- Email: [email protected]
MEASURED AND PREDICTED CREATININE CLEARANCE
815
MEASURED AND PREDICTED CREATININE CLEARANCE
1.73m2])
*Results
as
median
IN
(mlm7ri [per
70 WOMEN*
(first quartile, third quartile).
tMeasured/predicted.
sophisticated version of the formula, which depends on the expected excretion of creatinine per kilogram body weight at different ages, is necessary. The discrepancy was least for the lowest clearance values found in the highest age groups. Hence the prediction of clearance is a reasonable guide to the glomerular filtration rate in very elderly patients, in whom urine collection may be impossible without catheterisation. The very low clearance rates which we found in the age group 85-94 years fit in with the trend shown in the graphs of Elseviers et al. M. R. BLISS S. VELLUPILLAI P. A. C. JULIAN J. E. H. SHAW J. THOMAS
RH/H Clinical improvement and RH/H ratios.
improvement (cut-off below 20% improvement in BPRS); B = improvement (by more than 20%). A= no
concentrations
measuredand the ratio reduced haloperidol haloperidol/haloperidol (RH/H) was calculated. Patients were classed as non-responders (group A; BPRS improvement below 20%) or responders (group B; BPRS improvement more than 20%). Group A had a higher mean RH/H ratio than group B (2-87 [2’40] vs 0-94 [0’35]) (figure). The two groups did not differ in respect of age, duration of illness, BPRS before treatment, daily dosage of haloperidol, or absolute plasma concentrations of H, RH, orH+RH. Our fmdings suggest that the inconsistent fmdings in studies of plasma haloperidol and clinical response in schizophrenic patients is at least partly due to failure to assess RH/H ratios. were
A. C. ALTAMURA M. C. MAURI R. CAVALLARO
University Department of Psychiatry, Policlinico Guardia II, 20122 Milan, Italy
Department of Geriatric Medicine, Hackney Hospital, London E9 6BE 1 Cockcroft
SEROLOGICAL MARKERS FOR DELTA HEPATITIS
SIR,—Dr Aragona and colleagues (Feb 28, p 478) reported on the serological profile of hepatitis delta virus markers in 74 patients with acute delta hepatitis. Using a radioimmunoassay, they detected delta antigen in 17 patients (20 %) while IgM antibody was present in 69 (93%). They concluded that IgM anti-delta is the most important marker for delta hepatitis during acute infection. We have done a similar study in 59 patients with acute delta infection (42 co-infections of hepatitis B and delta hepatitis and 17 superinfections). At the time of the first sample, obtained within 2 weeks of the onset of symptoms delta antigen was detected in 3% and IgM antibody in 77%:
Curry SH, Montgomery S, et al. Early unwanted effects of fluphenazine esters related to plasma fluphenazine concentrations in schizophrenic patients Psychopharmacology 1985; 87: 30-33. 2. Smith RC, Schooler NR. Blood levels of haloperidol and clinical response. Psychopharmacol Bull 1985; 21: 48-72. 3 Ereshefsky L, Davis CM, Harrington CA, et al. Haloperidol and reduced haloperidol plasma levels in selected schizophrenic patients. J Clin Psychopharmacol 1984; 4: 138-42. 5. Moulin
J, Gorham D. Brief psychiatric rating scale. Psychol Rep 1962; 10: 799-812. MA, Camsonne R, Davy JP. Gas-chromatography electron impact and
chemical ionization
mass
antigen*
(with or without A. GORNI
1. Altamura AC,
4 Overall
Total
Co-infection Superinfection Delta
Mass Spectrometry Laboratory, State Health Department, Milan
DW, Gault MH. Prediction of creatinine clearance from serum creatinine.
Nephron 1976; 16: 31-41.
spectrometry of
homologue. J Chromatogr 1979; 178:
haloperidol
and its chloridrated
324-29.
MEASURED AND PREDICTED CREATININE CLEARANCE MR,—JJr blsevlers and
colleagues (-Feb 21, p 457) predicted creatinine clearance with the formula of Cockcroft and Gault! for outpatients in whom accurate urine collection may be difficult. In a study of changes of urine production with age, we have compared creatinine clearance predicted by this formula with measured clearance in 70 women without known renal disease, aged 19-100 years.
The predicted clearance underestimated the observed values by 15-20 ml/min (per 1-73 m2) between the ages of 25 to 75 (table). There was a break in the linear relation between the two sets of values under and over the age of 70, suggesting that a more
delta antibody) IgM anti-deltat
37/42 27/36
12/17 14/17
49/59 (83%) 41/53 (77%)
*’Deltassay’ (Notched, Dublin, Ireland). tMethod of Aragona et al; not tested for m 6 patients with co-infection.
The difference in delta antigen detection rate between our series and Aragona’s could be related to differences in the interval between onset of symptoms and hospital admission (not clearly stated in the report by Aragona et al) or to different sensitivities in the assays used. In our area almost all cases of delta hepatitis are in drug abusers, and such patients are difficult to follow up; thus, the diagnosis of acute delta infection should be established as soon as possible. We agree with Aragona and colleagues that IgM anti-delta is a useful diagnostic marker. However, this test is not readily available in most laboratories and repeat testing may be required. We believe that, for the present, the measurement of delta antigen by a sensitive technique is the best marker for the diagnosis of acute delta
hepatitis.’ Department of Internal Medicine, Ciudad Sanitaria Valle de Hebron, Universidad Autonoma, Barcelona, Spain 1. Buti M, Esteban R, Jardi
M. BUTI R. ESTEBAN R. JARDI J. I. ESTEBAN J. GUARDIA
R, Esteban JI, Guardia J Serological diagnosis of acute delta hepatitis. J Med Virol 1986; 1: 81-86.
MEASURED AND PREDICTED CREATININE CLEARANCE
1.73m2])
*Results
as
median
IN
(mlm7ri [per
70 WOMEN*
(first quartile, third quartile).
tMeasured/predicted.
sophisticated version of the formula, which depends on the expected excretion of creatinine per kilogram body weight at different ages, is necessary. The discrepancy was least for the lowest clearance values found in the highest age groups. Hence the prediction of clearance is a reasonable guide to the glomerular filtration rate in very elderly patients, in whom urine collection may be impossible without catheterisation. The very low clearance rates which we found in the age group 85-94 years fit in with the trend shown in the graphs of Elseviers et al. M. R. BLISS S. VELLUPILLAI P. A. C. JULIAN J. E. H. SHAW J. THOMAS
RH/H Clinical improvement and RH/H ratios.
improvement (cut-off below 20% improvement in BPRS); B = improvement (by more than 20%). A= no
concentrations
measuredand the ratio reduced haloperidol haloperidol/haloperidol (RH/H) was calculated. Patients were classed as non-responders (group A; BPRS improvement below 20%) or responders (group B; BPRS improvement more than 20%). Group A had a higher mean RH/H ratio than group B (2-87 [2’40] vs 0-94 [0’35]) (figure). The two groups did not differ in respect of age, duration of illness, BPRS before treatment, daily dosage of haloperidol, or absolute plasma concentrations of H, RH, orH+RH. Our fmdings suggest that the inconsistent fmdings in studies of plasma haloperidol and clinical response in schizophrenic patients is at least partly due to failure to assess RH/H ratios. were
A. C. ALTAMURA M. C. MAURI R. CAVALLARO
University Department of Psychiatry, Policlinico Guardia II, 20122 Milan, Italy
Department of Geriatric Medicine, Hackney Hospital, London E9 6BE 1 Cockcroft
SEROLOGICAL MARKERS FOR DELTA HEPATITIS
SIR,—Dr Aragona and colleagues (Feb 28, p 478) reported on the serological profile of hepatitis delta virus markers in 74 patients with acute delta hepatitis. Using a radioimmunoassay, they detected delta antigen in 17 patients (20 %) while IgM antibody was present in 69 (93%). They concluded that IgM anti-delta is the most important marker for delta hepatitis during acute infection. We have done a similar study in 59 patients with acute delta infection (42 co-infections of hepatitis B and delta hepatitis and 17 superinfections). At the time of the first sample, obtained within 2 weeks of the onset of symptoms delta antigen was detected in 3% and IgM antibody in 77%:
Curry SH, Montgomery S, et al. Early unwanted effects of fluphenazine esters related to plasma fluphenazine concentrations in schizophrenic patients Psychopharmacology 1985; 87: 30-33. 2. Smith RC, Schooler NR. Blood levels of haloperidol and clinical response. Psychopharmacol Bull 1985; 21: 48-72. 3 Ereshefsky L, Davis CM, Harrington CA, et al. Haloperidol and reduced haloperidol plasma levels in selected schizophrenic patients. J Clin Psychopharmacol 1984; 4: 138-42. 5. Moulin
J, Gorham D. Brief psychiatric rating scale. Psychol Rep 1962; 10: 799-812. MA, Camsonne R, Davy JP. Gas-chromatography electron impact and
chemical ionization
mass
antigen*
(with or without A. GORNI
1. Altamura AC,
4 Overall
Total
Co-infection Superinfection Delta
Mass Spectrometry Laboratory, State Health Department, Milan
DW, Gault MH. Prediction of creatinine clearance from serum creatinine.
Nephron 1976; 16: 31-41.
spectrometry of
homologue. J Chromatogr 1979; 178:
haloperidol
and its chloridrated
324-29.
MEASURED AND PREDICTED CREATININE CLEARANCE MR,—JJr blsevlers and
colleagues (-Feb 21, p 457) predicted creatinine clearance with the formula of Cockcroft and Gault! for outpatients in whom accurate urine collection may be difficult. In a study of changes of urine production with age, we have compared creatinine clearance predicted by this formula with measured clearance in 70 women without known renal disease, aged 19-100 years.
The predicted clearance underestimated the observed values by 15-20 ml/min (per 1-73 m2) between the ages of 25 to 75 (table). There was a break in the linear relation between the two sets of values under and over the age of 70, suggesting that a more
delta antibody) IgM anti-deltat
37/42 27/36
12/17 14/17
49/59 (83%) 41/53 (77%)
*’Deltassay’ (Notched, Dublin, Ireland). tMethod of Aragona et al; not tested for m 6 patients with co-infection.
The difference in delta antigen detection rate between our series and Aragona’s could be related to differences in the interval between onset of symptoms and hospital admission (not clearly stated in the report by Aragona et al) or to different sensitivities in the assays used. In our area almost all cases of delta hepatitis are in drug abusers, and such patients are difficult to follow up; thus, the diagnosis of acute delta infection should be established as soon as possible. We agree with Aragona and colleagues that IgM anti-delta is a useful diagnostic marker. However, this test is not readily available in most laboratories and repeat testing may be required. We believe that, for the present, the measurement of delta antigen by a sensitive technique is the best marker for the diagnosis of acute delta
hepatitis.’ Department of Internal Medicine, Ciudad Sanitaria Valle de Hebron, Universidad Autonoma, Barcelona, Spain 1. Buti M, Esteban R, Jardi
M. BUTI R. ESTEBAN R. JARDI J. I. ESTEBAN J. GUARDIA
R, Esteban JI, Guardia J Serological diagnosis of acute delta hepatitis. J Med Virol 1986; 1: 81-86.