Spacing between Peg injections

[Mymble]

Hello, I’ve been on Peg for PV for 2 years. Now down to 45 mcg every two weeks. Platelets remain where my doc wants them (between 100 and 200). Despite PV, I have only ever had HCT at higher end of normal - never higher than that. Over last year, my lymphocytes have been a bit low but no cause for concern. Neutrophils, basophils and hg normal but downward trend. Just received latest blood results and platelets still lower end of target range, HCT right at lower end of range, lymphocytes lower and neutrophils, basophils and Hg now also low.

I’m wondering if I should suggest spacing out my injections longer than a two week interval? Has anyone had any experience of that? I don’t want to undo the good work done by Peg but neither do I want to end up with worse anemia and vulnerable to infection . I feel I could bear higher platelets and HCT than I currently have but it seems like a fine balancing act and an extra week could have a bigger impact than I think. Many thanks to anyone who has any experience to share.

[charl17]

I am on the same Pegasys dose. I plan to have this same conversation with my specialist in two weeks. If this is on your mind, you should discuss it. I would be willing to stop Pegasys and monitor blood counts quarterly.

I have been on INF for almost 4 years. HCT under control for 3.5 years.

[Mymble in reply to charl17]

Thanks charl17. That’s really interesting. My worry about stopping completely is that I don’t want to lose the other benefits of being on INF, relating to disease progression that recent research seems to be hinting at. Secondly, with NHS finances the way they are, if I needed to restart treatment, would Peg still be on offer or would I be pushed towards hydroxy? But you’re right, it’s on my mind so I’ll discuss it at my appt this week. Let me know how you get on.

[hunter5582]

The target for a complete hematologic response for PV is HCT<45% (male) or HCT<42/43% (female) and PLT<400 when thrombocytosis is evident, It is common for the IFNs to also decrease WBCs since the interferon affects hemopoietic stem cells. My MPN Specialist and hematologist pay particular attention to Neutrophils, which need to stay >1.0.

Suggest you review your treatment goals with a MPN Specialist. Your concerns are quite valid and should be properly addressed.

[EPguy in reply to hunter5582]

I confirmed with my specialist the same min Neut value your Dr recommends. He also said Lymph at 0.5, which is different from his prior comment that zero is ok.

[hunter5582 in reply to EPguy]

i have also heard 0.50 to don't care on the LYMPHs.

[Mymble]

Thanks, Hunter. I will get my questions ready. 🙂

[EPguy]

If your Dr is setting your dose for PLT, and yours are that low, it does seem reasonable to cut your dose by interval or size. Has Dr said why such a low PLT goal? We see here that PLT normally does not require even near such levels for better outcomes. And low range HCT is another indicator lower dose could be ok. But it could be something unusual has your Dr going this way.

Some reports discuss stopping IFN. But there is concern about any marrow progress being lost even if allele burden reduction holds. As usual no definitive answers.

[Mymble in reply to EPguy]

Hi, and thanks for your thoughts.

I checked back over clinic letters to remind myself of the discussion when I suggested reducing injections to fortnightly- my platelet target is set at 100-400 and HCT <42. I’m high risk because of previous clot. At that point my platelets were around 110 and because lymphocytes had started to go low (although still above 1) I didn’t see the point in risking low counts in white cells when everything else was well within target. This was in Sept 2021. Since starting with fortnightly injections, platelets rose slightly to around 140 but now back down to 107. Lymphocytes didn’t really recover and neutrophils which we’re always 0.02 (bottom of normal) now low at 0.01. HCT is now 0.363 and hg 19. So I wondered if there was again, a rationale for increasing the time between injections.

Another possible factor is that I am now hypothyroid (possible peg AR) As thyroxine is required for proper functioning of every cell in the body I’m wondering if that includes blood cell production and once the replacement thyroxine begins to have its effects ( can take months to get dose right) things will improve.

Worryingly, the clinic letter also said that if I continue to be cytopenic another BMB should be done to check for fibrosis progression. My first BMB back in 2019 showed no fibrosis.

Anyway, I have a teleconsultation this afternoon so thank you for the opportunity to get my thoughts in order through writing this down and apologies for the lengthy, rambling reply!!

[EPguy in reply to Mymble]

Is that the correct Hg (19) and HCT (.363)? That is a very unusual discrepancy, with HCT at 36 one would usually see a much lower Hb. If Hb is 19 that does usually require substantial reduction and might be why Dr want to keep the dose up. Everything else is plenty low by most standards.

[Mymble in reply to EPguy]

Ah - haemoglobin is 119 (lab range is 120-150) so just below normal. The doctor I spoke to yesterday suggested sticking with current treatment regime and doing bloods again in 4 weeks rather than 3 months. He is not worried about the results at the moment but wants to review a bit sooner.

[SueBas]

Hi there. Interested to hear this. I had apppt yesterday. Have been on Peg Interferon 90 per week for 9 months. White cells now down to 2.4 and neutrophyls down to 0.9. Now stopping for 2 weeks to see if neutrophyls come back up. Also hypothyroidism and had to raise levothyroxine twice in last 6 months. Now on 75mcg daily. Will try 45 dose of Pegasys weekly depending on blood results. Glad this forum is here to compare experiences. Many thanks all.