Cytoplasmic nucleophosmin (cNPM) in acute myeloid leukaemia: Relation to disease characteristics

Available online 26 August 2011

Peer review under responsibility of Alexandria University Faculty of Medicine

Figures & data

Table 1 The correlation between the AML subtype and cytoplasmic expression of NPM (cNPM).

Crosstab
FAB subtype	cNPM		Total
	Negative	Positive
M1
Count	8	1	9
% within CNPM	33.3%	3.8%	18.0%
M4
Count	4	1	5
% within CNPM	16.7%	3.8%	10.0%
M5b
Count	1	12	13
% within CNPM	4.2%	46.2%	26.0%
M5a
Count	2	5	7
% within CNPM	8.3%	19.2%	14.0%
M2
Count	2	4	6
% within CNPM	8.3%	15.4%	12.0%
M0
Count	4	2	6
% within CNPM	16.7%	7.7%	12.0%
Biphenotypic
Count	1	0	1
% within CNPM	4.2%	0%	2.0%
M7
Count	1	1	2
% within CNPM	4.2%	3.8%	4.0%
M6
Count	1	0	1
% within CNPM	4.2%	0%	2.0%
Total
Count	24	26	50
% within CNPM	100.0%	100.0%	100.0%

Figure 1 H&E stain: (a) M0 acute myeloid leukaemia. ×1000. (b) M1, note thumbprinting (arrows). ×1000. (c) M2 prominent promyelocytes (arrow) having abundant cytoplasm with variable size, markedly lobulated and invaginated nuclei. Note abnormal mitosis (arrow head). ×1000. (d) M4 note giant multilobulated nuclei (arrow) with the prominent nucleoli. ×1000. (e) M5 with evident hemophagocytosis (arrow heads). ×1000. (f) M6 with erythroblastic differentiation and nucleated RBC (arrow heads). ×1000. (g) M7 with megakaryocytes (arrows). ×400. (h) Biphenotypic acute leukaemia (BAL), mixture of small and large blasts. ×400.

Figure 2 Patterns of NPM immunostaining in AML: (a) nuclear and cytoplasmic (arrows) positivity of leukemic cells. ×1000. (b) Nuclear and cytoplasmic positivity with some leukemic cells showing only cytoplasmic staining (arrow). ×1000. (c) Nucleus restricted immunostaining majority of leukemic cells. ×1000. (d) Strong nuclear and nucleolar (arrows) positivity in leukaemic cells. ×1000.

Figure 3 NPM immunostaining in acute myeloid leukaemia: (a) M5 showing nuclear and cytoplasmic reactivity (arrows). ×1000. (b) M4 showing distinct but heterogeneous nuclear and cytoplasmic staining (arrows). ×1000. (c) BAL showing strong homogeneous nucleus restricted immunostaining. ×400. (d) M6 showing focal nucleus restricted immunostaining (arrow) with absent cytoplasmic staining. ×400.

Table 2 Relation between FLT3 positivity and cytoplasmic NPM expression.

	cNPM		Total
	Negative	Positive
Count	8	15	23
% within FLT3	34.8%	65.2%	100.0%
% within CNPM	33.3%	57.7%	46.0%
Count	16	11	27
% within FLT3	59.3%	40.7%	100.0%
% within CNPM	66.7%	42.3%	54.0%
Count	24	26	50
% within FLT3	48.0%	52.0%	100.0%
% within CNPM	100.0%	100.0%	100.0%

Figure 4 Survival of the study groups according to cytoplasmic NPM expression.

Figure 5 Hazard function of the study groups according to cytoplasmic NPM expression.

Figure 6 Survival function according to cNPM expression with FLT3 mutational status.

Figure 7 Survival function according to cNPM expression with FLT3 mutational status after exclusion NPMc−/FLT3 negative cases in which no deaths have occurred during the study time.

Table 3 Outcome of the first induction cycle.

Outcome_First_Cycle	cNPM negative	cNPM positive
Failure (IF)
Count	11	4
% within CNPM	50.0%	17.4%
Partial remission (PR)
Count	4	12
% within CNPM	18.2%	52.2%
Complete remission (CR)
Count	1	5
% within CNPM	4.5%	21.7%
Induction death (ID)
Count	6	2
% within CNPM	27.3%	8.7%
Total
Count	22	23
% within CNPM	100.0%	100.0%

Table 4 Outcome of the second induction cycle.

Outcome_Second_Cycle	cNPM negative	cNPM positive
Failure (IF)
Count	7	2
% within CNPM	43.8%	9.5%
Partial remission (PR)
Count	4	1
% within CNPM	25.0%	4.8%
Complete remission (CR)
Count	2	15
% within CNPM	12.5%	71.4%
Induction death (ID)
Count	2	0
% within CNPM	12.5%	0%
Relapse
Count	1	3
% within CNPM	6.3%	14.3%
Total
Count	16	21
% within CNPM	100.0%	100.0%