Is it still worthwhile to perform quarterly cd4+ t lymphocyte cell counts on hiv-1 infected stable patients?
In the last 20 years routine T CD4+ lymphocyte (CD4+) cell count has proved to be a key factor to determine the stage of HIV infection and start or discontinue of prophylaxis for opportunistic infections. However, several studies recently showed that in stable patients on cART a quarterly CD4+ cell count monitoring results in limited (or null) clinical relevance. The research is intended to investigate whether performing quarterly CD4+ cell counts in stable HIV-1 patients is still recommendable and to provide a forecast of the cost saving that could be achieved by reducing CD4+ monitoring in such a category of patients.



The study is based on data referring to all HIV-infected patients > 18 years of age being treated at two large infectious diseases units located in the metropolitan area of Genoa, Italy. The probability of CD4+ cell counts dropping below a threshold value set at 350 cells/mm3is assessed using confidence intervals and Kaplan-Meier survival estimates, whereas multivariate Cox analysis and logistic regression are implemented in order to identify factors associated with CD4+ cell count falls below 350 cells/mm3.



Statistical analysis reveals that among stable patients the probability of maintaining CD4+ >350 cell/mm3is more than 98%. Econometric models indicate that HCV co-infection and HIV-RNA values >50 copies/mL in previous examinations are associated with CD4+ falls below 350 cells/mm3. Moreover, results suggest that the cost saving that could be obtained by reducing CD4+ examinations ranges from 33 to 67%.



Empirical findings shows that patients defined as stable at enrollment are highly unlikely to experience a CD4+ value <350 cell/mm3in the space/arc of a year. The research supports a recommendation for annual CD4+ monitoring in stable HIV-1 patients.
Infectious Disease Clinic, IRCCS San Martino - IST Hospital, Genoa, Italy.
Antonio
A
Di Biagio
Department of Economics, University of Genoa, Via Vivaldi 5, 16126, Genoa, Italy. marta.ameri@unige.it.
Marta
M
Ameri
Infectious Disease Clinic, IRCCS San Martino - IST Hospital, Genoa, Italy.
Davide
D
Sirello
Infectious Diseases Unit, EO Galliera, Genoa, Italy.
Giovanni
G
Cenderello
Department of Economics, University of Genoa, Via Vivaldi 5, 16126, Genoa, Italy.
Enrico
E
Di Bella
Infectious Disease Clinic, IRCCS San Martino - IST Hospital, Genoa, Italy.
Lucia
L
Taramasso
Department of Informatics, Bioengineering, Robotics and System Engineering, University of Genoa, Genoa, Italy.
Barbara
B
Giannini
Department of Informatics, Bioengineering, Robotics and System Engineering, University of Genoa, Genoa, Italy.
Mauro
M
Giacomini
Infectious Disease Clinic, IRCCS San Martino - IST Hospital, Genoa, Italy.
Claudio
C
Viscoli
Infectious Diseases Unit, EO Galliera, Genoa, Italy.
Giovanni
G
Cassola
Department of Economics, University of Genoa, Via Vivaldi 5, 16126, Genoa, Italy.
Marcello
M
Montefiori
D000328:Adult; D000368:Aged; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology*; D060085:Coinfection / Q000150:complications; D005260:Female; D015658:HIV Infections / Q000276:immunology / Q000401:mortality / Q000473:pathology* / Q000821:virology; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007558:Italy; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012367:RNA, Viral / Q000032:analysis; D019562:Viral Load
D012367:RNA, Viral
Cost; HIV; Lymphocyte T CD4+; Monitoring