Chlamydial serology: comparative diagnostic value of immunoblotting, microimmunofluorescence test, and immunoassays using different recombinant proteins as antigens

To improve the reliability of the serodiagnosis of Chlamydia trachomatis infections, an immunoblot analysis, a microimmunofluorescence titration, and different immunoassays using synthetic peptides derived from species-specific epitopes in variable domain IV of the major outer membrane protein or recombinant antigens (heat shock protein 70 [hsp70], hsp60, hsp10, polypeptide encoded by open reading frame 3 of the plasmid [pgp3], macrophage infectivity potentiator, and a fragment of the total lipopolysaccharide) were evaluated. Because cross-reactions between chlamydial species have been reported, the microimmunofluorescence tests were also performed with Chlamydia pneumoniae and Chlamydia psittaci used as antigens, and C. pneumoniae-specific antibodies were also determined by immunoassays. Since the presence of antimicrobial antibodies must be interpreted in light of their prevalence in the general population, responses obtained with serum samples from patients with well-defined infection (i.e., with positive urethral or endocervical C. trachomatis DNA amplification) were compared to those obtained with samples from healthy blood donors. The best sensitivity (86%) with a specificity of 81% was obtained for immunoblotting results, when the number of individuals with > or =10 immunoglobulin G (IgG) and/or > or =2 IgM responses to the different C. trachomatis antigens was considered. A 13-kDa antigen was recognized by most of the samples (86% for IgG) from patients with acute urogenital infection but rarely (3%) by those from healthy blood donors (P < 0.0001). The sensitivity and specificity results obtained for serum antibodies to peptides or recombinant antigens were slightly lower than those results obtained for the number of responses to whole C. trachomatis antigens, which were 76 and 77%, respectively, when IgG responses to both recombinant hsp60 and pgp3 were considered.

Resistant herpes simplex virus type 1 infection: an emerging concern after allogeneic stem cell transplantation

Fourteen cases of severe acyclovir-resistant herpes simplex virus type 1 (HSV-1) infection, 7 of which showed resistance to foscarnet, were diagnosed among 196 allogeneic stem cell transplant recipients within a 29-month period. Recipients of unrelated stem cell transplants were at higher risk. All patients received foscarnet; 8 subsequently received cidofovir. Strains were initially foscarnet-resistant in 3 patients and secondarily so in 4 patients. In vitro resistance to acyclovir or foscarnet was associated with clinical failure of these drugs; however, in vitro susceptibility to foscarnet was associated with complete response in only 5 of 7 patients. No strain from any of the 7 patients was resistant in vitro to cidofovir; however, only 3 of 7 patients achieved complete response. Therefore, acyclovir- and/or foscarnet-resistant HSV-1 infections after allogeneic stem cell transplantation have become a concern; current strategies need to be reassessed and new strategies must be evaluated in this setting.

Development of cytomegalovirus resistance to ganciclovir after oral maintenance treatment in a renal transplant recipient

The emergence of a resistant strain is a theoretical threat after extensive use of antiviral drugs. We report the emergence of a ganciclovir-resistant cytomegalovirus (CMV) strain in a kidney transplant recipient during oral ganciclovir maintenance treatment. The patient was treated by oral ganciclovir for 2 months after successful treatment of CMV primary infection by intravenous ganciclovir. He developed a new episode of CMV infection with no clinical response to intravenous ganciclovir. The CMV isolate exhibited both phenotypic and genotypic resistance to ganciclovir. The CMV isolate was constituted of a mixture of strains, with and without a mutation at codon 460 of the UL97 gene. The clinical condition improved when mycophenolate mofetil (MMF) was discontinued, and a short course of intravenous globulin was added to ganciclovir. The emergence of the CMV strain could be secondary to more potent immunosuppression provide by MMF or subtherapeutic level obtained during oral ganciclovir treatment. We believe that ganciclovir resistance must be part of the differential diagnosis when a patient relapses or fails to respond to ganciclovir treatment.

Astrovirus enteritis in a chronic lymphocytic leukemia patient treated with fludarabine monophosphate

We report on a case of severe astrovirus gastroenteritis in a chronic lymphocytic leukemia (CLL) patient treated with fludarabine monophosphate (FAMP). Astrovirus was detected in stools using both an immunoenzymatic assay and an electronic microscopy analysis. Treatment consisted in symptomatic care and the outcome was favorable. Astrovirus infection might constitute a common etiology of gastroenteritis in patients with hematologic malignancies that have been severely immunocompromised with FAMP or other purine analogues, and therefore should be more systematically investigated.

Haemorrhagic cystitis associated with adenovirus in a patient with AIDS treated for a non-Hodgkin's lymphoma

Adenovirus-induced haemorrhagic cystitis has been reported chiefly in bone marrow or kidney transplant recipients. We report here on an HIV-positive patient treated for a Burkitt's lymphoma who developed gross haematuria associated with fever and burning urination. Usual causes of haematuria were ruled out: lithiasis, urinary tract lesions, glomerulonephritis, mycobacterium and schistosoma infections, and drug toxicity. Adenovirus was detected by cellular cultures and BK/JC virus DNA sequences were detected using a polymerase chain reaction method. Because BK/JC virus shedding is very common (75%) in HIV patients receiving chemotherapy, our data strongly suggest that adenovirus was responsible for the haemorrhagic cystitis in our patient. In conclusion, adenovirus should be considered as a potential cause of haemorrhagic cystitis in AIDS patients whose immunosuppression is aggravated by cytotoxic drugs.

Different humoral immune response to Chlamydia trachomatis major outer membrane protein variable domains I and IV in Chlamydia-infected patients with or without reactive arthritis

OBJECTIVE

The possibility that some bacterial-specific factor(s) may play a role in triggering Chlamydia trachomatis reactive arthritis was investigated.

METHODS

Since the variable domains of the major outer membrane protein (MOMP) contain the serovar-determining epitopes of C. trachomatis, the ability of serum IgG to recognize peptides mimicking these epitopes was determined in 2 groups of infected patients, one with and the other without reactive arthritis. Because asymptomatic C. trachomatis infections are frequent, and nonspecific reactions due to inflammation could be observed, this study was also performed with samples from healthy blood donors and from patients with inflammatory arthritis unrelated to C. trachomatis infection.

RESULTS

A predominant reactivity against peptides duplicating the J serovar-specific epitopes was only observed in the group of patients with reactive arthritis. For positive samples, differences between the two groups of C. trachomatis-infected patients were clearly observed. The mean numbers of positive responses obtained for each of the 7 peptides of the MOMP domain I or each of the 8 peptides of the MOMP domain IV were significantly higher for samples from patients with reactive arthritis (4.7 and 6) than for those from patients with only C. trachomatis urogenital infection (1.3 and 2.9).

CONCLUSION

Patients with reactive arthritis had a pattern of reactivities that was compatible with infection by several serotypes of bacteria. Repeated exposures to C. trachomatis might therefore be involved in the development of the disease.

Usefulness of the cytomegalovirus (CMV) antigenemia assay for predicting the occurrence of CMV disease and death in patients with AIDS

A cohort study of 214 human immunodeficiency virus (HIV)-infected patients was performed to assess the usefulness of the cytomegalovirus (CMV) antigenemia assay for predicting the occurrence of CMV disease and death. Multivariate analysis revealed that only positive baseline CMV antigenemia assays (relative risk [RR], 7.2; 95% confidence interval [CI], 3.7-14.2; P = .0001) and CD4 cell counts (RR, 0.98; 95% CI, 0.97-0.99; P = .009) were associated with CMV disease. A positive baseline CMV antigenemia assay was also associated with death by multivariate analysis (RR, 2.2; 95% CI, 1.5-3.4; P = .0003). Increasing levels of CMV antigenemia during follow-up were associated with increased risks of CMV disease and death. A positive CMV antigenemia assay that showed > 10 cells per 2 x 10(5) polymorphonuclear leukocytes during follow-up was 91% sensitive and 84% specific for predicting a diagnosis of CMV disease; the negative predictive value for this positive test was high (97%). Therefore, the CMV antigenemia assay appears to be a simple, rapid, and inexpensive test for predicting the occurrence of CMV disease and death in patients with advanced HIV infection.

Squamous cell carcinomas after allogeneic bone marrow transplantation for aplastic anemia: further evidence of a multistep process

BACKGROUND

Secondary solid tumors are rare events occurring in patients who underwent allogeneic marrow transplantation for aplastic anemia and Fanconi's anemia. Human herpes virus 8 (HHV8), Epstein-Barr virus (EBV), and human papillomaviruses (HPV) sequences have been found in squamous cell carcinoma (SCC) occurring in organ transplant recipients. The tumor suppressor gene p53 has been strongly linked to the occurrence of SCC in the nonimmunocompromised population.

PATIENTS AND METHODS

In eight patients with SCC, we searched for HHV8, EBV, varicella zoster virus, adenovirus, and HPV sequences from DNA extracted from selected areas of SCC. We also looked for p53 expression in those specimens as well as the presence of anti-p53 antibodies in the serum of these patients at the onset of SCC.

RESULTS

In one patient, we found the presence of both HHV8 and EBV sequences, and in another patient we found HPV16 sequences. All five tumors that could be studied disclosed evidence of p53 accumulation, but none of the eight patients had anti-p53 antibodies in the sera.

CONCLUSION

SCC developing in marrow transplant recipients seems to occur via a multistep process. Genetic predisposition may be present, as in patients with Fanconi's anemia. Transplantation-related factors, such as irradiation and chronic graft-versus-host disease, also have a role. In this article, we add two more potent risk factors: p53 alteration(s) and in some cases the presence of oncogenic viruses.

Inhibition of human immunodeficiency type 1 virus replication in monocytic U-937 cells by superinfection with Chlamydia trachomatis

The aim of this study was to investigate the effects of infection of monocytic cells with both the human immunodeficiency type 1 virus (HIV-1) and Chlamydia trachomatis on the replication of each pathogen. U-937 cells, chronically infected with HIV-1 (strain LaVLai), either induced to differentiate into immature macrophage-like cells by 32 pM 12-O-tetradecanol phorbol-13-acetate or uninduced, were superinfected with C. trachomatis serovar L2. Both HIV-1 infection and differentiation rendered the U-937 cells highly susceptible to C. trachomatis lytic infection. Differentiation and superinfection of HIV-1-infected cells with C. trachomatis both affected cell viability and reduced viral production in vitro. RT activity was one tenth the original value after differentiation of HIV-1-infected cells, one twentieth the original value after superinfection with C. trachomatis, and one hundredth the original value after differentiation and superinfection with C. trachomatis.

[Comparison of the in vitro sensitivity to cidofovir and ganciclovir of clinical cytomegalovirus isolates. Coordinated Action Group 11]

Cidofovir (CDF) or Vistid is a monophosphate nucleoside analogue that inhibits the DNA polymerase of herpes viruses including the cytomegalovirus (CMV). CDF is active on GCV-resistant strains with a mutation on the phosphotransferase gene (UL97). However, DNA polymerase gene mutations that induce resistance to GCV are responsible for cross-resistance to CDF. Resistance phenotypes to GCV and CDF were determined for 57 CMV strains isolated from blood and urine samples. Sixteen strains were recovered after CDF therapy. Of the remaining 41 CDF-naive strains, 34 were susceptible and seven resistant to GCV. Fifty percent inhibitory concentrations (IC50) for CDF were in the 0.2-2.6 microM range for CDF-naive strains susceptible to GCV. For GCV-resistant strains, IC50 values for CDF were < or = 3 microM for strains with a low level of resistance to GCV (GCV IC50 < 30 microM) and > or = 6 microM for three of the five strains with a high level of resistance to GCV (GCV IC50 > or = 30 microM).

Severe respiratory syncytial virus pulmonary infection in a patient treated with fludarabine for chronic lymphocytic leukemia

Fludarabine phosphate is currently proposed for the treatment of refractory chronic lymphocytic leukemia (CLL). CD4 T-lymphocyte depletion, myelosuppression, and subsequent severe infections are the major side effects of fludarabine phosphate therapy. We report here on a heretofore undescribed respiratory syncytial virus (RSV) infection in a patient with a long-standing history of refractory CLL that was treated with fludarabine phosphate. The patient developed a severe infection of the upper and lower respiratory tract with bilateral pulmonary infiltrates and severe hypoxemia. RSV was the only infectious agent that could be isolated, and treatment with aerosolized ribavirin lead to prompt improvement of all symptoms.

Use of the cytomegalovirus (CMV) antigenemia assay for the rapid diagnosis of primary CMV infection in hospitalized adults

We assessed the value of the cytomegalovirus (CMV) antigenemia assay for diagnosing primary CMV infection in adults. The CMV antigenemia assay was performed for 40 patients admitted to our unit over a 2-year period with unexplained fever and suspected primary CMV infection. Nine of the 10 patients with primary CMV infection had positive CMV antigenemia assays, and the results were available within 5 hours. All 10 patients had a mononucleosis-like syndrome. All but one of the 30 other patients had negative CMV antigenemia assays. A false-positive result was obtained for a patient with systemic lupus erythematosus. Overall, the CMV antigenemia assay was 90% sensitive and 96% specific for the diagnosis of primary CMV infection. Therefore, the CMV antigenemia assay appears to be a simple, rapid, inexpensive test for the diagnosis of primary CMV infection in hospitalized adults.

Chlamydia trachomatis growth stimulates interleukin 8 production by human monocytic U-937 cells

Growth of Chlamydia trachomatis serotypes L2 and L3 in a human monocytic cell line, U-937, increased the rate of interleukin 8 (IL-8) release 100-fold. Heat-killed chlamydiae induced a 10-fold-lower level of production of IL-8. IL-8 may play an important role in the inflammatory reaction to chlamydial infection.

[Herpes simplex virus and macrophages]

Macrophages, widely distributed in the body, play a central role in mediating host defense against herpes simplex virus (HSV) infections. Both intrinsic antiviral activities of macrophages (phagocytic and degradative function leading to presentation of viral antigens, inhibition of viral replication) and extrinsic antiviral resistance (inhibition of the spread of HSV, inhibition of HSV replication in permissive cells and selecting lysing of HSV-infected cells) are modulated by cytokines such as interferons (IFN) and tumor necrosis factor (TNF). Macrophages in the presence of an interactive network of cytokines are involved in the orchestration of non specific host defense and specific immune responses against HSV infections. Further investigations of physiopathology and complex interactions of macrophages-HSV should lead to the development of immunotherapy for HSV infections in immunocompromised individuals.

[Detection of Chlamydia trachomatis infection by PCR in first voided urines in men]

The goal of this study was to evaluate whether the new commercially available PCR-based assay Amplicor C. trachomatis (Roche Molecular Systems) could improve the diagnosis of chlamydial urogenital infections in men, compared with cell culture of C. trachomatis considered as the reference method. A total of 466 men attending the STD clinic were tested by the Amplicor test in urine and by cell culture in urethra. The prevalence of C. trachomatis was 13.7% (64/466) by cell culture and 14.4% (67/466) by the Amplicor test. After resolution of the discrepant results, the sensitivity of culture was 91.4% in male urethral specimens. The resolved sensitivity of the PCR assay was 92.7% in male urine and the specificity was 99.5%. We concluded that this rapid PCR-based assay showed an improvement in quality for diagnosing C. trachomatis infections in men.

Male urethritis with and without discharge: a clinical and microbiological study

BACKGROUND

The definition of male urethritis in the absence of urethral discharge has not been well established. The sensitivity of urethral swabs and first-catch urine is controversial.

GOAL OF THIS STUDY

To correlate clinical data (discharge or not), urethral swabs, and first-catch urine examinations with the microorganisms found within the urethra in a cohort of men attending the sexually transmitted disease clinic of Hôpital Saint Louis (Paris) for treatment of urethral symptoms with or without discharge.

STUDY DESIGN

Two-hundred-seventy-three consecutive male patients entered this prospective study between October 1, 1992 and November 30, 1992. Fifty-two patients were excluded because they had been treated with antibiotics in the previous 3 months. All patients were screened for Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, Ureaplasma urealyticum, Mycoplasma hominis, and Candida albicans.

RESULTS

Two-hundred-nineteen patients were eligible for the study (122 with discharge and 97 with no discharge). The prevalence of microorganisms was as follows: Chlamydia trachomatis in 13%, Neisseria gonorrhoeae in 11%, Ureaplasma urealyticum in 7%, Mycoplasma genitalium in 17%, Trichomonas vaginalis in 1%, and indeterminate pathogens alone in 20%. All major pathogens and Mycoplasma genitalium were more common in patients with discharge. Stratification of results according to the presence of polymorphonuclear leukocytes on the urethral swab and first-catch urine showed a low sensitivity of both tests for Chlamydia trachomatis (29%), Mycoplasma genitalium (50% and 62%), and Ureaplasma urealyticum (33%) in patients with no discharge.

CONCLUSION

A specific and sensitive search for Chlamydia trachomatis should be done in every patient with urethral symptoms whether or not the classic symptoms of urethritis are present (discharge, presence of polymorphonuclear leukocytes in the urethra or first-catch urine).

An evaluation of the polymerase chain reaction amplicor Chlamydia trachomatis in male urine and female urogenital specimens

BACKGROUND AND OBJECTIVES

The new commercially available polymerase chain reaction (PCR)-based assay, Amplicor C. trachomatis, was compared with cell culture of C. trachomatis, for the detection of chlamydial urogenital infections.

GOAL OF THIS STUDY

To evaluate whether the Amplicor C. trachomatis PCR could improve the diagnosis of chlamydial urogenital infections, compared with cell culture of C. trachomatis considered as the reference method.

STUDY DESIGN

A total of 466 men and 290 women attending a sexually transmitted disease (STD) clinic were tested by the Amplicor test in urine in men, and in the cervix and urethra in women, and by cell culture in the urethra of both men and women and in the cervix of the women.

RESULTS

The prevalence of C. trachomatis was 13.7% by cell culture and 14.4% by the Amplicor test in men, and 3.5% by cell culture and 4.5% by the Amplicor test in women. After resolution of the discrepant results, the sensitivity of culture was 91.4% in male urethral specimens and 83.3% in endocervical and female urethral specimens. The resolved sensitivity of the PCR assay was 92.7% in male urine, 91.7% in endocervical samples, and reached 100% in testing both endocervical and female urethral specimens.

CONCLUSION

This rapid PCR-based assay showed an improvement in quality for diagnosing C. trachomatis infections.