Tag: immunofluorescence

Evaluation of a recombinant line blot for diagnosis of Epstein-Barr Virus compared with ELISA, using immunofluorescence as reference method

Abstract:

A commercial line blot using recombinant antigens was compared with a commercial ELISA and ‘in-house’ IFA (reference test). Two panels were evaluated: Panel A was selected to distinguish between primary infections (89), past infections (20) and seronegatives (8) in immunocompetent individuals. In panel B, patients with a high number of reactivations were included: immunosuppressed patients (37), lymphoma (19), nasopharyngeal carcinoma (10), chronic fatigue syndrome (14). Blood donors (43) and cross-reactive sera (29) were added as controls.

Line blot and IFA were concordant in 94% of primary infections, 100% of seronegatives and 100% of past infections, similar to ELISA. Results differed significantly with regard to reactivations. When compared with IFA, the incidence of reactivations was overestimated by the blot, 24 and 58% in blood donors and cross-reactive sera, respectively. ELISA showed a similar problems with 21 and 34% indeterminate results, respectively.

The line blot is easy to carry out, has a good concordance with the reference IFA for primary infections, and is, therefore, a sufficient choice for distinguishing primary infection from seronegative and past infection. EBV reactivation assessment will require other methods such as EBV viral load.

 

Source: Gärtner BC, Fischinger JM, Roemer K, Mak M, Fleurent B, Mueller-Lantzsch N. Evaluation of a recombinant line blot for diagnosis of Epstein-Barr Virus compared with ELISA, using immunofluorescence as reference method. J Virol Methods. 2001 Apr;93(1-2):89-96. http://www.ncbi.nlm.nih.gov/pubmed/11311347

 

Clinical features and IgG subclass distribution of anti-p80 coilin antibodies

Abstract:

We examined the clinical features of patients presenting antinuclear autoantibodies against p80-coilin and the IgG subclass distribution of anti- p80-coilin antibodies. Sera from 365 Japanese patients were analysed. Immunoblotting and indirect immunofluorescence microscopy techniques were used with a polyclonal rabbit antiserum against p80-coilin. Eleven patients with anti-p80-coilin antibodies were found. All the patients were female and nine were in their twenties. None could be diagnosed with differentiated rheumatic disease except for one case of systemic scleroderma and another of Sjögren’s syndrome. Most patients had general fatigue, arthralgia, headaches, dysmenorrhea, lymph node swelling and/or low grade fever such as chronic fatigue syndrome (CFS), and showed low complement. One patient fulfilled the criteria for CFS. All were younger females than those often diagnosed with rheumatic disease in previous reports. Patients’ sera had a predominant distribution of subclass IgG(1)anti-p80-coilin antibodies and five sera had concomitant subclass IgG(2). Two rheumatic disease patients had a relatively high titer of IgG(2)anti-p80-coilin antibodies. The IgG(2)subclass of anti-p80-coilin antibodies may be a specific marker for systemic autoimmune disease.

 

Source: Onouchi H, Muro Y, Tomita Y. Clinical features and IgG subclass distribution of anti-p80 coilin antibodies. J Autoimmun. 1999 Sep;13(2):225-32. http://www.ncbi.nlm.nih.gov/pubmed/10479391

 

High prevalence without reactivation of herpes virus 6 in subjects with chronic fatigue syndrome

Abstract:

INTRODUCTION: Chronic fatigue syndrome (CFS) is a disorder of unknown etiology. Some viruses have been associated with CFS etiology, specially herpesviruses, enteroviruses and retroviruses. Some studies suggest an association between human herpesvirus-6 (HHV-6) and CFS. In order to know if there is an active HHV-6 infection in CFS patients we studied the immunologic and virologic status of HHV-6.

MATERIALS AND METHODS: Twenty patients with CFS were studied. IgG and IgM anti HHV-6 were determined by indirect immunofluorescence assay. DNA from serum and peripheral blood mononuclear cells (PBMC) were studied by dot- and Southern-blotting and nested-PCR to detect HHV-6 DNA. HHV-6 RNA from PBMC were amplified by RT(retrotranscription)-PCR.

RESULTS: Ten patients (50%) had IgG anti-HHV-6 in serum but none had IgM anti-HHV-6. Dot-blotting of DNA from 200 microliters of serum and Southern-blotting of 10 micrograms of PBMC DNA were negative. Nested-PCR from sera were negative. Nested-PCR with 1 microgram PBMC DNA were positive in 8 out 20 (40%) and with 5 micrograms PBMC DNA were positive in 16 out of 20 (80%). No viral RNA were detected in PBMC.

CONCLUSIONS: There is a high proportion of CFS patients infected with HHV-6 but with low viral load. Results do not support HHV-6 reactivation in CFS patients.

 

Source: Cuende JI, Civeira P, Diez N, Prieto J. High prevalence without reactivation of herpes virus 6 in subjects with chronic fatigue syndrome. An Med Interna. 1997 Sep;14(9):441-4. [Article in Spanish] http://www.ncbi.nlm.nih.gov/pubmed/9453750

 

High frequency of autoantibodies to insoluble cellular antigens in patients with chronic fatigue syndrome

Abstract:

OBJECTIVE: To elucidate the humoral immune response in patients with chronic fatigue syndrome (CFS), by identification and characterization of autoantibodies.

METHODS: Initial immunofluorescence histochemistry studies of sera using human HEp-2 cell substrate were followed by antibody class subtyping and colocalization studies with reference antibodies. Association of CFS autoantigens with insoluble cellular components was determined by in situ extraction of soluble components and subsequent immunofluorescence histochemistry studies on the extracted cell substrate.

RESULTS: Of 60 CFS patients, 41 (68%) were positive for antinuclear antibodies. Localization of nuclear staining was found at the nuclear envelope (52%), in reticulated speckles (25%), in nucleoli (13%), and in dense fine speckles (5%). Twenty-eight CFS sera (47%) also had antibodies to cytoplasmic antigens. The major cytoplasmic staining pattern was of the intermediate filament type (35%). The observed nuclear envelope pattern of staining co-localized with lamina-associated polypeptide 2 (an integral nuclear membrane protein), the reticulated speckle pattern co-localized with non-small nuclear RNP splicing factor SC-35, and the intermediate filament pattern co-localized with vimentin. The intermediate filament antigen was shown to be vimentin in immunoblotting experiments using recombinant human vimentin, and one of the nuclear envelope antigens was shown previously to be lamin B1. Fifty of the 60 CFS patients (83%) had antibodies to one or another of these antigens, all of which are relatively insoluble cellular antigens, whereas a control group of patients without chronic fatigue had a significantly lower frequency of such antibodies (17%).

CONCLUSION: The high frequency of autoantibodies to insoluble cellular antigens in CFS represents a unique feature which might help to distinguish CFS from other rheumatic autoimmune diseases.

Comment in: Incidence of antinuclear antibodies in Japanese patients with chronic fatigue syndrome. [Arthritis Rheum. 1997]

 

Source: von Mikecz A, Konstantinov K, Buchwald DS, Gerace L, Tan EM. High frequency of autoantibodies to insoluble cellular antigens in patients with chronic fatigue syndrome. Arthritis Rheum. 1997 Feb;40(2):295-305. http://www.ncbi.nlm.nih.gov/pubmed/9041942

 

Autoantibodies to nuclear envelope antigens in chronic fatigue syndrome

Abstract:

We have identified and partially characterized the autoantibodies in sera of 60 patients with chronic fatigue syndrome. Approximately 52% of the sera were found to react with nuclear envelope antigens.

The combination of nuclear rim staining observed in immunofluorescence microscopy and immunoblot analysis of highly purified nuclear envelope proteins provided initial characterization of these autoantibodies. Further characterization showed that some sera immunoprecipitated the in vitro transcription and translation product of a human cDNA clone encoding the nuclear envelope protein lamin B1. The autoantibodies were of the IgG isotype.

The occurrence of autoantibodies to a conserved intracellular protein like lamin B1 provides new laboratory evidence for an autoimmune component in chronic fatigue syndrome.

 

Source: Konstantinov K, von Mikecz A, Buchwald D, Jones J, Gerace L, Tan EM. Autoantibodies to nuclear envelope antigens in chronic fatigue syndrome. J Clin Invest. 1996 Oct 15;98(8):1888-96. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC507629/ (Full article)

 

Human herpesvirus 6 and chronic fatigue syndrome

Abstract:

The cause of chronic fatigue syndrome (CFS) is still enigmatic. Using indirect immunofluorescence testing for measuring antibody against human herpesvirus 6 (HHV-6), this study investigated the association of CFS with infection by HHV-6. Seventeen patients (group A) fulfilling the Centers for Disease Control (CDC) definition for CFS were compared with eight patients (group B) with chronic fatigue but not meeting the CDC criteria.

No significant difference was found between the two groups for 30 parameters including sex, age, exposure to children and serology for Epstein-Barr virus, cytomegalovirus, herpes simplex virus, and toxoplasma. Univariate analysis showed that patients in group A complained more frequently of a sore throat, headache and of recurrent type of fatigue.

These three parameters are discriminant in identifying patients who will meet the CDC case definition of CFS. The titre of antibody against HHV-6 in group A (1:99) was significantly higher than in group B (1:15) (P=0.007). Elevated HHV-6 titres suggests that this virus could be a cofactor in the pathogenesis of CFS.

 

Source: Eymard D, Lebel F, Miller M, Turgeon F. Human herpesvirus 6 and chronic fatigue syndrome. Can J Infect Dis. 1993 Jul;4(4):199-202. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3250792/  (Full article)

 

Japanese patients with chronic fatigue syndrome are negative for known retrovirus infections

Abstract:

Although chronic fatigue syndrome (CFS) is known to be the syndrome that begins with an acute flu-like illness that may be due to the exposure to an infectious agent, there has been no convincing evidence on the causative agents.

Recently, human T-lymphotropic virus type II (HTLV-II)-like virus has been reported to be associated with the CFS by using HTLV Western blot analysis and polymerase chain reaction. However, some investigators could not detect HTLV-II by indirect immunofluorescence analysis.

Lately, CFS patients have been reported in Japan. We detected all 30 tested patients with CFS were seronegative for HTLV-II, HTLV-I and HIV by specific peptide ELISA and Western blot. Further, PCR analysis was negative for HTLV-II and retrovirus was not detected by coculture method with patients’ PBMC. Thus, known human retrovirus infections do not cause a CFS in Japan.

 

Source: Honda M, Kitamura K, Nakasone T, Fukushima Y, Matsuda S, Nishioka K, Matsuda J, Hashimoto N, Yamazaki S. Japanese patients with chronic fatigue syndrome are negative for known retrovirus infections. Microbiol Immunol. 1993;37(10):779-84. http://www.ncbi.nlm.nih.gov/pubmed/7507200

 

Infectious mononucleosis, Epstein-Barr virus, and chronic fatigue syndrome: a prospective case series

Abstract:

Epstein-Barr viral infection, specifically infectious mononucleosis, typically has a more protracted course than other acute viral illnesses. Some recent observers have additionally suggested the possibility that Epstein-Barr virus (EBV) is the etiologic infectious agent in chronic fatigue syndrome, based on the finding of higher proportions of elevated antibodies to the EBV early antigen in some patients complaining of chronic fatigue.

Straus et al reported on 23 patients with chronic fatigue, 83% of whom exhibited persistently elevated antibodies in modest titer to the early antigen. Ten of these patients had never fully recovered from an episode of acute infectious mononucleosis. Other studies had noted similar associations between persistently elevated antibodies to EBV-specific antigens and chronic symptoms in patients who presented with chronic symptoms after mononucleosis.

Three important antigen complexes, demonstrable by immunofluorescence procedures, are expressed in EBV-infected cells. The early antigen is thought to function perhaps in early replication of viral DNA. A late antigenic complex, the viral capsid antigen, may represent, in addition to structural capsid proteins, components of the viral enzymatic machinery for late phases of replication or transformation. The Epstein-Barr nuclear antigen is felt to function in viral transformation of host cells.

 

Source: Fark AR. Infectious mononucleosis, Epstein-Barr virus, and chronic fatigue syndrome: a prospective case series. J Fam Pract. 1991 Feb;32(2):202, 205-6, 209. http://www.ncbi.nlm.nih.gov/pubmed/1846641