Are modern methods powerful enough to simplify clinical testing?

Recently, sophisticated multilaser multiparameter analytical systems have emerged. These provide great precision during the flow cytometric analysis of biological phenomena. Recent developments all point to the direction that the increased performance can also lead to simpler clinical systems [6-8] but the successful introduction of this new concept of 'mini-flow-metry' (MFM) will require a coordinated approach from 6 different directions as follows:

1. Novel antibody policy (primary CD4 + CD45 gating) leads to savings

A single CD4 antibody can be used [8,11].  If red diode laser is employed, this can be directly labeled with Cy-5 or APC [18]. Extra reagents CD45 and/or CD8 can be added [12] according to clinical needs (e.g. in children) if the local cost allocations allow it [8,11,12].  

2.  Fixatives stabilize cells for longer travel, easier operation and QC

Large “catchment areas” can be established. Quality control and training is provided  to satisfy NEQAS, QASI and CDC [15-17].    

3.  The new equipment for AffordCD4 will be different from
the multi-laser giants used in Western laboratories:  

These will be small durable flow cytometers with
(a) volumetric measurement facility provided by Hamilton precision syringes similar to those that operate on  the Cytoron with great reliability [13]. Microbeads used for absolute counting [14] are prohibitively expensive and have no place in resource-poor setting. If volumetric cytometers are not available, double-platform arrangements are the suitable alternatives [8,12]. These should use CD4+CD45 staining, leukogating and white blood cell counting as common denominator [8,12].

(b) New flow cytometers are likely to be fitted with red-diode lasers as shown in the first four cases (see previous page - Currently Available Sysems)

4.    Finally, the success will also depend upon digital processing and user-friendly software.   

A novel package for affordable CD4 flow cytometry could look like this:

Legend: Such a novel flow cytometer, operating one scatter and two fluorescence channels on a single laser light source, could cost <$15,000. Some red diode operating instruments already exist (ref. 18). These instruments still need to be checked for their exact specifications. The volumetric absolute counting facilities and the features of the associated computer programmes, to provide convenient service, are particularly important in routine operations.

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