G6PD activity is reduced in sickle cell disease attributed to rigidity and lose of red cell integrity. This enhances the hemolysis with increased oxidative stress.

Interference between the two conditions has been extensively studied but data from the literature are controversial. Most studies report no effect of G6PD deficiency on the clinical course of SCD, but some report a worsening of the condition.

In our experience, G6PD deficiency worsens chronic anaemia and increases the incidence of acute anaemic episodes and transfusion needs in SCD patients in the two first years of life. This effect is no longer observed after 2 years of life.

Benkerrou et al, Brit J Haematol, 2013, 163:646-54

Concerning Gopal's comment, I am not sure that G6PD activity is reduced in SCD patients because these patients in general have a high reticulocyte count and retics have a high G6PD activity.

Thank u Jacques sir. There was a study depicting the fact that I v mentioned. But still it needs many more study to comment particularly the association between the two entity

Completely agree with Jacques Ellison. Logically speaking, once the G6PD deficiency is diagnosed, oxidative agents would be avoided by patients so the G6PD deficiency wouldn't realistically be an issue.

Thank you all for your wonderful contributions.

Thank you all for your wonderful contributions.

I had an afterthought concerning Gopal’s comment. I think he is probably right in stating that in sickle cells G6PD activity is decreased, but this should be only in the dense sickle cells and irreversible sickle cells (ICSs). In the SCD patients actually, there is a wide heterogeneity of RBC subpopulations, from the young hyperhydrated reticulocytes with a very active metabolic machinery to the aged dense cells and ICSs. In these latter, as very correctly mentioned by Gopal, because of the intense production of ROS, most of the metabolic enzymes (including anti-oxidative enzymes) are altered and their activity is drastically reduced. This actually should also apply to G6PD. But at the same time, because of a high percentage of young cells (reticulocytes) as compared to the percentage of dense cells and ISCs, I would predict a high G6PD activity when measured on the whole RBC population in a given SCD patient.

Similarly, in general (outside the SCD context) G6PD measurement during the regenerating phase after a haemolytic event may show high G6PD activity even though the underlying cause of haemolysis is a G6PD deficiency. Thus, to diagnose G6PD deficiency, enzyme measurement should be done at steady state (at distance from a haemolytic event). It will be also useful to measure another metabolic enzyme concomitantly (like PK-which will be high also in young reticulocytes). Then a drastically decreased G6PD/PK activities ratio, will be more significant than measurement of GPDD activity alone.

Finally, I fully agree with Indu in stating that drugs and nutriments which should be avoided in a patient with G6PD deficiency should also be avoided in a SCD patients with G6PD deficiency. Thanks Indu for this important comment.

Nicely described by Elion sir.

Thanks

Hi All,

An interesting discussion.

We have previously reported a case of "Episodic exacerbation of haemolysis in a patient with co-inheritance of sickle cell anaemia and G6PD deficeincy" in a Nigerian patient at a conference presentation (find RG link below please). The unique things about this particular case we reported were 1) the oxidant substance was "wax" of petrochemical origin. Although several petrochemical substances have been reported to induce haemolysis in G6PD deficiency from the literature, we could not find a prior report linking this particular substance with haemolysis in G6PD deficiency. 2) The exposure route was not through oral ingestion but through inhalation and skin contact as far as we could establish. We acknowledge our diagnostic limitation of using fluorescent spot method, which is semi-quantitative, for the diagnosis of G6PD deficiency, as we could not have enzyme kinetic or molecular genetic assays to confirm the diagnosis. As both the the s-beta globin and G6PD deficiency genes are highly prevalent in Africa, it is quite possible many co-inheritance conditions exist but are not diagnosed due to the overlapping clinical manifestation of haemolytic anaemia. Whether or not this co-inheritance leads to severer manifestations of haemolysis or haemolysis-associated end-organ damage is not clear, but the patient we reported apparently have fairly stable sickle cell phenotype with both few VOCs and never had blood transfusion. It will be interesting to study the potential interaction between these two very prevalent inherited haemolytic anaemias with overlapping clinical manifestations.

Best wishes,

Aminu.

Poster Episodic exacerbation of haemolysis in a patient with co-inh...

G6PD deficiency is commonly associated with haemoglobinopathies .