fgfr3 dysregulation and clinical outcome in myeloma

Correspondence

FGFR3 DYSREGULATION AND CLINICAL OUTCOME IN MYELOMA

We fully agree with Winkler and co-workers that, in orderto give final proof of the presence of a t(4;14) translocation,fluorescence in situ hybridization or reverse-transcriptionpolymerase chain reaction analysis for hybrid IgH-MMSETneeds to be performed. However, to date the only reportedmechanism of FGFR3 dysregulation in multiple myeloma(MM) is by t(4;14) and only a single case of t(4;14) withoutFGFR3 dysregulation has been reported (Nakazawa et al,2000). In addition, in our study, mRNA from 7 ⁄16 FGFR3-positive MM patients was available for analysis of MMSETdysregulation, showing MMSET dysregulation in 7 ⁄7patients (Rasmussen et al, 2002). The good correlationbetween t(4;14) and FGFR3 dysregulation and the fact thatall tested FGFR3-positive patients simultaneously showedMMSET dysregulation suggest that it is unlikely that theuse of FGFR3 dysregulation as a surrogate marker fort(4;14) is the explanation for the discrepancy between thestudy reported by Fonseca et al (2001a) and our results(Rasmussen et al, 2002). The discrepancy may originatefrom the low number of FGFR3-positive MM patientsincluded in the clinical follow-up and ⁄ or it may illustratethat, to understand the clinical outcome of the t(4;14)subgroup of patients, both the mutational status of FGFR3(Chesi et al, 2001) and presence of D13 (Fonseca et al,2001b; Avet-Loiseau et al, 2002) need to be assessed attime of diagnosis.

We are in favour of the hypothesis that reciprocaltranslocations involving the immunoglobulin genes repre-sent primary events in myeloma oncogenesis as suggestedby Kuehl & Bergsagel (2002). We interpreted the signifi-cantly lower incidence of t(4;14) in monoclonal gammo-pathy of uncertain significance (MGUS) than in MM,reported by (Avet-Loiseau et al, 2002), as the t(4;14)occurring as a primary event, but patients harbouring at(4;14) have an increased likelihood for malignant trans-formation. The increased likelihood of malignant transfor-mation may result from the possibility of introducingtransforming mutations in dysregulated FGFR3 (Chesi et al,2001) and ⁄ or the co-occurrence of D13 in the majority ofMM patients with t(4;14) (Fonseca et al, 2001b; Avet-Loiseau et al, 2002). As pointed out by Winkler andco-workers, the frequency of t(4;14) in MGUS is stillcontroversial. Only a single study has been performed ona large cohort of MGUS patients (Avet-Loiseau et al, 2002)and, overall, few MGUS patients with t(4;14) have beenidentified to date. The follow-up of the reported t(4;14)-positive MGUS patients is awaited as it may clarify whether

these patients are stable MGUS patients or early stage MMpatients.

Thomas Rasmussen

Heidi Rye Hudlebusch

Lene Meldgaard Knudsen

Hans Erik Johnsen

Department ofHaematology L,Herlev Hospital,University of Copenhagen,Herlev, Denmark.E-mail: [email protected]

REFERENCES

Avet-Loiseau, H., Facon, T., Grosbois, B., Magrangeas, F., Rapp,

M.J., Harousseau, J.L., Minvielle, S. & Bataille, R. (2002) Onco-

genesis of multiple myeloma: 14q32 and 13q chromosomal

abnormalities are not randomly distributed, but correlate with

natural history, immunological features, and clinical presenta-

tion. Blood, 99, 2185–2191.

Chesi, M., Brents, L.A., Ely, S.A., Bais, C., Robbiani, D.F.,

Mesri, E.A., Kuehl, W.M. & Bergsagel, P.L. (2001) Activated

fibroblast growth factor receptor 3 is an oncogene that con-

tributes to tumor progression in multiple myeloma. Blood, 97,

729–736.

Fonseca, R., Harrington, D., Blood, E., Oken, M.M., Dewald, G.,

Kyle, R., Van Wier, S., Henderson, K., Bailey, R. & Greipp, P.

(2001a) A molecular classification of multiple myeloma (MM)

based on cytogenetic abnormalities detected by interphase FISH,

is powerful in indentifying discrete groups of patients with dis-

similar prognosis. Blood, 98, 733a.

Fonseca, R., Oken, M.M. & Greipp, P. (2001b) The t(4;14)(p16.3;q32)

is strongly associated with chromosome 13 abnormalities in both

multiple myeloma and monoclonal gammopathy of undetermined

significance. Blood, 98, 1271–1272.

Kuehl, W.M. & Bergsagel, P.L. (2002) Multiple myeloma: evolving

genetic events and host interactions. Nature Reviews Cancer, 2,

175–187.

Nakazawa, N., Nishida, K., Tamura, A., Kobayashi, M., Iwai, T.,

Horiike, S., Nishigaki, H., Otsuki, T., Tomiyama, Y., Fujii, H.,

Kashima, K. & Taniwaki, M. (2000) Interphase detection of

t(4;14)(p16.3;q32.3) by in situ hybridization and FGFR3 over-

expression in plasma cell malignancies. Cancer Genetics and

Cytogenetics, 117, 89–96.

Rasmussen, T., Hudlebusch, H.R., Knudsen, L.M. & Johnsen, H.E.

(2002) FGFR3 dysregulation in multiple myeloma: frequency

and prognostic relevance. British Journal of Haematology, 117,

626–628.

Keywords: multiple myeloma, FGFR3, monoclonalgammopathy of uncertain significance.

British Journal of Haematology, 2003, 120, 166–171

166 � 2003 Blackwell Publishing Ltd

PLASMA EXCHANGE AS A SOURCE OF PROTEIN C FOR ACUTE-ONSET PROTEIN C PATHWAY

FAILURE

We read with interest the report of Hodgson et al (2002)documenting a single case of septic shock and purpurafulminans treated with high-volume plasma exchange(PEX) with fresh-frozen plasma (FFP) as the replacementfluid. We report the successful use of a similar protocol ofPEX in the treatment of four patients with meningococcalsepsis all of whom had disseminated intravascular coagu-lation (DIC). The pathophysiology of this condition isbelieved to be acquired protein C deficiency caused by anumber of factors, including consumptive coagulopathy,capillary leakage, decreased hepatic synthesis and upregu-lation of protein C binding sites on mononuclear phagocytes(Esmon & Schwarz, 1995; Smith & White, 1999). It hasbeen suggested that protein C replacement therapy shouldbe used in these patients (Smith & White, 1999). Protein Cconcentrate was not available to us but, in the four patientsreported below, it was possible to predict the frequency ofPEX to maintain PC levels above 50 l ⁄ dl by serial meas-urements of protein C (Fig 1).

Patient 1 was a 48-year-old woman. Her initial coagu-lation results were prothrombin time (PT) 21 s [normalrange (NR) 11–14 s], activated partial thromboplastin time(APTT) 47 s (NR 22–34 s), fibrinogen 1Æ5 g ⁄ l (NR 1Æ5–4Æ0 g ⁄ l), D-dimers 1200 lg ⁄ l (NR < 500 lg ⁄ l) and PC23 l ⁄ dl (NR 70–143 l ⁄ dl). Her condition rapidly deterio-rated and she was transferred to the intensive therapy unit(ITU). Subsequent results showed a marked decline incoagulation status until PEX was performed on d 2, whichimproved PC levels to 57 l ⁄ dl. PC levels were maintainedabove 50 l ⁄ dl by one further PEX, followed by infusion ofFFP (1 l ⁄ d). Her haemostatic parameters improved and shewas discharged from ITU on d 7.

Patient 2 was a 28-year-old woman. The initial coagu-lation results were: PT 15 s, APTT 30 s, fibrinogen 1Æ6 g ⁄ l,D-dimers 1200 lg ⁄ l and PC 73 l ⁄ dl. Her condition deteri-orated and she was admitted to ITU. Her PC fell to 27 l ⁄ dl,

after which PEX was performed and this raised the PC levelto 83 l ⁄ dl. On d 2 her PC level had fallen to 42 l ⁄ dl andfurther PEX was carried out. She subsequently received 1 lof FFP on d 3 and 5, and this was adequate to maintainnormal coagulation until discharge from ITU on d 7.

Patient 3 was a 32-year-old woman, whose initialcoagulation results were: PT 25Æ3 s, APTT 51Æ3 s, fibrin-ogen 3Æ0 g ⁄ l and PC 50 l ⁄ dl. The PC level decreased to36 l ⁄ dl within 3 h, after which PEX was carried out. Nofurther PEX was required and her PC levels remained above50 l ⁄ dl for the duration of her illness.

Patient 4 was a 16-year-old woman, whose initialcoagulation results were: PT 16Æ7 s, APTT 45Æ5 s, fibrin-ogen 0Æ2 g ⁄ l and PC 71 l ⁄ dl. Her condition deterioratedand she was transferred to ITU. By this time her resultswere: PT > 100 s, APTT > 240 s, fibrinogen 0Æ2 g ⁄ l,D-dimers > 32 000 lg ⁄ l and PC 15 l ⁄ dl. At this point,haemofiltration and FFP replacement were initiated, raisingher PC level to 75 l ⁄ dl.

DIC caused by meningococcal septicaemia has beenassociated with 54% mortality (Fijnvandraat et al, 1995).Unusually this form of DIC is accompanied by a dispropor-tionate decrease in protein C when compared with othernatural anticoagulants and there is evidence to suggest thatprotein C levels provide a very reliable predictor of mortality(Esmon & Schwarz, 1995; Smith & White, 1999). Further-more, it is been suggested that protein C replacementtherapy should be used in these patients (Smith & White,1999). Protein C concentrate was not available to us butthe use of PEX enabled PC to be replenished. PEX may alsoremove endotoxin, but our experience with patients 3 and4, and that of the patient reported by Hodgson et al (2002)suggest that haemofiltration (which may not removeendotoxin) may also be effective, indicating that replace-ment of protein C is the most important therapeuticmeasure. We conclude that plasma exchange provides an

Fig 1. Serial measurement of protein C (PC)

levels in four patients of meningococcal sepsis.

PEX ¼ plasma exchange.

� 2003 Blackwell Publishing Ltd, British Journal of Haematology 120: 166–171

Correspondence 167

alternative means to protein C concentrate to treat DICassociated with meningococcal septicaemia.

P. M. Baker1

D. M. Keeling2

M. Murphy3

1Department of Haematology,John Radcliffe Hospital,2Oxford Haemophilia Centre andThrombosis Unit,Churchill Hospital, and3National Blood Service,Oxford, UK. E-mail:[email protected]

REFERENCES

Esmon, C.T. & Schwarz, H.P. (1995) An update on clinical and

basic aspects of the protein C anticoagulant pathway. Trends in

Cardiovascular Medicine, 5, 141–148.

Fijnvandraat, K., Derkx, B., Peters, M., Bijlmer, R., Sturk, A., Prins,

M.H., van Deventer, S.J. & ten Cate, J.W. (1995) Coagulation

activation and tissue necrosis in meningococcal septic shock:

severely reduced protein C levels predict a high mortality.

Thrombosis and Haemostasis, 73, 15–20.

Hodgson, A., Ryan, T., Moriarty, J., Mellotte, G., Murphy, C. &

Smith, O.P. (2002) Plasma exchange as a source or protein C for

acute onset protein C pathway failure. British Journal of Haema-

tology, 116, 905–908.

Smith, O.P. & White, B. (1999) Infectious purpura fulminans: di-

agnosis and treatment. British Journal of Haematology, 104, 202–

207.

Keywords: protein C, plasma exchange, Meningococcalsepsis.

PARVOVIRUS B19 INFECTION AND ACUTE LYMPHOBLASTIC LEUKAEMIA

We read the recent report on parvovirus B19 (PB19)-induced pancytopenia before acute lymphoblastic leukae-mia (ALL) diagnosis with interest (Heegaard et al, 2001).There have been a few additional case reports thatsuggested a possible link between PB19 infection andhypoplastic ALL or pre-ALL (Petrella et al, 1992; Lee et al,1994). We also followed a similar patient whose diagnosisof ALL was preceded by a serologically confirmed PB19infection (Savasan et al, 1996). As this relationship isbecoming recognized more frequently and causing difficul-ties in diagnosis, we would like to share our experiences.

A 1-year-old girl presented with fever and pallor. Onphysical examination, she had generalized lymphadenopa-thy and mild hepatosplenomegaly. She was found to beseverely anaemic and neutropenic (Table I). Her absoluteneutrophil count (ANC) was 0Æ25 · 109 ⁄ l, reticulocytes 1%and Coomb’s test was negative. Bone marrow aspiration(BMA) showed erythroid hypoplasia, megaloblastic changesin the myeloid cells and mild lymphocytosis. Parvovirus B19(PB19) IgG and IgM antibodies were positive by enzyme-linked immunosorbent assay. She received three packed redblood cell transfusions.

During a follow-up visit, 2 weeks after presentation, thehepatosplenomegaly had resolved and her ANC had risen to2Æ0 · 109 ⁄ l, however, she continued to be anaemic, which

improved later. A repeat BMA revealed an increase inerythroid cells compared with the previous BMA withoccasional clusters of lymphoid cells that had scantycytoplasm and loose chromatin network, constituting 15%of bone marrow cellularity. At 9 weeks, she presented withworsening of anaemia; a BMA and biopsy were consistentwith ALL (40% L1-type lymphoblasts). PB19 IgM antibodyhad become negative, but the IgG antibody was still positiveat that time.

Both the quality and the quantity of the anti-PB19immune response of the host are critical in the developmentand the clinical course of PB19 infection. The case reportedby Heegaard et al (2001) took a long time to mount ahumoral immune response and clear viral DNA, suggestinga defective immunity against PB19. It has been reportedthat PB19 can cause chronic anaemia in immunocompro-mised patients who develop antibody response against PB19that is incapable of neutralizing the virus (Kurtzman et al,1989). Whether delayed immunity resulted from thepresence of leukaemic clone or was an individual charac-teristic in their case is not known.

Parvovirus B19 infection can rarely cause anaemiawithout underlying increased erythroid turnover or docu-mented immunodeficiency. It is possible that, early in thecourse, PB19 could have affected erythropoiesis in additionto the known suppressive effect of leukaemic blasts on non-malignant haematopoiesis that became more pronouncedwith the increasing leukaemic burden. As observed in ourpatient, transient resolution of neutropenia and furtherincrease in haemoglobin without transfusion betweenweeks 2 and 7 can be explained by PB19 infection-inducedanaemia and neutropenia, which resolved upon develop-ment of immune response.

It could be suggested that PB19 infection might providean advantage for the malignant clone by suppressing non-leukaemic haematopoiesis. Thirty-one per cent of human

Table I. Peripheral blood count profile of the patient.

Time

Haemoglobin

(g ⁄ dl) WBC (· 109 ⁄ l)Platelet count

(· 109 ⁄ l)

Presentation 2Æ6 3Æ6 243

2 weeks 8Æ4 4Æ2 –

7 weeks 10Æ4 4Æ3 352

9 weeks 5Æ9 2Æ6 276


168 Correspondence

bone marrow non-erythroid cells were shown to expressblood group P antigen; PB19 receptor and human PB19vectors have been shown to transduce CD34+ bone marrowprogenitor cells (Weigel-Kelly et al, 2001), indicating thepossibility of non-erythroid bone marrow cells as targets forPB19. Parvovirus B19 was shown to induce apoptoticchanges in target cells. In the light of these observations,PB19 infection could have delayed the development of full-blown ALL symptoms by inducing apoptosis of the leukae-mic cells. Therefore, the eradication of the virus by thedeveloping immune response might have facilitated theexpansion of the leukaemic clone as a result of escape fromthe PB19-induced inhibitory effect on leukaemic cells in bothpatients. It would be interesting to study PB19 viral DNA inleukaemia cells at the time of diagnosis in such patients.

S. Savasan

O. Ozdei_rChildren’s Hospital of Michigan,Division of Hematology ⁄Oncology,Barbara Ann Karmanos CancerInstitute, Wayne State University,Detroit, MI, USA. E-mail:[email protected]

REFERENCES

Heegaard, E.D., Madsen, H.O. & Schmiegelow, K. (2001) Transient

pancytopenia preceding acute lymphoblastic leukemia (pre-ALL)

precipitated by parvovirus B19. British Journal of Haematology,

114, 810–813.

Kurtzman, G.J., Cohen, B.J., Field, A.M., Oseas, R., Blaese, R.M. &

Young, N.S. (1989) Immune response to B19 parvovirus and an

antibody defect in persistent viral infection. Journal of Clinical

Investigation, 84, 1114–1123.

Lee, S.M., Kim, D.G. & Bang, D. (1994) Persistent erythema

infectiosum-like rash as a prodrome of acute lymphocytic

leukemia. Pediatric Dermatology, 11, 156–159.

Petrella, T., Bailly, F., Mugneret, F., Caillot, D., Chavanet, P., Guy,

H., Solaty, E., Waldner, A., Devilliers, E. & Carli, P.M. (1992)

Bone marrow necrosis and human parvovirus associated infec-

tion preceding an Ph1+ acute lymphoblastic leukemia. Leukemia

and Lymphoma, 8, 415–419.

Savasan, S., Ozdemir, O., Ovali, F., Zulfikar, B. & Yilmaz, K. (1996)

Various associations of human parvovirus B19 infection. Journal

of the Pakistan Medical Association, 46, 235–239.

Weigel-Kelly, K.A., Yoder, M.C. & Srivastava, A. (2001)

Recombinant human parvovirus B19 vectors: erythrocyte P

Antigen is necessary but not sufficient for successful trans-

duction of human hematopoietic cells. Journal of Virology, 75,

4110–4116.

Keywords: parvovirus B19, acute lymphoblastic leukaemia,cytopenia, immune deficiency.

MEAN PLATELET VOLUME IS AN INDEPENDENT RISK FACTOR FOR MYOCARDIAL

INFARCTION BUT NOT FOR CORONARY ARTERY DISEASE

The elegant work by Endler et al (2002) showed that anincreased mean platelet volume (MPV) was associated witha greater risk of myocardial infarction (MI) in patients withcoronary artery disease. This effect was independent ofseveral well-established risk factors (e.g. hypertension,smoking and dyslipidaemia).

We have shown that platelet activation (in vivo andin vitro) results in an increase in MPV (Mikhailidis et al,1990; Barradas et al, 1992). In vitro, this increase tends tobe reversible; it is essentially aspirin resistant and it occursduring the platelet shape change (PSC; an early phase ofplatelet activation that precedes aggregation). We repro-ducibly assessed PSC with a high-resolution (0Æ07 fl)channelyser (Jagroop et al, 1996). We also matched thechanges in MPV with platelet morphology using electronmicroscopy (Jagroop et al, 2000). Nevertheless, an EDTAmethod (like that of Endler et al, 2002) is ideal for clinicaluse in contrast to our slower (research) technique thatrequires the preparation of platelet-rich plasma.

It remains to be established if platelet activation contri-buted to the increased MPV observed by Endler et al (2002)in the patients with a greater risk of MI.

The effect of drugs on MPV was poorly documented. Ourpreliminary findings suggest that the administration ofclopidogrel to patients with peripheral arterial diseasesignificantly inhibits the ADP-induced increase in MPV,in vitro. This inhibition was enhanced when aspirin wasadministered together with clopidogrel.

There is an urgent need for a practical test to identifywhich patients would benefit from a change in antiplate-let drug or the addition of a second one. Such a testwould also allow the routine assessment of the antiplate-let effect of other drugs, like antihypertensives (e.g. in thestudies cited by Endler et al, 2002) and lipid-loweringdrugs (Milionis et al, 1999).

I. A. Jagroop

D. P. Mikhailidis

Department of ClinicalBiochemistry (Royal Free Campus),Royal Free and University CollegeMedical School (University ofLondon), London, UK. E-mail:[email protected]


Correspondence 169

DECLARATION OF INTEREST

Dr D. P. Mikhailidis has participated in advisory panels,received research grants and was sponsored for educationalmeetings by Sanofi-Synthelabo, the manufacturers of clopi-dogrel.

REFERENCES

Barradas, M.A., O’Donoghue, S. & Mikhailidis, D.P. (1992)

Measurement of platelet volume using a channelyzer:

assessment of the effect of agonists and antagonists. In Vivo, 6,

629–634.

Endler, G., Klimesch, A., Sunder-Plassmann, H., Schillinger, M.,

Exner, M., Mannhalter, C., Jordanova, N., Christ, G., Thalham-

mer, R., Huber, K. & Sunder-Plassmann, R. (2002) Mean platelet

volume is an independent risk factor for myocardial infarction

but not for coronary artery disease. British Journal of Haematol-

ogy, 117, 399–404.

Jagroop, I.A., Barradas, M.A. & Mikhailidis, D.P. (1996) A low

molecular weight heparin, nadroparin (Fraxiparine), inhibits

thrombin induced platelet shape change and does not enhance

spontaneous platelet aggregation. British Journal of Clinical

Pharmacology, 41, 163–165.

Jagroop, I.A., Clatworthy, I., Lewin, J. & Mikhailidis, D.P. (2000)

Shape change on human platelet-measurements with a chan-

nelyzer and visualisation by electron microscopy. Platelets, 11,

28–32.

Mikhailidis, D.P., Barradas, M.A., O’Donoghue, S. & Dandona, P.

(1990) Evidence for in vivo platelet activation following the

injection of conventional unfractionated heparin. Platelets, 1,

189–192.

Milionis, H.J., Elisaf, M.S. & Mikhailidis, D.P. (1999) Platelets and

lipid lowering interventions. Platelets, 10, 357–367.

Keywords: mean platelet volume, platelet shape change,myocardial infarction.

t(4;14)(P16.3;Q32) IS STRONGLY ASSOCIATED WITH A SHORTER SURVIVAL

IN MYELOMA PATIENTS

We read with great interest the report by Rasmussen et al(2002), showing no correlation between FGFR3 overex-pression and clinical outcome in myeloma. This wassurprising, as we have recently demonstrated by cyto-plasmic immunoglobulin fluorescence in situ hybridization(cIg-FISH) a significantly shorter survival (26 vs 45 months,P < 0Æ001) in myeloma patients having t(4;14)(p16.3;q32), (Fonseca et al, 2001). We would like readersto be aware of this conflicting information and would warnagainst using FGFR3 expression as a surrogate marker tothe translocation. Did the authors determine the presence oft(4;14)(p16.3;q32) by interphase FISH or IgH-MMSETreverse-transcription polymerase chain reaction (the latterbeing easy to perform on stored RNA)? This informationwould clarify whether their results are truly representativeof patients with the specific translocation.

Consistent with their results, Rasmussen et al (2002) alsosuggested that t(4;14)(p16.3;q32) is a monoclonal gamm-opathy of uncertain significance (MGUS)-to-myeloma trans-ition event rather than a primary event, citing as support thelower prevalence of t(4;14)(p16.3;q32) in MGUS comparedwith multiple myeloma in some studies (Avet-Loiseau et al,2002). This latter point is still controversial, as we havedemonstrated a similar incidence of t(4;14)(p16.3;q32) inMGUS and myeloma using interphase FISH; it is, therefore,not clear that this abnormality represents a progressionevent. Others have detected t(4;14)(p16.3;q32) in other low-grade plasma cell disorders such as light-chain associatedamyloidosis (Perfetti et al, 2001). Rather, we favour thehypothesis that most immunoglobulin heavy chain translo-cations in myeloma represent primary events (Bergsagel

et al, 1996). Furthermore, this hypothesis is not in conflictwith the possibility that specific translocations impartunique biological features to patients.

Jerry M. Winkler

Philip R. Greipp

Rafael Fonseca

Division of Hematology and InternalMedicine, Mayo Clinic, Rochester,MI, USA. E-mail:[email protected]

REFERENCES

Avet-Loiseau, H., Facon, T., Grosbois, B., Magrangeas, F., Rapp,

M.-J., Harousseau, J.-L., Minvielle, S. & Bataille, R. (2002)

Oncogenesis of multiple myeloma: 14q32 and 13q chromosomal

abnormalities are not randomly distributed, but correlate with

natural history, immunological features, and clinical presenta-

tion. Blood, 99, 2185–2191.

Bergsagel, P.L., Chesi, M., Nardini, E., Brents, L.A., Kirby, S.L. &

Kuehl, W.M. (1996) Promiscuous translocations into

immunoglobulin heavy chain switch regions in multiple myelo-

ma. Proceedings of the National Academy of Sciences of the United

States of America, 93, 13931–13936.

Fonseca, R., Harrington, D., Blood, E., Rue, M., Oken, M., Dewald,

G., Kyle, R., Van Wier, S., Henderson, K., Bailey, R. & Greipp, P.

(2001) A molecular classification of multiple myeloma (MM),

based on cytogenetic abnormalities detected by interphase FISH,

is powerful in identifying discrete groups of patients with dissi-

milar prognosis. Blood, 98, 733a.

Perfetti, V., Coluccia, A., Intini, D., Malgeri, U., Colli Vignarelli, M.,

Casarini, S., Merlini, G. & Neri, A. (2001) Translocation t(4;14)

(p16.3;q32) is a recurrent genetic lesion in primary amyloidosis.

Leukemia, 158, 1599–1603.


170 Correspondence

Rasmussen, T., Hudlebusch, H., Knudsen, L. & Johnsen, H. (2002)

FGFR3 dysregulation in multiple myeloma: frequency and

prognostic relevance. British Journal of Haematology, 117, 626–

628.

Keywords: multiple myeloma, translocation 4;14, FGFR3,prognosis, fluorescence in situ hybridization.

SERUM ERYTHROPOIETIN VALUES AND ENDOGENOUS ERYTHROID COLONY GROWTH

IN ERYTHROCYTOSES AND ESSENTIAL THROMBOCYTHAEMIA

We read with interest the recent paper by Messinezy et al(2002) describing serum erythropoietin (Epo) values inerythrocytoses and in thrombocythaemia. The authorsreported a high specificity (92%) and a moderatesensitivity (64%) of low serum Epo values(< 2Æ9 mIU ⁄ml) in the diagnosis of polycythaemia vera(PV). One third of patients with primary thrombocythae-mia (PT) had a low Epo value. The authors concludedthat ‘a more robust diagnostic marker for PV is needed’and that ‘growth of endogenous erythroid colonies …could further subdivide the PT group and showcorrelations with Epo value’.

In fact, we recently reported the interest for thediagnosis of PV and PT of associating dosage of serumEpo and endogenous erythroid colony (EEC) formationassay in collagen-based medium (Dobo et al, 2001). TheEEC assay is often considered a difficult, expensive andnon-standardized technique. However, our experience ofthe EEC assay performed in serum-free collagen gels led usto consider this method as reliable, sensitive and currentlythe most appropriate to standardize the EEC assay (Doboet al, 1995, 1999, 2001). Our most recent study of thecollagen-based EEC assay (Dobo et al, 2001) includedpatients with PV (n ¼ 26), PT (n ¼ 19) or secondaryerythrocytosis (SE) (n ¼ 17) and healthy donors (n ¼ 11);serum aliquots were available for Epo evaluation for 30patients (14 PV patients, six PT patients and 10 SEpatients). We showed that the EEC assay performed inserum-free, cytokine-free collagen-based medium has aspecificity (100%) and a sensitivity (68Æ2% for PV patients,47Æ4% of PT patients) similar to those of the serum Epoassay reported by Messinezy et al (2002). Serum Epoevaluation was performed in duplicate with the sameQuantikine IVD erythropoietin ELISA kit (RD, Abingdon,UK) used by Messinezy et al (2002). None of the SEpatients, but 33Æ3% of PT patients, 66Æ6% of PV patientsand 87Æ5% of PV patients with a positive EEC assay hadlow serum Epo (£3 mIU ⁄ml). Taking into account the resultof the EEC assay and the serum Epo value, the diagnosis ofPV could be safely confirmed for patients with low serumEpo and a positive EEC assay, and eliminated for patients

with normal serum Epo and no EEC formation, ensuring areliable diagnosis for 91% of patients with erythrocytosis.Our results indicate that the association of the serum-free,collagen-based EEC assay and the serum Epo dosage iscurrently the most specific, sensitive and reliable diagnostictest for PV.

Francois Girodon1

Sylvie Hermouet2

Irene Dobo3

Pascal Mossuz4

and le groupe de

standardization

des techniques

de culture

de progeniteurs

hematopoıetiques

1Haematology Laboratory,University Hospital Dijon,2Haematology Laboratory,University Hospital Nantes,3Haematology Laboratory,University Hospital Angers, and4Haematology Laboratory,University Hospital Grenoble,France. E-mail:[email protected]

REFERENCES

Dobo, I., Allegraud, A., Navenot, J.M., Boasson, M., Bidet, J.M. &

Praloran, V. (1995) Collagen matrix: an attractive alternative to

agar and methylcellulose for the culture of hematopoietic pro-

genitors in autologous transplantation products. Journal of

Hematotherapy, 4, 281–287.

Dobo, I., Pineau, D., Zandecki, M., Hunault, M. & Hermouet,

S. (1999) Endogenous erythroid and megakaryocytic colony

formation in serum-free, cytokine-free collagen gels. Journal of

Hematotherapy and Stem Cell Research, 8, 601–607.

Dobo, I., Mossuz, P., Campos, L., Girodon, F., Allegraud, A., Latger-

Cannard, V., Boiret, N., Pineau, D., Wunder, E., Zandecki, M.,

Praloran, V. & Hermouet, S. (2001) Comparison of four serum-

free, cytokine-free media for analysis of endogenous erythroid

colony growth in polycythemia vera and essential thrombo-

cythemia. Hematology Journal, 2, 396–403.

Messinezy, M., Westwood, N.B., El-Hemaidi, I., Marsden, J.T.,

Sherwood, R.S. & Pearson, T.C. (2002) Serum erythropoietin

values in erythrocytoses and in primary thrombocythaemia.

British Journal of Haematology, 117, 47–53.

Keywords: erythrocytosis, essential thrombocythaemia,erythropoietin, endogenous erythroid colony growth.


Correspondence 171

fgfr3 dysregulation and clinical outcome in myeloma

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