S. D. Gardner

New human papovavirus (B.K.) isolated from urine after renal transplantation.

Abstract The isolation of a new papovavirus Summary from the urine of a renal allograft recipient with ureteric obstruction is described. Virus particles were observed in the cells lining the ureter by electron microscopy, and high, rising antibody titres to the virus were demonstrated in the patients serum. This virus is not identical with any of the previously described members of the polyoma subgroup and has provisionally been named B.K. virus after the patient.

BK virus specific IgM responses in cord sera, young children and healthy adults detected by RIA.

SummaryAn IgM capture solid-phase radioimmunoassay (MACRIA) for BK virus (BKV) specific IgM is described. This test was found to be more sensitive in detecting BKV specific IgM than both haemagglutination inhibition and immune electron microscopy with serum fractions from sucrose density gradients. The use of this specific assay allowed large numbers of sera to be examined with ease so that the distribution of BKV specific IgM in different populations could be studied more fully.BKV specific IgM was detected in 11/300 sera from London blood donors, in 24/114 sera from children aged between 2 and 11 years admitted to a paediatric unit and 14/79 sera taken from children aged between 2 and 5 years for the investigation of anti-streptolysin 0 titres. BKV specific IgM was not detected in 404 cord sera examined to investigate the transplacental transfmission of BK virus.

Detection of human polyomavirus DNA in urine specimens by hybridot assay.

SummaryA hybridot assay method using a labelled BK virus probe has been used to detect the presence of human polyomavirus DNA in 81 urine specimens from 61 patients, most of whom were immuno-compromised to some degree. Twenty-eight urines from 23 patients had detectable DNA. The results have been compared to virus isolation and electron microscopy on the same specimens. In 90 per cent a comparable result was obtained by at least one of the other two tests and in the 73 specimens on which all 3 tests were performed there was 80 per cent agreement between all. In 6 cases the hybridot assay was more sensitive in detecting infection.

Characterisation of a Polyomavirus in two foetal rhesus monkey kidney cell lines used for the growth of hepatitis A virus

Electron microscopy and prolonged incubation of cell cultures have revealed the presence of a papovavirus in two foetal rhesus monkey kidney cell lines, FRhK-4 and FRhK-6, which are used to grow hepatitis A virus. The papovavirus, designated FRKV, was present in culture fluids from both cell lines and in thin sections of FRhK-4 cells. The size of the virus, 47 nm, places FRKV within the Polyomavirus genus. FRKV has been grown in primary human embryo kidney and calf kidney cell cultures. Haemagglutinin has not been demonstrated.

An indirect immunofluorescence method for detection of infectious BK virus in urine

An indirect immunofluorescence (IF) method is described for the detection of infectious BK virus in urine within seven days in contrast to up to three months or longer using routine tissue culture. Virus is pelleted from the urine, inoculated onto pre-formed monolayers of human embryo lung (HEL) fibroblasts, and infected cells are detected in an indirect fluorescent antibody test using a human serum. The sensitivity of the IF method is 91%. Positive isolates may be confirmed as BK virus using specific rabbit antisera on the original inoculated cultures. Furthermore, a virus stock may be grown up by passage from the original culture fluids for further studies such as DNA analysis. As a broadly-reactive human serum is used for screening the cultures, other viruses which grow in HEL cells, such as CMV, may also be detected.