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munofluorescence’ and electron-microscopic studies of kidneybiopsy material from four patients with epidemic nephropathy. Patients were males, 19-36 years of age. Biopsies were done 8-18 days after the onset of fever. The highest serum-creatinine and urine-protein values varied between 207 and 670 mg/ml, respectively. timol/1 and 2-0and 12-0 studies showed patchy granular deImmunofluorescence and C3 the capillary basement memIgG, along of IgM, posits brane and in the mesangium in three cases (figure). The deposition was less heavy than that usually seen in proliferative glomerulonephritis. In one patient in whom biopsy was done 18 days after the onset of fever, IgM, IgG, and C3 were found in the mesangial areas. No IgA was found. In all patients occasional tubules showed deposition of the three components along their basement membranes. Electron microscopy demonstrated sparse intramembranous granular deposits and light fibrillar subendothelial deposits in all cases. In the patient tested 18 days after the onset of fever there were dark mesangial deposits also. Our studies suggest that immune complexes are deposited in the glomeruli and tubules in epidemic nephropathy. The medullary haemorrhagic and inflammatory changes are so prominent that they might be due to a different mechanism, perhaps the presence of the aetiological agents (possibly virus) in the medulla. Departments of Serology and Bacteriology and Pathology, and Third Department of Medicine, University of Helsinki SF-00290 Helsinki 29, Finland

E. J. JOKINEN Y. COLLAN

J. LÄHDEVIRTA

tion. A strain Ps. aeruginosa was isolated from a catheter specimen of urine from a tetraplegic patient and a strain of Ps. stutzeri from a neck abscess. The patients were in different wards of the same hospital. The pigment was similar in colour to the prodigiosin produced by S. marcescens, but differed from it in that it diffused into the surrounding medium. Public Health Laboratory, St. Mary’s General Hospital, East Wing, Milton Road, Portsmouth PO3 6AQ

ROSALIND MASKELL J. CRUMP R. LEE

LYMPHOCYTOTOXIC ANTIBODIES IN SUBACUTE SCLEROSING PANENCEPHALITIS AND AMYOTROPHIC LATERAL SCLEROSIS

SIR,-Cold-reactive lymphocytotoxic antibodies (L.C.A.) have been demonstrated in patients with viral infectionsl and various autoimmune diseases thought to be related to viral infection (e.g., systemic lupus erythematosus,2 rheumatoid arthritis,2 inflammatory bowel disease,3 chronic active hepatitis,44 and multiple sclerosis5). We have found L.C.A. in the sera of 46% of multiple-sclerosis patients tested, and, although there was no correlation between L.C.A. and activity or extent of disease, there was a correlation between serum measles-antibody titre and L.C.A. cytotoxicity indices.6 In view of this we have looked for L.C.A. in the sera of eleven children with subacute sclerosing panencephalitis (S.S.P.E.), a disorder of the central nervous system associated with a persistent and aberrant measles infection. The accompanying figure shows a significant increase of L.c.A. in children with S.S.P.E. S. W., Lattos, D. B., Nelson, D. B., Reeb, K., Huang, R. J. clin. In1973, 52, 103. 2. Terasaki, P. I., Mottironi, V. D., Barnett, E. V. New Engl. J. Med. 1970, 283, 724. 3. Korsmeyer, S., Strickland, R. G., Wilson, I. D., Williams, R. C. Gastroenterology, 1974, 67, 578. 4. Husby, G., Pierce, P. E., Williams, R. C. Ann. intern. Med. 1975, 83, 801. 5. Kuwert, E., Bertrams, J. J. Eur. Neurol. 1972, 7, 65. 6. Schocket, A. L., Weiner, H. L., Walker, J., McIntosh, K., Kohler, P. F. Clin. Immun. Immunopath. 1977, 7, 15.

1.

Huang, vest.

IMPORTANCE OF SERRATIA MARCESCENS

SIR,-In your editorial (March 19, p. 636) you discuss the importance of Serratia marcescens as an opportunistic pathogen in hospital. This organism is also seen in domiciliary practice. During the first three months of 1976 we identified all the pathogens isolated in significant culture from urine specimens examined in our laboratory at the request of general practitioners.’ Amongst these were two strains of Serratia, and a third strain was isolated at the end of the study. The patients, two women and one man, were all over 65, and had presented with symptoms of urinary infection. None had been in hospital for at least three years before the infection. Two strains were identified as S. marcescens and one as S. liquefaciens ; their identity was confirmed by the N.C.T.C. (Computer Trials Laboratory). None were pigment producers. All were sensitive in vitro to co-trimoxazole and nalidixic acid, and the S. liquefaciens was also sensitive to sulphonamide and amoxycillin. Two were tested for sensitivity to gentamicin, and both were sensitive. They were, therefore, not unduly resistant, and it is unlikely that they would have been singled out for identification as part of the routine laboratory procedures. We agree with Dr Severn (April 2, p. 750) that testing of Enterobacteriacex for D.N.A.se production is not a routine procedure in most diagnostic laboratories; the strains we report would probably not have been identified had they been isolated at a time other than that of the study cited; furthermore, the strain of

S, liquefaciens did not produce D.N.A.se. You state that the strains of S. marcescens which cause infection are not pigmented. Two years ago, however, we repeatedly isolated a pigment-producing strain of S. marcescens from an elderly man with acute urinary symptoms and pyuria. He responded symptomatically and bacteriologically to co-trimoxazole. We have lately isolated two red pigment-producing strains of Pseudomonas from patients with clinical evidence of infec-

5. Runeberg,

L. Lähdevirta, J., Collan, Y., Jokinen, E. J. 1971, 189, 341. 1. Crump, J., Pead, L., Maskell, R. Lancet, 1976, i, 1184.

Acta med scand.

indices for children with S.S.P.E. and age and matched controls.

Cytotoxicity

sex

The mean ± s.E. index for S.S.P.E. patients was 35.9 ± 3-8 compared with 17.7 + 2.4 for the controls (r