiasis.

METHODS

We studied a cohort of extremely low birth-weight infants who survived > or = 72 hours and were admitted to 1 of 12 tertiary centers between 1998 and 2001. Multivariable logistic regression was used to validate previous broad-spectrum antibiotics use as a risk factor for subsequent candidiasis in individual infants. We calculated correlation coefficients to assess the relationship between center incidence of candidiasis with antibiotic practice patterns.

RESULTS

There were 3702 infants from 12 centers included, and 284 (7.7%) developed invasive candidiasis. Broad-spectrum antibiotics use was associated with candidiasis for individual infants. Center candidiasis incidence ranged from 2.4% to 20.4%. Center incidence of candidiasis was correlated with average broad-spectrum antibiotics use per infant and average use of broad-spectrum antibiotics with negative cultures per infant.

CONCLUSIONS

Center incidences of invasive candidiasis differ substantially, and antibiotic practice differences are possible contributors to center variation in candidiasis risk.

Association of Torulopsis glabrata infections with fluconazole prophylaxis in neutropenic bone marrow transplant patients

Because the use of fluconazole prophylaxis had been associated with an increased rate of Candida krusei infections at The John Hopkins Oncology Center, early empiric amphotericin B plus flucytosine were given to febrile neutropenic patients colonized by C. krusei. By this practice, the proportion of fungemias attributable to C. krusei was low (12.5%) in patients receiving fluconazole over a 6-month interval. However, Torulopsis (Candida) glabrata assumed a much higher proportion of fungemias (75%) among patients receiving fluconazole. In vitro susceptibility testing combined with this clinical experience suggests that some T. glabrata isolates are not susceptible to fluconazole and can cause breakthrough infections in patients receiving fluconazole.

Hepatic candidiasis in cancer patients: the evolving picture of the syndrome

Focal hepatosplenic candidiasis has been recognized with increasing frequency in recent years. We reviewed the cases of eight patients seen between 1982 and 1985, and information on 60 patients whose cases have been reported in the world literature. The characteristics of focal hepatosplenic candidiasis include persistent fever in a neutropenic patient whose leukocyte count is returning to normal, often coupled with abdominal pain; an elevated alkaline phosphatase level; and less commonly, rebound leukocytosis. The characteristic "bull's eye" lesions seen with hepatic ultrasound examination or computed tomography generally are not detectable until neutrophil recovery has occurred. Diagnosis can be established only by biopsy evidence of yeasts or pseudohyphae in the granulomatous lesions. Cultures are frequently negative, however, especially in patients who have been pretreated with antifungal agents. We review the evolving nature of hepatosplenic candidiasis, focusing on diagnosis and treatment.