271
CORRESPONDENCE AND CORRECTIONS
comparison data." Other statistical parameters are more valuable, in fact essential, for proper comparisons. To provide a data base that can be more easily evaluated by other readers, the suggestions by Godfrey6 should be considered if and when simple linear regression analysis is appropriately used in publications. I would suggest that a Deming type of analysis deserves additional investigation as a tool for evaluating methods for determining white cell differential counts. WILLIAM R. SWAIN,
2.
3.
4.
M.D.
Department of Veterans Affairs Medical Center Minneapolis, Minnesota References
5.
6.
1. Swaim WR. Laboratory and clinical evaluation of white blood cell differential
counts, comparison of the Coulter VCS, Technicon H-l, and 800-cell manual method. Am J Clin Pathol 1991;95:381388. Cornbleet PJ, Gochman N. Incorrect least-squares regression coefficients in method-comparison analysis. Clin Chem 1979;25:432-438. Wakkers PJM, Hellendoorn HBA, Op de Weegh GJ, Heerspink W. Applications of statistics in clinical chemistry. Clin Chem Acta 1975;64:173-184. Rumke CL. The statistically expected variability in differential counting. In: Koepke JA, ed. Differential Leukocyte Counting. Skokie, Illinois: College of American Pathologists, 1978:39-45. Westgaard JO, Hunt MR. Use and interpretation of common statistical tests in method-comparison studies. Clin Chem 1973;19:49-57. Godfrey K. Statistics in practice. Simple linear regression in medical research. N Engl J Med 1985;313:1629-1636.
Pseudosarcomatous Tumors of the Lower Urinary Tract To the Editor:—The recent report to Sahin and colleagues' on pseudosarcomatous tumors of the lower urinary tract indicating the limited follow-up on these unusual proliferative lesions, prompted me to write this brief note. The patient I described in 19802 is
without evidence of disease at this time. Close clinical follow-up has been assured because the patient married the treating urologist. JOEL A. ROTH,
M.D.
Overlook Hospital Summit, New Jersey
References 1. Sahin AA, Ro JY, El-Naggar AK, et al. Pseudosarcomatousfibromyxoidtumor of the prostate. Am J Clin Pathol 1991;96:253-258. 2. Roth JA. Reactive pseudosarcomatous response in the urinarv bladder. Urology 1980;16:635-637.
The Authors' Reply To the Editor:—We thank Dr. Roth for his letter that updates the follow-up information on his previously reported case of pseudosarcoma of urinary bladder.1 Obviously, the 12-year follow-up with no disease recurrence in this case
strongly supports the benign nature of this process. AYSEGUL A. SAHIN, JAE
M.D.
Y. Ro, M.D.
ALBERTO G. AYALA,
M.D.
The University of Texas
MD Anderson Cancer Center Houston, Texas Reference 1. Roth JA. Reactive Pseudosarcomatous response in the urinarv bladder. Urology 1980;16:635-637.
Cold Agglutinin Disease After Chickenpox To the Editor:—I would like to add an additional case of cold agglutinin disease after chickenpox to the report by Friedman and Dracker.' In the mid-1970s, a 6-year-old boy was admitted to the North Carolina Memorial Hospital in Chapel Hill because of anemia that was first noted approximately 5 days after the eruption
of the varicella exanthem. His hemoglobin level, as I recall, was between 8 and 9 g/ dL on admission. He was treated with a short course of corticosteroids and recovered within a few days with no complications. During admission workup, we found that the boy had an IgM cold agglutinin
Vol. 98 • No. 2
with Pr specificity but with no apparent reactivity of the antibody with his own red cells after recovery. We wanted to determine whether the varicella virus acted as a hapten or directly resulted in red cell antigenic alteration, but we were unable to do so. The case was not reported at the time.
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 6, 2016
manual optical differential would have significant error. A Deming regression of the data by Vinatier, Picard, and Fialon would be of interest. An additional estimate of accuracy could be obtained by an evaluation of the fit of data points within a Rumke binomial envelope.4 Information of interest would also include estimates of imprecision from analysis of replicates and pair differences. Correlation coefficients are one of the more frequently used statistical values. Unfortunately, this coefficient cannot be used with confidence to indicate that the accuracy of monocyte recognition has improved. At best, the correlation coefficient provides an incomplete estimate of random error that could be provided more completely, as indicated above. As Westgaard5 has indicated, it is of "no practical use in the statistical analyses of
272
CORRESPONDENCE AND CORRECTIONS
According to the report by Friedman and Dracker,' this patient represents the sixth reported case of autoimmune hemolytic anemia and the third with anti-Pr cold agglutinin disease after chickenpox.
A. MYRON JOHNSON,
M.D.
University of North Carolina School of Medicine Moses H. Cone Memorial Hospital Greensboro, North Carolina
Reference 1. Friedman HD, Dracker RA. Cold agglutinin disease after chickenpox: An uncommon complication of a common disease. Am J Clin Pathol 1992;97:9296.
The Authors' Reply
We share his fascination with the origin of cold agglutinin disease in chickenpox. Although significant progress has been made toward elucidation of the mechanism of cold agglutinin-mediated hemolysis, the basis for the association of cold agglutinins with infection remains obscure. Simple cross-immunity between microbial and red cell-surface antigens would appear to be the pathogenesis of most cold agglutinins; however, this is difficult and often impossible to demonstrate. 35 Other hypotheses are centered about: 1. microbial-induced alteration of normal erythrocytic antigens,
2. microbial-induced immune dysfunction, 23 and 3. the cold agglutinin as an anti-idiotype antibody.5 Another mystery is the late appearance of most infection-associated cold agglutinins, typically in the convalescent period.1 Possible reasons for this include: 1. many sick patients simply may not expose themselves to the cold until convalescence, 2. cellular immunity may be paramount in overcoming certain infections, 3. the cold agglutinin may be a component of an evolving immune response, 4. microbe-induced immune suppression, and 5. microbe-induced alteration of normal erythrocytic surface antigens (i.e., their reappearance is met with an antigenic response). The extent to which these two fundamental issues are avoided, even in recent and otherwise outstanding reviews on the subject,4"6 reflects the extent of general ignorance. We, and many far wiser than we,
A.J.C.P. • August 1992
surmise that these answers are intricately interwoven in the foundation of the immune system, whose many mysteries are generally well recognized (and, in 1992, well accepted). H. D. FRIEDMAN R. A. DRACKER
VA Medical Center Syracuse, New York References 1. Dacie JV. The haemolytic anaemias-part II: The auto-immune haemolytic anaemias. Second edition. New York: Grune and Stratton, 1962 pp 526-540. 2. Gieseler RG, Koebberling J. Koelteagglutininkrankheit. Klin Wochenschr 1988;66:277-283. 3. Habibi B. Anaemies hemolytiques autoimmunes. Pathol Biol (Paris) 1988,36: 1151-1171. 4. Nydegger UE, Kazatchkine MD, Miescher PA. Immunopathologic and clinical features of hemolytic anemia due to cold agglutinins. Semin Hematol 1991;28: 66-77. 5. Roelcke D. Cold agglutination. Transfus Med Rev 1989;3:140-166. 6. Engelfriet CP, Overbeeke MAM, von dem Borne AEGK. Autoimmune hemolytic anemia. Semin Hematol 1992;29:3-12.
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 6, 2016
To the Editor:—We thank Dr. Johnson for making us aware of an additional case of cold agglutinin disease after chickenpox. It is indeed curious that the cold agglutinin in his case also had anti-Pr specificity. Dr. Johnson's observation that the cold agglutinin in his case failed to react with the patient's own cells after recovery is indeed interesting. Our patient's cold agglutinin reacted with all panel cells tested during workup. Therefore we think it probable that it would have reacted with the patient's red cells after recovery had we tested for this.
CORRESPONDENCE AND CORRECTIONS
comparison data." Other statistical parameters are more valuable, in fact essential, for proper comparisons. To provide a data base that can be more easily evaluated by other readers, the suggestions by Godfrey6 should be considered if and when simple linear regression analysis is appropriately used in publications. I would suggest that a Deming type of analysis deserves additional investigation as a tool for evaluating methods for determining white cell differential counts. WILLIAM R. SWAIN,
2.
3.
4.
M.D.
Department of Veterans Affairs Medical Center Minneapolis, Minnesota References
5.
6.
1. Swaim WR. Laboratory and clinical evaluation of white blood cell differential
counts, comparison of the Coulter VCS, Technicon H-l, and 800-cell manual method. Am J Clin Pathol 1991;95:381388. Cornbleet PJ, Gochman N. Incorrect least-squares regression coefficients in method-comparison analysis. Clin Chem 1979;25:432-438. Wakkers PJM, Hellendoorn HBA, Op de Weegh GJ, Heerspink W. Applications of statistics in clinical chemistry. Clin Chem Acta 1975;64:173-184. Rumke CL. The statistically expected variability in differential counting. In: Koepke JA, ed. Differential Leukocyte Counting. Skokie, Illinois: College of American Pathologists, 1978:39-45. Westgaard JO, Hunt MR. Use and interpretation of common statistical tests in method-comparison studies. Clin Chem 1973;19:49-57. Godfrey K. Statistics in practice. Simple linear regression in medical research. N Engl J Med 1985;313:1629-1636.
Pseudosarcomatous Tumors of the Lower Urinary Tract To the Editor:—The recent report to Sahin and colleagues' on pseudosarcomatous tumors of the lower urinary tract indicating the limited follow-up on these unusual proliferative lesions, prompted me to write this brief note. The patient I described in 19802 is
without evidence of disease at this time. Close clinical follow-up has been assured because the patient married the treating urologist. JOEL A. ROTH,
M.D.
Overlook Hospital Summit, New Jersey
References 1. Sahin AA, Ro JY, El-Naggar AK, et al. Pseudosarcomatousfibromyxoidtumor of the prostate. Am J Clin Pathol 1991;96:253-258. 2. Roth JA. Reactive pseudosarcomatous response in the urinarv bladder. Urology 1980;16:635-637.
The Authors' Reply To the Editor:—We thank Dr. Roth for his letter that updates the follow-up information on his previously reported case of pseudosarcoma of urinary bladder.1 Obviously, the 12-year follow-up with no disease recurrence in this case
strongly supports the benign nature of this process. AYSEGUL A. SAHIN, JAE
M.D.
Y. Ro, M.D.
ALBERTO G. AYALA,
M.D.
The University of Texas
MD Anderson Cancer Center Houston, Texas Reference 1. Roth JA. Reactive Pseudosarcomatous response in the urinarv bladder. Urology 1980;16:635-637.
Cold Agglutinin Disease After Chickenpox To the Editor:—I would like to add an additional case of cold agglutinin disease after chickenpox to the report by Friedman and Dracker.' In the mid-1970s, a 6-year-old boy was admitted to the North Carolina Memorial Hospital in Chapel Hill because of anemia that was first noted approximately 5 days after the eruption
of the varicella exanthem. His hemoglobin level, as I recall, was between 8 and 9 g/ dL on admission. He was treated with a short course of corticosteroids and recovered within a few days with no complications. During admission workup, we found that the boy had an IgM cold agglutinin
Vol. 98 • No. 2
with Pr specificity but with no apparent reactivity of the antibody with his own red cells after recovery. We wanted to determine whether the varicella virus acted as a hapten or directly resulted in red cell antigenic alteration, but we were unable to do so. The case was not reported at the time.
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 6, 2016
manual optical differential would have significant error. A Deming regression of the data by Vinatier, Picard, and Fialon would be of interest. An additional estimate of accuracy could be obtained by an evaluation of the fit of data points within a Rumke binomial envelope.4 Information of interest would also include estimates of imprecision from analysis of replicates and pair differences. Correlation coefficients are one of the more frequently used statistical values. Unfortunately, this coefficient cannot be used with confidence to indicate that the accuracy of monocyte recognition has improved. At best, the correlation coefficient provides an incomplete estimate of random error that could be provided more completely, as indicated above. As Westgaard5 has indicated, it is of "no practical use in the statistical analyses of
272
CORRESPONDENCE AND CORRECTIONS
According to the report by Friedman and Dracker,' this patient represents the sixth reported case of autoimmune hemolytic anemia and the third with anti-Pr cold agglutinin disease after chickenpox.
A. MYRON JOHNSON,
M.D.
University of North Carolina School of Medicine Moses H. Cone Memorial Hospital Greensboro, North Carolina
Reference 1. Friedman HD, Dracker RA. Cold agglutinin disease after chickenpox: An uncommon complication of a common disease. Am J Clin Pathol 1992;97:9296.
The Authors' Reply
We share his fascination with the origin of cold agglutinin disease in chickenpox. Although significant progress has been made toward elucidation of the mechanism of cold agglutinin-mediated hemolysis, the basis for the association of cold agglutinins with infection remains obscure. Simple cross-immunity between microbial and red cell-surface antigens would appear to be the pathogenesis of most cold agglutinins; however, this is difficult and often impossible to demonstrate. 35 Other hypotheses are centered about: 1. microbial-induced alteration of normal erythrocytic antigens,
2. microbial-induced immune dysfunction, 23 and 3. the cold agglutinin as an anti-idiotype antibody.5 Another mystery is the late appearance of most infection-associated cold agglutinins, typically in the convalescent period.1 Possible reasons for this include: 1. many sick patients simply may not expose themselves to the cold until convalescence, 2. cellular immunity may be paramount in overcoming certain infections, 3. the cold agglutinin may be a component of an evolving immune response, 4. microbe-induced immune suppression, and 5. microbe-induced alteration of normal erythrocytic surface antigens (i.e., their reappearance is met with an antigenic response). The extent to which these two fundamental issues are avoided, even in recent and otherwise outstanding reviews on the subject,4"6 reflects the extent of general ignorance. We, and many far wiser than we,
A.J.C.P. • August 1992
surmise that these answers are intricately interwoven in the foundation of the immune system, whose many mysteries are generally well recognized (and, in 1992, well accepted). H. D. FRIEDMAN R. A. DRACKER
VA Medical Center Syracuse, New York References 1. Dacie JV. The haemolytic anaemias-part II: The auto-immune haemolytic anaemias. Second edition. New York: Grune and Stratton, 1962 pp 526-540. 2. Gieseler RG, Koebberling J. Koelteagglutininkrankheit. Klin Wochenschr 1988;66:277-283. 3. Habibi B. Anaemies hemolytiques autoimmunes. Pathol Biol (Paris) 1988,36: 1151-1171. 4. Nydegger UE, Kazatchkine MD, Miescher PA. Immunopathologic and clinical features of hemolytic anemia due to cold agglutinins. Semin Hematol 1991;28: 66-77. 5. Roelcke D. Cold agglutination. Transfus Med Rev 1989;3:140-166. 6. Engelfriet CP, Overbeeke MAM, von dem Borne AEGK. Autoimmune hemolytic anemia. Semin Hematol 1992;29:3-12.
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 6, 2016
To the Editor:—We thank Dr. Johnson for making us aware of an additional case of cold agglutinin disease after chickenpox. It is indeed curious that the cold agglutinin in his case also had anti-Pr specificity. Dr. Johnson's observation that the cold agglutinin in his case failed to react with the patient's own cells after recovery is indeed interesting. Our patient's cold agglutinin reacted with all panel cells tested during workup. Therefore we think it probable that it would have reacted with the patient's red cells after recovery had we tested for this.
